corrosion and voltage on neutral

[bitcoin miner]

If underground conduit is compromised, Foam is not going to fix it. Also the compromised conduit and collapsing concrete above it will eventually compromise the wiring making for a potential fault condition that can be dangerous let alone inconvenient. Scheduled outage is far better and less expensive than an emergency situation.

I replaced a panel yesterday that I installed less than a month ago. I used regular great stuff foam at that time. When I took the panel cover off my plug of foam had been pushed out of the conduit. I am assuming steam pressure did that. Probably because I didn't use the purple foam(sarcasm intended).

 

[bitcoin miner]

Just giving a notable reference.

That said, I work in a facility that has its own “eNgiNEERing SOOPERvisOn” and effectively act as their own AHJ. They do what they want. I do what I can to stay gainfully employed.
It’s fun.

I do what I can to stay employed also but it's getting harder to not just lose it every now and then.

 

[ptonsparky]

Sounds like you need to vent each raceway much like plumbing, then seal. Let us know how you do that, although I am already picturing something.

Wow. Water cooled conductors. A guy usually pays a lot of money to do that on purpose.

Dewatering pumps may be the quickest solution.

 

[Fred B]

In combination with sealing the ducts, drilling a small weep hole to allow water to leave conduit before getting into the panels. Above grade and in an area that can be monitored can add the impotence to motivate owners to do something "more expensive" but really needed to FIX the underlying issue.

Had a service that another company had hit the underground service conduit, breaking it open, inadequately repaired, that due to elevation difference had enough "head pressure" that it created a fountain out of the top of the conduit at the pole. Made quite the ice sculpture at the pole. All just ground water.