Trenching suggestions?

I was under the impression there was a lot of controversy around grounding arrays. No problem grounding the frame to earth, but the arrays themselves are DC without the need for a ground. The inverters get ground via their AC hookup from the main panel.

The PV panel frames need a wire bonding them back to inverter chassis.
Many inverters drive AC superimposed on PV+/-, and people get shocked by the frames.

Hedges said:

The PV panel frames need a wire bonding them back to inverter chassis.
Many inverters drive AC superimposed on PV+/-, and people get shocked by the frames.

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Is that known for Victrons?

Interesting read, might be vendor hype, don't know.


Maybe Dexter knows? Alas, don't know how to ping someone here.

KevinC_63559 said:

Is that known for Victrons?

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Cheap AIO are known for this.

Victron AIO or separate SCC?
The SCC wouldn't even have AC available to it. An AIO or hybrid from Victron, I don't know.

But I think you should always have that ground wire bonding PV frame to inverter. If current leaked from PV to frame, frame could become a shock hazard. Even if grounded, because the earth has resistance and your body touching earth or ground elsewhere would provide an alternate path.

Hedges said:

DIY cable plow?

View attachment 231547

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The zip ties would not last long.

KevinC_63559 said:

I was under the impression there was a lot of controversy around grounding arrays. No problem grounding the frame to earth, but the arrays themselves are DC without the need for a ground. The inverters get ground via their AC hookup from the main panel.

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Grounding the PV array is referring to the metal PV frames and support structure. (Not the DC conductors)
This is done with an appropriately sized EGC (Equipment Grounding Conductor) ran with the PV circuit conductors, back to the electrical grounding system. With an AIO, the simplest solution is to connect it to the EGC at the AIO. Since it's already there.

Put @ symbol infront of their name.

outboard1196 said:

If there is a flexible conduit that can be used a subsoiler pipe layer would be ideal.
with a ripper tooth the trench tends to fill right back in .

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AFAIK Flex PVC is limited to 1" for direct burial. Anything over is hard pipe. I'd consider Quadraplex direct burial.

ksmithaz1 said:

AFAIK Flex PVC is limited to 1" for direct burial. Anything over is hard pipe. I'd consider Quadraplex direct burial.

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There is a pex type roll conduit certified fir burial.

HDPE

Supervstech said:

There is a pex type roll conduit certified fir burial.

HDPE

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How fat? Can you get shorter piece? The orange stuff I've seen on trucks looks to be 2-3" at most, but that would handle it. Heck once you've trenched you could run TWO pipes.

If the controversy around grounding is from random YouTube videos of questionable provenance, you should stop watching those.

If the controversy is around maybe which flavor of NEC approved grounding config has safety advantages, ok you can talk that in circles a longtime. The EGC in the same conduit or cable is the easiest to install.

KevinC_63559 said:

Is that known for Victrons?

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Even if it’s not (unlikely to have a problem with Victron as stated above, because their standard architecture is SCC into the battery), it’s a good idea to plan for the lowest common denominator/common situation.

The most common architecture is ungrounded DC (where panel frames still need to be grounded but there is no grounded DC conductor) into a non isolated hybrid.

I buried my ground mount PV wires (2 wires) 2 ft down with rigid metal conduit (RMC) and elbows from home depot. 3/4 inch diameter. I used the conduit as the grounding conductor, you can run a separate wire instead if you want. All to code. 30 feet from array to side of barn, about 50 feet total and including upright connection to combiner box at array and to disconnect at side of barn.

The orange stuff the cable/internet companies use is 2" HDPE. Main problem is nothing will glue to it so you have to use the rubber couplings with hose clamps.

They were boring in fiber in the subdivision that surrounds my house. They gave me all their cutoffs. I have almost enough to do what I need so I have to track them down next week to get a few more pieces.

Supervstech said:

There is a pex type roll conduit certified fir burial.

HDPE

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That is exactly what I used (even UL listed) but you'd be hard pressed getting only 100 feet of it.

I drove one hour one-away to rent a trencher. Was well worth it. There surely has to be someone within hour drive who rents those. Makes for really clean trench only 4" wide. Only issue would be is if you have rocks.

Do people in rural areas put tools like this on share grid?

rhino said:

That is exactly what I used (even UL listed) but you'd be hard pressed getting only 100 feet of it.

I drove one hour one-away to rent a trencher. Was well worth it. There surely has to be someone within hour drive who rents those. Makes for really clean trench only 4" wide. Only issue would be is if you have rocks.

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Did I mention Rural. Closest town of 20,000 with a United Rent all is 20 miles away - and they don't rent trenchers. Next largest town is over 100 miles away, a town of 250,000 which probably would. Think I try the spade on my tractor - its less than an all day rental would be and I'll own it afterwards.

Really appreciate everyone's feedback

KevinC_63559 said:

Did I mention Rural. Closest town of 20,000 with a United Rent all is 20 miles away - and they don't rent trenchers. Next largest town is over 100 miles away, a town of 250,000 which probably would. Think I try the spade on my tractor - its less than an all day rental would be and I'll own it afterwards.

Really appreciate everyone's feedback

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Shovel. Seriously. I buried ~200' of 2/2/4 urd ~24" deep from the shop to the deck roof. If anyone here has ever operated a Mexican dragline, you know how hard it is to dig through hard clay dirt. The trick is wait till there is some moisture in the dirt, and to keep plenty of cool refreshments handy.

Good, or bad thing about MO, no statewide adoption of NEC. 24" is a sefety issue, it's below most burrowing animals, including man w/shovel ... usually.

If you use plain white schedule40 pvc (considerably cheaper than gray pvd) use marker tape higher up in the trench do delineate it from a common water carrying pipe. It could save someone from serious injury later. Like mentioned earlier, use the largest diameter pipe you can afford. Trust me, it comes in handy later.

Thinking out loud. Since you are here, you are most likely someone that likes to diy things. Also indicates you will more than likely be upgradeing at some future date. mppt controllers are tending to go the way of higher voltages and that's great for saving on copper. I would run thhn inside conduit as it's made for pulling, pv wire is not, add a ground run with those wires (as mentioned earlier, many AIO have some ac riding the pv inputs), and run extra wires if there might be room to add more panels to the array at a later date, because ... you have the diy bug and if more panels will fit, it will keep bugging you till more panels find their way up there.