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.

In article , RoyJ wrote:


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

And since there is likely no load in shop when the install was taking
place, the 245 would be a higher than normal reading.

But I question the use of "3phase" and "245 volts" in the OP question.
Around here, 245 volts would be perfectly normal for a single phase
circuit, very high for a "standard" 208/3 phase delta.

OTOH, why would the machine be set up for 220V as described, if intended to be
connected to a 208V supply?

"Doug Miller" wrote in message
...
In article , RoyJ
wrote:


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

And since there is likely no load in shop when the install was taking
place, the 245 would be a higher than normal reading.

But I question the use of "3phase" and "245 volts" in the OP question.
Around here, 245 volts would be perfectly normal for a single phase
circuit, very high for a "standard" 208/3 phase delta.

OTOH, why would the machine be set up for 220V as described, if intended
to be
connected to a 208V supply?

Because CNC controls are designed to run at 220V plus Zero/minus 5%.
They love straight 208 three phase power because of the balance. You can
usually just change control paremeters without fiddling with the
transformers.

Anyway, this shop owner did it so it's his job now to step in it.

JC

Doug Miller wrote:
You're missing the point. This has nothing to do with the voltage supplied
by the utility. The utility doesn't supply 220V or 240V or whatever. They
supply (for example) 4KV. A transformer at the point of service reduces that
to 220V, or 240V, or whatever. Different transformers connected to the *same*
4KV primary voltage could easily produce different secondary voltages.

No, I'm not. When I lived in the US, (PECO) the electric company sold
me 240 volt 2 phase electricity. It was nominaly 127 volts, but often
dropped down during times of high usage.

They did not supply or sell me 4kv volts, or anything else.

Here it's even simpler. Israel electric sells me 230 volts, 50Hz electicity
and except for just before the power going out it has been that way for 12
years. When I had a UPS monitoring the voltage, it was never more than
1 volt +- spec.

Ok, since you insist would anyone out there who gets 4kv from their local
electric company please raise your hand.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM

"Jon Danniken" wrote in message
...
William Sommerwerck wrote:


My drier sees 250VAC. Low voltage stuff in this house gets 125VAC.
Everything is working just fine.

sniff sniff Is that burning cotton I smell?


Drier has a temperature limiter,

It's called a thermostat

so although the slightly higher voltage
results in a slightly quicker "turn on" time for the elements, they still
are shut off at the same temperature regardless of incoming voltage.

Of course. I was jesting.

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

On Sun, 5 Jul 2009 17:29:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

Doug Miller wrote:
You're missing the point. This has nothing to do with the voltage supplied
by the utility. The utility doesn't supply 220V or 240V or whatever. They
supply (for example) 4KV. A transformer at the point of service reduces that
to 220V, or 240V, or whatever. Different transformers connected to the *same*
4KV primary voltage could easily produce different secondary voltages.

No, I'm not. When I lived in the US, (PECO) the electric company sold
me 240 volt 2 phase electricity. It was nominaly 127 volts, but often
dropped down during times of high usage.

240V isn't "two phase", rather single phase, or otherwise known as
"split phase". ...and it had better not be 127V (maybe twice that).

They did not supply or sell me 4kv volts, or anything else.

They supplied that to the pole. Please read.

Here it's even simpler. Israel electric sells me 230 volts, 50Hz electicity
and except for just before the power going out it has been that way for 12
years. When I had a UPS monitoring the voltage, it was never more than
1 volt +- spec.

Lots of good that does after the power goes out.

Ok, since you insist would anyone out there who gets 4kv from their local
electric company please raise your hand.

All of us who can read.

"Wes" wrote in message
...
John E. wrote:


He hires a guy who's not a pro (and later discovers is not insured) but
has
done shop wiring before and had a good attitude and track record. The guy
does good work. No complaints about the quality of his work.


I'm going to translate this. Hires a guy that isn't a licensed
electrician but does do
the job for less than the licensed guys with liability insurance.

Now your friend that was shopping for a free lunch now wants his evening
meal paid for.

We don't know the voltage it was running at prior to the move, we don't
know the
variability of the supply voltage where it is now.

The handyman wired it to the disconnect. Made sure there was power to
that point.

Somewhere after that the machine was powered up. I'm going to assume for
the sake of
argument that the handyman got the shop owner or the owners designee to do
it. I don't
know any compenent electricans or for that matter decent handymen that
will turn on a
complex piece of equipment on their own.

So the owner or designee that has the manuals and such for the machine and
should be the
most knowledgeable person in the room is the one that is at fault.

Hey Wes.
If you open up one of your older Fanucs you will see a tag somewhere that
says 200V AC.
That is the design spec.

JC

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

I have been asked to offer an opinion in a sensitive situation.

A machinist moved his shop across town and required some rewiring (3-phase
outlets, conduit, etc.) in order to locate some machines where he wanted
them.

He hires a guy who's not a pro (and later discovers is not insured) but has
done shop wiring before and had a good attitude and track record. The guy
does good work. No complaints about the quality of his work.

Owner throws the switch, all works fine.

The story continues 4 weeks later when the very expensive CNC fries its
controller PCB to the tune of $4000.

Turns out the voltage in the shop was upward of 245 and the taps in the CNC's
power supply were set for 220.

What is the legal and moral responsibility of each party?

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

Thanks.
First of all, 245 VAC is a common AC voltage in the US. Yes, I know
we say 110 / 220, but it is more like 120 / 240.

Second, what was the 'handyman' hired to do? If he wired a number of
1 and 3 phace 110 / 220 volt outlets, he has no liability. If he
hard-wired (ran conduit directly to) the equipment, it is open to
discussion. If he adjusted wiring taps, etc than he MAY be
responsible.

However, every controller I have ever seen uses a regulated power
supply. Decades ago my employer built them. We tested the supplies
at full load while varying input voltage from 20% below nominal to 20%
above nominal voltage (90 - 130 VAC). If the equipment operated for 4
weeks, I would say the 'handyman' is not responsible.

PlainBill

At this point, I think there are two questions (at least) that we need
to OP to answer.

1) Did the "wiring guy" hook up the equipment or just run wiring to
the locations where it was to go? And if he hooked up the equipment,
did this require opening it or did the owner just tell him to connect
cables that were already attached to the machines.

2) What were the agreed upon responsibilities of the "guy"? I assume
the owner hired him to save money, so he might be expected to do as
little as necessary to set things up, unless something more was agreed
upon. Asking what a licensed electrician would normally do might not
really be relevant...

Also, don't forget that in most places if the owner knew he hired an
unlicensed person, he (the owner) is probably liable for fines,
permits (possibly at doube the price) and at least having all this
work gone over by a real electrician if the authorities find out. If
it's anything like residential work, they might even force him to pay
a licensed electrician to rip it all out and redo it. I'd consider
that before raising a stink.

"Doug Miller" wrote in message
...
In article , "William
Sommerwerck" wrote:

1) 245VAC is *not* a problem in a nominal 240VAC supply.


That is correct until you factor in that the taps were set to 220v. If the
taps were set at 240, then 245v would never have been a problem.

On Jul 5, 2:11*pm, wrote:
On Sat, 4 Jul 2009 23:40:18 -0700, John E.
wrote:



I have been asked to offer an opinion in a sensitive situation.

A machinist moved his shop across town and required some rewiring (3-phase
outlets, conduit, etc.) in order to locate some machines where he wanted
them.

He hires a guy who's not a pro (and later discovers is not insured) but has
done shop wiring before and had a good attitude and track record. The guy
does good work. No complaints about the quality of his work.

Owner throws the switch, all works fine.

The story continues 4 weeks later when the very expensive CNC fries its
controller PCB to the tune of $4000.

Turns out the voltage in the shop was upward of 245 and the taps in the CNC's
power supply were set for 220.

What is the legal and moral responsibility of each party?

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

Thanks.

First of all, 245 VAC is a common AC voltage in the US. *Yes, I know
we say 110 / 220, but it is more like 120 / 240. *

Second, what was the 'handyman' hired to do? *If he wired a number of
1 and 3 phace 110 / 220 volt *outlets, he has no liability. *If he
hard-wired (ran conduit directly to) the equipment, it is open to
discussion. *If he adjusted wiring taps, etc than he MAY be
responsible.

Just to muddy it up even further, we recently put a medical device
through CE approval and were advised by the examiner that our label
should read "110/240", and that's the label we passed with.


However, every controller I have ever seen uses a regulated power
supply. *Decades ago my employer built them. *We tested the supplies
at full load while varying input voltage from 20% below nominal to 20%
above nominal voltage (90 - 130 VAC). *If the equipment operated for 4
weeks, I would say the 'handyman' is not responsible.

Fully agreed.


PlainBill

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

krw wrote:
On Sun, 5 Jul 2009 17:29:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

Doug Miller wrote:
You're missing the point. This has nothing to do with the voltage supplied
by the utility. The utility doesn't supply 220V or 240V or whatever. They
supply (for example) 4KV. A transformer at the point of service reduces that
to 220V, or 240V, or whatever. Different transformers connected to the *same*
4KV primary voltage could easily produce different secondary voltages.
No, I'm not. When I lived in the US, (PECO) the electric company sold
me 240 volt 2 phase electricity. It was nominaly 127 volts, but often
dropped down during times of high usage.

240V isn't "two phase", rather single phase, or otherwise known as
"split phase". ...and it had better not be 127V (maybe twice that).

They did not supply or sell me 4kv volts, or anything else.

They supplied that to the pole. Please read.


What they carry on the pole is immaterial. What they supply to the
customer service entrance is the 'point of sale'.

Very few homes or light commercial service is in the 4kV range in the
US. The service entrance voltage is usually much lower, 240 or 480. In
these cases, the step-down transformer used to convert from distribution
voltage (e.g. 4kV) to the service entrance voltage is the utility's
responsibility.

The utility is responsible for supplying the voltage/frequency at the
service entrance / metering point of sale, not 'the pole'.

daestrom

On Sun, 05 Jul 2009 14:39:27 -0400, daestrom
wrote:

krw wrote:
On Sun, 5 Jul 2009 17:29:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

Doug Miller wrote:
You're missing the point. This has nothing to do with the voltage supplied
by the utility. The utility doesn't supply 220V or 240V or whatever. They
supply (for example) 4KV. A transformer at the point of service reduces that
to 220V, or 240V, or whatever. Different transformers connected to the *same*
4KV primary voltage could easily produce different secondary voltages.
No, I'm not. When I lived in the US, (PECO) the electric company sold
me 240 volt 2 phase electricity. It was nominaly 127 volts, but often
dropped down during times of high usage.

240V isn't "two phase", rather single phase, or otherwise known as
"split phase". ...and it had better not be 127V (maybe twice that).

They did not supply or sell me 4kv volts, or anything else.

They supplied that to the pole. Please read.


What they carry on the pole is immaterial. What they supply to the
customer service entrance is the 'point of sale'.

It is material to what the OP wrote. It may be immaterial to the
facts of the case, but it *is* what was written.

Very few homes or light commercial service is in the 4kV range in the
US. The service entrance voltage is usually much lower, 240 or 480. In
these cases, the step-down transformer used to convert from distribution
voltage (e.g. 4kV) to the service entrance voltage is the utility's
responsibility.

That may be, but that wasn't what was written. The step down
transformer was part of the post too.


The utility is responsible for supplying the voltage/frequency at the
service entrance / metering point of sale, not 'the pole'.

Irrelevant to what was written and objections to same.

This to me is starting to get tedious.

The standard USENET rule applies:

THEN DON'T RESPOND.

USA, N. American continent, planet Earth.

On Jul 5, 6:26*am, (Doug Miller) wrote:

Turns out the voltage in the shop was upward of 245 and the taps in the CNC's
power supply were set for 220.

So what? Equipment designed for 220V should be able to handle 245V. It's not
the electrician's responsibility to open the CNC machine to see what it's set
for.

Absolutely correct. The CNC controller burned up, BUT the line
voltage
is no smoking gun, you have NO reason to believe that was the cause.
Overvoltage would usually result in relatively simple, inexpensive
faults (fuses blowing), or at most a power supply failure (figure
$300 for that kind of part, no WAY it's $4000).

Manufacturer of the controller should be replacing it under warranty.
And, there should be an install procedure to determine tap placement:
who
did the install? Wiring an outlet for the equipment does NOT make
the electrician responsible for install procedure, nor for installed
equipment.

John E. wrote:
I have been asked to offer an opinion in a sensitive situation.

BZZZT! Danger Will Robinson!

Before offering your opinion, examine what *you* stand to
gain/lose.

The "sensitive situation" could be a bucket of rattlesnakes,
and your participation might direct some of those snakes
your way.

Someone is looking at you as the "expert" whose opinion
carries weight in his/her mind. Your opinion is bound
to be used to bolster the argument of whichever side
asked you: "Well John said ... "
That bolstering could get you in trouble with the other
person - and it is likely or possible that whatever you
say will be misquoted.

Taking sides in a "sensitive situation" is fraught with
danger.

The next issue is that you are not sure enough of your
opinion to voice it without seeing what people here
think. Or, if you have already voiced it, you have
enough doubt to seek other's viewpoints here. Either
way, it highlights the problem(s) that sensitive
situations create.

If, for the moment, we take the possible danger to you
out of the equation and just look at the situation:
Who can tell? Does anyone replying to the post have
all of pertinent the facts? We don't know the details
of the agreement between the handyman and the shop
owner, whether there was any specific discussion concerning
the CNC machine, what claims the handyman made as to his
experience or expertise, any applicable laws in the location
the work was done, whether/if/when the power utility changed
things and on and on. People could reply with 100% valid
opinions that might not apply to the specific situation.
So, while there may be a clear legal and moral responsibility
for each party, it is impossible for us to to know what it is
at this point.

Ed



A machinist moved his shop across town and required some rewiring (3-phase
outlets, conduit, etc.) in order to locate some machines where he wanted
them.

He hires a guy who's not a pro (and later discovers is not insured) but has
done shop wiring before and had a good attitude and track record. The guy
does good work. No complaints about the quality of his work.

Owner throws the switch, all works fine.

The story continues 4 weeks later when the very expensive CNC fries its
controller PCB to the tune of $4000.

Turns out the voltage in the shop was upward of 245 and the taps in the CNC's
power supply were set for 220.

What is the legal and moral responsibility of each party?

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

Thanks.

On Sun, 05 Jul 2009 16:53:25 GMT, (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.


Indeed it does.

My single phase home 220 volt service runs between 245-252 volts

Pacific Greed and Extortion claims that is nominal and within spec for
home wiring.

Fortunately..most of my gear runs fine on this, with the exception of
the VFD on my Gorton mill. At times, it shows an over voltage alarm and
refuses to run until the voltage drops back down to under 246.

Ive called this to the attention of the local PG&E wanks..and they
simply shrug, send someone out to measure the voltage, confirm that
indeed its 252, blither a bit and then leave.

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

On Sun, 5 Jul 2009 13:54:05 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:


You missed the point of the original post. The person who did the work was
NOT an electrician, they were a "handyman" hired to do the work.


We must ask you at this point...what is your definition of an
electrician.

If the same person gets a license, does that automatically make him no
longer a handyman, but an electrician?

Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

Gunner Asch wrote:
Fortunately..most of my gear runs fine on this, with the exception of
the VFD on my Gorton mill. At times, it shows an over voltage alarm and
refuses to run until the voltage drops back down to under 246.

Ive called this to the attention of the local PG&E wanks..and they
simply shrug, send someone out to measure the voltage, confirm that
indeed its 252, blither a bit and then leave.

Before there were UPS's there were constant voltage transformers, the most
popular made by Sola. UPS's put out really crap AC, and are designed to
work with a switching power supply as a load.

Sola transformers were used with all sorts of things, there may be one that
fits your needs. I used them with computers that had linear power supplies,
but I think they will work with motors, it's worth checking out.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM

Gunner Asch wrote:

We must ask you at this point...what is your definition of an
electrician.

Someone who has a license, (and/or) is a member of the union, passed a
test that entitles him to call himself an electrician.

But not someone with no formal training, licensure or certification.

Geoff.

--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM

On 5 Jul., 08:58, Spehro Pefhany
wrote:
On Sat, 4 Jul 2009 23:40:18 -0700, the renowned John E.



wrote:
I have been asked to offer an opinion in a sensitive situation.

A machinist moved his shop across town and required some rewiring (3-phase
outlets, conduit, etc.) in order to locate some machines where he wanted
them.

He hires a guy who's not a pro (and later discovers is not insured) but has
done shop wiring before and had a good attitude and track record. The guy
does good work. No complaints about the quality of his work.

Owner throws the switch, all works fine.

The story continues 4 weeks later when the very expensive CNC fries its
controller PCB to the tune of $4000.

Turns out the voltage in the shop was upward of 245 and the taps in the CNC's
power supply were set for 220.

What is the legal and moral responsibility of each party?

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

Thanks.

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


a loose neutral can result in all kinds of strange voltages depending
on the load on the
phases, so the 11% might just be what the voltage was when it was
measured, not what
it was when the controller was fried

-Lasse

John E. wrote:
I have been asked to offer an opinion in a sensitive situation.

A machinist moved his shop across town and required some rewiring (3-phase
outlets, conduit, etc.) in order to locate some machines where he wanted
them.

He hires a guy who's not a pro (and later discovers is not insured) but has
done shop wiring before and had a good attitude and track record. The guy
does good work. No complaints about the quality of his work.

Owner throws the switch, all works fine.

The story continues 4 weeks later when the very expensive CNC fries its
controller PCB to the tune of $4000.

Turns out the voltage in the shop was upward of 245 and the taps in the CNC's
power supply were set for 220.

What is the legal and moral responsibility of each party?

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

Thanks.



The failure that you had was probably caused by your rigger not using an
airride trailer to move the equipment and something got shaken up. Four
weeks of running proves the voltage was not the problem. Some
disgruntled employee probably ****ed in the cabinet.


245 volts is within the normal specs from the utility. AS far as
changing the tap, you should have called in a machine tech to set it up.
An electrician wires only to the safety disconnect switch in the
machine, after that it is your responsibility to call in a machine setup
tech.


John

On Sun, 5 Jul 2009 21:04:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:

Gunner Asch wrote:

We must ask you at this point...what is your definition of an
electrician.

Someone who has a license, (and/or) is a member of the union, passed a
test that entitles him to call himself an electrician.

But not someone with no formal training, licensure or certification.

Geoff.

So then what am I? I passed the tests, at one time held a (California)
C7 and C10 license, ( as responsible managing employee for a large
company who before me had NO liceneses), have worked for the past 12 yrs
as a machine shop electrician (with no failures to date), CNC repair
tech and so forth.

However..Ive refused to belong to any union since 1974, when my 6 week
stint as a UAW worker left me cold about unions.

Am I just a "handyman" because I dont belong to a union spit?

My business cards indicate that I do electrical (non licensed) as well
as CNC and Machine Tool Repair.

So am I simply a "handyman"?

Inquiring minds really want to know.

Gunner



"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

On Sun, 05 Jul 2009 13:44:18 -0700, Gunner Asch
wrote:


We must ask you at this point...what is your definition of an
electrician.

I guarantee it doesn't match yours.

You seem to think that since you understand the rules of making a
connection that you understand electrical power.

I doubt seriously that you have such a grasp of the industry.

Bruce L. Bergman wrote:
On Sat, 4 Jul 2009 23:40:18 -0700, John E.
wrote:

I have been asked to offer an opinion in a sensitive situation.

A machinist moved his shop across town and required some rewiring (3-phase
outlets, conduit, etc.) in order to locate some machines where he wanted
them.

He hires a guy who's not a pro (and later discovers is not insured) but has
done shop wiring before and had a good attitude and track record. The guy
does good work. No complaints about the quality of his work.

Owner throws the switch, all works fine.

The story continues 4 weeks later when the very expensive CNC fries its
controller PCB to the tune of $4000.

Turns out the voltage in the shop was upward of 245 and the taps in the CNC's
power supply were set for 220.

What is the legal and moral responsibility of each party?

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

The nominal utility power as supplied is supposed to be 240V. 5
volts over is a touch hot, but not out of the bounds of normal
tolerances - turn everything on in the neighborhood some hot August
afternoon with the AC units cranked, and tell me what the voltage
reads then...




That is not always the case. I'm a little rusty when it comes to 3 phase
distribution, but I've dealt with some things like this in a machine
shop friends of mine own. The voltage depends on the service to the
building. Some shops have 208V and some have 240V, and we've had to
reconfigure machines from time to time that were purchased from other
locations, or run some off buck/boost transformers if they were not
configurable. Perhaps someone more knowledgeable can fill in the details.

It's good practice of course to measure the voltage and double check the
configuration of the particular machine prior to applying power.

$4K seems pretty high though, did anyone look into repairing the damaged
board?

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.

Ignoramus20157 wrote:
245 volts is only mildly on the high side and should not cause the
symptom described.

i



As well as sometimes things just do fail. If only I had a dollar for
every time someone with zero technical knowledge told me "this failed
because so and so did this or that". Just because something broke
shortly after work was done, does not automatically mean that the work
done is what caused it to break.

On Sun, 05 Jul 2009 15:26:07 -0700, StickThatInYourPipeAndSmokeIt
wrote:

On Sun, 05 Jul 2009 13:44:18 -0700, Gunner Asch
wrote:


We must ask you at this point...what is your definition of an
electrician.

I guarantee it doesn't match yours.

You seem to think that since you understand the rules of making a
connection that you understand electrical power.

Odd...so Im simply a wire hooker-upper? And my CNC machine repair is
simply making connections? No understanding of the trade?

I doubt seriously that you have such a grasp of the industry.

Why...because Im not a Union Member?

Chuckle...I charge MORE than most Union Members do. And I get the work.

I suggest you review what you wrote..and why you wrote it.

VBG

Gunner




"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

Jon Danniken wrote:
William Sommerwerck wrote:
My drier sees 250VAC. Low voltage stuff in this house gets 125VAC.
Everything is working just fine.
sniff sniff Is that burning cotton I smell?

Drier has a temperature limiter, so although the slightly higher voltage
results in a slightly quicker "turn on" time for the elements, they still
are shut off at the same temperature regardless of incoming voltage.

Jon




I rented a house for a while that had unusually high line voltage. It
varied from around 122V to 125V depending on the time of day. If it was
much higher than that, I'd be concerned, but anything from 115V to 125V
is pretty normal.

A friend of mine over in the UK is near the end of a long run from the
transformer that powers his street. His voltage varies considerably,
from as low as 220V to nearly 250V.

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

John E. wrote:
I have been asked to offer an opinion in a sensitive situation.

A machinist moved his shop across town and required some rewiring (3-phase
outlets, conduit, etc.) in order to locate some machines where he wanted
them.

He hires a guy who's not a pro (and later discovers is not insured) but has
done shop wiring before and had a good attitude and track record. The guy
does good work. No complaints about the quality of his work.

Owner throws the switch, all works fine.

The story continues 4 weeks later when the very expensive CNC fries its
controller PCB to the tune of $4000.

Turns out the voltage in the shop was upward of 245 and the taps in the CNC's
power supply were set for 220.

What is the legal and moral responsibility of each party?

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

Thanks.
Sorry, but that little upward swing didn't cause the issue..

Sounds to me like some one couldn't properly determine the real
problem with the control board and opted to simply replace the whole
thing or, the person doing the work on the repairs caused more damage
them self's and are covering their tracks.

I'm sorry, but 4 weeks into operation and it worked fine all that
time, I think you should look else where for the problem or just simply
eat the coast of a broken down CNC machine.

My guess is the moving process may have caused some sensitive
electronics on the board to get ajar if the CNC was possibly dropped
or whacked hard enough to cause a fracture crack in a solder joint that
finally showed it's oats.

Of course, that is just my opinion. You can take it with a grain of salt.

Ignoramus20157 wrote:

On 2009-07-05, John E wrote:

2. Is it normal for electricians to measure the voltage, and "do something"
about it if it's not correct (if only reporting the problem to the
businessman)?

This is the basic question I'm asking. Is it common and regular practice to
inform the owner of a voltage as high as 245? And to suggest that he have
factory personnel come and look at each machine and examine PS taps and such?
And if he had hired a licensed electrician would the electrician likely had
informed the owner of the voltage difference?


I have 245 volts in my garage. Everything works great.

245 volts is a perfectly normal voltage. It corresponds to 122.5 volts
AC from a regular outlet.

There is no causal relationship, as far as I can tell, between
perfectly normal voltage provided in your shop, and your CNC machine
frying after 3 more weeks.

I have not yet seen a more inane discussion thread.


Dont worry there will be more. Its a great form of mindless intertainment.

Any CNC control or machine that cannot take a 10% overvoltage is a
piece of junk to begin with. Power supply technology in the last 20
years can easily design units that will handle these variations. The
power company likes to hold the voltage on the supply lines as high as
possible to reduce the losses per kw metered and delivered.
I have a number of CNC machines running on 515 volts measured at the
machine internal disconnect and never had a control failure from
overvoltage. Undervoltage is what damages equipment because the
currents run higher for the same work done and the power components get
hotter from the higher current.


John

"Ignoramus20157" wrote in message
...
245 volts is a perfectly normal voltage. It corresponds to 122.5 volts
AC from a regular outlet.

Oddly enough, that's exactly what I've measured (give or take a few tenths)
in the MSOE power lab (which is equipped with 208V 3 phase), and very nearly
the same at my own bench at home.

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

On Sun, 05 Jul 2009 15:33:48 -0700, James Sweet
wrote:

Bruce L. Bergman wrote:
On Sat, 4 Jul 2009 23:40:18 -0700, John E.
wrote:

I have been asked to offer an opinion in a sensitive situation.

A machinist moved his shop across town and required some rewiring (3-phase
outlets, conduit, etc.) in order to locate some machines where he wanted
them.

He hires a guy who's not a pro (and later discovers is not insured) but has
done shop wiring before and had a good attitude and track record. The guy
does good work. No complaints about the quality of his work.

Owner throws the switch, all works fine.

The story continues 4 weeks later when the very expensive CNC fries its
controller PCB to the tune of $4000.

Turns out the voltage in the shop was upward of 245 and the taps in the CNC's
power supply were set for 220.

What is the legal and moral responsibility of each party?

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

The nominal utility power as supplied is supposed to be 240V. 5
volts over is a touch hot, but not out of the bounds of normal
tolerances - turn everything on in the neighborhood some hot August
afternoon with the AC units cranked, and tell me what the voltage
reads then...




That is not always the case. I'm a little rusty when it comes to 3 phase
distribution, but I've dealt with some things like this in a machine
shop friends of mine own. The voltage depends on the service to the
building. Some shops have 208V and some have 240V, and we've had to
reconfigure machines from time to time that were purchased from other
locations, or run some off buck/boost transformers if they were not
configurable. Perhaps someone more knowledgeable can fill in the details.

It's good practice of course to measure the voltage and double check the
configuration of the particular machine prior to applying power.

$4K seems pretty high though, did anyone look into repairing the damaged
board?

CNC electronics cost about 4-8 times as much to fix as normal
electronics. Shrug..its called :"the going rate" unfortunately.

Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

On Sun, 05 Jul 2009 19:10:07 -0400, john wrote:


I have not yet seen a more inane discussion thread.


Dont worry there will be more. Its a great form of mindless intertainment.

Any CNC control or machine that cannot take a 10% overvoltage is a
piece of junk to begin with.


As a CNC tech..I agree with you. Unfortunately however...there are far
far too many Big Name manufactures out there who utilize minimal design
perameters when they make something (very expensive) and then charge out
the ass when it goes tits up.

Gunner

"Lenin called them "useful idiots," those people living in
liberal democracies who by giving moral and material support
to a totalitarian ideology in effect were braiding the rope that
would hang them. Why people who enjoyed freedom and prosperity worked
passionately to destroy both is a fascinating question, one still with us
today. Now the useful idiots can be found in the chorus of appeasement,
reflexive anti-Americanism, and sentimental idealism trying to inhibit
the necessary responses to another freedom-hating ideology, radical Islam"

Bruce C. Thornton, a professor of Classics at American University of Cal State Fresno

"Gunner Asch" wrote in message
...
On Sun, 5 Jul 2009 21:04:04 +0000 (UTC), "Geoffrey S. Mendelson"
wrote:


So then what am I? I passed the tests, at one time held a (California)
C7 and C10 license, ( as responsible managing employee for a large
company who before me had NO liceneses), have worked for the past 12 yrs
as a machine shop electrician (with no failures to date), CNC repair
tech and so forth.

However..Ive refused to belong to any union since 1974, when my 6 week
stint as a UAW worker left me cold about unions.

Am I just a "handyman" because I dont belong to a union spit?

My business cards indicate that I do electrical (non licensed) as well
as CNC and Machine Tool Repair.

So am I simply a "handyman"?

Inquiring minds really want to know.

Gunner

Yes, you're a glorified handyman...happy? ;-)

Yes you have the knowledge and experience, but as long as you do not hold a
valid license, you can call yourself an electrician, but you cannot call
yourself a licensed electrician. As an unlicensed electrician you cannot
LEGALLY perform ANY electrical work outside of your own single family
residence. BTW, union or not makes no difference, it's state law we're
talking about.

"James Sweet" wrote in message
...

Depends on where you are. Here in the US, the work has to be inspected by
an inspector, not an electrician. You have to be a licensed electrician to
be hired by most electrical contracting companies, but there is no law
against unlicensed people electrical work. I've replaced electrical
service panels and added circuits for renovations in the homes of quite a
few friends and family members, I'm not licensed, but it was no trouble to
get a permit and have the work inspected when it was complete. Even
licensed electricians have to get their work inspected.

You're fooling yourself. You cannot legally do any electrical work at the
homes of your friends or family. If there is ever an electrical fire at any
building that you did electrical work in...you can kiss your life goodbye.
You can be arrested, tried in a criminal court, and sentenced to prison,
plus sued for everything you own in a civil court. This can happen to you
because it is a crime in any state (as far as I know) for you to do this
work. Liability insurance is not even an option for you because you have to
be licensed to get the insurance in the first place.