Outside conduit

[JJJJ]

Starting to consider the next phase of the project. Installing ground mount panels and connecting them to the system

There is a lot on line about line depths. Metal conduit requires less depth but might have water concerns?

PVC is more robust but burial depth is 18 inches if I read things correctly.

Someplace I thought I read that if the line is encased in concrete that the burial depth is not as much.

@FilterGuy is up on the NEC. I would also be interested in hearing that perspective.

Considering options before I do anything.

 

[EastTexCowboy]

Starting to consider the next phase of the project. Installing ground mount panels and connecting them to the system

There is a lot on line about line depths. Metal conduit requires less depth but might have water concerns?

PVC is more robust but burial depth is 18 inches if I read things correctly.

Someplace I thought I read that if the line is encased in concrete that the burial depth is not as much.

@FilterGuy is up on the NEC. I would also be interested in hearing that perspective.

Considering options before I do anything.

I can't see putting metal conduit in the ground but maybe there are scenarios where it might work okay. I used pvc conduit and went about 18 inches but then I'm rural so there are no compliance issues. The warning tape is a nice option if your concern is damage from future digging/construction. I didn't think about adding that until I was already done, but mine is only about a 60 ft run underground.

 

[JJJJ]

And then there are times I wonder if a Nema outlet attached to a 50 amp extension cord rated for generators and motor homes would be simpler. It is about 25 to 30 feet to the backyard site.

 

[EastTexCowboy]

And then there are times I wonder if a Nema outlet attached to a 50 amp extension cord rated for generators and motor homes would be simpler. It is about 25 to 30 feet to the backyard site.

Simpler for sure. I know I would almost certainly hit it with the mower somewhere down the line.

 

[timselectric]

Depth of conduit also depends on the voltage.
Under 125v can be at a minimum of 12". Everything else is required to be at a minimum of 18". If passing under a driveway the minimum is 24". (Only at the driveway portion)

 

[chrisski]

And then there are times I wonder if a Nema outlet attached to a 50 amp extension cord rated for generators and motor homes would be simpler. It is about 25 to 30 feet to the backyard site.

The 6/3 SOOW I was looking at is rated for 600 volts and $8 per foot.

I wish I knew what type of cable our the 240 volt power connectors at work are. Those have been in the sun for 35 years.

I’d rather get 3 pieces of 10’ PVC conduit and bury it.

If passing under a driveway the minimum is 24". (Only at the driveway portion)

I am on my way out to fix a leaking irrigation line under the driveway. I hope its not that deep.

 

[JJJJ]

6/3 SOOW I was looking at is rated for 600 volts and $8 per foot.

6/2 should do it since it also includes a ground

 

[timselectric]

I am on my way out to fix a leaking irrigation line under the driveway. I hope its not that deep.

Water lines only need to be below the frost line if they will have water in them when it's freezing out.
In my area irrigation lines self drain when not in use.

 

[timselectric]

I wish I knew what type of cable our the 240 volt power connectors at work are. Those have been in the sun for 35 years.

I use type W cable in exposed industrial locations.
That's probably what they also used. Either that or type SOOW. which is also rated for high abuse.

 

[timselectric]

6/2 should do it since it also includes a ground

Actually, cords include the green conductor in the total count. (6/2 would only have a black and white)
And yes, it can get confusing. lol

 

[Hedges]

I used rigid steel underground where necessary, above ground for most of the length.
Any underground conduit, wire has to be rated for wet. Mine I think is always full of water.
Steel, 12" under, PVC 18" under.
If PVC is exposed, it will heat and cool and rip apart glue joints or break fittings. Maybe a meander or "S" shape would allow expansion. You can buy fittings with O-ring slip joints.

 

[JJJJ]

 

[sollap]

That's wire. The ground doesn't get counted. In cord, it does.

 

[Skypower]

That's wire. The ground doesn't get counted. In cord, it does.

Just when I thought I had a grasp on things

 

[JJJJ]

Same here

 

[timselectric]

Yup
It's the cable versus cord fiasco.
But there is a reason. Green isn't always a ground in a cord. Cords are used for many controls.
There are types of cables that are the same way, also.

 

[JJJJ]

Understood. Still wiping the egg off my face.... sorry, still learning

 

[Hedges]

Gotta be careful about "ground" wire being a different gauge. Also not separately insulated in many wire types.

I have a 4-wire 120/240V + ground extension cord I've been using for 3-phase. It has a 4-wire "trailer" connector bundled to it (was meant for generator control), so I am able to use it for 3-phase L1/L2/L3/N/G. The "N" I use for 3rd phase, the "G" for neutral, the extra 4 "trailer" wires for ground. Only for temporary test setups.

 

[JJJJ]

"ground" wire being a different gauge

I've noted that. It is not uncommon for the ground to be 8 awg.

Looking at things, the SOOW and W are much better quality!

 

[JJJJ]

It's the cable versus cord fiasco

Learned this the expensive way with indoor wire. Spent more than I needed.

Now to rethink for cord....

 

[mountkay]

While I did most of my systems installation myself, I did hire a solar installer to make a planset for me so I could be sure I was doing everything up to code. I consider myself very lucky I was able to find someone that would draw up plans for me while allowing me to do the installation myself (although he did help me with insallation for about 15 hours).

If PVC is exposed, it will heat and cool and rip apart glue joints or break fittings. Maybe a meander or "S" shape would allow expansion. You can buy fittings with O-ring slip joints.

They make an "expansion joint" for this purpose. It has the ability to slide over itself to deal with PVC expansion. This was indicated on the planset I got. Not sure if it is required by NEC.

PVC is more robust but burial depth is 18 inches if I read things correctly

For my underground PVC, I used Schedule 40, for above ground and when coming out of the ground I was required to use Schedule 80 pipe. I believe that is because the Schedule 80 can handle UV.

Any underground conduit, wire has to be rated for wet

I used #10 THWN-2 wire. Different from THHN. I believe the W in THWN stands for wet. This exact type of wire was indicated to me in the planset.


.. my system was designed so it would be up to code in New York state, for last year. Not sure what version of the NEC we had adapted at that point.

My trench probably wasnt 18" but I did put some warning tape above it. I just took a picture of it to show the electrical inspector if he asked, but he never asked about the depth or warning tape. Not sure if the warning tape is part of the NEC. The planset said I had to go 18" with Magnetic Warning Tape, but im pretty sure I asked the installer who wrote the plan for me and he said regular warning tape was fine.

 

[Hedges]

Sand backfill is another indicator for someone trenching.

 

[CoolWill]

Depth of conduit also depends on the voltage.
Under 125v can be at a minimum of 12". Everything else is required to be at a minimum of 18". If passing under a driveway the minimum is 24". (Only at the driveway portion)

It can be 12" if it's 120 volts or less and GFCI protected, max 20 amps. Residential driveways only require 18" depth.