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Poco meter change causing thermal trips?

1536 Views 3 Replies 3 Participants Last post by  forgotflying
I have had 2 service calls in the past year in which one phase would "trip" and the other would remain live. The one i just came back from was pretty easy to diagnose. 120v on phase 1 at service drop, 90v on on phase 1 at load side of the meter(obviously a lot of resistance in between the two points). On both of the aforementioned service calls the meter had recently been changed from an analog to a digital meter.
I wonder why this is happening?
Are the jaws on the digital meter wider?
Are the poco guys just to aggressive?
Anyone else have a similar experience?

It's interesting that a thermal trip doesn't actually trip the breaker it just shuts the power down to the overheated phase until it cools off.

It sucks because we are not allowed to open meter side of the panel so i have to wait for a troubleshooter to come out and confirm my suspicions:mad:

Ill post some pics of the meter socket as soon as i get a chance.
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· Registered
4,653 Posts
To see if it is a thermal trip or just sloppy meter installation, you can try this test:

WARNING: Wear PPE including gloves, safety glasses and flameproof shirt at the minimum!!

With an observer inside to watch lights, etc. for flickering...

Give the meter a sharp smack on each side, top, bottom then face.

If it is a thermal trip (not likely) nothing will happen.

If the meter is not in the socket correctly (99.9999999999999999999% probability) then the lights will flicker, you may even hear arcing from the meter socket.

A lot of POCO's (at least out here) have subcontractors doing the meter swapouts. I have met a few and some are as dumb as a box of rocks. They don't take the time to align the meter properly, they just force it in..I saw one such swapout at an apartment complex where ALL of the meters were forced in.....you could tell by the angle of the displays. :eek:

At my brother in law's old hair salon they forced a 3 phase (non-CT) meter in so badly he kept losing a phase. We first thought we had a bad fuse clip in the disconnect, but right as I was about to open the disconnect he hit his head on the meter (he's a bull in a china shop)..I heard the arcing as saw his lights flickering.:D A quick call to the POCO and one of the trouble guys I knew came out, reset the meter and all was good.

· Chief Hack
386 Posts
Discussion Starter · #4 ·

Well there's your problem :eek:

Im guessing the salt air, acid rain and the high sulfur dioxide content of the air here doesn't help with the longevity of electrical equipment.

Main thing is another house saved and another happy old lady :thumbup:
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