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Liability & responsibility of electrician?
john wrote:
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. Moving a machine unleases the devils inside. We move a machine a hundred feet across the plant and we often have issues in the near term. Moving introduces physical shock loads into the electrics, often causes connectors to lose connection, marginal components to fail, ect. We moved one machine 200 feet and when we powered it up, I had to reload parameters and pc parameters. No mention was made of the age of the machine by the OP. Caps dry out and such. It might have just been the machines time to go. I still think the shop owner is looking for a free lunch. Wes -- "Additionally as a security officer, I carry a gun to protect government officials but my life isn't worth protecting at home in their eyes." Dick Anthony Heller |
Liability & responsibility of electrician?
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. We still use 208 for ligthing only.. |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 15:40:26 -0700, James Sweet
wrote: 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. That depends entirely on the jurisdiction. Several cities have tradesmen full employment laws. Some have no inspectors at all. |
Liability & responsibility of electrician?
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Liability & responsibility of electrician?
In article , 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'. Very few homes or light commercial service is in the 4kV range in the US. Nobody ever said it was. The service entrance voltage is usually much lower, 240 or 480. Right, I think we all know that. 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'. Exactly so. Anyone who still doesn't understand how different premises attached to the same local grid could have service entrance voltages which are *nominally* the same but *actually* different by five or ten percent, please raise your hand. |
Liability & responsibility of electrician?
John Larkin wrote:
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 You can only do that if the electric company is actually providing that 245V. It's possible they are providing 480/460 V 3 Phase, and a in house transformer is being used. If that is the case, then there should be taps on the primary side to adjust this how ever, this measurement must be taken with at least 50% load of the shop on it to get a true reading. 245V is not uncommon and shouldn't cause any issues, actually, induction motors run better on peppier voltages. I may sound like I'm getting fired up over this with multiple reply's I have made, it's nothing against you John how ever, this comes from events that I have seen take place at work where expensive electronics just went faulty on normal use and caused a lot of down time and material loss. The powers to be that don't know anything about the field start pointing fingers and when they research to see who was the last one to have their hands in the machine no matter how long ago it was. They think its a good justification to start blame storming. Some time people loss their jobs when they did absolutely nothing wrong only to save the ass of some one else!. |
Liability & responsibility of electrician?
Doug Miller wrote:
Yes, I'm afraid you are missing the point. Different locations, even though attached to the same local grid, may have different supply voltages because they are receiving those supplies through different transformers. I got that. What is wrong is that the person who wrote that originally (was it you?) used that to explain why a regular house outlet could be 220 volts on one side of town, and 240 volts on another, both connected to the same "grid". There's going to be some variation, but not that much. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM |
Liability & responsibility of electrician?
"Geoffrey S. Mendelson" wrote: Doug Miller wrote: Yes, I'm afraid you are missing the point. Different locations, even though attached to the same local grid, may have different supply voltages because they are receiving those supplies through different transformers. I got that. What is wrong is that the person who wrote that originally (was it you?) used that to explain why a regular house outlet could be 220 volts on one side of town, and 240 volts on another, both connected to the same "grid". There's going to be some variation, but not that much. Nonsense! Do you believe that the entire town is powered by a single substation, and that there are no I/R losses? It IS possible that an older part of a town hasn't been upgraded in a long time, and that the additional load pulls the line voltage down at the end of a MV feed while another site is closer to a substation and has higher voltage available to the building. -- You can't have a sense of humor, if you have no sense! |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 15:16:00 -0700, Gunner Asch
wrote: 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. You can get a license without being in the union. Excuses do not make you qualified. Especially if the tests you took were way back in '74. |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 22:48:41 -0700, StickThatInYourPipeAndSmokeIt
wrote: On Sun, 05 Jul 2009 15:16:00 -0700, Gunner Asch wrote: 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. You can get a license without being in the union. Of course I can. And did. Excuses do not make you qualified. Especially if the tests you took were way back in '74. Where did you get that date from? Was that the year you were spawned? I put my C7-C10 on "Hold" with the California BCA in 1998. I think its expired now..as I recall, it only had a 10 yr life on hold. Shrug..another weekend at a Contractors Fast Learn and take the test on Monday. Not a big deal. Except the fees and costs. Which means Ill simply continue on as a CNC tech who occasionally does electrical work, until the economy turns around. Of course..I may be near retirement age by that time...assuming the US doesnt melt down totally. Shrug 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 16:40:10 -0700, Gunner Asch
wrote: CNC electronics cost about 4-8 times as much to fix as normal electronics. Shrug..its called :"the going rate" unfortunately. Motor controllers are 70s technology with MAYBE 90s electronics, if you are lucky. Even if it is a brand new design, it still isn't worth anything more than any other industrial application. $4000 is a bit much for a simple swap out. Perhaps it is guys like you that have inflated the price over the years. Overt greed is such a sad thing. It produces jerks that thumb their noses at the entire industrial world, then cannot figure out why God handed you a heart condition. I guess that's what they all deserve for buying Japanese CNC hardware. Buy American. I'll bet that one of Cincinnati Milacron's controller boards do not cast that much. Laugh laugh laugh? You say? I laugh at you, jackass. I say that I hope that chest gripper of death hits you soon, because you are a major Asch hole. |
Liability & responsibility of electrician?
William Sommerwerck wrote:
1. Did the electrician have any control over the voltage when the system was rewired? 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)? 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. I didn't miss the point (I think). He was doing the work of an electrician. And whether or not he was a licensed electrician, he is still morally responsible for the quality of his work. (Think Hamurabi.) Only if it can be shown that he did something wrong. I don't know what US tolerances on voltage are but in the UK 245v on a nominally 240 line (these days 230v with asymetric tolerancing) wouldn't raise eyebrows. Since the person never said where they were, it's hard to guess what the rules are but in (almost?) every jurisdiction that licenses electricians, a license is needed to do electrical work. 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? No, there wouldn't be. But if he botched the job, he has to be held responsible. Doesn't he? Iff he botched the job. The kit worked for a while after he left. And he did not claim to be a qualified electrician. Had he connected the machine chassis to live and electrocuted someone then it would be a different matter. But even then the employer who got in a cut price handyman to do a qualified industrial electricians job would still be guilty of more serious fundamental health and safety offences for not having the installation inspected by a competent person before switching it on. What are the US regs like on employer liability? Of course, one might argue that if the person who hired him /knew/ he wasn't an electrician, and didn't have the work inspected, then he (the hirer) is responsible for whatever went wrong. Exactly. And that is how the insurers would argue it to avoid paying out a dime if the whole building burnt down as a result of unqualified electrical work that had not been properly inspected before switch on. I don't see that the handyman has anything to answer for although he may still have problems with frivolous litigation from the OP's mate. Regards, Martin Brown |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 16:43:44 -0700, Gunner Asch
wrote: 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. Yeah, this dopey **** really knows about quality. NOT! "Big Name manufacturers"? What easy sleazy Japanesey? Cite, asswipe? US makers? Don't jack off at the mouth without backing it up. What are you ****ed about? Single sided boards? What? How ****ing hard can it be to be one that touts hi,mself as a CNC tech if all the gear is so "cheaply made". Jeez, when are you going to go tit up? |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 20:00:41 -0400, Wes wrote:
Moving introduces physical shock loads into the electrics, Jeez. Unless it is full of improperly torqued screw type terminations, there is NOTHING in a simple shock that would damage ANY CNC "electrics" as you call them. They can handle like 40Gs, Just like a hard drive can. They can certainly handle ten, and unless you dropped the ****ing thing, you cannot possibly shock a PWA to that degree. "Physical shock loads" is a bunch of crap too. They get subjected to physical shocks, which get transferred across an assembly, but their is no remnant "load" or anything else. If there is, the entire damned thing all the way out to the containment case for it is designed wrong. You would have to drop a machine from a foot in the air to cause a big enough shock. I would be hiring new material handling personnel if they were not able to move a few tons around gracefully enough to keep from damaging any electronics contained on the load. |
Liability & responsibility of electrician?
On Mon, 06 Jul 2009 01:11:46 -0700, Archimedes' Lever
wrote: On Sun, 05 Jul 2009 16:40:10 -0700, Gunner Asch wrote: CNC electronics cost about 4-8 times as much to fix as normal electronics. Shrug..its called :"the going rate" unfortunately. Motor controllers are 70s technology with MAYBE 90s electronics, if you are lucky. Even if it is a brand new design, it still isn't worth anything more than any other industrial application. $4000 is a bit much for a simple swap out. Yes it is indeed. Take that up with the Japanese btw..and their US agents. Perhaps it is guys like you that have inflated the price over the years. Overt greed is such a sad thing. It produces jerks that thumb their noses at the entire industrial world, then cannot figure out why God handed you a heart condition. My greed? Hummm perhaps you havent any idea that Im one of the cheapest CNC service techs in So. Cal? Or is it simply that Im A service tech that busts your chops? Or are you simply an argumentative Leftwing piece of **** who doesnt like anyone to the Right of Trotsky? Powa to da Pipples!!! I guess that's what they all deserve for buying Japanese CNC hardware. Buy American. I'll bet that one of Cincinnati Milacron's controller boards do not cast that much. How much do you care to wager on that? Be specific......I could use a nice score. But then..it would appear you are a Leftwinger..and you would lose, whimper and whine, and then steal someone elses money if I held a gun to your head and made you pay up on your bet. Laugh laugh laugh? You say? I laugh at you, jackass. yawn I say that I hope that chest gripper of death hits you soon, because you are a major Asch hole. And I hope you have a nice day too. Gunner, off to LA to finish taking apart a factory "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 Mon, 06 Jul 2009 01:15:08 -0700, StickThatInYourPipeAndSmokeIt
wrote: On Sun, 05 Jul 2009 16:43:44 -0700, Gunner Asch wrote: 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. Yeah, this dopey **** really knows about quality. NOT! "Big Name manufacturers"? What easy sleazy Japanesey? Mori Seiki, Sharnoa, Toyoda, Mitsubish and so forth. Now I know you are simply masturbating while typing..as you dont have a clue that there are any US manufactures left besides Haas and Fadal....but hey...enjoy yourself and the rest of us can laugh our asses off at you. Cite, asswipe? US makers? Don't jack off at the mouth without backing it up. Shush..you must missed a stroke. What are you ****ed about? Single sided boards? What? How ****ing hard can it be to be one that touts hi,mself as a CNC tech if all the gear is so "cheaply made". VBG Jeez, when are you going to go tit up? Long after Ive had the chance to **** on your grave. 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 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. Since i am not sure where you are at, and you did not mention. In the US if the shop owner knowingly hired an non-licensed electrician to do the install, 'e would have to eat the loss. Similar in UK and much of Europe. The selected tap voltages and delivered line should have been within normal acceptance range for the controller power supply. As for why the controller fried that is unclear at this time; causation from the mains connections has yet to be discussed adequately. |
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. 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. Household feeds and commercial/industrial feeds are not the same thing. I have seen many modest size office buildings take 480 V feeds. I have worked on systems that take 12 kV feeds. I know of electric service customers that take 138 kV feeds. None of these i mentioned are industrial. You could check out what an aluminum smelter takes as feed with a search engine. |
Liability & responsibility of electrician?
On Mon, 06 Jul 2009 03:48:34 -0700, Gunner Asch
wrote: Hummm perhaps you havent any idea that Im one of the cheapest CNC service techs in So. Cal? Bwuahahahahaha! I'll bet your skill set matches your price schedule. Low and lame. Hummm? Yeah, you'd probably be better at that. |
Liability & responsibility of electrician?
On Mon, 06 Jul 2009 03:53:52 -0700, Gunner Asch
wrote: Now I know you are simply masturbating while typing..as you dont have a clue that there are any US manufactures left besides Haas and Fadal....but hey...enjoy yourself and the rest of us can laugh our asses off at you. You're an idiot. There are about three in Cincinnati alone, including the biggest in the world, the Cincinnati Milacron. You are only about as dopey as it gets. |
Liability & responsibility of electrician?
On Mon, 06 Jul 2009 03:53:52 -0700, Gunner Asch
wrote: Long after Ive had the chance to **** on your grave. Doubtful. What is that a pussy surfer boy threat? I will live far longer than a twit like you. |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 17:56:15 -0500, 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. i Mere ignorance is curable. I have seen worse in this NG. I have seen far, far worse in other NG. Stick around and learn something, even if it is only how crazy people get. |
Liability & responsibility of electrician?
On Sun, 5 Jul 2009 18:11:46 -0500, "Tim Williams"
wrote: "Ignoramus20157" wrote in message m... 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 Your apparent conflation of single phase systems and 3 phase systems only serves to confuse outsiders. |
Liability & responsibility of electrician?
On Sun, 05 Jul 2009 12:04:07 -0500, 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. Can't say that i have ever heard of 208 V 3 phase delta sources. All of the 208 V, 3 phase stuff i have seen has been 120/208 V, 3 phase "Y". Wiring motors for 208 V, 3 phase delta i have seen though, they typically also have taps for 240 V, 3 phase and other voltages as well. |
Liability & responsibility of electrician?
In article , wrote:
Since i am not sure where you are at, and you did not mention. In the US if the shop owner knowingly hired an non-licensed electrician to do the install, 'e would have to eat the loss. Nonsense. There are *many* areas of the U.S. in which there is *no* regulation of the electrical trade. |
Liability & responsibility of electrician?
"Doug Miller" wrote in message ... Nonsense. There are *many* areas of the U.S. in which there is *no* regulation of the electrical trade. Such as....? |
Liability & responsibility of electrician?
On Sun, 5 Jul 2009 11:31:43 -0700 (PDT), rangerssuck
wrote: 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. Ah!! More of the old 'nominal' vrs 'actual' nonsense. 3/4" iron pipe isn't. Neither is 3/4" copper because it has the same flow characteristics as 3/4" iron. Except there are three ratings of copper water pipe with the same OD, but different IDs. And 2 x 4s haven't been 2" x 4" since they started planing them. The latest change in size was to bring them in line with metric lumber sizes, but metrification of the US is dead.... PlainBill 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?
John,
Sounds like no formal contract was in effect. The shop owner hired labor, not a licensened electrician. In point of fact the owner should have had the service inspected and certified by law in most areas. He didn't. Secondly, even if he had, the conformability of his equipment to the new installation would never be the responsibility of the electrician, unless it was specifically mentioned in a formal contract. So, the owner and receiver of this service, owns the sole burdon of responsibility., no question. There is no such thing as a free lunch. If the owner wanted this level of assurance, he would have hired a firm that does this professionally and his price would naturally reflect the cost of the necessary insurance and the maintenance of all the appropriate license costs. By lo-balling the job, he assumed all the risks and consequences. This should be a lesson for all of us. Steve "John E." wrote in message obal.net... 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. -- John English |
Liability & responsibility of electrician?
"Tom Horne" wrote in message ... 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 The sole exception to that is if the wild leg is wired to ground. It then yields 208 volts, at least on my panel. No, I don't use it that way. Just tested voltage out of curiosity. Harold |
Liability & responsibility of electrician?
Paul Hovnanian P.E. wrote:
"John E." wrote: [snip] 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 far, no problem. A nominal 240V service can vary +/- 5% and be within power quality specifications. Equipment (nameplate) ratings are normally lower to acount for voltage drop. A 120V service powers 110V appliances. A 240V service powers 220V loads. Paul, I take my hat off to you sir... I knew some one here would finally get it right! :) |
Liability & responsibility of electrician?
"Steve Lusardi" wrote:
John, Sounds like no formal contract was in effect. The shop owner hired labor, not a licensened electrician. In point of fact the owner should have had the service inspected and certified by law in most areas. He didn't. Secondly, even if he had, the conformability of his equipment to the new installation would never be the responsibility of the electrician, unless it was specifically mentioned in a formal contract. So, the owner and receiver of this service, owns the sole burdon of responsibility., no question. There is no such thing as a free lunch. If the owner wanted this level of assurance, he would have hired a firm that does this professionally and his price would naturally reflect the cost of the necessary insurance and the maintenance of all the appropriate license costs. By lo-balling the job, he assumed all the risks and consequences. This should be a lesson for all of us. Steve A few thoughts. Wiring inside an industrial facility gets pretty sketchy at times. Using Michigan for an example, there is nothing saying plant personnel can not run circuits. I've worked for two firms that were big enough to be concerned about this and could not find anything stopping us from running power inside the plant ourselves. (Gunners Temp worker exception) New machine installations, we hire a licensed electrician, and have the sellers or manufacturers technical staff commision it. That means they make sure the line voltage and taps are correct. They throw the switch. Put a million dollars or more of machinery on the floor, you want the warranty to be in effect. Now repositioning machines, we tend to do our own wiring assuming we have the manpower to do it. If not, we hire a licensed electrican. Recently we aquired used machining centers from a plant the corporation closed down, those we wired ourselves after making sure we knew how the taps were set. Earlier this year, my brother, a licensed master electrican with a michigan electrical contractors license wired up an used CNC near where I live. My brother is pretty good, knew I worked with CNC's and lucky for him, he was installing the same model we have on the plant floor. Had he not had me for a resource, he would have depended on the customer to tell him what the machines electrical requirements are. In the case of this machine, it does have a transformer, not all CNC's do. Quite often you get 2xx v machines and step down 480v to match it. 480v is pretty much the standard in US manufacturing facilites of any decent size. Copper and switch gear adds up at half the voltage. Now if the japs would just design around 480V nominal, life would be very nice. Since it was my brother and he likes to give more than expected, I went over to check things. Most electricians don't have CNC techs to call on. Btw, shock loads that our troll ridiculed? Somehow a breaker on the spindle drive managed to trip during the move. It wasn't from an overload or overvoltage. It was from rigging and transporting. There was some slack jaws concerning their investment when it powered up with a spindle alarm. Some of those drives go for 5-12 grand. BTDT. Smiles all around when I found the problem and made it spin and move. I'd really like to hear the handymans side of the story. I wonder if the OP can get him to post? Wes |
Liability & responsibility of electrician?
"John E." wrote:
[snip] 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 far, no problem. A nominal 240V service can vary +/- 5% and be within power quality specifications. Equipment (nameplate) ratings are normally lower to acount for voltage drop. A 120V service powers 110V appliances. A 240V service powers 220V loads. -- Paul Hovnanian ------------------------------------------------------------------ Steinbach's Guideline for Systems Programming Never test for an error condition you don't know how to handle. |
Liability & responsibility of electrician?
On Mon, 6 Jul 2009 04:44:03 +0000 (UTC), "Geoffrey S. Mendelson"
wrote: Doug Miller wrote: Yes, I'm afraid you are missing the point. Different locations, even though attached to the same local grid, may have different supply voltages because they are receiving those supplies through different transformers. I got that. What is wrong is that the person who wrote that originally (was it you?) used that to explain why a regular house outlet could be 220 volts on one side of town, and 240 volts on another, both connected to the same "grid". There's going to be some variation, but not that much. Geoff. Depends entirely where you are. I've seen wider variations than that. GENERALLY the power company will correct if the voltage is "out of tolerance" but you don't count on it in some third world countries. Or some older inner-city areas. My current line voltage is 116. I have seen 123, and 108 and just about anything in between in sites seviced by the same power utility here in Ontario - but generally 117 is pretty standard. |
Liability & responsibility of electrician?
|
Liability & responsibility of electrician?
On Jul 5, 2:40*am, 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. From my past experience in industrial environments, it's 100% guaranteed that the electrician will wire the 3-phase feeds wrong. Either the phases will be out of sequence (motor spins backwards), or it'll be Delta instead of Wye, or wrong voltages, or something. It has absolutely nothing to do with how much specifying you try, it'll get hooked up wrong every single time. Tim. |
Liability & responsibility of electrician?
Tim Shoppa wrote:
On Jul 5, 2:40Â*am, 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. From my past experience in industrial environments, it's 100% guaranteed that the electrician will wire the 3-phase feeds wrong. Either the phases will be out of sequence (motor spins backwards), or it'll be Delta instead of Wye, or wrong voltages, or something. It has absolutely nothing to do with how much specifying you try, it'll get hooked up wrong every single time. Tim. You need to dump the outfit you are using and use a competent electrician. -- Paul Hovnanian ---------------------------------------------------------------------- Have gnu, will travel. |
Liability & responsibility of electrician?
On Wed, 8 Jul 2009 08:04:32 -0700 (PDT), Tim Shoppa
wrote: On Jul 5, 2:40*am, 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. From my past experience in industrial environments, it's 100% guaranteed that the electrician will wire the 3-phase feeds wrong. Either the phases will be out of sequence (motor spins backwards), or it'll be Delta instead of Wye, or wrong voltages, or something. It has absolutely nothing to do with how much specifying you try, it'll get hooked up wrong every single time. Tim. Your name Shoppa or Lammeh? Just wondering, because that is a pretty lame outlook. |
Liability & responsibility of electrician?
On Jul 5, 11:39*am, "Geoffrey S. Mendelson"
wrote: Doug Miller wrote: Incorrect. Distribution voltages are on the order of a few thousand volts, stepped down by transformers at the point of service to a few hundred. New location = different transformer = possibly different service voltage even if the distribution voltages are exactly the same. Yes, BUT, a power company attempts to keep a constant voltage through their service area. While the voltage fluctuates due to equipment, load, etc, I don't think you can honestly say that if it is 220 volts on one side of town, the same "grid" produces 240 on the other side of town. It might be 242 in one place and 239 in another, but even that's a big difference unless there is a heavy load in one location and not another. The EU spec allowing household line voltage to be 240 volts while claiming 230 was to allow the UK to keep their current system while being "in spec" but I doubt it was intended to allow variations from as much as 220 in one place and 240 in another within the same country. Geoff. -- Geoffrey S. Mendelson, Jerusalem, Israel *N3OWJ/4X1GM Was going to ask someone knowledgeable to post the percentage voltage variation allowed in the USA (or wherever it is) for 'normal service'. For example if one were to look at European and similar so-called 230 volt systems might find that plus 10% to minus 5% (or some such thing) quite normal? Just using those as an example that is around 218 to to 253 volts! The question posted states "Upwards of 245 volts, whereas the machine taps were set for 220 volts". That is only a 12% difference! And when was the voltage found to be at 245? Immediately upon installation or several days/weeks later? To answer the question as asked; I don't think the workman who did the wiring is/was responsible. More so the owner who should take responsibility for not using the proper trade/profession. If it was say an insurance or warranty situation surely whoever has to repair or supply the 'blown' part would ask "What tests or checks were made after the machine was moved here and hooked up anew? There is also nothing to say that the machine had not been working on 245 volts, or whatever , at the old location. Also what was the agreement or contract with the worker about testing the machines at the new location once hooked. Maybe? Maybe not? Maybe more a task for the people who regularly operate and service the machines regardless of whether they are in the old or new location? Did the owner get a cheaper job by taking the risk of using a non-registered electrician. Two cents fom here based on what's provided! |
Liability & responsibility of electrician?
On Jul 5, 12:34*pm, wrote:
I work on lasers that use a buck/boost with 16 tap possibilities *on 3 phase all the time, and I used to use the same units in theatrical touring service until more modern solid state lasers dominated the laser show industry. . *From that perspective, *I'm amazed at the replies here that have failed to ask two simple questions. *I will state that I never met a house electrician who ever looked at the rating plate on the gear, although I did have a few that asked about phase sequences. * * Two, I never met a house electrician who ever checked anything hooked to the pigtail I gave him to connect, including "professional" rental generator technicians (actually they were the worst) *In the theatrical business, it is up to the touring operator to check the local guys work, and in most cases, we preferred they stand in a corner and watch us, after your first blown passbank with 3 or 4 out of 22 power *transistors blown in the laser, you get the idea to check the taps both preshow and under load condition. * In one case I asked for 220/3, went to lunch, *and came out to find 380V European power from the generator *in my distro box, which is why the box had its own"tagged out" *disconnect switch. Its a rotary switch in big modern generators, easy to mess up. Questions: *One, *Did the "electrician" hook straight to the machine's tappable control transformers, or did he meet a simple *junction box on the side of the machine. *If it were the later, I'd say he's off the hook. *On the other hand if he was staring at a tap strip , he should have asked. There is also the possibility of a "cascade" of transformers in some machines, ie little CTs all over the place in the machine, that need tapped. ?????? Two, Did anybody bother to read the manual chapter on setup? Machine shop gear needs leveled and "trammed" *when moved, its not a simple matter of tossing a CNC off the truck onto any old pad of concrete and expecting good parts to tolerances, and the first paragraph usually reads, something like "check settings" and have appropriate safety gear. ?????? The fault occurred months down the road, a instant *":poof and shower of sparks:" would point to the electrician, but months down the road is lack of due diligence on the part of the owner. BTW just measured our North American domestic single phase here! Leg A = 119 volts, Leg B = 121 volts. Leg A to b = 232 volts. 119/115 = 3.4% high 121/115 = 5.2% high 232/230 = 0.8% high It's about 02.00h in mid summer so system load is probably light and utility will have adjusted. No AC loads here; not needed. |
Liability & responsibility of electrician?
On Wed, 15 Jul 2009 21:48:36 -0700 (PDT), stan
wrote: On Jul 5, 12:34*pm, wrote: I work on lasers that use a buck/boost with 16 tap possibilities *on 3 phase all the time, and I used to use the same units in theatrical touring service until more modern solid state lasers dominated the laser show industry. . *From that perspective, *I'm amazed at the replies here that have failed to ask two simple questions. *I will state that I never met a house electrician who ever looked at the rating plate on the gear, although I did have a few that asked about phase sequences. * * Two, I never met a house electrician who ever checked anything hooked to the pigtail I gave him to connect, including "professional" rental generator technicians (actually they were the worst) *In the theatrical business, it is up to the touring operator to check the local guys work, and in most cases, we preferred they stand in a corner and watch us, after your first blown passbank with 3 or 4 out of 22 power *transistors blown in the laser, you get the idea to check the taps both preshow and under load condition. * In one case I asked for 220/3, went to lunch, *and came out to find 380V European power from the generator *in my distro box, which is why the box had its own"tagged out" *disconnect switch. Its a rotary switch in big modern generators, easy to mess up. Questions: *One, *Did the "electrician" hook straight to the machine's tappable control transformers, or did he meet a simple *junction box on the side of the machine. *If it were the later, I'd say he's off the hook. *On the other hand if he was staring at a tap strip , he should have asked. There is also the possibility of a "cascade" of transformers in some machines, ie little CTs all over the place in the machine, that need tapped. ?????? Two, Did anybody bother to read the manual chapter on setup? Machine shop gear needs leveled and "trammed" *when moved, its not a simple matter of tossing a CNC off the truck onto any old pad of concrete and expecting good parts to tolerances, and the first paragraph usually reads, something like "check settings" and have appropriate safety gear. ?????? The fault occurred months down the road, a instant *":poof and shower of sparks:" would point to the electrician, but months down the road is lack of due diligence on the part of the owner. BTW just measured our North American domestic single phase here! Leg A = 119 volts, Leg B = 121 volts. Leg A to b = 232 volts. 119/115 = 3.4% high 121/115 = 5.2% high 232/230 = 0.8% high It's about 02.00h in mid summer so system load is probably light and utility will have adjusted. No AC loads here; not needed. Except for the fact that the NA standard is 120/240 volts (there are a number of authorative references, feel free to Google them). So your two 'phases' are almost dead on (probably measurement error) and the 240 is slightly low (measurement error, seems odd that it can be off consdiering that it is supposed to be the sum of the two 120 legs.) The reason that it was standardized at 120 volts was because of the massive interconnecting done in North America in the past 25 years. Old standards included the 115 volts you mention, and 117 volts in some areas, and even some with 110 volts. It was determined that it would be necessary to standardize all voltages (just not the low voltages we are discussing here) to allow interconnection, and direct substitution of equipment. |
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