Solar Panel System

RNeumann · Jan 9, 2017

Ok perfect you have a lot of your info. The utility will pull 1 smallish wire to the transformer and then 3 large wires to your panel. You can do grounds outside. In that case it's 2 rods 8' long and 10'apart (verify distance). Those can be added later. I suggested the ufer as it's easier for most to just bury the rebar before you pour the concrete.

I want to make sure to provide good info here so let's make sure we all understand. The utility will install a transformer and then pull wires to the meter which is on the house? You are then wanting to take 200a to a guest house and 200a to the shop? Is this correct? The 3" you are asking about is the 200a leg to the shop? If that is the case 3" would work fine. You could run copper or aluminum THHN wire in that. In fact you could run smaller conduit if you wanted.
Interesting to note the utility is wanting 4"'conduit for the wires they are running....way oversized! They have much lower wire size standards and don't have to run 4 wires like you would.

Pettrix · Jan 10, 2017

RNeumann said:
Ok perfect you have a lot of your info. The utility will pull 1 smallish wire to the transformer and then 3 large wires to your panel. You can do grounds outside. In that case it's 2 rods 8' long and 10'apart (verify distance). Those can be added later. I suggested the ufer as it's easier for most to just bury the rebar before you pour the concrete.

I want to make sure to provide good info here so let's make sure we all understand. The utility will install a transformer and then pull wires to the meter which is on the house? You are then wanting to take 200a to a guest house and 200a to the shop? Is this correct? The 3" you are asking about is the 200a leg to the shop? If that is the case 3" would work fine. You could run copper or aluminum THHN wire in that. In fact you could run smaller conduit if you wanted.
Interesting to note the utility is wanting 4"'conduit for the wires they are running....way oversized! They have much lower wire size standards and don't have to run 4 wires like you would.

I already did the Ufer Ground in my rebar footing.

Yes, the utility will install a transformer about 80' from the house and then pull the wires to the meter on the outside of the garage. I will then take 200 amps to the guest house and the remaining 200 amps will be pulled to the future main house about 150' away.

The 3" conduit will be used for the 200 amps going to the future main house.

RNeumann · Jan 10, 2017

You are in good shape with 3" with either aluminum or copper.

prichard · Jan 10, 2017

I thought you were asking what you needed for the 400A. As RN said, you're good to go.

prichard · Jan 10, 2017

BTW, it's very common for utilities to require oversized conduit. Telephone companies used to require 2" conduit for a cable that was less than 1/2".

RNeumann · Jan 10, 2017

prichard said:
BTW, it's very common for utilities to require oversized conduit. Telephone companies used to require 2" conduit for a cable that was less than 1/2".

Yep in my current location the phone company requires 3" conduit to their box. Our work around is to have the phone company put their box near the property line and then we run 1" or 1 1/4" conduit to the house. It's only one cat5/6 line normally- which is good up to about 350'

Pettrix · Jan 10, 2017

So I can install a solar panel system later on by tying into the outside meter connection. I just wanted to make sure I don't need to leave an open sleeve in the concrete wall for future access.

Pettrix · Jan 10, 2017

Another ridiculous thing is the utility company wants me to put 6" of 1" minus shading over the SCH 40 conduit. That's completely unnecessary. I've buried SCH 40 PVC pipe with native soil that had large rocks in it. One just has to push the soil back on top and not DROP it from a high height. SCH40 is tough pipe and a large rock sitting on top of it will not puncture it. A large boulder dropped from 10 feet might crack it.

RNeumann · Jan 10, 2017

Pettrix said:
So I can install a solar panel system later on by tying into the outside meter connection. I just wanted to make sure I don't need to leave an open sleeve in the concrete wall for future access.

I read up on Tesla's system a year or two ago so I'm going off memory- from what I recall they mount a large lithium battery to a wall (like in your garage) that is 480v DC. From their they transform that to AC and lower the voltage to match the utility. When I looked at it a lot of the details were not worked out.

I'm assuming Tesla will provide some specs for what they want.

As far as the solar I would add a 3" conduit about 4' -6' from the utility conduit on the same wall. That will allow the the solar to enter the structure and tie in as needed to either the Tesla setup or the main panel- depending on how Tesla wants it setup- I'm guessing it's into the Tesla side.

Are you doing the electrical? Is the main panel going on the outside with a sub-panel on the inside? Or is the main with all your breakers going on the outside? I'm guessing if you want conduit in the concrete something is going on the inside?

As far as the utility conduit- they have their ways...shaking my head. Not much you can do other than say OK.