Irregular voltage in residence AFTER service upgrade

[MartyB]

Hello,
My apologies for bit lengthy b7t wanted everyone to have an idea of what I came across.

I recently upgraded a residential overhead service from 100 to 200 amp with a subpanel.
Poco renergized system. Like a Newby I didn't confirm voltages at that time. Turned on main breaker and sub panel breaker. Lights worked, receps, oven, etc.
Left jobsite. Customer called said kitchen breaker kept tripping. Checked VAC at single pole breaker on phase B to find 243 v to neutral.
Checked main breaker and have phase A to neutral 120, phase B 243 to N.
Phase to phase reads 122. Poco just dropped service at mast, not at transformer.
Has anyone else ever experienced such a thing?
Thank you for your time

 

[LarryFine]

Welcome to the forum.

Sounds like one phase and the neutral got swapped, probably at the mast.

You need to check voltages at the meter. That will tell you who messed up.

 

[gar]

230323-2351 EDT

MartyB:

My guess is that one of the two hot lines from the power company is connected to neutral and ground in the main panel. This would provide one 120 V output, and one 240 V output relative to earth, and what should be netrual is actually a hot wire relative to earth.

The two wires that should a 180 degree difference in phase are going to read as in phase.

.

 

[gar]

230323-2433 EDT

MartyB:

A continuation of my comments.

Assume that the power company or possibly trailer park distribution transformer is correctly wired on its secondary side, then we can expect its secondary center tap to be earthed ( grounded ) at or near the transformer.

Then, if my guess as to what are the connections to earth at your trailer are correct you would have a hot wire connected to earth at your trailer. This would mean 120 V is applied from your trailer ground rod thru earth back to the transformer ground rod. That ground path resistance might be as low as 10 ohms thru both ground rods, and earth. Also it could be much higher. Whatever this total resistance is it will determine a current path that will waste power, and depending upon where your ground rod is connected will determine if you pay for this wasted power. It also causes a safety hazzard.

.

.

 

[AC\DC]

Get pics and document what you can incase its power company fault so you don’t have to pay for damaged items

 

[ptonsparky]

Get pics and document what you can incase its power company fault so you don’t have to pay for damaged items

and just in case, have you insurance agents # handy unless you can cover it out of pocket.

A customer had a genset installed but the guys (not mine) marked the wires AFTER pulling them. Fortunately they had checked voltage prior to loading it up and the customer asked me for help at that point.

 

[MartyB]

Welcome to the forum.

Sounds like one phase and the neutral got swapped, probably at the mast.

You need to check voltages at the meter. That will tell you who messed up.

That's EXACTLY what it was. Poco connected hot to neutral. I figured That's what it was but it was a long and windy day on a 10/12 roof for mass.
Thank you for your reply

 

[MartyB]

230323-2351 EDT

MartyB:

My guess is that one of the two hot lines from the power company is connected to neutral and ground in the main panel. This would provide one 120 V output, and one 240 V output relative to earth, and what should be netrual is actually a hot wire relative to earth.

The two wires that should a 180 degree difference in phase are going to read as in phase.

.

That was what happened. Poco goofed on reconnect.
Thank you for replying

 

[MartyB]

Get pics and document what you can incase its power company fault so you don’t have to pay for damaged items

I always take pics of my mast with N marked to cover my behind. Thank you for the reminder

 

[Shaneyj]

I always take pics of my mast with N marked to cover my behind. Thank you for the reminder

Was your service neutral taped white? Was it same size as line conductors? Poco neutral bare?
IME with Centerpointe energy, Puget Power, Dixie Escalante - I don’t think I’ve seen a lineman connect, slam the meter in, then exit.
I’ve always seen them DMM the line side sockets at the meter before plugging it in.


Sent from my iPhone using Tapatalk

 

[LarryFine]

Let us not forget the energized plumbing and electrodes, and lack of arcing and over-current reaction.

 

[ptonsparky]

Was your service neutral taped white? Was it same size as line conductors? Poco neutral bare?
IME with Centerpointe energy, Puget Power, Dixie Escalante - I don’t think I’ve seen a lineman connect, slam the meter in, then exit.
I’ve always seen them DMM the line side sockets at the meter before plugging it in.


Sent from my iPhone using Tapatalk

I've never seen it either, but it was California.

 

[growler]

Let us not forget the energized plumbing and electrodes, and lack of arcing and over-current reaction.

Someone deserves a Darwin Award or at least an honorable mention.

 

[ActionDave]

Someone deserves a Darwin Award or at least an honorable mention.

Darwin awards are only given out posthumously.