# High Voltage Service call



## aftershockews (Dec 22, 2012)

Lectric said:


> Had a service call this morning where the homeowner reported a bath fan fire along with GFCIs tripping throughout the house. We discovered that almost every electronic device throughout the house was fried, the homeowner did the correct thing by shutting off all of the circuits but he did keep the main on. When I tested the line to neutral and then to ground I discovered the one phase was reading 137 volts the other was at 126,correspondingly the line to line reading was 263 volts. I did not open the meter because POCO was on the way after I discovered this (homeowner was using choice words at them on phone) and they said they would take care of it. Any thoughts on whats up? I checked all connections at panel and all was good, the readings were the same with main on or off.


Loss of neutral.


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## McClary’s Electrical (Feb 21, 2009)

Probably. Two things. Lost neutral, and the batteries are weak in your multimeter. The reason I say that is, loss neutral will give you the unbalanced phases, but phase to phase should still read correctly.


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## Lectric (Nov 22, 2014)

mcclary's electrical said:


> Probably. Two things. Lost neutral, and the batteries are weak in your multimeter. The reason I say that is, loss neutral will give you the unbalanced phases, but phase to phase should still read correctly.


See, I had that before with a loss of the noodle but then my phases rang out correctly and thats what had me asking. And as far as the batteries in the multi meter we checked it with two different just to be sure. Thanks:thumbsup:


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## macmikeman (Jan 23, 2007)

Shorted windings in the secondary side of the poco xfmr can drift the voltage up to one of the higher tap percentage levels. This may have happened.


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## jarhead0531 (Jun 1, 2010)

Like others have said probably a bad neutral. To verify I will pull the meter and hook up my little cheaper box I use for service changes to one phase and plug my cheap HF heat gun into it. The unbalance load will show a neutral problem mucho fasto.

I have seen it as bad as 200 on one leg, 40 on the other.

On that call the HO told my dispatcher they smelled something burning. I showed up and smelled it too. I immediately killed the main and started looking for those $5 power strips. Found 2 burned up. One behind the entertainment center that discolored the hardwood floor, and another behind their 6 yr old daughters bed.

They were very lucky.


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## oliquir (Jan 13, 2011)

i would say bad poco xfmr since he had 263V and both reading to neutral were over 120v


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## heavysparky (Jun 2, 2009)

I second the poco xfermer going bad. Poco should come out. Check at your meter. Than check the neighbors meter. After that the transformer should be checked. Since you are in the neighborhood. You should hand out business cards to all the affected houses.


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## Lectric (Nov 22, 2014)

Just got the call from my boss , Poco lineman said shorted neutral somewhere between xformer and house. Fried a lot of items, all small motors, stereo, all the gfcis .lineman ran a temp feeder from pole to meter said they will be back when the snow melts. Power company told us to tell homeowner to submit all bills to their claims department. At least they can sleep tonight.


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## McClary’s Electrical (Feb 21, 2009)

So explain your high voltage readings then, because that did not.


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## 51360 (Jun 9, 2014)

Lectric said:


> Just got the call from my boss , *Poco lineman said shorted neutral somewhere between xformer and house.* Fried a lot of items, all small motors, stereo, all the gfcis .lineman ran a temp feeder from pole to meter said they will be back when the snow melts. Power company told us to tell homeowner to submit all bills to their claims department. At least they can sleep tonight.


In your jurisdiction, the utility is always responsible for the feed to the meter? I am assuming an underground feed originally. Yes?

Borgi


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## Lectric (Nov 22, 2014)

mcclary's electrical said:


> So explain your high voltage readings then, because that did not.


That's what I said, lineman said , that's what's up...


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## Lectric (Nov 22, 2014)

Borgi said:


> In your jurisdiction, the utility is always responsible for the feed to the meter? I am assuming an underground feed originally. Yes?
> 
> Borgi


On commercial jobs the electrician must calculate and supply feeder to meter from pole including the sweep and first 10' of conduit up pole. In residential the Poco supplies or has it outsoursed.


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## Lectric (Nov 22, 2014)

mcclary's electrical said:


> So explain your high voltage readings then, because that did not.


Any thoughts on your end?


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## Lectric (Nov 22, 2014)

*High Voltage Question*

I recently had a service call where a residential service 120/240 single phase had a high volt readings on the phases. One was 137 and the other was 126, the combined voltages were 263. This of course smoked many items in the dwelling, the POCO lineman said it was a shorted neutral saying something about mice in the conduit. He temporarily fixed it by running new conductors from the Xformer to the meter above ground, he said they would be back to fix when the snow melts. I have had open neutrals with feeders before where the voltage had spiked on one of the phases but not on both. Anybody else dealt with this before? As I am intrigued why the voltage in the one phase didn't "dip" as the other one "spiked". I am primarily a resi guy so please excuse my ignorance, insults are welcome.


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## Black Dog (Oct 16, 2011)

Lectric said:


> I recently had a service call where a residential service 120/240 single phase had a high volt readings on the phases. One was 137 and the other was 126, the combined voltages were 263. This of course smoked many items in the dwelling, the POCO lineman said it was a shorted neutral saying something about mice in the conduit. He temporarily fixed it by running new conductors from the Xformer to the meter above ground, he said they would be back to fix when the snow melts. I have had open neutrals with feeders before where the voltage had spiked on one of the phases but not on both. Anybody else dealt with this before? As I am intrigued why the voltage in the one phase didn't "dip" as the other one "spiked". I am primarily a resi guy so please excuse my ignorance, insults are welcome.


Sounds like the transformer is bad.


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## Lectric (Nov 22, 2014)

Black Dog said:


> Sounds like the transformer is bad.


Transformer feeds another dwelling and all was good there.


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## heavysparky (Jun 2, 2009)

did the faultsmen actually check the other homes? I seen this happen. where it was a problem that was effecting a whole city block. The issue was going on for month. Until I had a service call at a dumpy rental. Their " laid off journeyman millwright" was convinced the tenant just needed better light bulbs. My numbers were similar to yours. I also was leaning towards lost neutral. After removing meter and seeing numbers. I knew right away it was a poco problem. The faultsmen that called me back was surely convinced I was a flipping idiot . Once he was on sight and did his measurements. he offered to buy me a beer in apology .

attached are pics of what my meter was reading. and yes I re checked with a different meter with fresh batteries that day

keep us posted on what really happens


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## 51360 (Jun 9, 2014)

Agreed heavysparky, unfortunately you can't always take the word of other pros at face value. The utility makes a mistake once in a while too.

Chased my tail for months with an intermittent service problem, that should have been an easy fix. I had to eliminate almost everything first, before the utility finally fixed ther junk switch at the pole. 

Lesson learned, again! 

Borgi


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## oliquir (Jan 13, 2011)

if there neutral is now ok, what are the new voltages?


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## macmikeman (Jan 23, 2007)

Secondary side neutral loss on the xfmr will not raise the line to line voltage readings above nominal. The transformer is defective. And needs to be replaced.


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## Lectric (Nov 22, 2014)

oliquir said:


> if there neutral is now ok, what are the new voltages?


Voltages are 125 equal according to the lineman's meter, Talked to my boss again today and he went back to check on a few things of concern for the homeowner. The explanation that the POCO gave the homeowner is that there was voltage coming in on the neutral which is caused by a fault somewhere along the line from Xformer to house. There is another dwelling utilizing this same Xformer and all readings were and are normal there.


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