Conduit Routing

[pchiquit]

I'm struggling to find information about any restrictions on conduit routing through the roof and wall, so maybe you guys can confirm that I'll have no problems with the county inspector. Basically my plan to connect my solar panels to the AC combiner box is to route EMT 3/4 conduit through the roof ridge, through the attic, inside a wall, crawlspace and then exit close to the service panel where the AC combiner will reside. Before I give more details this is a 16 panel using Enphase microinverters with two circuits. All wires will be on metal conduit.
Anyway, on the roof penetration, I have a standing seam metal roof. I don't want to make more penetrations, so my idea is to route the conduit through the ridge, similar to this picture:
https://www.metalera.com/CMSPages/Ge...b-99059c0e4507
So the pipe will penetrate the barrier under the ridge cap and then take a 90 degree turn down.
Does anybody see any problem with that?

My second question is if is fine to just drill roles on the wall beans and route a conduit straight from the attick to the crawlspace. That would go on a inside wall that has gypsum boards on both side.

Anyway, appreciate any comment. I'm not sure where to find information if that is allowed or not.
Thanks

[Mike90250]

The inspector is always right.
My inspector is not your inspector.

Drilling holes in beams will often require engineering to sign off for it to be OK

[foo1bar]

How are you going to make the 90 degree turn?
A long sweep elbow won't fit under a ridge cap.
If you use a fitting I don't see how you're going to have access to the fitting to pull the wires through the fitting.

Also, are you going to be able to get the conduit through the roof at the ridge, but have it not make a notch in the ridge beam?
(I would much rather have a roof penetration with a rubber boot than make any notch in my home's ridge beam.)

My second question is if is fine to just drill roles on the wall beans and route a conduit straight from the attick to the crawlspace. That would go on a inside wall that has gypsum boards on both side.

Put another way - can you drill big holes in the top-plate and bottom-plate of the wall in order to run a conduit top to bottom.
I think the answer is going to be "maybe".
Having holes from attic to basement for a plumbing stack (vent going out the roof, sewer going down to the basement) is fairly common. So it definitely can be done with even bigger holes than what you're probably planning.
But I wouldn't just do it anywhere without some long hard looks at what removing those chunks of wall structure will mean for your building.
If there's already a chase for plumbing in place I'd probably try to put the conduit there. (no structural changes, so no worries about having changed a sheer wall, nor worries about drilling through the wallboard accidentally or drilling into a wire or pipe. on the other side of that top/bottom plate.)

[pchiquit]

Thanks for sharing your knowledge and opinion. I see the wisdom of avoiding drilling on the wall plates, so I will change my plans and avoid the walls.

[NewBostonConst]

I your roof is made of trusses you won't have to worry about a ridge board and likely can use your plan of using the ridge cap.

Might want to use a LB instead of the pipe 90. An LB is a tight 90 with a cap so you can access your wires.

From the size of your array size you will have at the most four 12 gauge wires plus ground.

Not sure if you really need the combiner box? I just wired my inverters using the Q-cable to a small junction box. You will have 2 strings. Don't need a ground to the inverters but inspector might want one. I am wiring mine now but is a ground mount. I plan on grounding the panels but not the inverters. I have 24 panels on two 10 gauge circuits.

I am an old licenced builder that has built my last two houses and done all the electrical myself. I think this is a very simple way we are doing it. Use my recommendations as you want and let me know if I am giving bad info....

Good luck.

[pchiquit]

Thanks you NewBostonConst . The roof like you said is made of trusses and don't have a ridge board. I was outside with a flashlight and found a gap the roof installer left on the venting that fits the pipe perfectly. I also checked if there is space for an LB and I think it will work just fine, so I'm going to do that.
But I'm going to avoid drilling on the walls and just run the pipe through the laundry area.
Thanks again for the feedback.

[thastinger]

I used this for my off grid garage, it has several knockout you can use to attach the metal conduit to the back of the box

https://www.altestore.com/store/enclosures-electrical-safety/electrical-enclosures/combiner-pass-through-boxes/soladeck-dc-combiner-box-3-din-rail-p10397/?gclid=Cj0KCQiAi57gBRDqARIsABhDSMpAnhKK0V1qexpoGDWvTPezic07hABietr-7HxhOmqAYgrqB3d4ntEaAuXAEALw_wcB

[NewBostonConst]

thastinger. Nice box and cheaper then the other combiner box. The only problem it says it is for DC. We are using micro inverters so we don't have to deal with the DC side, only the AC side.

Thanks

[tyab]

Just bringing this up since you already had someone say to use 12 gauge. That may or may not work in meeting the under 2% total losses from wire resistance to help prevent tripping by the Enphase micro's. Remember that is 2% from the service to the furthest micro taking into account the losses from the Enphase cable. Enphase has some papers on their site that help calculate this - one example is below for the IQ series but they have similar charts for the older cable types.

https://enphase.com/sites/default/files/downloads/support/TechBrief-CalculatingACVoltageRise-IQ.pdf