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#134320 - 11/01/02 07:30 PM Transposed Mains
Trumpy Offline


Member

Registered: 07/05/02
Posts: 8553
Loc: SI,New Zealand
Have just finished a job at a local house,
got rang up at 0600, this morning, to go and
investigate the reason why the kids living in the house were getting shocks off the u/stairs taps in the bathroom.
Long story short, Electrician, came in y/day
had replaced the Mains cable, never tested his work, I tested the work and found the Phase and Neutral wires around the wrong way at the meters, this subject has been referred to the Electrical Workers Registration Board, as all of the metal in the house was live at 230V to Earth.
How would this be dealt with in your country?
Your comments please-
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#134321 - 11/02/02 01:51 AM Re: Transposed Mains
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Here the meter is sealed, so it would only be a PoCo employee who could connect the cables into the meter the wrong way around.

Despite slipping standards all round, at least most of the local utility engineers test polarity when reconnecting a main.

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#134322 - 11/02/02 05:27 PM Re: Transposed Mains
David UK Offline
Member

Registered: 10/03/02
Posts: 134
Loc: Inverness, Scotland
I've seen reverse polarity at the meter on several occasions, Trumpy.
However due to the fact that our PME (MEN) connection is made at the PoCo service cut-out, installation metalwork doesn't usually become live @ 240V. Obviously if the reverse was external, on an o/h line for example, metalwork would be live in the installation.
I have heard of this happening recently, but I believe it was spotted before the consumer touched anything.

Around 6 or 7 years ago we had a spate of reverse polarity at meters in this area.
All meters have to be re-certified after 20 years max, & the PoCo employed a contractor to replace meters. One bright spark was connecting the meters: red, black, red, black, instead of: red, black, black, red.
I found 5 installations like this in a 3 month period and heard of similar finds by other electricians.
I heard the contractor was not employed on meter changes after that.

Fortunately such occurances are rare, PoCo meter fitters are supposed to polarity & loop impedance check at least 1 socket after changing a meter.

[This message has been edited by David UK (edited 11-02-2002).]

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#134323 - 11/03/02 12:11 AM Re: Transposed Mains
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Good point about the earth-neutral bonding position. I know that at least some of the 24-Seven crew around here are very careful on this point.

A year or so ago we had a high-res connection on a pole that feeds my house and two others. The engineers had to re-splice my service drop along with one other, and were careful to go and check for correct polarity at my neighbor's house. (He had me check in mine as well.)

Quote:
One bright spark was connecting the meters: red, black, red, black, instead of: red, black, black, red.

Allow me to interject a note for our non-U.K. contingent: Our meters generally have a row of four terminals at the bottom, with the middle two acting as a direct feed-through for the neutral.

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#134324 - 11/03/02 09:29 PM Re: Transposed Mains
Trumpy Offline


Member

Registered: 07/05/02
Posts: 8553
Loc: SI,New Zealand
Thanks David and Paul, for your comments on this subject.
Over here, Electricians who replace Mains cables, are allowed only because the local lines company lets them, this is a local thing, this could change after this prosecution goes ahead, because the person involved did none of the required tests, not even a Polarity Test.
I would invite the comments of Old Appy, on what is allowed in his area, with Electricians working on the Electricity Network, even if it is just a consumers Mains.
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#134325 - 11/04/02 02:11 AM Re: Transposed Mains
old Appy Offline
Member

Registered: 03/18/01
Posts: 120
Loc: Auckland, New Zealand
Hello there,
I have been involved in changing the supply cable from a plinth and pit never a pole, i have never connected it, this must be done by an inspector as far as i am aware.

CW

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#134326 - 11/04/02 10:26 PM Re: Transposed Mains
Trumpy Offline


Member

Registered: 07/05/02
Posts: 8553
Loc: SI,New Zealand
Craig,
Thanks for your reply, whose supply area do you work in?, although since all the power companies were split up, it's been nothing but a bloody nightmare down here, you ring up a place in the North Island, that doesn't even know where Ashburton is, they have no idea what you are talking about with respect to metering,just to get a Night-Store heater hooked up to the right rate,etc.
Might be good for the customer, until they get the bill for running around and so forth, then the complaints start.
So much for our lovely power reforms.
But, I have not had any problems with our local lines company, however, I used to work for them, but I do think that good Electricians that can demonstrate they can do hook up's to O/H lines, should be allowed to, it's not really Linework, you just have to be that much more careful.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

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#134327 - 11/05/02 01:08 AM Re: Transposed Mains
C-H Offline


Member

Registered: 09/17/02
Posts: 1508
Loc: Stockholm, Sweden
A electrician friend was doing a job at a house undergoing renovation or some remodel. He was using his new drill and was impressed by the stunning performance. Eventually the sparks engulfing the drill made him suspicious: Checked and found 400V in socket. Turns out the building contractor had connected temporary power to the house and reversed two wires...

Another friend of mine (a less talented D-I-Y'er) wired a socket for his car engine heater (don't know what it's called in English). All winter long he was happy with the new heater. The car was warm in a few minutes rather than half an hour. He did eventually figure out that sockets should be connected between breaker and neutral bus, not between two breakers...

[This message has been edited by C-H (edited 11-05-2002).]

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#134328 - 11/07/02 01:44 PM Re: Transposed Mains
pauluk Offline
Member

Registered: 08/11/01
Posts: 7693
Loc: Norfolk, England
Quote:
car engine heater (don't know what it's called in English).


I think that term is as good as any. I've also seen them called a block heater (i.e. cylinder block). You don't see them much in England, but I think they're also quite popular in Canada and many of the northern plains States in the U.S. I know an ex-neighbor of mine said he used one regularly when he lived in Wisconsin.

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#134329 - 11/07/02 09:52 PM Re: Transposed Mains
Trumpy Offline


Member

Registered: 07/05/02
Posts: 8553
Loc: SI,New Zealand
C-H,
The thing that you talking about, is called a pre-heater, all Emergency service vehicles over here use them to keep the engine block and oil warm.
I remember one of these nearly burning down the Fire Station in Timaru, when it shorted,the oil was boiling,I noticed it when going outside for a cigarette.
On the subject of 400V, a guy rang me up at home one Saturday morning, said that the rings on his range were too hot, long story short, he had remodelled his own Kitchen and had moved his stove, I went and had a look, Two phases, no Neutral, no Earth wire either!, some people should never be allowed anywhere near Electricity.
_________________________
Let's face it, these days if you're not young, you're old - Red Green grin

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