Solar Array Conduit - Seeking Advice

[ChrisG]

That's called an auxiliary ground rod.
While they are allowed, but not required. (And not recommended by me)
They don't take the place of the required equipment grounding conductor.

Thanks @timselectric. Seems like some of the less expensive AIOs don’t have an input or ground bar for PV ground like the Schneider Conext or MidniteSolar SCCs do. Just so I’m clear the ground wire tying panels and mounts should go all the way back to the inverter and tie to AC ground (not neutral)?

 

[timselectric]

Thanks @timselectric. Seems like some of the less expensive AIOs don’t have an input or ground bar for PV ground like the Schneider Conext or MidniteSolar SCCs do. Just so I’m clear the ground wire tying panels and mounts should go all the way back to the inverter and tie to AC ground (not neutral)?

Yes, your original grounding system. (Never neutral)
It's all one grounding system. All grounding is tied together.

 

[Hedges]

From what I understand, sol-arks so not use ground at all for the PV arc fault detection.

Arc fault detection is a different animal. Think digital signal processing, FFT, analyze the spectrum. Anything less like analog filters might work, but would probably suffer from nuisance tripping due to interference.

Ground fault detection is often an 0.5A to 1A fuse or breaker between PV and ground, at least for older grounded arrays.
Through dirt, you may not get enough current to trip that, but still enough to kill you.

It is likely different in transformerless inverters; my Sunny Boy TL momentarily ground the array to test for leakage current, then float. If a fault occurred later during operation, it could wreak havoc on utility transformers. And expose the hapless human to AC as well as DC if frame not grounded back to inverter.

And the manual even says not to connect a ground wire from the PV frames to the solark's ground.

Can you copy/paste that portion of the manual?
Many manuals say not to ground the array (PV wires), which is different from not grounding the frames.
With frames not grounded by a wire back to the inverter, it can be a shock hazard.

 

[timselectric]

And the manual even says not to connect a ground wire from the PV frames to the solark's ground.

I think that you might have misunderstood what the manual says. Sol-Ark is designed to be compliant with NEC. They wouldn't instruct you to do anything against code.

 

[Subdood]

Just a anecdote relating to grounding of arrays. I got a small zing one day out at the array when I was checking some things on the frames while the inverter was running. At that time, I didn't have the frames grounded. I later measured about 180VAC between the frames/rails and a small rebar pole driven a few inches into the ground near the array. Apparently AC voltage can be coupled onto the frames, and this voltage was there if the inverter was in solar or bypass mode.

Before I ran my PV wires back to the inverter, I tied all the panel frames and rails together with a bare 6awg wire and grounding lugs. From the array junction box, I ran a 10awg ground wire along with the PV wires thru my conduit back to the inverter's ground terminal. Now there's no more voltage on the frames.

 

[PreppenWolf]

I ran 4" sch40 pvc for my installation. Dig the trench once. Make pulling a non-issue. Learn to plan better for future you. Future you will appreciate it.

 

[timselectric]

I always plan for the future.
Future me is always appreciative of past me's forethought.

 

[dougbert]

I always plan for the future.
Future me is always appreciative of past me's forethought.

I have tried to do that over the past 30 years of solar hobby

but the tech ran much faster and further than I every thought possible for that 30 year ago me.

When I put in my SW5548 system back in 2016, even then I didn't think I would need what I recently put in.

Beefing up the AC side from 6 awg (from back in the day's plans) to today's install of 2 and 1 awg in that same AC side of things, gives me some better feelings I have "planned" for the future. DUAL XW Pro's (in the future) will make use of those bigger wires.

We do our best, and still leave some room on the power wall for future devices, LOL

 

[ChrisG]

What is code compliant to transition from PVC outside to MC or metal conduit entering the house where the inverter(s) are? Interesting to see what everyone is using

 

[timselectric]

What is code compliant to transition from PVC outside to MC or metal conduit entering the house where the inverter(s) are? Interesting to see what everyone is using

This can be done at the wall penetration.
A box or LB on the outside. Change to metal from there.

 

[WattAboutThat]

I am thoroughly confused!

But greatly appreciate the discussion, and differing points of view.

I also want to be safe so no one can get hurt.

 

[WattAboutThat]

 

[timselectric]

Seen that when he uploaded it.
Will it pass an inspection, yes.
Would I do it that way, absolutely not.
Way too much contact with the earth, at a great distance from the power room/equipment.
Hopefully he has lightning arrestors at the power room. And I hope that they'll save his equipment, when lightning strikes nearby.

 

[ungrounded]

I am in the process of planning out how to get pv wire from inverters to the solar arrays. The distance is 450 feet.

I have concluded with advice from others that
I need to use 8AWG (8 guage), pv rated wire.

I will have 16 total wires, each 8awg, going thru the conduit.

If I use schedule 40 pvc the pipe is going to be around $1,300 not including elbows, etc., but that is the proper method in my opinion.

I calculated area of 1 8awg wire, multiplied by 16, and determined that 1-1/2” should give enough cross sectional area to pull 18 wires, and include room for a nylon pull string.

But it would save a ton of money, almost $1000, if I used non-perforated culvert pipe and have extra room in case i want to run 4 more solar strings in the future.

But it may not keep water out, although i would amply caulk all joined sections.

What are the consequences, that I may not perceive of using culvert pipe.

Open to any