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#1
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Genset voltage reg: capacitor vs. AVR
What are the pro's/cons of each? One pro for caps is that they are cheaper! The AVR ditty for my unit would cost another near-$400. The pro for AVR is, presumably, much tighter voltage regulation with load. But mebbe AVR has its limits ito ruggedness? The voltage swing on my genset is 250 - 230 V, 0-50 A. Units with AVR claim 1-2% regulation. Should I spring for the AVR? If a major outtage occurs, I'll be running cnc equpment from it. -- EA |
#2
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Genset voltage reg: capacitor vs. AVR
I don't understand your question.
If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? Pete Stanaitis ---------------- |
#3
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
On Feb 16, 8:17*pm, "Pete S" wrote:
I don't understand your question. If you mean "capacitors" when you say "caps", I don't *know how they would deal with output voltage regulation in any meaningful way. What kind, model and serial number *of genset do you have that currently has no voltage regulation built in to it? Pete Stanaitis ---------------- I think he's saying he has a cheap generator that uses a cap for voltage regulation. They apparently do that by using a cap in conjuction with the power source for excitation. But a better question might be why would someone living in NYC, who has a critical need to run CNC eqpt during a major power outage, be concerned about spending $400 for decent voltage regulation? You think that would have been in the decision for the generator from the start. And how could anyone forecast what regulation is required, what the possible voltage swings might be, without knowing what all the actual loads are, what their tolerance is, etc? |
#4
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
"Pete S" wrote in message
... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...sp?page=H04599 modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. An AVR sharpens this up. I don't quite understand how this works, and part of the intent of Q was to shed some light on this. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Pete Stanaitis ---------------- |
#5
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Genset voltage reg: capacitor vs. AVR
On Feb 17, 8:49 am, "Existential Angst" wrote:
"Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. An AVR sharpens this up. I don't quite understand how this works, and part of the intent of Q was to shed some light on this. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Pete Stanaitis ---------------- I thought that it was a possibly that you had heard of a "capacitor regulator' that I haven't, after 35 years as an electronics design engineer. So I googled the subject and was unable to come up with a single circuit/instance where a capacitive system was used as a regulator.... I have the background to comment on the subject, so if you will provide a website that comments on how a capacitor or "capacitive circuit" can regulate the output of a genset, I will study it and give you an opinion, which, obviously you can accept or reject.... I don't post this to insult you, but I really don't see what you are asking .. |
#6
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
wrote in message
... On Feb 16, 8:17 pm, "Pete S" wrote: I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? Pete Stanaitis ---------------- I think he's saying he has a cheap generator that uses a cap for voltage regulation. They apparently do that by using a cap in conjuction with the power source for excitation. ================================================ Except it's not so cheap. Which is why I was disappointed in the regulation. AVR IS available for the unit, they just chose to use caps.. But a better question might be why would someone living in NYC, who has a critical need to run CNC eqpt during a major power outage, be concerned about spending $400 for decent voltage regulation? You think that would have been in the decision for the generator from the start. ============================================= I thought it did have AVR, and the point was, which you of course missed (in your premature judgmental fervor), was *how much* better can AVR be expected to improve things.... more of a general query as to how these things work. And how could anyone forecast what regulation is required, what the possible voltage swings might be, without knowing what all the actual loads are, what their tolerance is, etc? ================================================= That's the mfr's job. I in fact DID measure these things, whose values I gave in the OP. What size is YOUR generator, what fuel is used, and how well regulated is it? And what do you do about the noise? Or do you just let your neighbors suffer?? lol -- EA |
#7
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
On Sun, 17 Feb 2013 06:57:39 -0800 (PST), Robert
wrote: On Feb 17, 8:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. An AVR sharpens this up. I don't quite understand how this works, and part of the intent of Q was to shed some light on this. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Pete Stanaitis ---------------- I thought that it was a possibly that you had heard of a "capacitor regulator' that I haven't, after 35 years as an electronics design engineer. So I googled the subject and was unable to come up with a single circuit/instance where a capacitive system was used as a regulator.... I have the background to comment on the subject, so if you will provide a website that comments on how a capacitor or "capacitive circuit" can regulate the output of a genset, I will study it and give you an opinion, which, obviously you can accept or reject.... I don't post this to insult you, but I really don't see what you are asking .. Without following this thread, it seems to me that he's looking at a filter circuit for suppressing voltage spikes rather than a voltage regulator. I'll leave it to you to comment. -- Ed Huntress |
#8
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
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#9
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
"Robert" wrote in message
... On Feb 17, 8:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. An AVR sharpens this up. I don't quite understand how this works, and part of the intent of Q was to shed some light on this. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Pete Stanaitis ---------------- I thought that it was a possibly that you had heard of a "capacitor regulator' that I haven't, after 35 years as an electronics design engineer. So I googled the subject and was unable to come up with a single circuit/instance where a capacitive system was used as a regulator.... I have the background to comment on the subject, so if you will provide a website that comments on how a capacitor or "capacitive circuit" can regulate the output of a genset, I will study it and give you an opinion, which, obviously you can accept or reject.... I don't post this to insult you, but I really don't see what you are asking .. OK..... I am actually reciting what the company told me. Apropos of your comment (and Pete's confusion, as well), what I think they actually meant was that the caps are used to TUNE or balance the system, somewhat like you would the legs of a 3 ph rotary converter -- which I do all the time. As I mentioned above, the "first stage" of regulation is accomplished via some linkage between the generator and the motor, as in gas powered welders -- which I've always been curious about how that works. AVR would then seem to improve this. Not sure how all this occurs, just exploring the idea of tighter regulation. Part of my Q was a suspicion that an AVR proly regulates voltage more tightly, but perhaps at the expense of raw current flow. Iow, I might get "better" juice, just less of it. Just wondering..... -- EA |
#10
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
"Scott Dorsey" wrote in message
... wrote: I think he's saying he has a cheap generator that uses a cap for voltage regulation. They apparently do that by using a cap in conjuction with the power source for excitation. I'm not sure how that works. The original AC voltage regulation system, which I think is called a Tillen regulator, and dates back to the 19th century, involves a buzzer that produces a square wave whose duty cycle is inversely proportional to the output voltage of the generator. This is integrated by a capacitor into a voltage that is inversely proportional to the output and that drives the field coil. This is how automotive alternators used to work until the seventies. (There is another method used with big generators that involves a DC motor generator set used to regulate the field coil, but we are talking small gensets here.) Anyway, the Tillen regulator is history and as far as I know nobody is using it today. Instead they use a solid state circuit whose output voltage is inversely proportional to the AC input voltage. Early on these used SCRs that acted as switching devices more or less like the Tillen mechanism, but by the 1970s they were mostly using big bipolar transistors. This is what I think the original poster is calling an "AVR" and it's pretty much how regular constant-speed AC generators work today. Now.... the interesting thing is that today we have a whole new breed of generators which are not constant speed. They generate AC, which is rectified and then used to power an inverter that creates constant frequency AC. This means the engine throttle can be adjusted to regulate voltage as well as the field coil... and it means the engine is throttled way back where it is quiet when there is little load and opened up all the way when there is more load. Which is what cars do, right? In generators, I think they call it automatic idle, in the better units. There's a lot more stuff inside the box to go wrong and some of the inverters are kind of crappy (although I am really amazed at how good a waveform and how little RF noise we get from the Honda 2000i), so repair and diagnosis is a little trickier. But if I were buying a baby generator (sub 5KVA) today, I would definitely go the inverter route. In the 5-20 KVA range it would depend. There's also the issue of "true sine" vs. std inverter output. True sine is sig'ly more expensive. But a better question might be why would someone living in NYC, who has a critical need to run CNC eqpt during a major power outage, be concerned about spending $400 for decent voltage regulation? You think that would have been in the decision for the generator from the start. Personally, if I were running CNC equipment, I'd get out of NYC as fast as possible and get to a place with better support for manufacturing and lower tax rates... AMEN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Hopefullyl they'll let me into VanCouver, BC, Canada.... LOL fuknBloomberg has no sympathy for people unwilling/unable to spend $1 mil on a 1 BR apt, whose rent (before he and Guiliani gutted rent control) was proly $500/mo. "Buying" apts. is essentially mega "key money", which is illegal. But when sed key money allows you to "flip" a hot potato to some other sucker, which generates all kinds of minicipal revenue, then I guess it's ok..... Parts of NYC used to be machining meccas, partic. in the small parts industry (spring-making, lighting, for example), and in knitting. Pre-1990, parts of Brooklyn, Queens were the knitting capital of the world, I'm told, with a large machining infrastructure (mom&pop machining, btw) to make the many *very* intricate parts that would wear in the needle/knitting process. -- EA --scott -- "C'est un Nagra. C'est suisse, et tres, tres precis." |
#11
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
On Feb 17, 9:57*am, Robert wrote:
On Feb 17, 8:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't *know how they would deal with output voltage regulation in any meaningful way. Ditto. *ergo my Q. *I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number *of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, *that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. *There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. *An AVR sharpens this up. I don't quite understand how this works, and part of the intent of Q was to shed some light on this. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Pete Stanaitis ---------------- I thought that it was a possibly that you had heard of a "capacitor regulator' that I haven't, after 35 years as an electronics design engineer. *So I googled the subject and was unable to come up with a single circuit/instance where a capacitive system was used as a regulator.... I have the background to comment on the subject, so if you will provide a website that *comments on how a capacitor or "capacitive circuit" can regulate the output of a genset, I will study it and give you an opinion, which, obviously you can accept *or reject.... *I don't post this to insult you, but I really don't see what you are asking ..- Hide quoted text - - Show quoted text - It's not hard to find discussion of caps as voltage regulators. Here's an example, about a third of the way down in this thread: http://www.smokstak.com/forum/showthread.php?t=16338 Seems like a pretty crappy thing to find though on a $3000 generator. |
#12
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
"Existential Angst" wrote in message
... Part of my Q was a suspicion that an AVR proly regulates voltage more tightly, but perhaps at the expense of raw current flow. Iow, I might get "better" juice, just less of it. Just wondering..... -- EA For lower power demands a high-end APC SmartUPS can regulate the AC output if the line goes high or low. I got one free with bad, swollen batteries. It works without them, or with external batteries plugged into the rear connector. http://www.apcmedia.com/salestools/A...8L9X_R0_EN.pdf |
#13
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
wrote in message
... On Feb 17, 9:57 am, Robert wrote: On Feb 17, 8:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. An AVR sharpens this up. I don't quite understand how this works, and part of the intent of Q was to shed some light on this. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Pete Stanaitis ---------------- I thought that it was a possibly that you had heard of a "capacitor regulator' that I haven't, after 35 years as an electronics design engineer. So I googled the subject and was unable to come up with a single circuit/instance where a capacitive system was used as a regulator.... I have the background to comment on the subject, so if you will provide a website that comments on how a capacitor or "capacitive circuit" can regulate the output of a genset, I will study it and give you an opinion, which, obviously you can accept or reject.... I don't post this to insult you, but I really don't see what you are asking ..- Hide quoted text - - Show quoted text - It's not hard to find discussion of caps as voltage regulators. Here's an example, about a third of the way down in this thread: http://www.smokstak.com/forum/showthread.php?t=16338 Seems like a pretty crappy thing to find though on a $3000 generator. ================================================== Inneresting thread. But I think one can conclude that caps are not regulating, they are tuning, balancing. with mebbe an itty bitty bit of regulation as a perk to tuning. But if you follow the op Jim McIntyre, what his cap(s) did was raise/lower the voltage. The unit itself, apparently pretty high quality, seems to have had inherently good regulation between the generator itself and the motor. Anthony W. commented that "It sounds as if Kubota did their homework on the winding ratios in your set. As you found, the cap value isn't too critical in a "good" set within a reasonable range. Problems usually only show up when a certain critical cap value is exceeded. Also in the case of a non-linear load such as a switching power supply,(if you run your computer off of one) plug an incandesent lamp or two in as well. I don't know that it would hurt anything, but the waveform looks "slanted" on a 'scope when only a switching-type load is applied. The only troubles I have had with the several old Cap regulated sets I have owned are bearing issues and the cap going "open". " And the quality of the linkage between the generator/engine was proly superior. Notice, tho, that when McIntyre increased his cap size, the voltage regulation went from about 1% to 2%. Note that in mine, a much larger unit, the regulation, from midpoint, is 4% right now -- not terrible terrible, but again, not 1%. -- EA |
#14
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
On Feb 17, 9:49*am, "Existential Angst" wrote:
"Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't *know how they would deal with output voltage regulation in any meaningful way. Ditto. *ergo my Q. *I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number *of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, *that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. *There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. That would be the mechanical engine governor. An AVR sharpens this up. Yes I don't quite understand how this works, and part of the intent of Q was to shed some light on this. See my other post to a discussion. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Do you realize what you got for $2800? They take a Honda engine and bolt it on to some generator made by someone else. Perhaps you can shed light on to who that someone else is, but given that it uses a cap for voltage regulation, I would not be surprised that it's a cheap Chinese one. Then they take pretty pictures of the thing with Honda showing all over in the pretty pics and a lot of people make the assumption that they are buying a Honda generator. I don't believe that is the case. Further arousing suspicion is that they claim it's 15KW. Then if you read the specs, it says it's rated at 13.5KW continuous. Then they say it has a 50 amp main breaker, which equates to 12KW, in my world. You with me so far? Further arrousing suspicion, they quote fuel consumption in gallons, ie it's based on running the engine on gas. So, next, let's look at the spec for a Honda GX690. It says it produces 22hp running gasoline. I'm no expert in conversions from gasoline to nat gas, but AFAIK, when you run a gasoline engine on nat gas, you have about 15% less energy output. Maybe someone has the exact number. That means you really have about an 18hp engine. I've looked into generators a bit and what it takes to power them. I don't think you can get 15KW out of an 18hp engine. A Generac 12KW unit for example, uses a 26hp engine. Just some more things to think about. |
#15
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
On 02/17/2013 06:57 AM, Robert wrote:
On Feb 17, 8:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. An AVR sharpens this up. I don't quite understand how this works, and part of the intent of Q was to shed some light on this. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Pete Stanaitis ---------------- I thought that it was a possibly that you had heard of a "capacitor regulator' that I haven't, after 35 years as an electronics design engineer. So I googled the subject and was unable to come up with a single circuit/instance where a capacitive system was used as a regulator.... it's possible they're being used for power factor correction rather than regulation. pfc gets to be important with some reactive loads. I have the background to comment on the subject, so if you will provide a website that comments on how a capacitor or "capacitive circuit" can regulate the output of a genset, I will study it and give you an opinion, which, obviously you can accept or reject.... I don't post this to insult you, but I really don't see what you are asking .. -- fact check required |
#16
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
wrote in message
... On Feb 17, 9:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. That would be the mechanical engine governor. ================================================== == I sure would like to know the details on how those work. An AVR sharpens this up. Yes I don't quite understand how this works, and part of the intent of Q was to shed some light on this. See my other post to a discussion. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Do you realize what you got for $2800? They take a Honda engine and bolt it on to some generator made by someone else. Perhaps you can shed light on to who that someone else is, but given that it uses a cap for voltage regulation, I would not be surprised that it's a cheap Chinese one. Then they take pretty pictures of the thing with Honda showing all over in the pretty pics and a lot of people make the assumption that they are buying a Honda generator. I don't believe that is the case. ================================================== === McCaulte (sp?) makes the generator. And yes, they mix'n'match.... but presumably they do it pretty well, altho I got a li'l short-shrifted on the AVR deal.... I don't know that they are being misleading, as much as emphasizing the Honda part.... LOL Thin line, admittedly. Further arousing suspicion is that they claim it's 15KW. Then if you read the specs, it says it's rated at 13.5KW continuous. ============================================= This is typical. Generac does this. Then they say it has a 50 amp main breaker, which equates to 12KW, in my world. ====================================== Yeah, I noticed that. And they trip fast, too! I may put in my own 50 A slower-tripping or even 60 A breakers. You with me so far? Further arrousing suspicion, they quote fuel consumption in gallons, ie it's based on running the engine on gas. So, next, let's look at the spec for a Honda GX690. It says it produces 22hp running gasoline. I'm no expert in conversions from gasoline to nat gas, but AFAIK, when you run a gasoline engine on nat gas, you have about 15% less energy output. Maybe someone has the exact number. That means you really have about an 18hp engine. =============================================== Again, par for the course. I simply went for the most watts. Those watts will be similarly de-rated in most scenarios, so I just went with the biggest number. I've looked into generators a bit and what it takes to power them. I don't think you can get 15KW out of an 18hp engine. A Generac 12KW unit for example, uses a 26hp engine. ================================================ Oh, but I did get very nearly the full 13.5 continuous (on gasoline), and proly could have gotten sig. more. I'll have to jump/replace the breaker, tho. Already at near-full load, it started a 26 gal compressor, w/ nary a hiccup. A 26 hp engine for 12 kW is suspect as well, from two povs: First, I suspect Generac hp is like Sears hp. Second, if it IS 26 hp, yer just sipping lots more gas.... which was one of the things I was going to discuss in my upcoming Generator Manifesto..... big-azz generators, in no-load conditions, are not economical. I really couldn't find much better overall bang fer the buck, watt-wise. The Honda motor is a plus, and the unit is VERY compact. Generacs are big and complicated. OK, I spose, for the home-moaner who justs likes to dial the telephone when sumpn goes wrong, and from what I've read about generac, they will be using their telephone fairly often. Here's some of my take on this: I would recommend the Sam's club 8,750 W blackmax, at $999, for most people with more than the basic needs. You can get it modified for tri-fuel, and the link I provided sells a modified blackmax for $1600 -- about a $200-$400 preimum over what you would pay if you did it yourself, but with a lot less headache, and somewhat of a guarantee. The blackmax also has AVR, iirc, and performed quite well, before it grew feet. My unit does not come with a gas tank, but which is actually an advantage, imo, because you just drop the genset's hose down any gas can (or your car's gas tank, if you can snake it in), and Wala, gasoline power. I went for the 15 kW unit, in the second go-around, for many of the reasons you stated: By the time you get done de-rating for whatever whatever reasons, you have a lot less than when you started, so I figgered I'd just double the size from the gitgo. Really a lot of g-d work. The other bottom line to all this is that unless you have a water-cooled 4 cylinder unit, you gotta simply build a separate sound-proofed shed for these noise buckets. A lot of my work so far went in to testing, given my cnc liabilities. So far so good, but really a pita -- for sumpn I may NEVER use. -- EA Just some more things to think about. |
#17
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
On Feb 17, 11:23*am, "Existential Angst" wrote:
wrote in message ... On Feb 17, 9:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. That would be the mechanical engine governor. ================================================== == I sure would like to know the details on how those work. Find the parts diagram for the Honda engine. They typically rely on centrifugal force. If the engine starts to slow down, the drop in centrifugal force causes movement of linkage connected to the carb throttle. An AVR sharpens this up. Yes I don't quite understand how this works, and part of the intent of Q was to shed some light on this. See my other post to a discussion. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Do you realize what you got for $2800? *They take a Honda engine and bolt it on to some generator made by someone else. *Perhaps you can shed light on to who that someone else is, but given that it uses a cap for voltage regulation, I would not be surprised that it's a cheap Chinese one. Then they take pretty pictures of the thing with Honda showing all over in the pretty pics and a lot of people make the assumption that they are buying a Honda generator. I don't believe that is the case. ================================================== === McCaulte (sp?) makes the generator. Meccalte. They are an Italian company. You can buy one of their 12-15KW generator heads for about $800. Not sure what kind of voltage regulation you get for that price. Find the model, look up the spec sheet. I'll bet it says you need 25hp or so to get full power out of it. And I doubt an engine rated at 22hp on gasoline is capable of that running on natural gas. Have you tried running it at full load on natural gas? And yes, they mix'n'match.... *but presumably they do it pretty well, altho I got a li'l short-shrifted on the AVR deal.... There isn't much to it. The engines and generators have common mounting standards that just bolt together. Oh, but I did get very nearly the full 13.5 continuous (on gasoline), and proly could have gotten sig. more. I'll have to jump/replace the breaker, tho. *Already at near-full load, it started a 26 gal compressor, w/ nary a hiccup. A 26 hp engine for 12 kW is suspect as well, from two povs: First, I suspect Generac hp is like Sears hp. It's not Generac specific. Take a look at what Meccalte or other generator head manufacturers spec for power required to support 12KW, 15KW, etc. Second, if it IS 26 hp, yer just sipping lots more gas.... *which was one of the things I was going to discuss in my upcoming Generator Manifesto..... big-azz generators, in no-load conditions, are not economical. You can't have it both ways. Well,, actually you can, if you're willing to pay for it. You can buy an inverter based generator. That completely decouples the rotational speed from the frequency. That way, the engine can run at low RPMs with low loads. It makes them very fuel efficient at lower loads and also quiet. But you'll pay $4,000 for maybe 3000 watts. I really couldn't find much better overall bang fer the buck, watt-wise. The Honda motor is a plus, and the unit is VERY compact. Generacs are big and complicated. *OK, I spose, for the home-moaner who justs likes to dial the telephone when sumpn goes wrong, and from what I've read about generac, they will be using their telephone fairly often. With a 5 to 7KW generator you can easily run a big house. Except for central AC and electric hot water. On a cheapo 5KW generator we ran 4 refigerator/freezers, two gas furnaces, 2 gas power vented water heaters, plus some lights. That was for two large houses. But if you need to run a machine shop, then it's a whole different ball game. Here's some of my take on this: I would recommend the Sam's club 8,750 W blackmax, at $999, for most people with more than the basic needs. *You can get it modified for tri-fuel, and the link I provided sells a modified blackmax for $1600 -- about a $200-$400 preimum over what you would pay if you did it yourself, but with a lot less headache, and somewhat of a guarantee. *The blackmax also has AVR, iirc, and performed quite well, before it grew feet. You can get a Briggs and Stratton for the same price. It's probably made in China, but at least B&S knows about engines, knows about QC, has a long track record and you know where to find them. Who is Blackmax? Probably a sticker and label on a China generic. My unit does not come with a gas tank, but which is actually an advantage, imo, because you just drop the genset's hose down any gas can (or your car's gas tank, if you can snake it in), and Wala, gasoline power. I went for the 15 kW unit, in the second go-around, for many of the reasons you stated: * * By the time you get done de-rating for whatever whatever reasons, you have a lot less than when you started, so I figgered I'd just double the size from the gitgo. Really a lot of g-d work. *The other bottom line to all this is that unless you have a water-cooled 4 cylinder unit, you gotta simply build a separate sound-proofed shed for these noise buckets. A lot of my work so far went in to testing, given my cnc liabilities. *So far so good, but really a pita -- for sumpn I may NEVER use. -- EA Just some more things to think about.- Hide quoted text - - Show quoted text - |
#18
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
On Feb 17, 8:23*am, "Existential Angst" wrote:
wrote in message ... On Feb 17, 9:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. That would be the mechanical engine governor. ================================================== == I sure would like to know the details on how those work. An AVR sharpens this up. Yes I don't quite understand how this works, and part of the intent of Q was to shed some light on this. See my other post to a discussion. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Do you realize what you got for $2800? *They take a Honda engine and bolt it on to some generator made by someone else. *Perhaps you can shed light on to who that someone else is, but given that it uses a cap for voltage regulation, I would not be surprised that it's a cheap Chinese one. Then they take pretty pictures of the thing with Honda showing all over in the pretty pics and a lot of people make the assumption that they are buying a Honda generator. I don't believe that is the case. ================================================== === McCaulte (sp?) makes the generator. And yes, they mix'n'match.... *but presumably they do it pretty well, altho I got a li'l short-shrifted on the AVR deal.... I don't know that they are being misleading, as much as emphasizing the Honda part.... *LOL Thin line, admittedly. Further arousing suspicion is that they claim it's 15KW. Then if you read the specs, it says it's rated at 13.5KW continuous. ============================================= This is typical. *Generac does this. *Then they say it has a 50 amp main breaker, which equates to 12KW, in my world. ====================================== Yeah, I noticed that. *And they trip fast, too! I may put in my own 50 A slower-tripping or even 60 A breakers. You with me so far? * Further arrousing suspicion, they quote fuel consumption in gallons, ie it's based on running the engine on gas. *So, next, let's look at the spec for a Honda GX690. *It says it produces 22hp running gasoline. I'm no expert in conversions from gasoline to nat gas, but AFAIK, when you run a gasoline engine on nat gas, you have about 15% less energy output. *Maybe someone has the exact number. *That means you really have about an 18hp engine. =============================================== Again, par for the course. *I simply went for the most watts. *Those watts will be similarly de-rated in most scenarios, so I just went with the biggest number. I've looked into generators a bit and what it takes to power them. *I don't think you can get 15KW out of an 18hp engine. *A Generac 12KW unit for example, uses a 26hp engine. ================================================ Oh, but I did get very nearly the full 13.5 continuous (on gasoline), and proly could have gotten sig. more. I'll have to jump/replace the breaker, tho. *Already at near-full load, it started a 26 gal compressor, w/ nary a hiccup. A 26 hp engine for 12 kW is suspect as well, from two povs: First, I suspect Generac hp is like Sears hp. Second, if it IS 26 hp, yer just sipping lots more gas.... *which was one of the things I was going to discuss in my upcoming Generator Manifesto..... big-azz generators, in no-load conditions, are not economical. I really couldn't find much better overall bang fer the buck, watt-wise. The Honda motor is a plus, and the unit is VERY compact. Generacs are big and complicated. *OK, I spose, for the home-moaner who justs likes to dial the telephone when sumpn goes wrong, and from what I've read about generac, they will be using their telephone fairly often. Here's some of my take on this: I would recommend the Sam's club 8,750 W blackmax, at $999, for most people with more than the basic needs. *You can get it modified for tri-fuel, and the link I provided sells a modified blackmax for $1600 -- about a $200-$400 preimum over what you would pay if you did it yourself, but with a lot less headache, and somewhat of a guarantee. *The blackmax also has AVR, iirc, and performed quite well, before it grew feet. My unit does not come with a gas tank, but which is actually an advantage, imo, because you just drop the genset's hose down any gas can (or your car's gas tank, if you can snake it in), and Wala, gasoline power. I went for the 15 kW unit, in the second go-around, for many of the reasons you stated: * * By the time you get done de-rating for whatever whatever reasons, you have a lot less than when you started, so I figgered I'd just double the size from the gitgo. Really a lot of g-d work. *The other bottom line to all this is that unless you have a water-cooled 4 cylinder unit, you gotta simply build a separate sound-proofed shed for these noise buckets. A lot of my work so far went in to testing, given my cnc liabilities. *So far so good, but really a pita -- for sumpn I may NEVER use. -- EA Just some more things to think about. It seems it's often impossible to buy the right package for what someone wants. An example is an air compressor. I don't intend to run my air compressor day in and day out so I don't have the need for a very heavy duty dual stage air compressor pump like this one: http://www.northerntool.com/shop/too...ct_42535_42535 I'd like this air compressor pump because it's got an 18 CFM rating at 90 PSI and it's got a decent price. http://www.northerntool.com/shop/too...7235_200387235 I'd like this motor: http://www.northerntool.com/shop/too...6765_200306765 When I try an find a reasonably priced horizontal air tank I'm ****ed. Prices are insane. Looks like my only choice will be to buy a used horizontal air tank. |
#20
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
"jon_banquer" wrote in message
... On Feb 17, 8:23 am, "Existential Angst" wrote: wrote in message ... On Feb 17, 9:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. That would be the mechanical engine governor. ================================================== == I sure would like to know the details on how those work. An AVR sharpens this up. Yes I don't quite understand how this works, and part of the intent of Q was to shed some light on this. See my other post to a discussion. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Do you realize what you got for $2800? They take a Honda engine and bolt it on to some generator made by someone else. Perhaps you can shed light on to who that someone else is, but given that it uses a cap for voltage regulation, I would not be surprised that it's a cheap Chinese one. Then they take pretty pictures of the thing with Honda showing all over in the pretty pics and a lot of people make the assumption that they are buying a Honda generator. I don't believe that is the case. ================================================== === McCaulte (sp?) makes the generator. And yes, they mix'n'match.... but presumably they do it pretty well, altho I got a li'l short-shrifted on the AVR deal.... I don't know that they are being misleading, as much as emphasizing the Honda part.... LOL Thin line, admittedly. Further arousing suspicion is that they claim it's 15KW. Then if you read the specs, it says it's rated at 13.5KW continuous. ============================================= This is typical. Generac does this. Then they say it has a 50 amp main breaker, which equates to 12KW, in my world. ====================================== Yeah, I noticed that. And they trip fast, too! I may put in my own 50 A slower-tripping or even 60 A breakers. You with me so far? Further arrousing suspicion, they quote fuel consumption in gallons, ie it's based on running the engine on gas. So, next, let's look at the spec for a Honda GX690. It says it produces 22hp running gasoline. I'm no expert in conversions from gasoline to nat gas, but AFAIK, when you run a gasoline engine on nat gas, you have about 15% less energy output. Maybe someone has the exact number. That means you really have about an 18hp engine. =============================================== Again, par for the course. I simply went for the most watts. Those watts will be similarly de-rated in most scenarios, so I just went with the biggest number. I've looked into generators a bit and what it takes to power them. I don't think you can get 15KW out of an 18hp engine. A Generac 12KW unit for example, uses a 26hp engine. ================================================ Oh, but I did get very nearly the full 13.5 continuous (on gasoline), and proly could have gotten sig. more. I'll have to jump/replace the breaker, tho. Already at near-full load, it started a 26 gal compressor, w/ nary a hiccup. A 26 hp engine for 12 kW is suspect as well, from two povs: First, I suspect Generac hp is like Sears hp. Second, if it IS 26 hp, yer just sipping lots more gas.... which was one of the things I was going to discuss in my upcoming Generator Manifesto..... big-azz generators, in no-load conditions, are not economical. I really couldn't find much better overall bang fer the buck, watt-wise. The Honda motor is a plus, and the unit is VERY compact. Generacs are big and complicated. OK, I spose, for the home-moaner who justs likes to dial the telephone when sumpn goes wrong, and from what I've read about generac, they will be using their telephone fairly often. Here's some of my take on this: I would recommend the Sam's club 8,750 W blackmax, at $999, for most people with more than the basic needs. You can get it modified for tri-fuel, and the link I provided sells a modified blackmax for $1600 -- about a $200-$400 preimum over what you would pay if you did it yourself, but with a lot less headache, and somewhat of a guarantee. The blackmax also has AVR, iirc, and performed quite well, before it grew feet. My unit does not come with a gas tank, but which is actually an advantage, imo, because you just drop the genset's hose down any gas can (or your car's gas tank, if you can snake it in), and Wala, gasoline power. I went for the 15 kW unit, in the second go-around, for many of the reasons you stated: By the time you get done de-rating for whatever whatever reasons, you have a lot less than when you started, so I figgered I'd just double the size from the gitgo. Really a lot of g-d work. The other bottom line to all this is that unless you have a water-cooled 4 cylinder unit, you gotta simply build a separate sound-proofed shed for these noise buckets. A lot of my work so far went in to testing, given my cnc liabilities. So far so good, but really a pita -- for sumpn I may NEVER use. -- EA Just some more things to think about. It seems it's often impossible to buy the right package for what someone wants. ============================================ Amazing how that works.... in almost everything! From vitamins to cars to cnc to real estate..... Canada here I come..... An example is an air compressor. I don't intend to run my air compressor day in and day out so I don't have the need for a very heavy duty dual stage air compressor pump like this one: http://www.northerntool.com/shop/too...ct_42535_42535 I'd like this air compressor pump because it's got an 18 CFM rating at 90 PSI and it's got a decent price. http://www.northerntool.com/shop/too...7235_200387235 ================================================== ====== I'd be careful of Northern Tool. They are not above shenannigans. I'd look at the displacement of the pistons, and try to guestimate the rpm, and match that to cfm claims of similar sized compressors. Ahm no 'spert, but 18 cfm at 90 psi seems pretty substantial. I'da thought more like 5 or 8 for that size. I'd check out comparable sized Quincy's, or other reputable brands, and see what they list. The husky compressor is surprisingly civilized. I'd like this motor: http://www.northerntool.com/shop/too...6765_200306765 When I try an find a reasonably priced horizontal air tank I'm ****ed. Prices are insane. Looks like my only choice will be to buy a used horizontal air tank. ================================================== ========== Well, mixing/matching is not a bad idea, and proly a really good one. Tanks are tanks, motors are motors, so really what you want are a nice (quiet) 'pressor head, and a good regulator, with separate set points for cut-in/cut-out, which bigbox stuff doesn't have. Also, recall from a previous discussion that a big tank will help compensate for smaller compressor size, and that instead of one big tank, a bunch of small ones are the same as one big one, and a lot more manageable. I have a bunch connected together, each one separately valved. You don't even need the motor/'pressor mounted on a tank, per se. I've even got some BBQ propane tanks I want to hook in, but goddamm, do they make it difficult to remove dat stuff in the 3/4 neck. Also, there's no drain, altho they are small enough you could put the drain on top, and just tilt it to drain it. -- EA |
#21
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
On Feb 17, 9:40*am, "Existential Angst" wrote:
"jon_banquer" wrote in message ... On Feb 17, 8:23 am, "Existential Angst" wrote: wrote in message .... On Feb 17, 9:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?.... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. That would be the mechanical engine governor. ================================================== == I sure would like to know the details on how those work. An AVR sharpens this up. Yes I don't quite understand how this works, and part of the intent of Q was to shed some light on this. See my other post to a discussion. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Do you realize what you got for $2800? They take a Honda engine and bolt it on to some generator made by someone else. Perhaps you can shed light on to who that someone else is, but given that it uses a cap for voltage regulation, I would not be surprised that it's a cheap Chinese one. Then they take pretty pictures of the thing with Honda showing all over in the pretty pics and a lot of people make the assumption that they are buying a Honda generator. I don't believe that is the case. ================================================== === McCaulte (sp?) makes the generator. And yes, they mix'n'match.... but presumably they do it pretty well, altho I got a li'l short-shrifted on the AVR deal.... I don't know that they are being misleading, as much as emphasizing the Honda part.... LOL Thin line, admittedly. Further arousing suspicion is that they claim it's 15KW. Then if you read the specs, it says it's rated at 13.5KW continuous. ============================================= This is typical. Generac does this. Then they say it has a 50 amp main breaker, which equates to 12KW, in my world. ====================================== Yeah, I noticed that. And they trip fast, too! I may put in my own 50 A slower-tripping or even 60 A breakers. You with me so far? Further arrousing suspicion, they quote fuel consumption in gallons, ie it's based on running the engine on gas. So, next, let's look at the spec for a Honda GX690. It says it produces 22hp running gasoline. I'm no expert in conversions from gasoline to nat gas, but AFAIK, when you run a gasoline engine on nat gas, you have about 15% less energy output. Maybe someone has the exact number. That means you really have about an 18hp engine. =============================================== Again, par for the course. I simply went for the most watts. Those watts will be similarly de-rated in most scenarios, so I just went with the biggest number. I've looked into generators a bit and what it takes to power them. I don't think you can get 15KW out of an 18hp engine. A Generac 12KW unit for example, uses a 26hp engine. ================================================ Oh, but I did get very nearly the full 13.5 continuous (on gasoline), and proly could have gotten sig. more. I'll have to jump/replace the breaker, tho. Already at near-full load, it started a 26 gal compressor, w/ nary a hiccup. A 26 hp engine for 12 kW is suspect as well, from two povs: First, I suspect Generac hp is like Sears hp. Second, if it IS 26 hp, yer just sipping lots more gas.... which was one of the things I was going to discuss in my upcoming Generator Manifesto...... big-azz generators, in no-load conditions, are not economical. I really couldn't find much better overall bang fer the buck, watt-wise.. The Honda motor is a plus, and the unit is VERY compact. Generacs are big and complicated. OK, I spose, for the home-moaner who justs likes to dial the telephone when sumpn goes wrong, and from what I've read about generac, they will be using their telephone fairly often. Here's some of my take on this: I would recommend the Sam's club 8,750 W blackmax, at $999, for most people with more than the basic needs. You can get it modified for tri-fuel, and the link I provided sells a modified blackmax for $1600 -- about a $200-$400 preimum over what you would pay if you did it yourself, but with a lot less headache, and somewhat of a guarantee. The blackmax also has AVR, iirc, and performed quite well, before it grew feet. My unit does not come with a gas tank, but which is actually an advantage, imo, because you just drop the genset's hose down any gas can (or your car's gas tank, if you can snake it in), and Wala, gasoline power. I went for the 15 kW unit, in the second go-around, for many of the reasons you stated: By the time you get done de-rating for whatever whatever reasons, you have a lot less than when you started, so I figgered I'd just double the size from the gitgo. Really a lot of g-d work. The other bottom line to all this is that unless you have a water-cooled 4 cylinder unit, you gotta simply build a separate sound-proofed shed for these noise buckets. A lot of my work so far went in to testing, given my cnc liabilities. So far so good, but really a pita -- for sumpn I may NEVER use. -- EA Just some more things to think about. It seems it's often impossible to buy the right package for what someone wants. ============================================ Amazing how that works.... in almost everything! *From vitamins to cars to cnc to real estate..... Canada here I come..... An example is an air compressor. I don't intend to run my air compressor day in and day out so I don't have the need for a very heavy duty dual stage air compressor pump like this one: http://www.northerntool.com/shop/too...ct_42535_42535 I'd like this air compressor pump because it's got an 18 CFM rating at 90 PSI and it's got a decent price. http://www.northerntool.com/shop/too...7235_200387235 ================================================== ====== I'd be careful of Northern Tool. *They are not above shenannigans. I'd look at the displacement of the pistons, and try to guestimate the rpm, and match that to cfm claims of similar sized compressors. *Ahm no 'spert, but 18 cfm at 90 psi seems pretty substantial. I'da thought more like 5 or 8 for that size. I'd check out comparable sized Quincy's, or other reputable brands, and see what they list. The husky compressor is surprisingly civilized. I'd like this motor: http://www.northerntool.com/shop/too...6765_200306765 When I try an find a reasonably priced horizontal air tank I'm ****ed. Prices are insane. Looks like my only choice will be to buy a used horizontal air tank. ================================================== ========== Well, mixing/matching is not a bad idea, and proly a really good one. *Tanks are tanks, motors are motors, so really what you want are a nice (quiet) 'pressor head, and a good regulator, with separate set points for cut-in/cut-out, which bigbox stuff doesn't have. Also, recall from a previous discussion that a big tank will help compensate for smaller compressor size, and that instead of one big tank, a bunch of small ones are the same as one big one, and a lot more manageable. I have a bunch connected together, each one separately valved. *You don't even need the motor/'pressor mounted on a tank, per se. I've even got some BBQ propane tanks I want to hook in, but goddamm, do they make it difficult to remove dat stuff in the 3/4 neck. *Also, there's no drain, altho they are small enough you could put the drain on top, and just tilt it to drain it. -- EA "You don't even need the motor/'pressor mounted on a tank, per se." For some reason I never thought about doing that. Thanks for bringing it up! Being able to move this setup around easily is going to be a factor. Also, this would allow me to go with a vertical tanks. |
#22
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Genset voltage reg: capacitor vs. AVR
On 2/17/2013 9:43 AM, Existential Angst wrote:
wrote in message ... On Feb 17, 9:57 am, Robert wrote: On Feb 17, 8:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. An AVR sharpens this up. I don't quite understand how this works, and part of the intent of Q was to shed some light on this. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Pete Stanaitis ---------------- I thought that it was a possibly that you had heard of a "capacitor regulator' that I haven't, after 35 years as an electronics design engineer. So I googled the subject and was unable to come up with a single circuit/instance where a capacitive system was used as a regulator.... I have the background to comment on the subject, so if you will provide a website that comments on how a capacitor or "capacitive circuit" can regulate the output of a genset, I will study it and give you an opinion, which, obviously you can accept or reject.... I don't post this to insult you, but I really don't see what you are asking ..- Hide quoted text - - Show quoted text - It's not hard to find discussion of caps as voltage regulators. Here's an example, about a third of the way down in this thread: http://www.smokstak.com/forum/showthread.php?t=16338 Seems like a pretty crappy thing to find though on a $3000 generator. ================================================== Inneresting thread. But I think one can conclude that caps are not regulating, they are tuning, balancing. with mebbe an itty bitty bit of regulation as a perk to tuning. But if you follow the op Jim McIntyre, what his cap(s) did was raise/lower the voltage. The unit itself, apparently pretty high quality, seems to have had inherently good regulation between the generator itself and the motor. Anthony W. commented that "It sounds as if Kubota did their homework on the winding ratios in your set. As you found, the cap value isn't too critical in a "good" set within a reasonable range. Problems usually only show up when a certain critical cap value is exceeded. Also in the case of a non-linear load such as a switching power supply,(if you run your computer off of one) plug an incandesent lamp or two in as well. I don't know that it would hurt anything, but the waveform looks "slanted" on a 'scope when only a switching-type load is applied. The only troubles I have had with the several old Cap regulated sets I have owned are bearing issues and the cap going "open". " And the quality of the linkage between the generator/engine was proly superior. Notice, tho, that when McIntyre increased his cap size, the voltage regulation went from about 1% to 2%. Note that in mine, a much larger unit, the regulation, from midpoint, is 4% right now -- not terrible terrible, but again, not 1%. I don't think it would be too far out in space to think of the capacitor regulated generator as being related to a ferroresonant transformer or a CVT, Constant Voltage Transformer. The only difference is there is a mechanically rotating winding. ^_^ TDD |
#23
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Genset voltage reg: capacitor vs. AVR
The Daring Dufas wrote: I don't think it would be too far out in space to think of the capacitor regulated generator as being related to a ferroresonant transformer or a CVT, Constant Voltage Transformer. The only difference is there is a mechanically rotating winding. ^_^ A CVT requres a sepereate winding to resonate with the cap. If it were part of an active circuit, the Q would be too low to do any good. |
#24
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Genset voltage reg: capacitor vs. AVR
On 2/17/2013 12:04 PM, Michael A. Terrell wrote:
The Daring Dufas wrote: I don't think it would be too far out in space to think of the capacitor regulated generator as being related to a ferroresonant transformer or a CVT, Constant Voltage Transformer. The only difference is there is a mechanically rotating winding. ^_^ A CVT requres a sepereate winding to resonate with the cap. If it were part of an active circuit, the Q would be too low to do any good. I did write "related". ^_^ TDD |
#25
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Genset voltage reg: capacitor vs. AVR
On Feb 17, 9:32*am, "
wrote: On Feb 16, 8:17*pm, "Pete S" wrote: I don't understand your question. If you mean "capacitors" when you say "caps", I don't *know how they would deal with output voltage regulation in any meaningful way. What kind, model and serial number *of genset do you have that currently has no voltage regulation built in to it? Pete Stanaitis ---------------- I think he's saying he has a cheap generator that uses a cap for voltage regulation. *They apparently do that by using a cap in conjuction with the power source for excitation. But a better question might be why would someone living in NYC, who has a critical need to run CNC eqpt during a major power outage, be concerned about spending $400 for decent voltage regulation? *You think that would have been in the decision for the generator from the start. Many of the transformers and other circuitry in lower manhattan are still being put back up. Most of that stuff was underwater (salt water) south of 32nd street. I wonder if he's reparing generators. I'd repair the diesel ones. There'd be more money in those, but stick to repair manuals and their one eight hundred tech numbers. |
#26
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Genset voltage reg: capacitor vs. AVR
On Feb 17, 10:09*am, (Scott Dorsey) wrote:
wrote: I think he's saying he has a cheap generator that uses a cap for voltage regulation. They apparently do that by using a cap in conjuction with the power source for excitation. I'm not sure how that works. You mean whether the cap is shunted to the load and power source? Because "in conjunction" means "in series with" right? At least, that's how I've heard it mentioned before. |
#27
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Genset voltage reg: capacitor vs. AVR
On Sat, 16 Feb 2013 10:13:55 -0500, Existential Angst wrote:
What are the pro's/cons of each? One pro for caps is that they are cheaper! The AVR ditty for my unit would cost another near-$400. The pro for AVR is, presumably, much tighter voltage regulation with load. But mebbe AVR has its limits ito ruggedness? The voltage swing on my genset is 250 - 230 V, 0-50 A. Units with AVR claim 1-2% regulation. Should I spring for the AVR? If a major outtage occurs, I'll be running cnc equpment from it. Do you have a link to a site that sells the AVR ditty? If it's regulating the field current of the generator in response to the generator voltage, and if all the genset does is rely on the motor's governor for speed regulation, then it should give better regulation. But I can only speak from a combination of a deep knowledge of control systems theory, a reasonably deep knowledge of how generators work and how Briggs and Stratton engines work, and a near total ignorance of how people actually put these things together in practice. -- Tim Wescott Control system and signal processing consulting www.wescottdesign.com |
#28
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Genset voltage reg: capacitor vs. AVR
On Feb 17, 9:24 am, "
wrote: It's not hard to find discussion of caps as voltage regulators. Here's an example, about a third of the way down in this thread: http://www.smokstak.com/forum/showthread.php?t=16338 Seems like a pretty crappy thing to find though on a $3000 generator. Thanks for the link. From that thread, I determined that the keyphrase I needed to google was "alternator feedback capacitor".... That gave me the link to a paper called "Field Initiation Design Fundamentals for Pulsed Alternators" which has an abstract giving a short explanation of how the capacitor works. This was an IEEE paper. It is simply a bootstrap giving feedback to the field of an alternator....... Not a particularly good regulator, but sufficient for non precise applications. I had never seen this before, as I had only used electronic regulators to the field windings of an alternator with a DC field and not pulsed alternators.... Live and learn..... Anyway, if the voltage regulation is critical , an electronic regulator would work far better. |
#29
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Genset voltage reg: capacitor vs. AVR
"Robert" wrote in message
news:11864198-e5a3-4016-b3dc- Anyway, if the voltage regulation is critical , an electronic regulator would work far better. Would it be better to regulate the peak, average or RMS voltage if the load draws non-sinusoidal current? I became concerned with the peak after a poorly regulated generator burned out the transient voltage suppressors in an outlet strip, in a cloud of purple smoke. jsw |
#30
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Genset voltage reg: capacitor vs. AVR
On Feb 17, 9:40*am, "Existential Angst" wrote:
"jon_banquer" wrote in message ... On Feb 17, 8:23 am, "Existential Angst" wrote: wrote in message .... On Feb 17, 9:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?.... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. That would be the mechanical engine governor. ================================================== == I sure would like to know the details on how those work. An AVR sharpens this up. Yes I don't quite understand how this works, and part of the intent of Q was to shed some light on this. See my other post to a discussion. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Do you realize what you got for $2800? They take a Honda engine and bolt it on to some generator made by someone else. Perhaps you can shed light on to who that someone else is, but given that it uses a cap for voltage regulation, I would not be surprised that it's a cheap Chinese one. Then they take pretty pictures of the thing with Honda showing all over in the pretty pics and a lot of people make the assumption that they are buying a Honda generator. I don't believe that is the case. ================================================== === McCaulte (sp?) makes the generator. And yes, they mix'n'match.... but presumably they do it pretty well, altho I got a li'l short-shrifted on the AVR deal.... I don't know that they are being misleading, as much as emphasizing the Honda part.... LOL Thin line, admittedly. Further arousing suspicion is that they claim it's 15KW. Then if you read the specs, it says it's rated at 13.5KW continuous. ============================================= This is typical. Generac does this. Then they say it has a 50 amp main breaker, which equates to 12KW, in my world. ====================================== Yeah, I noticed that. And they trip fast, too! I may put in my own 50 A slower-tripping or even 60 A breakers. You with me so far? Further arrousing suspicion, they quote fuel consumption in gallons, ie it's based on running the engine on gas. So, next, let's look at the spec for a Honda GX690. It says it produces 22hp running gasoline. I'm no expert in conversions from gasoline to nat gas, but AFAIK, when you run a gasoline engine on nat gas, you have about 15% less energy output. Maybe someone has the exact number. That means you really have about an 18hp engine. =============================================== Again, par for the course. I simply went for the most watts. Those watts will be similarly de-rated in most scenarios, so I just went with the biggest number. I've looked into generators a bit and what it takes to power them. I don't think you can get 15KW out of an 18hp engine. A Generac 12KW unit for example, uses a 26hp engine. ================================================ Oh, but I did get very nearly the full 13.5 continuous (on gasoline), and proly could have gotten sig. more. I'll have to jump/replace the breaker, tho. Already at near-full load, it started a 26 gal compressor, w/ nary a hiccup. A 26 hp engine for 12 kW is suspect as well, from two povs: First, I suspect Generac hp is like Sears hp. Second, if it IS 26 hp, yer just sipping lots more gas.... which was one of the things I was going to discuss in my upcoming Generator Manifesto...... big-azz generators, in no-load conditions, are not economical. I really couldn't find much better overall bang fer the buck, watt-wise.. The Honda motor is a plus, and the unit is VERY compact. Generacs are big and complicated. OK, I spose, for the home-moaner who justs likes to dial the telephone when sumpn goes wrong, and from what I've read about generac, they will be using their telephone fairly often. Here's some of my take on this: I would recommend the Sam's club 8,750 W blackmax, at $999, for most people with more than the basic needs. You can get it modified for tri-fuel, and the link I provided sells a modified blackmax for $1600 -- about a $200-$400 preimum over what you would pay if you did it yourself, but with a lot less headache, and somewhat of a guarantee. The blackmax also has AVR, iirc, and performed quite well, before it grew feet. My unit does not come with a gas tank, but which is actually an advantage, imo, because you just drop the genset's hose down any gas can (or your car's gas tank, if you can snake it in), and Wala, gasoline power. I went for the 15 kW unit, in the second go-around, for many of the reasons you stated: By the time you get done de-rating for whatever whatever reasons, you have a lot less than when you started, so I figgered I'd just double the size from the gitgo. Really a lot of g-d work. The other bottom line to all this is that unless you have a water-cooled 4 cylinder unit, you gotta simply build a separate sound-proofed shed for these noise buckets. A lot of my work so far went in to testing, given my cnc liabilities. So far so good, but really a pita -- for sumpn I may NEVER use. -- EA Just some more things to think about. It seems it's often impossible to buy the right package for what someone wants. ============================================ Amazing how that works.... in almost everything! *From vitamins to cars to cnc to real estate..... Canada here I come..... An example is an air compressor. I don't intend to run my air compressor day in and day out so I don't have the need for a very heavy duty dual stage air compressor pump like this one: http://www.northerntool.com/shop/too...ct_42535_42535 I'd like this air compressor pump because it's got an 18 CFM rating at 90 PSI and it's got a decent price. http://www.northerntool.com/shop/too...7235_200387235 ================================================== ====== I'd be careful of Northern Tool. *They are not above shenannigans. I'd look at the displacement of the pistons, and try to guestimate the rpm, and match that to cfm claims of similar sized compressors. *Ahm no 'spert, but 18 cfm at 90 psi seems pretty substantial. I'da thought more like 5 or 8 for that size. I'd check out comparable sized Quincy's, or other reputable brands, and see what they list. The husky compressor is surprisingly civilized. I'd like this motor: http://www.northerntool.com/shop/too...6765_200306765 When I try an find a reasonably priced horizontal air tank I'm ****ed. Prices are insane. Looks like my only choice will be to buy a used horizontal air tank. ================================================== ========== Well, mixing/matching is not a bad idea, and proly a really good one. *Tanks are tanks, motors are motors, so really what you want are a nice (quiet) 'pressor head, and a good regulator, with separate set points for cut-in/cut-out, which bigbox stuff doesn't have. Also, recall from a previous discussion that a big tank will help compensate for smaller compressor size, and that instead of one big tank, a bunch of small ones are the same as one big one, and a lot more manageable. I have a bunch connected together, each one separately valved. *You don't even need the motor/'pressor mounted on a tank, per se. I've even got some BBQ propane tanks I want to hook in, but goddamm, do they make it difficult to remove dat stuff in the 3/4 neck. *Also, there's no drain, altho they are small enough you could put the drain on top, and just tilt it to drain it. -- EA I'm hearing almost all air compressor pumps are made in either China or India. That includes Ingersoll Rand. Thinking that Northern Tool may not be the way to go. Found this. Like the price and the specs: http://www.eatoncompressor.com/catal...43/1320611.htm |
#31
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Genset voltage reg: capacitor vs. AVR
On Feb 17, 9:50*pm, jon_banquer wrote:
On Feb 17, 9:40*am, "Existential Angst" wrote: "jon_banquer" wrote in message ... On Feb 17, 8:23 am, "Existential Angst" wrote: wrote in message .... On Feb 17, 9:49 am, "Existential Angst" wrote: "Pete S" wrote in message ... I don't understand your question. If you mean "capacitors" when you say "caps", I don't know how they would deal with output voltage regulation in any meaningful way. Ditto. ergo my Q. I guess they must in some fashion, just like you balance rpc's with caps. What kind, model and serial number of genset do you have that currently has no voltage regulation built in to it? http://www.generatorsales.com/order/...Generator.asp?... modified for tri-fuel. It is regulated, just not to 1 or 2%, a swing of 230 to 250 V, from 50+ amps down to zero amps. If you at mid-load it's 240 V, that's +/-10V, which is not terrible, but it's not 1% either. Assume no electrical-type regulation at all. There is something between the generator itself and the gas engine that ups fuel flow with load, maintaining a semi-constant voltage. That would be the mechanical engine governor. ================================================== == I sure would like to know the details on how those work. An AVR sharpens this up. Yes I don't quite understand how this works, and part of the intent of Q was to shed some light on this. See my other post to a discussion. I also figgered that if the feedback between generator and engine was good enough, AVR wouldn't be needed. So basically I"m curious about the design of these things. -- EA Do you realize what you got for $2800? They take a Honda engine and bolt it on to some generator made by someone else. Perhaps you can shed light on to who that someone else is, but given that it uses a cap for voltage regulation, I would not be surprised that it's a cheap Chinese one. Then they take pretty pictures of the thing with Honda showing all over in the pretty pics and a lot of people make the assumption that they are buying a Honda generator. I don't believe that is the case. ================================================== === McCaulte (sp?) makes the generator. And yes, they mix'n'match.... but presumably they do it pretty well, altho I got a li'l short-shrifted on the AVR deal.... I don't know that they are being misleading, as much as emphasizing the Honda part.... LOL Thin line, admittedly. Further arousing suspicion is that they claim it's 15KW. Then if you read the specs, it says it's rated at 13.5KW continuous. ============================================= This is typical. Generac does this. Then they say it has a 50 amp main breaker, which equates to 12KW, in my world. ====================================== Yeah, I noticed that. And they trip fast, too! I may put in my own 50 A slower-tripping or even 60 A breakers. You with me so far? Further arrousing suspicion, they quote fuel consumption in gallons, ie it's based on running the engine on gas. So, next, let's look at the spec for a Honda GX690. It says it produces 22hp running gasoline. I'm no expert in conversions from gasoline to nat gas, but AFAIK, when you run a gasoline engine on nat gas, you have about 15% less energy output. Maybe someone has the exact number. That means you really have about an 18hp engine. =============================================== Again, par for the course. I simply went for the most watts. Those watts will be similarly de-rated in most scenarios, so I just went with the biggest number. I've looked into generators a bit and what it takes to power them. I don't think you can get 15KW out of an 18hp engine. A Generac 12KW unit for example, uses a 26hp engine. ================================================ Oh, but I did get very nearly the full 13.5 continuous (on gasoline), and proly could have gotten sig. more. I'll have to jump/replace the breaker, tho. Already at near-full load, it started a 26 gal compressor, w/ nary a hiccup. A 26 hp engine for 12 kW is suspect as well, from two povs: First, I suspect Generac hp is like Sears hp. Second, if it IS 26 hp, yer just sipping lots more gas.... which was one of the things I was going to discuss in my upcoming Generator Manifesto...... big-azz generators, in no-load conditions, are not economical. I really couldn't find much better overall bang fer the buck, watt-wise. The Honda motor is a plus, and the unit is VERY compact. Generacs are big and complicated. OK, I spose, for the home-moaner who justs likes to dial the telephone when sumpn goes wrong, and from what I've read about generac, they will be using their telephone fairly often. Here's some of my take on this: I would recommend the Sam's club 8,750 W blackmax, at $999, for most people with more than the basic needs. You can get it modified for tri-fuel, and the link I provided sells a modified blackmax for $1600 -- about a $200-$400 preimum over what you would pay if you did it yourself, but with a lot less headache, and somewhat of a guarantee. The blackmax also has AVR, iirc, and performed quite well, before it grew feet. My unit does not come with a gas tank, but which is actually an advantage, imo, because you just drop the genset's hose down any gas can (or your car's gas tank, if you can snake it in), and Wala, gasoline power. I went for the 15 kW unit, in the second go-around, for many of the reasons you stated: By the time you get done de-rating for whatever whatever reasons, you have a lot less than when you started, so I figgered I'd just double the size from the gitgo. Really a lot of g-d work. The other bottom line to all this is that unless you have a water-cooled 4 cylinder unit, you gotta simply build a separate sound-proofed shed for these noise buckets. A lot of my work so far went in to testing, given my cnc liabilities. So far so good, but really a pita -- for sumpn I may NEVER use. -- EA Just some more things to think about. It seems it's often impossible to buy the right package for what someone wants. ============================================ Amazing how that works.... in almost everything! *From vitamins to cars to cnc to real estate..... Canada here I come..... An example is an air compressor. I don't intend to run my air compressor day in and day out so I don't have the need for a very heavy duty dual stage air compressor pump like this one: http://www.northerntool.com/shop/too...ct_42535_42535 I'd like this air compressor pump because it's got an 18 CFM rating at 90 PSI and it's got a decent price. http://www.northerntool.com/shop/too...7235_200387235 ================================================== ====== I'd be careful of Northern Tool. *They are not above shenannigans. I'd look at the displacement of the pistons, and try to guestimate the rpm, and match that to cfm claims of similar sized compressors. *Ahm no 'spert, but 18 cfm at 90 psi seems pretty substantial. I'da thought more like 5 or 8 for that size. I'd check out comparable sized Quincy's, or other reputable brands, and see what they list. The husky compressor is surprisingly civilized. I'd like this motor: http://www.northerntool.com/shop/too...6765_200306765 When I try an find a reasonably priced horizontal air tank I'm ****ed. Prices are insane. Looks like my only choice will be to buy a used horizontal air tank. ================================================== ========== Well, mixing/matching is not a bad idea, and proly a really good one. *Tanks are tanks, motors are motors, so really what you want are a nice (quiet) 'pressor head, and a good regulator, with separate set points for cut-in/cut-out, which bigbox stuff doesn't have. Also, recall from a previous discussion that a big tank will help compensate for smaller compressor size, and that instead of one big tank, a bunch of small ones are the same as one big one, and a lot more manageable. I have a bunch connected together, each one separately valved. *You don't even need the motor/'pressor mounted on a tank, per se. I've even got some BBQ propane tanks I want to hook in, but goddamm, do they make it difficult to remove dat stuff in the 3/4 neck. *Also, there's no drain, altho they are small enough you could put the drain on top, and just tilt it to drain it. -- EA I'm hearing almost all air compressor pumps are made in either China or India. That includes Ingersoll Rand. Thinking that Northern Tool may not be the way to go. Found this. Like the price and the specs: http://www.eatoncompressor.com/catal...43/1320611.htm http://wiki.answers.com/Q/Are_Ingers...ade_in_the_USA |
#32
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Genset voltage reg: capacitor vs. AVR
The Daring Dufas wrote: On 2/17/2013 12:04 PM, Michael A. Terrell wrote: The Daring Dufas wrote: I don't think it would be too far out in space to think of the capacitor regulated generator as being related to a ferroresonant transformer or a CVT, Constant Voltage Transformer. The only difference is there is a mechanically rotating winding. ^_^ A CVT requres a sepereate winding to resonate with the cap. If it were part of an active circuit, the Q would be too low to do any good. I did write "related". ^_^ Maybe a third cousin, twice removed? |
#33
Posted to rec.crafts.metalworking,alt.home.repair,rec.autos.tech
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Genset voltage reg: capacitor vs. AVR
On Sun, 17 Feb 2013 16:33:03 -0800 (PST), Robert
wrote: On Feb 17, 9:24 am, " wrote: It's not hard to find discussion of caps as voltage regulators. Here's an example, about a third of the way down in this thread: http://www.smokstak.com/forum/showthread.php?t=16338 Seems like a pretty crappy thing to find though on a $3000 generator. Thanks for the link. From that thread, I determined that the keyphrase I needed to google was "alternator feedback capacitor".... That gave me the link to a paper called "Field Initiation Design Fundamentals for Pulsed Alternators" which has an abstract giving a short explanation of how the capacitor works. This was an IEEE paper. It is simply a bootstrap giving feedback to the field of an alternator....... Not a particularly good regulator, but sufficient for non precise applications. I had never seen this before, as I had only used electronic regulators to the field windings of an alternator with a DC field and not pulsed alternators.... Live and learn..... Anyway, if the voltage regulation is critical , an electronic regulator would work far better. A lot of folks replace the battery on English motorcycles with a big cap for the same reasons Gunner The methodology of the left has always been: 1. Lie 2. Repeat the lie as many times as possible 3. Have as many people repeat the lie as often as possible 4. Eventually, the uninformed believe the lie 5. The lie will then be made into some form oflaw 6. Then everyone must conform to the lie |
#34
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Genset voltage reg: capacitor vs. AVR
On 2/18/2013 12:33 AM, Michael A. Terrell wrote:
The Daring Dufas wrote: On 2/17/2013 12:04 PM, Michael A. Terrell wrote: The Daring Dufas wrote: I don't think it would be too far out in space to think of the capacitor regulated generator as being related to a ferroresonant transformer or a CVT, Constant Voltage Transformer. The only difference is there is a mechanically rotating winding. ^_^ A CVT requres a sepereate winding to resonate with the cap. If it were part of an active circuit, the Q would be too low to do any good. I did write "related". ^_^ Maybe a third cousin, twice removed? We could always ask Nikola. ^_^ TDD |
#35
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Genset voltage reg: capacitor vs. AVR
The Daring Dufas wrote: Michael A. Terrell wrote: The Daring Dufas wrote: Michael A. Terrell wrote: The Daring Dufas wrote: I don't think it would be too far out in space to think of the capacitor regulated generator as being related to a ferroresonant transformer or a CVT, Constant Voltage Transformer. The only difference is there is a mechanically rotating winding. ^_^ A CVT requres a sepereate winding to resonate with the cap. If it were part of an active circuit, the Q would be too low to do any good. I did write "related". ^_^ Maybe a third cousin, twice removed? We could always ask Nikola. ^_^ Nah, he's always so tesla... |
#36
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Genset voltage reg: capacitor vs. AVR
"Robert" wrote in message
... On Feb 17, 9:24 am, " wrote: It's not hard to find discussion of caps as voltage regulators. Here's an example, about a third of the way down in this thread: http://www.smokstak.com/forum/showthread.php?t=16338 Seems like a pretty crappy thing to find though on a $3000 generator. Thanks for the link. From that thread, I determined that the keyphrase I needed to google was "alternator feedback capacitor".... That gave me the link to a paper called "Field Initiation Design Fundamentals for Pulsed Alternators" which has an abstract giving a short explanation of how the capacitor works. This was an IEEE paper. It is simply a bootstrap giving feedback to the field of an alternator....... Not a particularly good regulator, but sufficient for non precise applications. I had never seen this before, as I had only used electronic regulators to the field windings of an alternator with a DC field and not pulsed alternators.... Live and learn..... Anyway, if the voltage regulation is critical , an electronic regulator would work far better. So caps ARE regulators of sorts? Not just tuning/balancing? I wonder, if/when I put on this AVR doodad, if the caps should be removed, or left in place. -- EA |
#37
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Genset voltage reg: capacitor vs. AVR
On 2/18/2013 2:44 AM, Michael A. Terrell wrote:
The Daring Dufas wrote: Michael A. Terrell wrote: The Daring Dufas wrote: Michael A. Terrell wrote: The Daring Dufas wrote: I don't think it would be too far out in space to think of the capacitor regulated generator as being related to a ferroresonant transformer or a CVT, Constant Voltage Transformer. The only difference is there is a mechanically rotating winding. ^_^ A CVT requres a sepereate winding to resonate with the cap. If it were part of an active circuit, the Q would be too low to do any good. I did write "related". ^_^ Maybe a third cousin, twice removed? We could always ask Nikola. ^_^ Nah, he's always so tesla... At least he alternates. ^_^ TDD |
#38
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Genset voltage reg: capacitor vs. AVR
On Feb 17, 7:04 pm, "Jim Wilkins" wrote:
ulator would work far better. Would it be better to regulate the peak, average or RMS voltage if the load draws non-sinusoidal current? I became concerned with the peak after a poorly regulated generator burned out the transient voltage suppressors in an outlet strip, in a cloud of purple smoke. jsw If the output is non-sinusoidal alternating current, it would depend on the use. If equipment is being used that uses the entire waveform, such as a heater, the RMS would be the choice. For a motor, I'm not sure, but I'd go with RMS unless better info is found. If the device is electronic, which uses a peak detector to form a DC for a power supply, the peak would be reasonable.... However, it would be necessary to look at the output waveform to make a really informed choice. For instance, if the output is a square wave the choice would be different from a stepped sinusoid. Note that rotating machinery will put out a sinusoid but many generators today use a speed lower than 3600 rpm and use an inverter to make the frequency controlled output voltage, often a "stepped sinusoid", which has the RMS of the sinusoid AND the peak level of the sinusoid, but synthesized in steps. Also, if the output is DC or pulsed DC, a capacitor stabilizes the voltage by reducing the ripple, the same function as the battery in an automobile. For this appication a big ass capacitor in parallel with a resistor can, in many cases, take the place of the battery. If a load is always present, the resistor won't be needed. \ Such stabilizing loads are often used in stabilizing the DC system in large RVs if a battery isn't used. The requirements are different for an AC system. That accounts for some of the different solutions posted here. |
#39
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Genset voltage reg: capacitor vs. AVR
On Feb 18, 4:01*am, "Existential Angst" wrote:
"Robert" wrote in message ... On Feb 17, 9:24 am, " wrote: It's not hard to find discussion of caps as voltage regulators. *Here's an example, about a third of the way down in this thread: http://www.smokstak.com/forum/showthread.php?t=16338 Seems like a pretty crappy thing to find though on a $3000 generator. Thanks for the link. *From that thread, I determined that the keyphrase *I needed to google was "alternator feedback capacitor".... *That gave me the link to a paper called "Field Initiation Design Fundamentals for Pulsed Alternators" which has an abstract giving a short explanation of how the capacitor works. *This was an IEEE paper. * It is simply a bootstrap giving feedback to the field of an alternator....... Not a particularly good regulator, but sufficient for non precise *applications. * I had never seen this before, as I had only used electronic regulators to the field windings of an alternator with a DC field *and not pulsed alternators.... *Live and learn..... * Anyway, if the voltage regulation is critical , an electronic regulator would work far better. So caps ARE regulators of sorts? *Not just tuning/balancing? I wonder, if/when I put on this AVR doodad, if the caps should be removed, or left in place. -- EA- Hide quoted text - - Show quoted text - Do you have the Meccalte spec sheet, manual etc for the actual generator head? That would be my source for information. Assuming of course that the offered voltage regulator from the company you bought the assembly from is using a M voltage regulator on an M generator.... I would think the cap does need to be removed as the electronic voltage regulator is going to control the winding field instead of relying on the cap. generator? |
#40
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Genset voltage reg: capacitor vs. AVR
"Robert" wrote in message
... On Feb 17, 7:04 pm, "Jim Wilkins" wrote: ulator would work far better. Would it be better to regulate the peak, average or RMS voltage if the load draws non-sinusoidal current?... jsw If the output is non-sinusoidal alternating current, it would depend on the use. If equipment is being used that uses the entire waveform, such as a heater, the RMS would be the choice. For a motor, I'm not sure, but I'd go with RMS unless better info is found. If the device is electronic, which uses a peak detector to form a DC for a power supply, the peak would be reasonable.... I asked because I have several small generators that regulate voltage poorly, typically they have to be set around 140V at no load to maintain 105-110V at full load. Unless I'm running one large insensitive load like the washing machine I pass the power through a metered 20A Variac indoors and change its setting as I add or remove loads. The APC SmartUps I found at a flea market recently looks like it would handle the variations automatically without modifying the generator. They are too expensive new and not common enough used to be a general solution. Unfortunately I don't know how much overvoltage things will stand without frying them. My house spiked up to 180VAC once from a powerline problem and the lights buzzed loudly. I knew there was an intermittent fault and was monitoring it. It turned out to be a corroded splice in the neutral in the drop from the street. I needed good evidence to convince the power company to replace the meter box and weatherhead. |
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