Liability & responsibility of electrician?

[John E.]

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

 

[Spehro Pefhany]

On Sat, 4 Jul 2009 23:40:18 -0700, the renowned 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.

IMO, 11% high voltage over nominal should not "fry" the controller
board in the first place.


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
speff@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

 

[Phil Allison]

"John E."

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 a STUPID troll !!!

The PSU in the CNC blew cos it was a pile of shit PLUS the design was 100%
incompetant cos it gave no protection to the delicate and expensive load.

Bet it was old and way past use by date too.

Piss off TROLL !!


..... Phil

 

[Archimedes' Lever]

On Sun, 5 Jul 2009 17:13:32 +1000, "Phil Allison" <phil_a@tpg.com.au>
wrote:

"John E."

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 a STUPID troll !!!

The PSU in the CNC blew cos it was a pile of shit PLUS the design was 100%
incompetant cos it gave no protection to the delicate and expensive load.

Bet it was old and way past use by date too.

Piss off TROLL !!


.... Phil

Probably a good call, since modern switchers, which the DC supplies
for these things usually are, can handle up to about 265 volts. Even a
bit more, typically.

 

[Bruce L. Bergman]

On Sat, 4 Jul 2009 23:40:18 -0700, 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.

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.

If the power supply on the CNC computer had changeable taps, and the
last guy that touched it didn't have any reason to look to see what it
was set for, IMHO it's nobody's fault. Especially if the shop they
moved from and the one they moved to had the same nominal operating
voltage, and they knew it - I'm not going to open 50 machines looking
for the unexpected when I'm charging by the hour unless I have a good
reason to... Just "Git Er Done" and go home.

If he had a reason to look inside and saw it was on the 220V tap he
should have moved it to the 240V - or told the owner - it's good
practice to follow but there's no responsibility to look involved.

And I wouldn't expect 255V on the 220V tap to kill it. Now if it
was set for 208V input and you fed it off the 'High Leg' from an Open
Delta service that's hovering around 280V to ground, THEN I'd expect
fireworks. Open Delta High Leg voltages can bounce around and go even
higher, then something flashes over...

That would be the /one/ time I'd call it against the Handyman,
putting the high leg on the control circuit would be a big goof. You
are supposed to put the regular 240V legs on the A and C phases coming
in, and the 'High Leg' Orange lead to B phase and NOT the controls.

The average power supply is supposed to feed +5V, +12V & -12V etc.
to the computer board, and have Crowbar protection so that's all that
gets through. If the supply blows up and lets line voltage through to
fry the controller board (even if you put an over-voltage on the
input) that's a badly built power supply.

Otherwise, it's entirely possible that it just reached End Of Life
and decided to go out in a spectacular manner, and the move had
nothing to do with it. The timer that makes things blow up three days
out of warranty finally went off.

Unless you want to spend a lot of money on Electronic Forensics to
analyze the power supply failure, "The world may never know..."

--<< Bruce >>--

PS - Have to trim off alt-r.c.m to make this go, 4 crosspost limit.

 

[Phil Allison]

"Archimedes' Lever"
"Phil Allison"

"John E."

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 a STUPID troll !!!

The PSU in the CNC blew cos it was a pile of shit PLUS the design was
100%
incompetant cos it gave no protection to the delicate and expensive load.

Bet it was old and way past use by date too.

Piss off TROLL !!


Probably a good call, since modern switchers, which the DC supplies
for these things usually are, can handle up to about 265 volts. Even a
bit more, typically.

** Unlikely it was a SMPS based on the OP's admittedly poor and incomplete
info.

Cos SMPS do not have multi-taps for AC input voltage - PLUS if an
off-line switcher fails from overvoltage, it just blows the fuse and goes
dead.

But losing regulation and over-voltaging the load ( as was alleged by the
OP) is another scenario altogether - more often associated with old age or
the failure of one of a few critical components in the regulation loop.



...... Phil

 

[Richard J Kinch]

John E. writes:

What is the legal and moral responsibility of each party?

None. It is George Bush's fault.

 

[Larry The Snake Guy]

On Jul 5, 2:40 am, John E. <incogn...@xbjcd.com> 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.

As others have said, there's not much the wiring guy could have done
wrong to get 245 volts rather than 220. He hooked up what was there
and couldn't be expected to have detailed knowledge of what the owner
was going to run, what setting he had it on or how sensitive it was.

Does the owner have some reason to believe that this was not the
voltage in the new shop before the additions?

 

[Geoffrey S. Mendelson]

John E wrote:

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.

It is the owner of the shop to make sure the electrician he hired was licensed
and if needed insured. Since you did not say where this happened, I can only
make a blanket statement.

If the "guy" represneted himself as a licensed electrictian, then there may
be some criminal liability here for fraud. If he did not claim to be licensed,
or the owner of the business knew that he was not licensed, he is free and
clear.

If the owner hired him knowing he was not licensed, then it was his
responsability to hire a licensed electrician to inspect the work before
he "threw the switch". If he did not, he may be subject to criminal and
civil penalties, have his electricity turned off, etc.

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.

And how do you know that? What device did you use to measure the voltage.
Assuming the voltmeter was accurate to 2% and rounded up, 240 volts would read
245. The difference is negligable anyway.

As for the voltage setting on the device, it's not the "wiring guy's" job.

Would you want some random "handyman" poking around inside of an expensive
CNC machine?

What is the legal and moral responsibility of each party?

I am not a lawyer, but from my (mis)understanding, as long as the "guy" did
not represent himself as an expert on the machine in question, or as a licensed
electrician, ALL of the responsability falls on the owner of the business and
none on the "guy" or anyone's insurance company.

What will not be helpful are replies about the character or intelligence of
either of the players or their actions.

Well, I'm going to make one. If the "guy" was up front about his not being
licensed, nor trained on the insides of the CNC machine, he is of good
character and reasonable intelligence.

Let's just say that the person who hired him was also of good character and
intelligence, but ignorant of the law and the requirments of equipment.

He's lucky that all he suffered was one $4000 board failing, not his
entire factory burning down around him with no insurance.

If in the future, he does not hire a licensed electrician to perform the
necessary inspections, etc, nor a properly trained technician to inspect
the equipment, you can say something very different.

I also think it is fair to assume that he has by now had a licensed electrician
in to inspect the work, and a trained technicain in to check all of his
equipment. If he has not done both.........


BTW, if both locations are connected to the same "power grid", it is
unlikely that the line voltage was 220 volts in the old location and 240
in the new one.

Geoff.

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

 

[Archimedes' Lever]

On Sun, 5 Jul 2009 02:04:47 -0700 (PDT), Larry The Snake Guy
<ldfishel@yahoo.com> wrote:

He hooked up what was there
and couldn't be expected to have detailed knowledge of what the owner
was going to run,

You're an idiot. If you are wiring POWER runs, you had better know
what your loads are, and how they get connected.

 

[Doug Miller]

In article <slrnh50ts8.jjt.gsm@cable.mendelson.com>, gsm@mendelson.com wrote:

BTW, if both locations are connected to the same "power grid", it is
unlikely that the line voltage was 220 volts in the old location and 240
in the new one.

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.

That said, though.... any device designed for 220V should be able to handle
245V.

 

[Doug Miller]

In article <0001HW.C67598E2001051EEB08A39AF@news.sf.sbcglobal.net>, 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.

Hard to make the case after 4 weeks that _anything_ the electrician did had
anything to do with this. At four seconds, or even four minutes, I'd consider
it obvious. But four weeks went by, and the owner thinks the electrician
caused this? No way.

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.

 

[William Sommerwerck]

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)?

 

[Andrew VK3BFA]

On Jul 5, 4:40 pm, John E. <incogn...@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.
--
John English

Tempting as it is to blame your Mr Bush for all the eveils of the
world, including my hens not laying, I would propose the following:
1.As noted, the main supply voltage is nominal, variations are normal
and to be expected.
2.Possibly, if the machine was let stand for a while in the unpowered
position, and it was an old controller (and with a linear power
supply, it probably was,) then the electrolytics in the power supply
could have failed due high ESR, and then it lost regulation and fried
the board.
3.My humble opinion is to just mark write it off to bad luck.
Otherwise, get the lawyers involved for years and huge amounts of
money......

Andrew VK3BFA

 

[Andrew VK3BFA]

On Jul 5, 4:40 pm, John E. <incogn...@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.
--
John English

Tempting as it is to blame your Mr Bush for all the eveils of the
world, including my hens not laying, I would propose the following:
1.As noted, the main supply voltage is nominal, variations are normal
and to be expected.
2.Possibly, if the machine was let stand for a while in the unpowered
position, and it was an old controller (and with a linear power
supply, it probably was,) then the electrolytics in the power supply
could have failed due high ESR, and then it lost regulation and fried
the board.
3.My humble opinion is to just mark write it off to bad luck.
Otherwise, get the lawyers involved for years and huge amounts of
money......

Andrew VK3BFA

 

[John E.]

I would have two simple questions...

1. Did the electrician have any control over the voltage when the system was
rewired?

No.

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

 

[SteveB]

"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.

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

Well, that eliminates anything that I would have to add to the conversation.

Steve

 

[William Sommerwerck]

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.)

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?

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.

 

[Bob Shuman]

In my opinion, No and no to both your questions below. The result would
likely have been the same.

Bob

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

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

 

[Ignoramus20157]

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.