Power Panel Changes Voltage with Branch Circuits

Rededdie · Oct 10, 2022

I have a Single Phase Power box for a townhouse. When I read voltage across the Hot legs (A) and (B) to ground I get 123 volts with the main breaker turned off. With all the circuit breakers turned off and powering up the main breaker to the panel I still have 123 volts across both (A) and (B). As I start to turn on the branch circuit breakers on to each Outlet, Light, Garbage Disposal, Washer etc..... The voltage changes but it ranges from (A) -- 134volts, (B)--- 104volts, as i keep going down the panel turning circuits on the voltage changes and never evens out back to (A) 123volts, (B) 123volts, or anywhere close to it. The worst I have seen on this panel is (A) -- 154volts, (B) -- 94volts. The panel did not have a ground on it from the ground rod which I corrected and tied it into the ground strip and Jumper'd over to the neutral bar.

Everything I have read about this issue is that it is a neutral problem and I thought it was a floating neutral at one time but had the feeling it has always been a neutral issue. But as I have researched this I have come to understand that it is more than likely the PoCo that has a broken neutral going to this panel on their end not on my end... Is this correct.? Is there another issue I should be looking at.?

Any assistance would be greatly appreciated. Thanks

Megawatt · Oct 17, 2022

Rededdie said:
I have a Single Phase Power box for a townhouse. When I read voltage across the Hot legs (A) and (B) to ground I get 123 volts with the main breaker turned off. With all the circuit breakers turned off and powering up the main breaker to the panel I still have 123 volts across both (A) and (B). As I start to turn on the branch circuit breakers on to each Outlet, Light, Garbage Disposal, Washer etc..... The voltage changes but it ranges from (A) -- 134volts, (B)--- 104volts, as i keep going down the panel turning circuits on the voltage changes and never evens out back to (A) 123volts, (B) 123volts, or anywhere close to it. The worst I have seen on this panel is (A) -- 154volts, (B) -- 94volts. The panel did not have a ground on it from the ground rod which I corrected and tied it into the ground strip and Jumper'd over to the neutral bar.

Everything I have read about this issue is that it is a neutral problem and I thought it was a floating neutral at one time but had the feeling it has always been a neutral issue. But as I have researched this I have come to understand that it is more than likely the PoCo that has a broken neutral going to this panel on their end not on my end... Is this correct.? Is there another issue I should be looking at.?

Any assistance would be greatly appreciated. Thanks

My friend you are correct about your readings on your voltage and it is definitely a neutral issue. 154vac is way to high and can burn up appliance’s, clocks, microwave etc. other than calling the power company check the voltage on the actual wires coming from the meter. It could easily be on the power company’s side