Breaker for sewer/grinder hook up

[hillbilly]

"I have the control wires running from the pit in 2" pvc to the 10x10 pvc box & then I'll finish it from there".

"Question, in regards to the 2" pvc coming from the pit/fiberglass tub where the control wires come from do I need to foam the pvc in case of back flow up into the main box. I know the float switch will turn it off etc. but I was just wondering. My answer is no but I need a confirmation."

If that conduit is continuous from the tank to the control, you may need to install a seal fitting in the pipe to prevent any sewer gas (methane) from backing up thru the conduit and into the control housing.
It can cause a hazard if enough gas accumulates in the disconnect/controls. One spark and look out.
I was required to install these fittings on a couple of commercial systems that I installed where the conduit was continuous between the tank and control box/disconnect.
The ones that I used looked like a plumbing "wye" strainer. After the wire was pulled, the plug in the fitting was removed and a sealing compound was poured in to seal around the wires and plug the passage.
On the smaller systems, I used a 5 conductor direct burial cable. That way I didn't have to run the conduit all the way to the tank, only far enough to protect the cable as it emerged from the ground to the disconnect. This way I didn't need to "block" the pipe.
Just a thought
steve

 

[Rollbar]

Thanks you, I did not know that, well I didn't even think about but it make since to me. So U think the great stuff yellow foam won't work?

 

[hillbilly]

Thanks you, I did not know that, well I didn't even think about but it make since to me. So U think the great stuff yellow foam won't work?

I don't know....I was required to use a listed fitting, so it took the guess work out of it for me.
I haven't done much work in explosive environments so I don't know what hazardous classification, if any, that this equals.
Maybe someone more familiar will post.
IMO...If there's a chance for creating a explosive environment in a electrical panel, I don't think that I'd depend on great stuff to prevent it.
If this is for a sewer, methane gas will be present. Whether it will ever be in explosive quantities, I don't know.
The systems (tanks and control panels) that I worked on were vented, so all of the equipment was at atmospheric pressure and any anticipated movement of gas thru the conduit to the control panel was simply by migration.
You might wany to read 501.15 in particular paragraph (A) and (C).
Again...I'm not and don't claim to be a expert on explosive environments, so my comments are for reference only.
You be the judge.
steve

 

[Rollbar]

Thanks Steve, I'll look into it.