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EMT to PVC Conduit transition

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S

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Discussion Starter · #1 ·
I have searched quite a bit, and haven't been able to find a direct answer to this question.

I am installing a small 1.4kW PV system on my roof, and my electrical inspector recommended EMT on the roof. My plan is to run EMT about 10' to the eave edge, then install a metallic LB conduit body at the roof edge to head down to the AC disconnect... using a threaded PVC fitting at the LB to switch to gray schd40 PVC.

Conduit includes a 8AWG bare equipment ground wire, along with three stranded 12AWG for the 6A 240V system.

Just prefer PVC, don't want to bend EMT...


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SharpT
 
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Discussion Starter · #6 ·
stickboy1375 said:
Why would an inspector recommend anything? That's not HIS job.
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When I went to pick up my plans at the permit office, he grabbed his copy and started to chat with me... bad timing I guess.

Anyway, I'll comply with his recommendations as to prevent any "issues".

I've read its OK to use a junction box, but wondering if I can just use a metallic LB. If it was non-metallic I would have to bond the EMT to the ground wire at the transition box, hence the choice to use a metallic LB.

I can't find any code that says this is not legal, but figured I'd throw this question out. I've read some Electricians will just switch PVC to EMT using just fittings, but I want to do this by the book.

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SharpT
 
electures

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stickboy1375 said:
Why would an inspector recommend anything? That's not HIS job.
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Recommending is the same as designing. Nope, not gonna happen. I have been known to tell someone what I will accept though.:whistling2: As long as it meets code the inspector has no input.
 
S

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Discussion Starter · #11 ·
Read up quite a bit last night on 2008 vs 2011 NEC code for PV installs.

So per 2011 it is now OK to combine the equipment ground and the GEC and run unspliced from the PV install to the main panel. This can simplify things.

But when running a GEC inside EMT, you must bond the EMT to the GEC at both ends, to prevent an electrical choke. (hence the reason most use PVC for GEC runs).

So an LB won't work in this situation to transition from EMT to PVC, as I've never seen an LB with a ground terminal. I need to use a box that will allow bonding, since I will need a terminal lug inside the box to bond the 8 AWG GEC to the box as it passes on into the PVC.

I'm assuming the inspector is using the "physical damage" clause to recommend EMT. So I guess I could go with schedule 80 PVC on the roof. But why did he say 8AWG was OK. Since exposed GEC needs to be 6AWG if you are using the physical damage clause.

Whatever, EMT will run straighter and need less strapping on the roof. So it will look neater I guess.

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SharpT
 
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