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'whole home backup' confusion

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I recently had a system installed (16kW, 2PW+, backup gateway 2) and all of my paperwork references 'whole home backup'. Basically, they pulled all of my loads from my main panel into a subpanel connected to the gateway. The only breaker in my main panel now is a 100A going to the gateway. What's odd to me is that they had me upgrade my main panel and service (which required significant trenching and $$$) from 100A to 200A, but they're only feeding this subpanel (which is capable of 225A) with 100A. There are several new loads I'd like to add in the coming months (EV chargers, electric dryer, water heater), which my project advisor was aware of, but there doesn't seem to be the bandwidth to support these in the subpanel. Am I mistaken? Should I ask Tesla to update the wiring/breaker to 200A?

My understanding (which may be wrong!) is that in order to be powered by my PV system or PWs when the grid is out, loads would need to be in the subpanel as no electricity would flow to the main.

I've included the wiring diagram below. Any insight would be much appreciated.

Thanks!


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If I ever get such an unenthusiastic OK, I stand there and watch them and don't let them leave until I'm satisfied.
Luckily, my new solar install went very smoothly. Unbelievable 12 days from start of install to PTO. Just don't ask about the 10 months from signing the contract to completion.


Yeah, I got a 18 month old that I need to feed and get to nap time. Only retired people like @h2ofun can pull up a lawn chair, beer, and watch for hours hah.
 
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@holeydonut "Yeah, what he said." @Vines summed it up beautifully. PG&E is on the issue correctly here in my view.

You should have grounds across your water heater, down to the gas line there, and a wire run back to the house ground rod near/by the main service panel which is grounded at that point as well. In an ideal world, everything else, the phone line, your cable, internet and your whole house surge protector grounds are all bonded at that same point. IIRC, code now requires two ground rods spaced at least 6' apart, but notes farther is more effective. The NFPA 780 wants it farther apart than the length of the grounds. I don't know about the spacing from an Ufer connection (grounding via the rebar in a concrete foundation, a far more effective ground for a variety of reasons). Books have been written about effective grounding, and in locations with frequent rainfall, and damp soils, it generally isn't much of an issue. Dry soils, and soils with complex chemistry can be remarkably poor grounds, without additional actions.

@Vines, @wwhitney is it true that the current NEC doesn't require a ground rod if an Ufer ground is used?

I think that the partially buried wire and clamp is probably PG&E's dielectric anode to keep the gas line from corroding. While newer lines are plastic as @miimura points out, older lines are not.

Your CCC inspector seems not only not to understand this part of the code, but also not to understand the theory behind the code. Presumably, as you have passed the CCC code inspection, PG&E's request can be attended to without finger pointing.

Good luck.

All the best,

BG


You'll be pleased to learn that a new Sunrun tech came out today... and we learned my house actually has a Ufer that is in the common wall that has my main service panel, gateway, and Powerwalls. The Ufer is visible only if you pull back a funky cover that I never thought to open up. The folks that did my main service panel replacement and installed the neutral-bonded-to-ground actually did tap into this UFER using some stranded #6. The water line coming into the house is also grounded to this Ufer.

I guess when the CCC inspector was at the house, nobody actually knew how to prove the stranded #6 was attached to the Ufer. So this may be why the CCC inspector made Sunrun add two grounding rods, and add bare/solid #6 from the Gateway and the Main Service Panel to those two new grounding rods. And of course that same inspector made them tie all this stuff to the gas riser because... who the hell knows.

This entire thing is total crap. I guess you can't actually ground a main service panel with stranded #6. But the bare/solid #6 isn't allowed to be strapped to the riser.

Anyway the Sunrun guy just removed all the bare #6 and left. He said the stranded #6 from the MSP and Gateway are connected to the Ufer, so that's the best we're going to get.

All I know is... Ufer, grounding, and neutral-to-whatever is the most inane topic I've come across. Even more inane than bollards.
 
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