Conduit

Eric Ernst

I think I have a handle on conduit wire loading but am confused as to if it is ok to use EMT conduit on the roof and in a 35 ft. outside run from my inverter to where my main power panel is located. I also need to find a water proof junction box that I can use above the roof penetration. If any of you folks have an answer off the top of your head, or can refer me to a thread that discusses this, I'd appreciate it. I've looked and haven't found anything that didn't confuse me.

Thanks,
E

dwh

Re: Conduit

Eric Ernst wrote: »

I think I have a handle on conduit wire loading but am confused as to if it is ok to use EMT conduit on the roof

Yes. Remember to factor in temperature for the de-rating to get the conduit sized correctly.

and in a 35 ft. outside run from my inverter to where my main power panel is located.

Depends. As long as it's not underground or hanging unsupported, then yes. Running it along the side of the building from one spot to another, no problem.

I also need to find a water proof junction box that I can use above the roof penetration. If any of you folks have an answer off the top of your head, or can refer me to a thread that discusses this, I'd appreciate it. I've looked and haven't found anything that didn't confuse me.

Thanks,
E

Standard rainproof enclosure - something like this:

http://store.solar-electric.com/mnpv6.html

Eric Ernst

Re: Conduit

Thanks dhw. Good info.

E

solartek

Re: Conduit

Eric,

I use the Soladeck roof mounted junction box on all my composition shingle installations.

Manufacturer Web Site


Scott.

Eric Ernst

Re: Conduit

Looks like a good box for on top combiner. I'm thinking of taking each string through the roof and putting the combiner box in the garage attic. It's a 12-12 roof so there is plenty of room there. What I will need for that is a conduit penetration that has a water tight box on the top side. I saw something like that when I was initially researching, but haven't been able to find it again.

E

solartek

Re: Conduit

You don't have to combine in the Soladeck if you don't want to. In some installations I just use it to transition the wire type from USE-2 to THHN and use a combiner box down near the inverter and disconnects.

Scott.

newenergy

Re: Conduit

If you're combining or transitioning in the attic, you can just penetrate the roof with EMT with a flashing and an LB on the top of the piece of EMT - using raintight fittings. If you just transition wire on the roof, rather than combine, you can use any weatherproof box - PVC or metal.

I've used the soladecks too and they make for a clean looking penetration.