|
Which compressor?
Ok, after checking eBay and Craigslist and some other sources, I've decided I'd rather get a new compressor that is delivered to my door (or in the case of Grizzly Freight, my driveway). So given that I need about 20 CFM @ 100psi, and trying to save a buck, is there any reason to NOT go for this Porter Cable compressor: http://www.grizzly.com/products/H3719 as opposed to this Campbell Hausfeld compressor: http://www.grizzly.com/products/G2815 The PC is about $160 less delivered. |
Which compressor?
You gets what you pays for with this machine.
If you'd like one that runs quiet and lasts forever: http://www.quincycompressor.com/products.html I bought two el-cheapos first. Would have been better to buy the good one like I finally did the third time. Karl |
Which compressor?
Todd Rich wrote:
Ok, after checking eBay and Craigslist and some other sources, I've decided I'd rather get a new compressor that is delivered to my door (or in the case of Grizzly Freight, my driveway). So given that I need about 20 CFM @ 100psi, and trying to save a buck, is there any reason to NOT go for this Porter Cable compressor: http://www.grizzly.com/products/H3719 as opposed to this Campbell Hausfeld compressor: http://www.grizzly.com/products/G2815 The PC is about $160 less delivered. Have you ever stood next to a cheap compressor running? They're LOUD! And they smell HOT. I once owned a DeVilbiss "6.5hp" vertical unit which looked great and spec'd out great. But when it started at night (it was in a huge basement space surrounded entirely by foundation and thick walls) it woke up my neighbors. And the damn thing wouldn't run a die grinder without running out of air, because of the phony specs. The specs are more believable these days but when you buy these import compressors and they wear out in 2 or 3 years what are you going to do? I sold my import and bought a used Quincy 5 horse 2-stage. When it runs, it's quiet and solid sounding. It's about 30 years old and runs like a top. I paid $150 for it and put another $400 or so into upgrading the motor to single phase. Works great for everything I need it for. And yes, it will run a die grinder! GWE |
Which compressor?
I also had a misfortune of buying a cheap compressor first. Promptly
sold it because it was unusable for the reasons that Karl and Grant mentioned. Bought a used Curtis 5 HP and have been very happy. I would say that with about $400, and some patience, you can get yourself a very nice vertical compressor. i |
Which compressor?
second the Quincy - I paid 850 for mine, 21 cfm at 160 psi, 5 hp motor,
single phase, delivered "Karl Townsend" wrote in message anews.com... You gets what you pays for with this machine. If you'd like one that runs quiet and lasts forever: http://www.quincycompressor.com/products.html I bought two el-cheapos first. Would have been better to buy the good one like I finally did the third time. Karl -- Posted via a free Usenet account from http://www.teranews.com |
Which compressor?
Karl Townsend wrote:
You gets what you pays for with this machine. If you'd like one that runs quiet and lasts forever: http://www.quincycompressor.com/products.html I bought two el-cheapos first. Would have been better to buy the good one like I finally did the third time. Karl Unfortunately I expect it will be more than $1600 retail from what I've seen on the used prices for ones large enough. I simply can't afford any more than that for the forseeable future. I was offered a used one when I posted an earlier compressor related question, and it was far enough away that transportation costs would have pushed me over my limit... Otherwise I would have jumped on it. Todd |
Which compressor?
seen on the used prices for ones large enough. I simply can't afford any
more than that for the forseeable future. Yea, I understand. I did the same thing on many items. But, it would have been cheaper in the long run to buy the good unit the first time around. In my case, I went through three cheap tractors and tons o' repair bills before buying a John Deere orchard tractor. Now, I bought it too late in my career to come anywhere close to wearing it out. karl |
Which compressor?
"Todd Rich" wrote in message
... Ok, after checking eBay and Craigslist and some other sources, I've decided I'd rather get a new compressor that is delivered to my door (or in the case of Grizzly Freight, my driveway). So given that I need about 20 CFM @ 100psi, and trying to save a buck, is there any reason to NOT go for this Porter Cable compressor: http://www.grizzly.com/products/H3719 as opposed to this Campbell Hausfeld compressor: http://www.grizzly.com/products/G2815 The PC is about $160 less delivered. You don't have a local supplier that can beat those prices?? Grizzly is high on their prices compared to buying local, at least in my area. Ported cable is carried by Mills Fleet Farm and Campbell Hausefeld by Tractor Supply. Home depot units are Campbell Hausefeld last I checked. Greg |
Which compressor?
Karl Townsend wrote:
seen on the used prices for ones large enough. I simply can't afford any more than that for the forseeable future. Yea, I understand. I did the same thing on many items. But, it would have been cheaper in the long run to buy the good unit the first time around. In my case, I went through three cheap tractors and tons o' repair bills before buying a John Deere orchard tractor. Now, I bought it too late in my career to come anywhere close to wearing it out. karl Well, with the encouragement here, I looked again, and there was one that was use, but local to me and what I could afford. http://cgi.ebay.com/ws/eBayISAPI.dll...m=150167291768 I'll be picking it up in 8 days. Of course since I don't have 3 phase, it looks like I'll finally be getting around to building a phase converter. Fortunatley I've found a 15 hp motor that is about as close and cheap enough that it will still be less than the Porter Cable one I was looking at. Time to research the best way to make a rotarty phase converter. Todd |
Which compressor?
On 2007-10-04, Todd Rich wrote:
Karl Townsend wrote: seen on the used prices for ones large enough. I simply can't afford any more than that for the forseeable future. Yea, I understand. I did the same thing on many items. But, it would have been cheaper in the long run to buy the good unit the first time around. In my case, I went through three cheap tractors and tons o' repair bills before buying a John Deere orchard tractor. Now, I bought it too late in my career to come anywhere close to wearing it out. karl Well, with the encouragement here, I looked again, and there was one that was use, but local to me and what I could afford. http://cgi.ebay.com/ws/eBayISAPI.dll...m=150167291768 I'll be picking it up in 8 days. Of course since I don't have 3 phase, it looks like I'll finally be getting around to building a phase converter. Fortunatley I've found a 15 hp motor that is about as close and cheap enough that it will still be less than the Porter Cable one I was looking at. Time to research the best way to make a rotarty phase converter. Wow. I am rather speechless. A very impressive compressor. Do not make a phase converter, this compressor would be best run from an electronic drive, especially if it has unloader valves. Running it will take about 70 amp from single phase under the best case (electronic drive). What source of electric power do you have (200 amp service?) It may not necessarily handle starting load of this compressor, unless you soft start the motor with a drive. You really should plan carefully as to how you wire this very large unit. I am not saying that I know the above for sure, but you should research it. i |
Which compressor?
Ignoramus8571 wrote:
(snip) Wow. I am rather speechless. A very impressive compressor. Do not make a phase converter, this compressor would be best run from an electronic drive, especially if it has unloader valves. Electronic drive as in inverter/variable frequency drive? Why is it it better than a phase converter. I was under the impression from articles I've read here that a balance rotary phase converter was the next best thing to having true 3 phase power. Also, every VFD I've seen requires 3 phase input for units over 3-5 HP. Running it will take about 70 amp from single phase under the best case (electronic drive). What source of electric power do you have (200 amp service?) 200 amp service at the house, 100 amp subpanel in the garage where this is going. It may not necessarily handle starting load of this compressor, unless you soft start the motor with a drive. You really should plan carefully as to how you wire this very large unit. I am not saying that I know the above for sure, but you should research it. i I'll be researching. I'm not necessarily that up on electrical theory, but I'm pretty good at following directions. Todd |
Which compressor?
Ignoramus8571 wrote:
(snip) Wow. I am rather speechless. A very impressive compressor. Do not make a phase converter, this compressor would be best run from an electronic drive, especially if it has unloader valves. (snorp) Sorry to follow up again, but I just got confirmation that I can pick up the motor in person and don't have to have it shipped. I really don't want to waste $150 for the motor, but I have to make a decision in the next few hours. Todd |
Which compressor?
On 2007-10-04, Todd Rich wrote:
Ignoramus8571 wrote: (snip) Wow. I am rather speechless. A very impressive compressor. Do not make a phase converter, this compressor would be best run from an electronic drive, especially if it has unloader valves. Electronic drive as in inverter/variable frequency drive? Yes. Why is it it better than a phase converter. Let's see. I have a phase converter with a 10 HP idler motor (there is another idler, that starts at a different time, but that is beside the point). When it starts, it draws about 120 amps. You would need a bigger idler than than, my guess about 25 HP idler. If it draws proportionally more current at startup, it has a need for about 120*25/10 = 300 amps. I am not sure if you can get that much from your service. I was under the impression from articles I've read here that a balance rotary phase converter was the next best thing to having true 3 phase power. You have some size issues here, besides other issues. Other issues are that the compressor is intermittent, so your phase converter would be either spinning idly a lot, or you would need some complicated starting arrangement to start it prior to kicking in the compressor motor. Also, every VFD I've seen requires 3 phase input for units over 3-5 HP. Not the case with ones I have seen (Siemens up to 60 HP) Running it will take about 70 amp from single phase under the best case (electronic drive). What source of electric power do you have (200 amp service?) 200 amp service at the house, 100 amp subpanel in the garage where this is going. It may not necessarily handle starting load of this compressor, unless you soft start the motor with a drive. You really should plan carefully as to how you wire this very large unit. I am not saying that I know the above for sure, but you should research it. i I'll be researching. I'm not necessarily that up on electrical theory, but I'm pretty good at following directions. This is a very interesting machine that you bought. Let us know how it goes. i |
Which compressor?
On 2007-10-04, Todd Rich wrote:
Ignoramus8571 wrote: (snip) Wow. I am rather speechless. A very impressive compressor. Do not make a phase converter, this compressor would be best run from an electronic drive, especially if it has unloader valves. (snorp) Sorry to follow up again, but I just got confirmation that I can pick up the motor in person and don't have to have it shipped. I really don't want to waste $150 for the motor, but I have to make a decision in the next few hours. Todd, ask around, your application is a little unusual due to size. i |
Which compressor?
Todd Rich wrote:
Ignoramus8571 wrote: (snip) Wow. I am rather speechless. A very impressive compressor. Do not make a phase converter, this compressor would be best run from an electronic drive, especially if it has unloader valves. Electronic drive as in inverter/variable frequency drive? Why is it it better than a phase converter. I was under the impression from articles I've read here that a balance rotary phase converter was the next best thing to having true 3 phase power. Also, every VFD I've seen requires 3 phase input for units over 3-5 HP. There is a hack for this: derate the drive unit by 50%, hook up two of the three inputs to one leg of 220 and the other input to the other leg. A 30HP drive is a big one but there is a big advantage to using one: no starting surge. It's not clear that you could start it from your 200amp service without a soft start unit or an electronic motor drive. Running it will take about 70 amp from single phase under the best case (electronic drive). At full load and 220 volts, over 100A. The electrical code & the motor starter would require one heckuva (technical term) feed for that baby! It would have to be fused for 120A according to the code at my reading, maybe more. Program the motor drive to ramp up over 5-10 seconds and there's no problem. You will have to wire the pressure switch to the control input of the motor drive and bypass the starter. The motor drive will NOT work (for more than a day or so) with the compressor turning itself on and off without telling the motor drive!!!! I did something very like this with a 4HP unit running off a single 20A breaker (240V). Worked like a charm. Remember, the motor drive MUST control the power to the compressor motor directly, with no relays or anything else in the way. A listed motor drive qualifies as a motor starter and a protective device under the electrical code, so you don't need them. You MUST connect any overheating sensor and the pressure sensor to the drive. Hope this helps. geoff |
Which compressor?
Ignoramus8571 wrote:
(snip) Also, every VFD I've seen requires 3 phase input for units over 3-5 HP. Not the case with ones I have seen (Siemens up to 60 HP) I see them now...weird I didn't find them before, but then again, I wasn't looking for them before when I got my 3HP VFD. (snip) This is a very interesting machine that you bought. Let us know how it goes. i Well, not sure where the original article I was looking at, but it looks like I read it wrong...double checking several others I see I would need a larger motor anyway, so I'll pass on this one. Thanks for the kick to check again. I've found at least one model of 15 HP VFD that takes single phase input. However they want $1400 for it, which I can't afford. I'll have to see if I can find a used one for less. On the plus side, there is an electrician who is marrying into my wife's side of the family. I can see how much it would take to do a 3-Phase drop from the power company.... |
Which compressor?
On 2007-10-04, gwes wrote:
Todd Rich wrote: Ignoramus8571 wrote: (snip) Wow. I am rather speechless. A very impressive compressor. Do not make a phase converter, this compressor would be best run from an electronic drive, especially if it has unloader valves. Electronic drive as in inverter/variable frequency drive? Why is it it better than a phase converter. I was under the impression from articles I've read here that a balance rotary phase converter was the next best thing to having true 3 phase power. Also, every VFD I've seen requires 3 phase input for units over 3-5 HP. There is a hack for this: derate the drive unit by 50%, hook up two of the three inputs to one leg of 220 and the other input to the other leg. A 30HP drive is a big one but there is a big advantage to using one: no starting surge. It's not clear that you could start it from your 200amp service without a soft start unit or an electronic motor drive. Agreed. Running it will take about 70 amp from single phase under the best case (electronic drive). At full load and 220 volts, over 100A. I have a 25 amp single phase 5 HP motor (Baldor). Multiplying this by (15 HP per OP's compressor) 3 gives you 75 amps. Use of a VFD and a efficient 3 phase motor could yield a bit more savings. Hence my 70 amp number. The electrical code & the motor starter would require one heckuva (technical term) feed for that baby! It would have to be fused for 120A according to the code at my reading, maybe more. Good question. Program the motor drive to ramp up over 5-10 seconds and there's no problem. You will have to wire the pressure switch to the control input of the motor drive and bypass the Yes. I did something very like this with a 4HP unit running off a single 20A breaker (240V). Worked like a charm. Remember, the motor drive MUST control the power to the compressor motor directly, with no relays or anything else in the way. A listed motor drive qualifies as a motor starter and a protective device under the electrical code, so you don't need them. You MUST connect any overheating sensor and the pressure sensor to the drive. The drive can be programmed to work as an overload, also. i |
Which compressor?
On 2007-10-04, Todd Rich wrote:
Ignoramus8571 wrote: (snip) Also, every VFD I've seen requires 3 phase input for units over 3-5 HP. Not the case with ones I have seen (Siemens up to 60 HP) I see them now...weird I didn't find them before, but then again, I wasn't looking for them before when I got my 3HP VFD. By the way, I used to sell such drives, bnut I no longer do so, so there is no profit motive in suggesting a VFD. This is a very interesting machine that you bought. Let us know how it goes. Well, not sure where the original article I was looking at, but it looks like I read it wrong...double checking several others I see I would need a larger motor anyway, so I'll pass on this one. Thanks for the kick to check again. What motor exactly are you talking? The possible motor for an idler? What kind? I've found at least one model of 15 HP VFD that takes single phase input. However they want $1400 for it, which I can't afford. I'll have to see if I can find a used one for less. You need a VFD rated for 30 HP three phase input. Basically you need a drive that 1) Can be run from single phase 2) Has motor FLA rating at least 150% of the FLA of your compressor's motor As for the cost, those Siemens drives sold for $400 apiece, more or less, up to 60 HP rating. With a little bit of looking, you can find a suitable drive for a lot less than $1400. You would need to do a little bit of research. On the plus side, there is an electrician who is marrying into my wife's side of the family. That's great, as long as he does a little more beyond house wiring. I can see how much it would take to do a 3-Phase drop from the power company.... A lot more than the drive. i |
Which compressor?
Wow. I am rather speechless. A very impressive compressor. Do not make a phase converter, this compressor would be best run from an electronic drive, especially if it has unloader valves. WOW, I'm GWE (green with envy) What a unit. Iggy's right, get a VFD to run this. Set it up to accelerate slow and not go to full speed. Then this compressor will run quiet and last forever. If you're short on electric line amp size, just running it slower with the VFD will solve the problem. Bet ya Iggy will help out with finding a suitable VFD and directions to set up. Karl |
Which compressor?
On 2007-10-04, Karl Townsend wrote:
Wow. I am rather speechless. A very impressive compressor. Do not make a phase converter, this compressor would be best run from an electronic drive, especially if it has unloader valves. WOW, I'm GWE (green with envy) What a unit. Me too. Iggy's right, get a VFD to run this. Set it up to accelerate slow and not go to full speed. Then this compressor will run quiet and last forever. If you're short on electric line amp size, just running it slower with the VFD will solve the problem. Just make sure that the motor is sufficiently cooled, as its fan may not be sufficient at lower speeds. (adding an extra fan is all that is necessary, if that) Bet ya Iggy will help out with finding a suitable VFD and directions to set up. I do not have any for sale in his size (mine are all 0.5-5 HP), but I saw several on eBay that may work, for a lot less money than $1,400. VFDs are not that expensive if you make an effort looking. i |
Which compressor?
Karl Townsend wrote:
Wow. I am rather speechless. A very impressive compressor. Do not make a phase converter, this compressor would be best run from an electronic drive, especially if it has unloader valves. WOW, I'm GWE (green with envy) What a unit. Iggy's right, get a VFD to run this. Set it up to accelerate slow and not go to full speed. Then this compressor will run quiet and last forever. If you're short on electric line amp size, just running it slower with the VFD will solve the problem. Oh he definately convinced me. The other option I'm pondering is if I can get a 10 hp motor and either use the 15 hp it comes with as the idler motor, or use a VFD with that one. I'm not as up on the mechanics as I would prefer to be at the moment. Bet ya Iggy will help out with finding a suitable VFD and directions to set up. Karl Well, I can go about $400-500 right now given my savings on the Quincy unit. Todd |
Which compressor?
On Thu, 4 Oct 2007 23:03:27 +0000 (UTC), Todd Rich
wrote: Karl Townsend wrote: Wow. I am rather speechless. A very impressive compressor. Do not make a phase converter, this compressor would be best run from an electronic drive, especially if it has unloader valves. WOW, I'm GWE (green with envy) What a unit. Iggy's right, get a VFD to run this. Set it up to accelerate slow and not go to full speed. Then this compressor will run quiet and last forever. If you're short on electric line amp size, just running it slower with the VFD will solve the problem. Oh he definately convinced me. The other option I'm pondering is if I can get a 10 hp motor and either use the 15 hp it comes with as the idler motor, or use a VFD with that one. I'm not as up on the mechanics as I would prefer to be at the moment. Bet ya Iggy will help out with finding a suitable VFD and directions to set up. Karl Well, I can go about $400-500 right now given my savings on the Quincy unit. Todd Starting a 10hp motor with a 15hp idler is kinda dicey according to motor folks I've spoken to. If the 10hp motor can be started with a small load it would probably work fine. Starting the 15hp idler will draw lots of current unless it is already spinning. This is a common way of starting 3 phase converters. In fact, you can even wrap a rope around the shaft of the motor and pull it to spin the motor up. Might be hard to spin up a 15hp motor that way though. Some folks use a single phase motor mounted on a hinge to start the larger motor spinning. Once it's up to speed the idler motor is energized and the belt from the single phase motor to the idler is flipped off by raising the smaller motor to relieve the belt tension. I have a converter that is well balanced and is based on a 15hp idler motor. It runs the whole shop and starts 2 10hp lathes with DC drives. But the starting is adjusted a little soft, about 1.5 seconds. Before I got the big converter I used one built around a 7.5hp motor and it could only start the lathes with a 6 second soft start. These are DC drives though and the motors are shunt wound DC units and so may draw less current when starting than an AC induction motor. I don't know. You could use the 10hp motor with a smaller motor pulley in order to lessen the starting current. This would mean the compressor would not pump as fast but maybe that isn't a problem for you. ERS |
Which compressor?
On Thu, 4 Oct 2007 23:03:27 +0000 (UTC), Todd Rich
wrote: Karl Townsend wrote: Wow. I am rather speechless. A very impressive compressor. Do not make a phase converter, this compressor would be best run from an electronic drive, especially if it has unloader valves. WOW, I'm GWE (green with envy) What a unit. Iggy's right, get a VFD to run this. Set it up to accelerate slow and not go to full speed. Then this compressor will run quiet and last forever. If you're short on electric line amp size, just running it slower with the VFD will solve the problem. Oh he definately convinced me. The other option I'm pondering is if I can get a 10 hp motor and either use the 15 hp it comes with as the idler motor, or use a VFD with that one. I'm not as up on the mechanics as I would prefer to be at the moment. Bet ya Iggy will help out with finding a suitable VFD and directions to set up. Karl Well, I can go about $400-500 right now given my savings on the Quincy unit. Todd You also might consider a smaller motor pulley for a greater reduction, lower top speed to reduce the power requirement (also the output). Pete Keillor |
Which compressor?
On 2007-10-04, Pete Keillor wrote:
You also might consider a smaller motor pulley for a greater reduction, lower top speed to reduce the power requirement (also the output). Also, the high power draw of the compressor at full speed may limit what other tools you can run when it kicks ni (e.g a plasma cutter). i |
Which compressor?
Ignoramus8571 wrote:
(snip) Bet ya Iggy will help out with finding a suitable VFD and directions to set up. I do not have any for sale in his size (mine are all 0.5-5 HP), but I saw several on eBay that may work, for a lot less money than $1,400. VFDs are not that expensive if you make an effort looking. i I'm not doing that well with my search strings. Any suggestions for what to look for? There are some used Allen-Bradley stuff I'm seeing that looks like it might work that is only a little over my budget. (And way oversize on capacity) Stuff like: http://cgi.ebay.com/ws/eBayISAPI.dll...m=330171342159 |
Which compressor?
On Thu, 04 Oct 2007 17:05:11 -0500, Ignoramus3531
wrote: On 2007-10-04, Todd Rich wrote: Ignoramus8571 wrote: You need a VFD rated for 30 HP three phase input. Basically you need a drive that 1) Can be run from single phase 2) Has motor FLA rating at least 150% of the FLA of your compressor's motor As for the cost, those Siemens drives sold for $400 apiece, more or less, up to 60 HP rating. With a little bit of looking, you can find a suitable drive for a lot less than $1400. You would need to do a little bit of research. I'd go for a VFD for a compressor, because that tends to be automatic equipment that will start and stop unattended. Much less to go wrong with a VFD than with a homebrew rotary converter. And if you need to derate the 15 HP compressor to use a smaller motor, you can slow down the compressor with a smaller motor pulley and reduce the HP needed to drive it. Check the paperwork on the compressor head first, some of them have a minimum speed and HP draw. On the plus side, there is an electrician who is marrying into my wife's side of the family. That's great, as long as he does a little more beyond house wiring. I can see how much it would take to do a 3-Phase drop from the power company.... A lot more than the drive. Yes, but Iggy gets enough "Interesting Stuff" through Mil-Surp bids and other "finds" that having a 277V/480V 3-Ph 4-wire service installed in his shop area would be very useful. If for nothing else than testing items before resale so he can say "It Works." The bugaboo is if the utility will /allow/ him to have a 3-Ph service installed at a residence, and that varies wildly by the utility rules and state/local laws & codes. And once you have a 480V service, dropping it down to 240V or 208V is as simple as a dry transformer or three. Taking voltage down is easy, up is hard - you run out of amps on the service way fast. -- Bruce -- |
Which compressor?
On 2007-10-05, Todd Rich wrote:
Ignoramus8571 wrote: (snip) Bet ya Iggy will help out with finding a suitable VFD and directions to set up. I do not have any for sale in his size (mine are all 0.5-5 HP), but I saw several on eBay that may work, for a lot less money than $1,400. VFDs are not that expensive if you make an effort looking. i I'm not doing that well with my search strings. Any suggestions for what to look for? There are some used Allen-Bradley stuff I'm seeing that looks like it might work that is only a little over my budget. (And way oversize on capacity) Definitely do NOT use search strings. Look in two categories: "AC drives" and "inverters". Stuff like: http://cgi.ebay.com/ws/eBayISAPI.dll...m=330171342159 It is a soft starter. Here's a brochure for it: http://literature.rockwellautomation...r021_-en-p.pdf Based on a quick look, it is not a VFD, it is more like a gradual solid state switch. It does not make three phase, it simply increases amount of three phase available to the motor gradually. Someone else may be able to comment more accurately. i |
Which compressor?
On 2007-10-05, Bruce L Bergman wrote:
On Thu, 04 Oct 2007 17:05:11 -0500, Ignoramus3531 wrote: On 2007-10-04, Todd Rich wrote: Ignoramus8571 wrote: You need a VFD rated for 30 HP three phase input. Basically you need a drive that 1) Can be run from single phase 2) Has motor FLA rating at least 150% of the FLA of your compressor's motor As for the cost, those Siemens drives sold for $400 apiece, more or less, up to 60 HP rating. With a little bit of looking, you can find a suitable drive for a lot less than $1400. You would need to do a little bit of research. I'd go for a VFD for a compressor, because that tends to be automatic equipment that will start and stop unattended. Much less to go wrong with a VFD than with a homebrew rotary converter. And if you need to derate the 15 HP compressor to use a smaller motor, you can slow down the compressor with a smaller motor pulley and reduce the HP needed to drive it. Check the paperwork on the compressor head first, some of them have a minimum speed and HP draw. The OP Can check this out http://cgi.ebay.com/DANFOSS-VLT6000-...QQcmdZViewItem If he can find a 10 HP motor and a smaller pulley, this drive would make his compressor into a useful 10 HP compressor. I am not saying that it is the way to go -- I would look for a 30 HP drive to run the 15 HP motor, but just showing what is out there. On the plus side, there is an electrician who is marrying into my wife's side of the family. That's great, as long as he does a little more beyond house wiring. I can see how much it would take to do a 3-Phase drop from the power company.... A lot more than the drive. Yes, but Iggy gets enough "Interesting Stuff" through Mil-Surp bids and other "finds" that having a 277V/480V 3-Ph 4-wire service installed in his shop area would be very useful. If for nothing else than testing items before resale so he can say "It Works." The bugaboo is if the utility will /allow/ him to have a 3-Ph service installed at a residence, and that varies wildly by the utility rules and state/local laws & codes. And once you have a 480V service, dropping it down to 240V or 208V is as simple as a dry transformer or three. Taking voltage down is easy, up is hard - you run out of amps on the service way fast. |
Which compressor?
Ignoramus8571 wrote:
(snip) If he can find a 10 HP motor and a smaller pulley, this drive would make his compressor into a useful 10 HP compressor. I am not saying that it is the way to go -- I would look for a 30 HP drive to run the 15 HP motor, but just showing what is out there. (snorp) Well, I called up the local Quincy service rep, and found out that it has already been sized down as far as the motor goes. The compressor is a 20 HP model. So the 15 HP motor is about as low as it will go. The service rep said that a 10 HP motor won't run that cylinder. So, 30 HP VFD it is. Just need to find a good one. Btw, thanks for all the help and suggestions. Todd |
Which compressor?
On 2007-10-05, Todd Rich wrote:
Ignoramus8571 wrote: (snip) If he can find a 10 HP motor and a smaller pulley, this drive would make his compressor into a useful 10 HP compressor. I am not saying that it is the way to go -- I would look for a 30 HP drive to run the 15 HP motor, but just showing what is out there. (snorp) Well, I called up the local Quincy service rep, and found out that it has already been sized down as far as the motor goes. The compressor is a 20 HP model. So the 15 HP motor is about as low as it will go. The service rep said that a 10 HP motor won't run that cylinder. So, 30 HP VFD it is. Just need to find a good one. Todd, I routinely monitor the drives categories for good deals, and I will keep an eye open for 30 HP drives. i |
Which compressor?
Ignoramus23835 wrote:
On 2007-10-05, Todd Rich wrote: (snip) Well, I called up the local Quincy service rep, and found out that it has already been sized down as far as the motor goes. The compressor is a 20 HP model. So the 15 HP motor is about as low as it will go. The service rep said that a 10 HP motor won't run that cylinder. So, 30 HP VFD it is. Just need to find a good one. Todd, I routinely monitor the drives categories for good deals, and I will keep an eye open for 30 HP drives. i Well, I just noticed this: http://cgi.ebay.com/Toshiba-E3-varia...mZ280026158272 Probably a 480V model, but I've got a question into the seller anyway. All the bad image links in the description make me a bit nervous though... |
Which compressor?
On 2007-10-07, Todd Rich wrote:
Ignoramus23835 wrote: On 2007-10-05, Todd Rich wrote: (snip) Well, I called up the local Quincy service rep, and found out that it has already been sized down as far as the motor goes. The compressor is a 20 HP model. So the 15 HP motor is about as low as it will go. The service rep said that a 10 HP motor won't run that cylinder. So, 30 HP VFD it is. Just need to find a good one. Todd, I routinely monitor the drives categories for good deals, and I will keep an eye open for 30 HP drives. i Well, I just noticed this: http://cgi.ebay.com/Toshiba-E3-varia...mZ280026158272 Probably a 480V model, but I've got a question into the seller anyway. All the bad image links in the description make me a bit nervous though... Call him at his phone listed at http://www.smilecaribbeancolor.com/ (602-358-****), and find out. I think that he messed up his website and URLs (they contain bad characters etc). i |
| All times are GMT +1. The time now is 06:37 AM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 DIYbanter