Liability & responsibility of electrician?

[SteveB]

"Ignoramus20157" <ignoramus20157@NOSPAM.20157.invalid> wrote in message
news:282dnV-elMqZXs3XnZ2dnUVZ_udi4p2d@giganews.com...

245 volts is only mildly on the high side and should not cause the
symptom described.

i

But iggy, we have to BLAME someone! The guy hires some unqualified person
to hook up used questionable machinery. The blame has to go somewhere. I
know where I'd direct it.

Steve

 

[Geoffrey S. Mendelson]

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 throught their
service area. While the voltage fluctates 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 gsm@mendelson.com N3OWJ/4X1GM

 

[Martin Riddle]

Nominal 3 phase voltage is 240v, nothing wrong there.

Sounds like the CNC tap was incorrectly selected. What were the other
options?

I know of ground problems with CNC's and Com cards that can cause the
same problem.

I believe it is something else, 245 is only 11% high, not a really big
issue.

Cheers

"Ignoramus20157" <ignoramus20157@NOSPAM.20157.invalid> wrote in message
news:282dnV-elMqZXs3XnZ2dnUVZ_udi4p2d@giganews.com...

245 volts is only mildly on the high side and should not cause the
symptom described.

i

On 2009-07-05, John E <incognito@xbjcd.com> 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.

 

[Stuart Wheaton]

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.

4 weeks is a long time. Especially on a used piece of equipment that
has been subjected to the strains and jostling of a cross town move.

Can you prove that the incoming voltage was 245 when the "electrician"
was on site?

Were the field connections made by the "electrician" made to a terminal
strip or to the original tails? IOW, Did he see/know that there were
tap options?

If it took 4 weeks to fail in the new shop, do you know that the old
shop didn't also have an overvoltage situation? Maybe the failure was
75% along before the move.

One of the side effects of the slowdown in manufacturing demand is that
there does appear to be an upward creep of utility supplies, in our
shop, this spring our water pressure began to creep upward to the point
where the TP valves on both water heaters began to dribble. Our supply
voltage is a few volts higher too.

If the "electrician" feels like he did miss something, he probably owes
the owner a pro-rated share of the cost, but if he feels he did the job
within the scope of the work he was hired to do, the owner ought to foot
the bill. Whether the 'electrician' gets future work or references
might factor into this....

 

[Rich.]

Equipment is designed to operate +/- 10% of the nameplate rating. In the
case of taps like what happened here, the taps are supposed to be set by the
electrician to fall within the 10% range. With the taps set at 220v the CNC
machine was good to operate from 218v to 242v. As the power installer, it
was the electrician's responsibility to verify the voltage coming into the
building and adjust the taps on the machine accordingly. He was paid to
correctly hook up power to the machine and failed to do so.


"John E." <incognito@xbjcd.com> wrote in message
news:0001HW.C67598E2001051EEB08A39AF@news.sf.sbcglobal.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.

 

[Geoffrey S. Mendelson]

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.

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?

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM

 

[Jon Danniken]

Bruce L. Bergman wrote:

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...

If they were seeing 250V - 255V or more, then I'd call the Utility
and get the transformer taps knocked down a notch.

My drier sees 250VAC. Low voltage stuff in this house gets 125VAC.

Everything is working just fine.

Jon

 

[Wes]

John E. <incognito@xbjcd.com> 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.

Wes

 

[Rich.]

"John E." <incognito@xbjcd.com> wrote in message
news:0001HW.C67607F4002A5A1EB08A39AF@news.sf.sbcglobal.net...

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?
--
John English

It is not regular practice to inform the owner, unless something is found to
be wrong. Having 245v in the building is not normal, and there is a lot of
equipment out there that does not have taps. Equipment without taps could be
damaged by this higher than usual voltage.

It is the responsibility of the electrician to make sure the equipment he is
wiring can correctly run on the power being supplied. IMO the electrician
did not do his job correctly.

 

[William Sommerwerck]

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?

 

[Jon Danniken]

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 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 "oof 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.

 

[Leo Lichtman]

"Doug Miller" wrote: (clip) That said, though.... any device designed for
220V should be able to handle

245V.
^^^^^^^^^^^^^^^^^

Years ago when household appliances ran on 110 volts, we had 220. Since
then, voltage from neutral to either side rose to about 120, and voltage
across both side rose to 240. For some reason we still talk about 220 as
though it were double 120. What I'm getting at is that systems are no
longer designed for 220--it's 240, so the discrepancy is only 5 volts, and
that's trivial.

I'm guessing that the failure was due to some totally different cause, not
an error in line voltage.

 

[Doug Miller]

In article <slrnh51b37.33s.gsm@cable.mendelson.com>, gsm@mendelson.com 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 throught their
service area. While the voltage fluctates 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.

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.

 

[Doug Miller]

In article <h2qa8l$rl4$1@news.eternal-september.org>, "William Sommerwerck" <grizzledgeezer@comcast.net> wrote:

I would have two simple questions...

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)?

Assuming a nominal 240VAC supply, 245V is in no way "not correct" -- it's only
about a 2% overvoltage.

 

[Doug Miller]

In article <h2qf18$8mn$1@news.eternal-september.org>, "William Sommerwerck" <grizzledgeezer@comcast.net> 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.)

Actually, you *are* missing the important point, which is that it's
_not_his_fault_:

1) 245VAC is *not* a problem in a nominal 240VAC supply.
2) If the equipment is actually labelled 220V, and not 240V, it's *old*.
3) Equipment designed for 220VAC normally operates just fine on 240VAC.
4) If the wiring, or the voltage, were in any way to blame, the failure almost
certainly would have occurred long before it did. Four weeks after the fact, I
can't see how that could be laid at the feet of the guy that did the wiring,
licensed or not.

 

[RoyJ]

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.

 

[Doug Miller]

In article <IPmdnUUGKqGVQM3XnZ2dnUVZ_o-dnZ2d@earthlink.com>, RoyJ <spamless@microsoft.net> 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?

 

[John R. Carroll]

"Doug Miller" <spambait@milmac.com> wrote in message
news:Ma54m.1908$cl4.1853@flpi150.ffdc.sbc.com...

In article <IPmdnUUGKqGVQM3XnZ2dnUVZ_o-dnZ2d@earthlink.com>, RoyJ
spamless@microsoft.net> 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

 

[Geoffrey S. Mendelson]

John E wrote:

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?

What you have not said is what was the voltage supposed to be?

Where? Common and regular practice as you call it varies from country to
country.

Also what was the actual voltage at the old location. If it was supposed to
be 240 volts then 245 is well within actual variations, or the calibration
of a meter.

If it was supposed to be 208 or 220 or 308, etc then it is too high.

This to me is starting to get tedious. A simple question of "who was at fault"
has become a "pissing contest" over who can make the most outrageous guess
as to why their champion is guilt free.

IMHO it really boils down to exactly what the owner of the business expected
when he hired "the guy". If he hired someone he knew was unlicensed, he
should have had the work inspected or hired a licensed electrician. Otherwise
he was taking a chance that he would never get caught cheating, and he lost.

As for the CNC device failing, his expectation of "the guy" to open it up
and adjust the voltage tapes is unreasonable. Again he took a chance that
he could move the device without hiring the proper technician to pack it up,
unpack it after arival and set it up. And again, he lost.

Considering the worst outcome of it would have been a fire destroying the
building, everything in it and killing all the people involved, a $4000
controller failure, which was probably not caused by the voltage problem
anyway, is a small price to pay for loosing.

As for insurance, no property insurance will cover damage due to illegal
repairs, etc, which includes uninspected work done by unlicensed electricians,
and no manufacturer will cover damage due to untrained technicians modifying
the equipment (even to move the voltage taps), or damage caused by over
voltage due to an unlicensed electrician wiring the equipment.

There may also be civil and criminal liability here, the best thing to do
IMHO is to have the company and "the guy" come to an agreement where they
will leave him alone, and eat the loss. They will then pay for any repairs
to the equipment and "the work" as legally mandated.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel gsm@mendelson.com N3OWJ/4X1GM