Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
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?
It's called a thermostatDrier has a temperature limiter,
Of course. I was jesting.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.
Yes. The controller was overly fragile, or it may have just had aOn 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.
240V isn't "two phase", rather single phase, or otherwise known asDoug 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 supplied that to the pole. Please read.They did not supply or sell me 4kv volts, or anything else.
Lots of good that does after the power goes out.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.
All of us who can read.Ok, since you insist would anyone out there who gets 4kv from their local
electric company please raise your hand.
Hey 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.
He was paid to
correctly hook up power to the machine and failed to do so.
we say 110 / 220, but it is more like 120 / 240.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
In article <h2qf18$8mn$1@news.eternal-september.org>, "William
Sommerwerck" <grizzledgeezer@comcast.net> wrote:
1) 245VAC is *not* a problem in a nominal 240VAC supply.
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.
What they carry on the pole is immaterial. What they supply to theOn Sun, 5 Jul 2009 17:29:04 +0000 (UTC), "Geoffrey S. Mendelson"
gsm@mendelson.com> 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.
It is material to what the OP wrote. It may be immaterial to thekrw wrote:
On Sun, 5 Jul 2009 17:29:04 +0000 (UTC), "Geoffrey S. Mendelson"
gsm@mendelson.com> 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'.
That may be, but that wasn't what was written. The step downVery 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.
Irrelevant to what was written and objections to same.The utility is responsible for supplying the voltage/frequency at the
service entrance / metering point of sale, not 'the pole'.
Any reasonable design for the power supply should have defended theOn 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.
The capacitors could have also failed in the leaky and then exploding2.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
No, I'm not. When I lived in the US, (PECO) the electric company soldYou'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.
The standard USENET rule applies:This to me is starting to get tedious.
BZZZT! Danger Will Robinson!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.
Just to muddy it up even further, we recently put a medical deviceOn Sat, 4 Jul 2009 23:40:18 -0700, 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.
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.
Fully agreed.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
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.
RoyAssuming 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.
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.