Author Topic: Criss-crossing conduit near the roof for home solar panel install  (Read 180 times)

a_scanner_brightly

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Is there code or best practice that says how to run conduit across walls near the roof when there's already other conduit in the way?

The back-story is that I'm putting together a plan for installing solar panels on my roof.  I need to figure out how to route power from the panels to the breaker box, which is on the outside of my house.

There are two separate prime spots on the south facing roof of my house for two separate banks of panels.  I don't have the ability to run the conduit inside of the attic because the roof of the house in that spot is converted garage; ceiling of the converted garage goes all the way to the roof.  So I think I'm better off punching through the edge of the roof and coming out of the soffits and snaking conduit along the outside wall of the house to the breaker box.  The trouble with that approach is that there's already other electrical conduit running across the top of the exterior walls where they meet the soffits.  Can I just lay another run of conduit immediately below them?  I don't really see conduit overlap any other conduit on houses so I'm wondering if this is some kind of code violation.

Thanks in advance.  Any other thoughts on my approach would be appreciated as well.
« Last Edit: October 11, 2018, 12:26:37 PM by a_scanner_brightly »

lthenderson

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Re: Criss-crossing conduit near the roof for home solar panel install
« Reply #1 on: October 11, 2018, 12:32:26 PM »
They make x-style conduit boxes for that situation but they have solid backs and lids so you would have to be able to partially unstring the other wires to thread them into the box.

https://www.amazon.com/Appleton-SEHX-50-Conduit-Outlet-Malleable/dp/B007QQQDU2

a_scanner_brightly

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Re: Criss-crossing conduit near the roof for home solar panel install
« Reply #2 on: October 11, 2018, 12:39:37 PM »
Hmm.  That solves the problem for some of the runs, but there's this one mad thick conduit run that has a 100A cable in it because it powers a sub-breaker.   :/

Can you run conduit along the soffit itself?  e.g. nail it into the overhanging part of the roof?

SweatingInAZ

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Re: Criss-crossing conduit near the roof for home solar panel install
« Reply #3 on: October 11, 2018, 02:02:53 PM »
I'm having trouble visualizing this, but do you just need to bend the new conduit over some existing conduit? Bending makes it harder to fish wires through, so I usually go up a conduit size.

This is called a 'saddle bend'

https://i.ytimg.com/vi/V4Z89u_S8gc/maxresdefault.jpg

a_scanner_brightly

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Re: Criss-crossing conduit near the roof for home solar panel install
« Reply #4 on: October 11, 2018, 03:14:38 PM »
Oh.  Are saddle bends allowed?  That solves pretty much everything if so!

SweatingInAZ

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Re: Criss-crossing conduit near the roof for home solar panel install
« Reply #5 on: October 11, 2018, 04:14:54 PM »
Yes! Bends are allowed. You should get a conduit bender, I wouldn't try doing it without one. If you have any friends who do electrical work professionally, they probably already have one. My AC-technician neighbor has one for 3/4" conduit, which is a very useful size. It's still easily bendable with the manual tool, but can legally house nearly double the wires that 1/2" can contain.

In 1/2" EMT, you can only have 9 12awg conductors
In 3/4" EMT, you can have 16!

https://solutions.borderstates.com/resource/conduit-fill-table/

Be prepared to ruin some conduit by bending it incorrectly.
« Last Edit: October 11, 2018, 04:17:52 PM by SweatingInAZ »

a_scanner_brightly

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Re: Criss-crossing conduit near the roof for home solar panel install
« Reply #6 on: October 11, 2018, 04:27:57 PM »
woop, thanks for the tips!

There's a non-profit tool library in-town that seems to have a conduit bender to borrow.  So that's good to go!