4 Breaker Panels Backfeeding on Neutral

[idratherbeknapping]

So this is the first time I’ve really ran into a neutral back feed on 4 different breaker panels. What ties them together is they are all on the same meter stack off of a 1200A Meter Base. All of the Breakers on the right side of my breaker panels (Even Numbers) can be turned on and off with no back feed to the neutral. The Breakers on the left side of my breaker panel (Odd Numbers) can be turned on somewhat if not AFCI/GFCI breakers tripping obviously. As soon as I turn on 1 breaker from my left side of my panel it causes a back feed through my neutral.

I’m thinking that the problem is within my meter stack, but is it possible for an induction short in my exhaust fan of even one unit to cause this back feed on my neutral. I have not disconnected my SER from my main lugs just yet and tested voltage on the four units. Yet, testing voltage incoming with all breakers off is 240V good to go. 120V for each hot, again, ready to go.

Does anyone have any other ideas as to what could be causing this? It’s possible that 1 of the 4 units could have a neutral ties in to a hot that’s causing that back feed just wanted to see if anyone had any ideas on how to isolate what could and could not be the issue, i.e. breaker panel or meter gear.

I am using the new BRP Plug in type Neutral Breaker Panel if anyone suspects that has something to do with it. These panels are fairly new and not sure if the neutral plug in can fault causing that back feed off of the breaker. This would be my 174-178 units that have been fired up off of these panels so not suspecting it to be a BreakerPanel issue.

Any knowledge or criticism would help...

Thanks guys,

 

[LarryFine]

Welcome to the forum.

My first thought is neutrals of different circuits connected together on the load side of the panel.

 

[Little Bill]

So your problem is AFCI or GFCI breakers tripping, and you think it's backfed neutrals?

 

[ptonsparky]

I’m thinking you need to verify each neutral is paired with the the correct branch circuit and NO cross connection exists any where in between. Time consuming but a decent tester such as a T+Pro or similar should be up to the task.

 

[Fred B]

I had one similar, may or may not apply but what someone had done is installed a small subpanel for a hot tub and sunroom (and WHYYYY They did the following I don't know) but they put the neutral on one of the hot bus terminals. The owner never reported any problems prior to beginning work to change out main panel. When turned on and turned on what ended up being the sub, breakers tripped all over, always on L2, started to trace out and found subpanel and its enclosed issue. He later confided that the hot tub never did get as hot as he thought it should have. Corrected reversal and no more tripping. Investigated why old panel never showed sign of tripping and found that original panel had installed 2SP breakers for that sub with no handle tie, also found the one SP that appeared to be on was evidently burned out as when tested never closed. Since then always double check what was and where it goes to prior to just replacing "like for like".
As I said I don't know if it applies to you but definitely worth checking for a hot-neutral reversal.