|
Liability & responsibility of electrician?
Assuming a nominal 240VAC supply, 245V is in no way "not correct" -- it's only about a 2% overvoltage. And since there is likely no load in shop when the install was taking place, the 245 would be a higher than normal reading. But I question the use of "3phase" and "245 volts" in the OP question. Around here, 245 volts would be perfectly normal for a single phase circuit, very high for a "standard" 208/3 phase delta. |
Liability & responsibility of electrician?
In article , RoyJ wrote:
Assuming a nominal 240VAC supply, 245V is in no way "not correct" -- it's only about a 2% overvoltage. And since there is likely no load in shop when the install was taking place, the 245 would be a higher than normal reading. But I question the use of "3phase" and "245 volts" in the OP question. Around here, 245 volts would be perfectly normal for a single phase circuit, very high for a "standard" 208/3 phase delta. OTOH, why would the machine be set up for 220V as described, if intended to be connected to a 208V supply? |
Liability & responsibility of electrician?
"Doug Miller" wrote in message ... In article , RoyJ wrote: Assuming a nominal 240VAC supply, 245V is in no way "not correct" -- it's only about a 2% overvoltage. And since there is likely no load in shop when the install was taking place, the 245 would be a higher than normal reading. But I question the use of "3phase" and "245 volts" in the OP question. Around here, 245 volts would be perfectly normal for a single phase circuit, very high for a "standard" 208/3 phase delta. OTOH, why would the machine be set up for 220V as described, if intended to be connected to a 208V supply? Because CNC controls are designed to run at 220V plus Zero/minus 5%. They love straight 208 three phase power because of the balance. You can usually just change control paremeters without fiddling with the transformers. Anyway, this shop owner did it so it's his job now to step in it. JC |
Liability & responsibility of electrician?
Doug Miller wrote:
You're missing the point. This has nothing to do with the voltage supplied by the utility. The utility doesn't supply 220V or 240V or whatever. They supply (for example) 4KV. A transformer at the point of service reduces that to 220V, or 240V, or whatever. Different transformers connected to the *same* 4KV primary voltage could easily produce different secondary voltages. No, I'm not. When I lived in the US, (PECO) the electric company sold me 240 volt 2 phase electricity. It was nominaly 127 volts, but often dropped down during times of high usage. They did not supply or sell me 4kv volts, or anything else. Here it's even simpler. Israel electric sells me 230 volts, 50Hz electicity and except for just before the power going out it has been that way for 12 years. When I had a UPS monitoring the voltage, it was never more than 1 volt +- spec. Ok, since you insist would anyone out there who gets 4kv from their local electric company please raise your hand. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM |
Liability & responsibility of electrician?
"Jon Danniken" wrote in message
... William Sommerwerck wrote: My drier sees 250VAC. Low voltage stuff in this house gets 125VAC. Everything is working just fine. sniff sniff Is that burning cotton I smell? Drier has a temperature limiter, It's called a thermostat so although the slightly higher voltage results in a slightly quicker "turn on" time for the elements, they still are shut off at the same temperature regardless of incoming voltage. Of course. I was jesting. |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 02:58:00 -0400, Spehro Pefhany
wrote: On Sat, 4 Jul 2009 23:40:18 -0700, the renowned John E. wrote: I have been asked to offer an opinion in a sensitive situation. A machinist moved his shop across town and required some rewiring (3-phase outlets, conduit, etc.) in order to locate some machines where he wanted them. He hires a guy who's not a pro (and later discovers is not insured) but has done shop wiring before and had a good attitude and track record. The guy does good work. No complaints about the quality of his work. Owner throws the switch, all works fine. The story continues 4 weeks later when the very expensive CNC fries its controller PCB to the tune of $4000. Turns out the voltage in the shop was upward of 245 and the taps in the CNC's power supply were set for 220. What is the legal and moral responsibility of each party? What will not be helpful are replies about the character or intelligence of either of the players or their actions. Thanks. IMO, 11% high voltage over nominal should not "fry" the controller board in the first place. Yes. The controller was overly fragile, or it may have just had a random failure unrelated to supply voltage. That happens. If the owner blames the electrician, don't use him again. Sue the power company for providing 245. John |
Liability & responsibility of electrician?
On Sun, 5 Jul 2009 17:29:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote: Doug Miller wrote: You're missing the point. This has nothing to do with the voltage supplied by the utility. The utility doesn't supply 220V or 240V or whatever. They supply (for example) 4KV. A transformer at the point of service reduces that to 220V, or 240V, or whatever. Different transformers connected to the *same* 4KV primary voltage could easily produce different secondary voltages. No, I'm not. When I lived in the US, (PECO) the electric company sold me 240 volt 2 phase electricity. It was nominaly 127 volts, but often dropped down during times of high usage. 240V isn't "two phase", rather single phase, or otherwise known as "split phase". ...and it had better not be 127V (maybe twice that). They did not supply or sell me 4kv volts, or anything else. They supplied that to the pole. Please read. Here it's even simpler. Israel electric sells me 230 volts, 50Hz electicity and except for just before the power going out it has been that way for 12 years. When I had a UPS monitoring the voltage, it was never more than 1 volt +- spec. Lots of good that does after the power goes out. Ok, since you insist would anyone out there who gets 4kv from their local electric company please raise your hand. All of us who can read. |
Liability & responsibility of electrician?
"Wes" wrote in message ... John E. wrote: He hires a guy who's not a pro (and later discovers is not insured) but has done shop wiring before and had a good attitude and track record. The guy does good work. No complaints about the quality of his work. I'm going to translate this. Hires a guy that isn't a licensed electrician but does do the job for less than the licensed guys with liability insurance. Now your friend that was shopping for a free lunch now wants his evening meal paid for. We don't know the voltage it was running at prior to the move, we don't know the variability of the supply voltage where it is now. The handyman wired it to the disconnect. Made sure there was power to that point. Somewhere after that the machine was powered up. I'm going to assume for the sake of argument that the handyman got the shop owner or the owners designee to do it. I don't know any compenent electricans or for that matter decent handymen that will turn on a complex piece of equipment on their own. So the owner or designee that has the manuals and such for the machine and should be the most knowledgeable person in the room is the one that is at fault. Hey Wes. If you open up one of your older Fanucs you will see a tag somewhere that says 200V AC. That is the design spec. JC |
Liability & responsibility of electrician?
On Sat, 4 Jul 2009 23:40:18 -0700, John E.
wrote: I have been asked to offer an opinion in a sensitive situation. A machinist moved his shop across town and required some rewiring (3-phase outlets, conduit, etc.) in order to locate some machines where he wanted them. He hires a guy who's not a pro (and later discovers is not insured) but has done shop wiring before and had a good attitude and track record. The guy does good work. No complaints about the quality of his work. Owner throws the switch, all works fine. The story continues 4 weeks later when the very expensive CNC fries its controller PCB to the tune of $4000. Turns out the voltage in the shop was upward of 245 and the taps in the CNC's power supply were set for 220. What is the legal and moral responsibility of each party? What will not be helpful are replies about the character or intelligence of either of the players or their actions. Thanks. First of all, 245 VAC is a common AC voltage in the US. Yes, I know we say 110 / 220, but it is more like 120 / 240. Second, what was the 'handyman' hired to do? If he wired a number of 1 and 3 phace 110 / 220 volt outlets, he has no liability. If he hard-wired (ran conduit directly to) the equipment, it is open to discussion. If he adjusted wiring taps, etc than he MAY be responsible. However, every controller I have ever seen uses a regulated power supply. Decades ago my employer built them. We tested the supplies at full load while varying input voltage from 20% below nominal to 20% above nominal voltage (90 - 130 VAC). If the equipment operated for 4 weeks, I would say the 'handyman' is not responsible. PlainBill |
Liability & responsibility of electrician?
At this point, I think there are two questions (at least) that we need
to OP to answer. 1) Did the "wiring guy" hook up the equipment or just run wiring to the locations where it was to go? And if he hooked up the equipment, did this require opening it or did the owner just tell him to connect cables that were already attached to the machines. 2) What were the agreed upon responsibilities of the "guy"? I assume the owner hired him to save money, so he might be expected to do as little as necessary to set things up, unless something more was agreed upon. Asking what a licensed electrician would normally do might not really be relevant... Also, don't forget that in most places if the owner knew he hired an unlicensed person, he (the owner) is probably liable for fines, permits (possibly at doube the price) and at least having all this work gone over by a real electrician if the authorities find out. If it's anything like residential work, they might even force him to pay a licensed electrician to rip it all out and redo it. I'd consider that before raising a stink. |
Liability & responsibility of electrician?
"Doug Miller" wrote in message
... In article , "William Sommerwerck" wrote: 1) 245VAC is *not* a problem in a nominal 240VAC supply. That is correct until you factor in that the taps were set to 220v. If the taps were set at 240, then 245v would never have been a problem. |
Liability & responsibility of electrician?
On Jul 5, 2:11*pm, wrote:
On Sat, 4 Jul 2009 23:40:18 -0700, John E. wrote: I have been asked to offer an opinion in a sensitive situation. A machinist moved his shop across town and required some rewiring (3-phase outlets, conduit, etc.) in order to locate some machines where he wanted them. He hires a guy who's not a pro (and later discovers is not insured) but has done shop wiring before and had a good attitude and track record. The guy does good work. No complaints about the quality of his work. Owner throws the switch, all works fine. The story continues 4 weeks later when the very expensive CNC fries its controller PCB to the tune of $4000. Turns out the voltage in the shop was upward of 245 and the taps in the CNC's power supply were set for 220. What is the legal and moral responsibility of each party? What will not be helpful are replies about the character or intelligence of either of the players or their actions. Thanks. First of all, 245 VAC is a common AC voltage in the US. *Yes, I know we say 110 / 220, but it is more like 120 / 240. * Second, what was the 'handyman' hired to do? *If he wired a number of 1 and 3 phace 110 / 220 volt *outlets, he has no liability. *If he hard-wired (ran conduit directly to) the equipment, it is open to discussion. *If he adjusted wiring taps, etc than he MAY be responsible. Just to muddy it up even further, we recently put a medical device through CE approval and were advised by the examiner that our label should read "110/240", and that's the label we passed with. However, every controller I have ever seen uses a regulated power supply. *Decades ago my employer built them. *We tested the supplies at full load while varying input voltage from 20% below nominal to 20% above nominal voltage (90 - 130 VAC). *If the equipment operated for 4 weeks, I would say the 'handyman' is not responsible. Fully agreed. PlainBill |
Liability & responsibility of electrician?
On Jul 5, 1:04*pm, RoyJ wrote:
Assuming a nominal 240VAC supply, 245V is in no way "not correct" -- it's only about a 2% overvoltage. And since there is likely no load in shop when the install was taking place, the 245 would be a higher than normal reading. But I question the use of "3phase" and "245 volts" in the OP question. Around here, 245 volts would be perfectly normal for a single phase circuit, very high for a "standard" 208/3 phase delta. Roy Three phase delta would not produce 208 volts unless it was a customer provided special purpose transformer. Three Phase Delta can be wired as corner grounded, grounded center tap in one phase with the opposite phase being the odd higher voltage to ground known as the wild leg or stinger, or completely ungrounded with or without ground fault detection. The way you end up with three phase 208 is to wire the transformer in a wye or star configuration with the transformer primary taps set to produce 120 volts to ground on each of the three secondary legs. -- Tom Horne |
Liability & responsibility of electrician?
krw wrote:
On Sun, 5 Jul 2009 17:29:04 +0000 (UTC), "Geoffrey S. Mendelson" wrote: Doug Miller wrote: You're missing the point. This has nothing to do with the voltage supplied by the utility. The utility doesn't supply 220V or 240V or whatever. They supply (for example) 4KV. A transformer at the point of service reduces that to 220V, or 240V, or whatever. Different transformers connected to the *same* 4KV primary voltage could easily produce different secondary voltages. No, I'm not. When I lived in the US, (PECO) the electric company sold me 240 volt 2 phase electricity. It was nominaly 127 volts, but often dropped down during times of high usage. 240V isn't "two phase", rather single phase, or otherwise known as "split phase". ...and it had better not be 127V (maybe twice that). They did not supply or sell me 4kv volts, or anything else. They supplied that to the pole. Please read. What they carry on the pole is immaterial. What they supply to the customer service entrance is the 'point of sale'. Very few homes or light commercial service is in the 4kV range in the US. The service entrance voltage is usually much lower, 240 or 480. In these cases, the step-down transformer used to convert from distribution voltage (e.g. 4kV) to the service entrance voltage is the utility's responsibility. The utility is responsible for supplying the voltage/frequency at the service entrance / metering point of sale, not 'the pole'. daestrom |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 14:39:27 -0400, daestrom
wrote: krw wrote: On Sun, 5 Jul 2009 17:29:04 +0000 (UTC), "Geoffrey S. Mendelson" wrote: Doug Miller wrote: You're missing the point. This has nothing to do with the voltage supplied by the utility. The utility doesn't supply 220V or 240V or whatever. They supply (for example) 4KV. A transformer at the point of service reduces that to 220V, or 240V, or whatever. Different transformers connected to the *same* 4KV primary voltage could easily produce different secondary voltages. No, I'm not. When I lived in the US, (PECO) the electric company sold me 240 volt 2 phase electricity. It was nominaly 127 volts, but often dropped down during times of high usage. 240V isn't "two phase", rather single phase, or otherwise known as "split phase". ...and it had better not be 127V (maybe twice that). They did not supply or sell me 4kv volts, or anything else. They supplied that to the pole. Please read. What they carry on the pole is immaterial. What they supply to the customer service entrance is the 'point of sale'. It is material to what the OP wrote. It may be immaterial to the facts of the case, but it *is* what was written. Very few homes or light commercial service is in the 4kV range in the US. The service entrance voltage is usually much lower, 240 or 480. In these cases, the step-down transformer used to convert from distribution voltage (e.g. 4kV) to the service entrance voltage is the utility's responsibility. That may be, but that wasn't what was written. The step down transformer was part of the post too. The utility is responsible for supplying the voltage/frequency at the service entrance / metering point of sale, not 'the pole'. Irrelevant to what was written and objections to same. |
Liability & responsibility of electrician?
This to me is starting to get tedious.
The standard USENET rule applies: THEN DON'T RESPOND. |
Liability & responsibility of electrician?
USA, N. American continent, planet Earth.
|
Liability & responsibility of electrician?
On Jul 5, 6:26*am, (Doug Miller) wrote:
Turns out the voltage in the shop was upward of 245 and the taps in the CNC's power supply were set for 220. So what? Equipment designed for 220V should be able to handle 245V. It's not the electrician's responsibility to open the CNC machine to see what it's set for. Absolutely correct. The CNC controller burned up, BUT the line voltage is no smoking gun, you have NO reason to believe that was the cause. Overvoltage would usually result in relatively simple, inexpensive faults (fuses blowing), or at most a power supply failure (figure $300 for that kind of part, no WAY it's $4000). Manufacturer of the controller should be replacing it under warranty. And, there should be an install procedure to determine tap placement: who did the install? Wiring an outlet for the equipment does NOT make the electrician responsible for install procedure, nor for installed equipment. |
Liability & responsibility of electrician?
John E. wrote:
I have been asked to offer an opinion in a sensitive situation. BZZZT! Danger Will Robinson! Before offering your opinion, examine what *you* stand to gain/lose. The "sensitive situation" could be a bucket of rattlesnakes, and your participation might direct some of those snakes your way. Someone is looking at you as the "expert" whose opinion carries weight in his/her mind. Your opinion is bound to be used to bolster the argument of whichever side asked you: "Well John said ... " That bolstering could get you in trouble with the other person - and it is likely or possible that whatever you say will be misquoted. Taking sides in a "sensitive situation" is fraught with danger. The next issue is that you are not sure enough of your opinion to voice it without seeing what people here think. Or, if you have already voiced it, you have enough doubt to seek other's viewpoints here. Either way, it highlights the problem(s) that sensitive situations create. If, for the moment, we take the possible danger to you out of the equation and just look at the situation: Who can tell? Does anyone replying to the post have all of pertinent the facts? We don't know the details of the agreement between the handyman and the shop owner, whether there was any specific discussion concerning the CNC machine, what claims the handyman made as to his experience or expertise, any applicable laws in the location the work was done, whether/if/when the power utility changed things and on and on. People could reply with 100% valid opinions that might not apply to the specific situation. So, while there may be a clear legal and moral responsibility for each party, it is impossible for us to to know what it is at this point. Ed A machinist moved his shop across town and required some rewiring (3-phase outlets, conduit, etc.) in order to locate some machines where he wanted them. He hires a guy who's not a pro (and later discovers is not insured) but has done shop wiring before and had a good attitude and track record. The guy does good work. No complaints about the quality of his work. Owner throws the switch, all works fine. The story continues 4 weeks later when the very expensive CNC fries its controller PCB to the tune of $4000. Turns out the voltage in the shop was upward of 245 and the taps in the CNC's power supply were set for 220. What is the legal and moral responsibility of each party? What will not be helpful are replies about the character or intelligence of either of the players or their actions. Thanks. |
Liability & responsibility of electrician?
|
Liability & responsibility of electrician?
On Sun, 5 Jul 2009 13:54:05 +0000 (UTC), "Geoffrey S. Mendelson"
wrote: You missed the point of the original post. The person who did the work was NOT an electrician, they were a "handyman" hired to do the work. We must ask you at this point...what is your definition of an electrician. If the same person gets a license, does that automatically make him no longer a handyman, but an electrician? Gunner "Lenin called them "useful idiots," those people living in liberal democracies who by giving moral and material support to a totalitarian ideology in effect were braiding the rope that would hang them. Why people who enjoyed freedom and prosperity worked passionately to destroy both is a fascinating question, one still with us today. Now the useful idiots can be found in the chorus of appeasement, reflexive anti-Americanism, and sentimental idealism trying to inhibit the necessary responses to another freedom-hating ideology, radical Islam" Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno |
Liability & responsibility of electrician?
Gunner Asch wrote:
Fortunately..most of my gear runs fine on this, with the exception of the VFD on my Gorton mill. At times, it shows an over voltage alarm and refuses to run until the voltage drops back down to under 246. Ive called this to the attention of the local PG&E wanks..and they simply shrug, send someone out to measure the voltage, confirm that indeed its 252, blither a bit and then leave. Before there were UPS's there were constant voltage transformers, the most popular made by Sola. UPS's put out really crap AC, and are designed to work with a switching power supply as a load. Sola transformers were used with all sorts of things, there may be one that fits your needs. I used them with computers that had linear power supplies, but I think they will work with motors, it's worth checking out. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM |
Liability & responsibility of electrician?
Gunner Asch wrote:
We must ask you at this point...what is your definition of an electrician. Someone who has a license, (and/or) is a member of the union, passed a test that entitles him to call himself an electrician. But not someone with no formal training, licensure or certification. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM |
Liability & responsibility of electrician?
On 5 Jul., 08:58, Spehro Pefhany
wrote: On Sat, 4 Jul 2009 23:40:18 -0700, the renowned John E. wrote: I have been asked to offer an opinion in a sensitive situation. A machinist moved his shop across town and required some rewiring (3-phase outlets, conduit, etc.) in order to locate some machines where he wanted them. He hires a guy who's not a pro (and later discovers is not insured) but has done shop wiring before and had a good attitude and track record. The guy does good work. No complaints about the quality of his work. Owner throws the switch, all works fine. The story continues 4 weeks later when the very expensive CNC fries its controller PCB to the tune of $4000. Turns out the voltage in the shop was upward of 245 and the taps in the CNC's power supply were set for 220. What is the legal and moral responsibility of each party? What will not be helpful are replies about the character or intelligence of either of the players or their actions. Thanks. IMO, 11% high voltage over nominal should not "fry" the controller board in the first place. * a loose neutral can result in all kinds of strange voltages depending on the load on the phases, so the 11% might just be what the voltage was when it was measured, not what it was when the controller was fried -Lasse |
Liability & responsibility of electrician?
John E. wrote:
I have been asked to offer an opinion in a sensitive situation. A machinist moved his shop across town and required some rewiring (3-phase outlets, conduit, etc.) in order to locate some machines where he wanted them. He hires a guy who's not a pro (and later discovers is not insured) but has done shop wiring before and had a good attitude and track record. The guy does good work. No complaints about the quality of his work. Owner throws the switch, all works fine. The story continues 4 weeks later when the very expensive CNC fries its controller PCB to the tune of $4000. Turns out the voltage in the shop was upward of 245 and the taps in the CNC's power supply were set for 220. What is the legal and moral responsibility of each party? What will not be helpful are replies about the character or intelligence of either of the players or their actions. Thanks. The failure that you had was probably caused by your rigger not using an airride trailer to move the equipment and something got shaken up. Four weeks of running proves the voltage was not the problem. Some disgruntled employee probably ****ed in the cabinet. 245 volts is within the normal specs from the utility. AS far as changing the tap, you should have called in a machine tech to set it up. An electrician wires only to the safety disconnect switch in the machine, after that it is your responsibility to call in a machine setup tech. John |
Liability & responsibility of electrician?
On Sun, 5 Jul 2009 21:04:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote: Gunner Asch wrote: We must ask you at this point...what is your definition of an electrician. Someone who has a license, (and/or) is a member of the union, passed a test that entitles him to call himself an electrician. But not someone with no formal training, licensure or certification. Geoff. So then what am I? I passed the tests, at one time held a (California) C7 and C10 license, ( as responsible managing employee for a large company who before me had NO liceneses), have worked for the past 12 yrs as a machine shop electrician (with no failures to date), CNC repair tech and so forth. However..Ive refused to belong to any union since 1974, when my 6 week stint as a UAW worker left me cold about unions. Am I just a "handyman" because I dont belong to a union spit? My business cards indicate that I do electrical (non licensed) as well as CNC and Machine Tool Repair. So am I simply a "handyman"? Inquiring minds really want to know. Gunner "Lenin called them "useful idiots," those people living in liberal democracies who by giving moral and material support to a totalitarian ideology in effect were braiding the rope that would hang them. Why people who enjoyed freedom and prosperity worked passionately to destroy both is a fascinating question, one still with us today. Now the useful idiots can be found in the chorus of appeasement, reflexive anti-Americanism, and sentimental idealism trying to inhibit the necessary responses to another freedom-hating ideology, radical Islam" Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 13:44:18 -0700, Gunner Asch
wrote: We must ask you at this point...what is your definition of an electrician. I guarantee it doesn't match yours. You seem to think that since you understand the rules of making a connection that you understand electrical power. I doubt seriously that you have such a grasp of the industry. |
Liability & responsibility of electrician?
Bruce L. Bergman wrote:
On Sat, 4 Jul 2009 23:40:18 -0700, John E. wrote: I have been asked to offer an opinion in a sensitive situation. A machinist moved his shop across town and required some rewiring (3-phase outlets, conduit, etc.) in order to locate some machines where he wanted them. He hires a guy who's not a pro (and later discovers is not insured) but has done shop wiring before and had a good attitude and track record. The guy does good work. No complaints about the quality of his work. Owner throws the switch, all works fine. The story continues 4 weeks later when the very expensive CNC fries its controller PCB to the tune of $4000. Turns out the voltage in the shop was upward of 245 and the taps in the CNC's power supply were set for 220. What is the legal and moral responsibility of each party? What will not be helpful are replies about the character or intelligence of either of the players or their actions. The nominal utility power as supplied is supposed to be 240V. 5 volts over is a touch hot, but not out of the bounds of normal tolerances - turn everything on in the neighborhood some hot August afternoon with the AC units cranked, and tell me what the voltage reads then... That is not always the case. I'm a little rusty when it comes to 3 phase distribution, but I've dealt with some things like this in a machine shop friends of mine own. The voltage depends on the service to the building. Some shops have 208V and some have 240V, and we've had to reconfigure machines from time to time that were purchased from other locations, or run some off buck/boost transformers if they were not configurable. Perhaps someone more knowledgeable can fill in the details. It's good practice of course to measure the voltage and double check the configuration of the particular machine prior to applying power. $4K seems pretty high though, did anyone look into repairing the damaged board? |
Liability & responsibility of electrician?
If an unlicensed person does electrical work, the work has to be inspected by a licensed electrician before the power is turned on. If that was not the case, there would be no point in licensing electricians, would there? Geoff. Depends on where you are. Here in the US, the work has to be inspected by an inspector, not an electrician. You have to be a licensed electrician to be hired by most electrical contracting companies, but there is no law against unlicensed people electrical work. I've replaced electrical service panels and added circuits for renovations in the homes of quite a few friends and family members, I'm not licensed, but it was no trouble to get a permit and have the work inspected when it was complete. Even licensed electricians have to get their work inspected. |
Liability & responsibility of electrician?
Ignoramus20157 wrote:
245 volts is only mildly on the high side and should not cause the symptom described. i As well as sometimes things just do fail. If only I had a dollar for every time someone with zero technical knowledge told me "this failed because so and so did this or that". Just because something broke shortly after work was done, does not automatically mean that the work done is what caused it to break. |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 15:26:07 -0700, StickThatInYourPipeAndSmokeIt
wrote: On Sun, 05 Jul 2009 13:44:18 -0700, Gunner Asch wrote: We must ask you at this point...what is your definition of an electrician. I guarantee it doesn't match yours. You seem to think that since you understand the rules of making a connection that you understand electrical power. Odd...so Im simply a wire hooker-upper? And my CNC machine repair is simply making connections? No understanding of the trade? I doubt seriously that you have such a grasp of the industry. Why...because Im not a Union Member? Chuckle...I charge MORE than most Union Members do. And I get the work. I suggest you review what you wrote..and why you wrote it. VBG Gunner "Lenin called them "useful idiots," those people living in liberal democracies who by giving moral and material support to a totalitarian ideology in effect were braiding the rope that would hang them. Why people who enjoyed freedom and prosperity worked passionately to destroy both is a fascinating question, one still with us today. Now the useful idiots can be found in the chorus of appeasement, reflexive anti-Americanism, and sentimental idealism trying to inhibit the necessary responses to another freedom-hating ideology, radical Islam" Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno |
Liability & responsibility of electrician?
Jon Danniken wrote:
William Sommerwerck wrote: My drier sees 250VAC. Low voltage stuff in this house gets 125VAC. Everything is working just fine. sniff sniff Is that burning cotton I smell? Drier has a temperature limiter, so although the slightly higher voltage results in a slightly quicker "turn on" time for the elements, they still are shut off at the same temperature regardless of incoming voltage. Jon I rented a house for a while that had unusually high line voltage. It varied from around 122V to 125V depending on the time of day. If it was much higher than that, I'd be concerned, but anything from 115V to 125V is pretty normal. A friend of mine over in the UK is near the end of a long run from the transformer that powers his street. His voltage varies considerably, from as low as 220V to nearly 250V. |
Liability & responsibility of electrician?
On 2009-07-05, John E wrote:
2. Is it normal for electricians to measure the voltage, and "do something" about it if it's not correct (if only reporting the problem to the businessman)? This is the basic question I'm asking. Is it common and regular practice to inform the owner of a voltage as high as 245? And to suggest that he have factory personnel come and look at each machine and examine PS taps and such? And if he had hired a licensed electrician would the electrician likely had informed the owner of the voltage difference? I have 245 volts in my garage. Everything works great. 245 volts is a perfectly normal voltage. It corresponds to 122.5 volts AC from a regular outlet. There is no causal relationship, as far as I can tell, between perfectly normal voltage provided in your shop, and your CNC machine frying after 3 more weeks. I have not yet seen a more inane discussion thread. i |
Liability & responsibility of electrician?
John E. wrote:
I have been asked to offer an opinion in a sensitive situation. A machinist moved his shop across town and required some rewiring (3-phase outlets, conduit, etc.) in order to locate some machines where he wanted them. He hires a guy who's not a pro (and later discovers is not insured) but has done shop wiring before and had a good attitude and track record. The guy does good work. No complaints about the quality of his work. Owner throws the switch, all works fine. The story continues 4 weeks later when the very expensive CNC fries its controller PCB to the tune of $4000. Turns out the voltage in the shop was upward of 245 and the taps in the CNC's power supply were set for 220. What is the legal and moral responsibility of each party? What will not be helpful are replies about the character or intelligence of either of the players or their actions. Thanks. Sorry, but that little upward swing didn't cause the issue.. Sounds to me like some one couldn't properly determine the real problem with the control board and opted to simply replace the whole thing or, the person doing the work on the repairs caused more damage them self's and are covering their tracks. I'm sorry, but 4 weeks into operation and it worked fine all that time, I think you should look else where for the problem or just simply eat the coast of a broken down CNC machine. My guess is the moving process may have caused some sensitive electronics on the board to get ajar if the CNC was possibly dropped or whacked hard enough to cause a fracture crack in a solder joint that finally showed it's oats. Of course, that is just my opinion. You can take it with a grain of salt. |
Liability & responsibility of electrician?
Ignoramus20157 wrote:
On 2009-07-05, John E wrote: 2. Is it normal for electricians to measure the voltage, and "do something" about it if it's not correct (if only reporting the problem to the businessman)? This is the basic question I'm asking. Is it common and regular practice to inform the owner of a voltage as high as 245? And to suggest that he have factory personnel come and look at each machine and examine PS taps and such? And if he had hired a licensed electrician would the electrician likely had informed the owner of the voltage difference? I have 245 volts in my garage. Everything works great. 245 volts is a perfectly normal voltage. It corresponds to 122.5 volts AC from a regular outlet. There is no causal relationship, as far as I can tell, between perfectly normal voltage provided in your shop, and your CNC machine frying after 3 more weeks. I have not yet seen a more inane discussion thread. Dont worry there will be more. Its a great form of mindless intertainment. Any CNC control or machine that cannot take a 10% overvoltage is a piece of junk to begin with. Power supply technology in the last 20 years can easily design units that will handle these variations. The power company likes to hold the voltage on the supply lines as high as possible to reduce the losses per kw metered and delivered. I have a number of CNC machines running on 515 volts measured at the machine internal disconnect and never had a control failure from overvoltage. Undervoltage is what damages equipment because the currents run higher for the same work done and the power components get hotter from the higher current. John |
Liability & responsibility of electrician?
"Ignoramus20157" wrote in message
... 245 volts is a perfectly normal voltage. It corresponds to 122.5 volts AC from a regular outlet. Oddly enough, that's exactly what I've measured (give or take a few tenths) in the MSOE power lab (which is equipped with 208V 3 phase), and very nearly the same at my own bench at home. Tim -- Deep Friar: a very philosophical monk. Website: http://webpages.charter.net/dawill/tmoranwms |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 15:33:48 -0700, James Sweet
wrote: Bruce L. Bergman wrote: On Sat, 4 Jul 2009 23:40:18 -0700, John E. wrote: I have been asked to offer an opinion in a sensitive situation. A machinist moved his shop across town and required some rewiring (3-phase outlets, conduit, etc.) in order to locate some machines where he wanted them. He hires a guy who's not a pro (and later discovers is not insured) but has done shop wiring before and had a good attitude and track record. The guy does good work. No complaints about the quality of his work. Owner throws the switch, all works fine. The story continues 4 weeks later when the very expensive CNC fries its controller PCB to the tune of $4000. Turns out the voltage in the shop was upward of 245 and the taps in the CNC's power supply were set for 220. What is the legal and moral responsibility of each party? What will not be helpful are replies about the character or intelligence of either of the players or their actions. The nominal utility power as supplied is supposed to be 240V. 5 volts over is a touch hot, but not out of the bounds of normal tolerances - turn everything on in the neighborhood some hot August afternoon with the AC units cranked, and tell me what the voltage reads then... That is not always the case. I'm a little rusty when it comes to 3 phase distribution, but I've dealt with some things like this in a machine shop friends of mine own. The voltage depends on the service to the building. Some shops have 208V and some have 240V, and we've had to reconfigure machines from time to time that were purchased from other locations, or run some off buck/boost transformers if they were not configurable. Perhaps someone more knowledgeable can fill in the details. It's good practice of course to measure the voltage and double check the configuration of the particular machine prior to applying power. $4K seems pretty high though, did anyone look into repairing the damaged board? CNC electronics cost about 4-8 times as much to fix as normal electronics. Shrug..its called :"the going rate" unfortunately. Gunner "Lenin called them "useful idiots," those people living in liberal democracies who by giving moral and material support to a totalitarian ideology in effect were braiding the rope that would hang them. Why people who enjoyed freedom and prosperity worked passionately to destroy both is a fascinating question, one still with us today. Now the useful idiots can be found in the chorus of appeasement, reflexive anti-Americanism, and sentimental idealism trying to inhibit the necessary responses to another freedom-hating ideology, radical Islam" Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 19:10:07 -0400, john wrote:
I have not yet seen a more inane discussion thread. Dont worry there will be more. Its a great form of mindless intertainment. Any CNC control or machine that cannot take a 10% overvoltage is a piece of junk to begin with. As a CNC tech..I agree with you. Unfortunately however...there are far far too many Big Name manufactures out there who utilize minimal design perameters when they make something (very expensive) and then charge out the ass when it goes tits up. Gunner "Lenin called them "useful idiots," those people living in liberal democracies who by giving moral and material support to a totalitarian ideology in effect were braiding the rope that would hang them. Why people who enjoyed freedom and prosperity worked passionately to destroy both is a fascinating question, one still with us today. Now the useful idiots can be found in the chorus of appeasement, reflexive anti-Americanism, and sentimental idealism trying to inhibit the necessary responses to another freedom-hating ideology, radical Islam" Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno |
Liability & responsibility of electrician?
"Gunner Asch" wrote in message ... On Sun, 5 Jul 2009 21:04:04 +0000 (UTC), "Geoffrey S. Mendelson" wrote: So then what am I? I passed the tests, at one time held a (California) C7 and C10 license, ( as responsible managing employee for a large company who before me had NO liceneses), have worked for the past 12 yrs as a machine shop electrician (with no failures to date), CNC repair tech and so forth. However..Ive refused to belong to any union since 1974, when my 6 week stint as a UAW worker left me cold about unions. Am I just a "handyman" because I dont belong to a union spit? My business cards indicate that I do electrical (non licensed) as well as CNC and Machine Tool Repair. So am I simply a "handyman"? Inquiring minds really want to know. Gunner Yes, you're a glorified handyman...happy? ;-) Yes you have the knowledge and experience, but as long as you do not hold a valid license, you can call yourself an electrician, but you cannot call yourself a licensed electrician. As an unlicensed electrician you cannot LEGALLY perform ANY electrical work outside of your own single family residence. BTW, union or not makes no difference, it's state law we're talking about. |
Liability & responsibility of electrician?
"James Sweet" wrote in message ... Depends on where you are. Here in the US, the work has to be inspected by an inspector, not an electrician. You have to be a licensed electrician to be hired by most electrical contracting companies, but there is no law against unlicensed people electrical work. I've replaced electrical service panels and added circuits for renovations in the homes of quite a few friends and family members, I'm not licensed, but it was no trouble to get a permit and have the work inspected when it was complete. Even licensed electricians have to get their work inspected. You're fooling yourself. You cannot legally do any electrical work at the homes of your friends or family. If there is ever an electrical fire at any building that you did electrical work in...you can kiss your life goodbye. You can be arrested, tried in a criminal court, and sentenced to prison, plus sued for everything you own in a civil court. This can happen to you because it is a crime in any state (as far as I know) for you to do this work. Liability insurance is not even an option for you because you have to be licensed to get the insurance in the first place. |
| All times are GMT +1. The time now is 03:15 PM. |
Powered by vBulletin® Copyright ©2000 - 2025, Jelsoft Enterprises Ltd.
Copyright ©2004 - 2014 DIYbanter