I need help deciphering Tesla diagrams

[dareed1]

Redesign? I don't think you had mentioned a need to redesign. What's driving it?

 

[holeydonut]

Install scheduled for June 7 and my redesign isn't done yet. When do I panic?

June 7? I think you're still fine with many weeks left to go. But yeah, what did you re-design? Or did they just make a few small tweaks?

Technically your installers can do an "as built" permit submission after the fact assuming they had to make changes to the initially permitted design because of some factors discovered during the install. I think the plan you already shared is looking pretty good.

So I can't imagine your installer having difficulty on June 7 unless they end up having to replace your main service panel or encounter something totally unexpected.

 

[SMAlset]

Three powerwalls are 30 amps each or 90 amps. Houses do tend to average about 70 amps, you can actually get some sort of amp meter, turn on everything in the house, and go hold it up in the main panel and see.

There are many threads on here about how two PW's (60 amps) may or may not get AC startup done. I am not aware of any AC units where people with three or more PWs had any problem.

Unless there is something special about your house, with three PWs they will go for whole home.

The rest of the calcs are highly technical which is why only electricians or electrical engineers understand them fully.

The rest of us sort of speculate.

We have 3 PWs and an old Carrier 5ton 10SEER AC unit (think a 2004 mfgr date) with a big start up draw for our 3800sqft 2-story home and it runs fine on our system with the extra controller they added to the outdoor unit (forgot the name). Fortunately this large unit used the scroll wheel, whereas their smaller ones did not.

BTW take a photo of your present main panel showing type of loads and breakers used. Before everything is done with your install, compare it to the new panel set up to make sure you have like-for-like and question any deviation you see.

 

[SMAlset]

....Some members here are finding that Tesla's installers are putting stickers that read "do not add loads" to the new panels during their installs. Naturally such a sticker could make a future electrician think twice about adding a load. In my case I am having a tough time finding an electrician who will touch a whole home backup out of legal-fears; and I don't even have warning stickers about adding loads.

Wonder if a Tesla approved installer for EV charging would have the same issues? Oh but almost forgot you went with Sunrun for the install. Shouldn’t Sunrun who did your electrical plans be the ones to be able to make any changes?

 

[holeydonut]

Wonder if a Tesla approved installer for EV charging would have the same issues? Oh but almost forgot you went with Sunrun for the install. Shouldn’t Sunrun who did your electrical plans be the ones to be able to make any changes?

Yeah, I had a few issues even with installers that came up on a search here:

Find a Certified Installer | Tesla

Tesla partners with local installers to install Wall Connector, Powerwall and Solar Roof. Find Tesla Certified Installers for an estimate, timeline and more.

www.tesla.com

It's not that they wouldn't install the wall charger, it's that they wouldn't land the breaker on the backup side of the gateway. And they definitely wouldn't run a CT upstream to where they put the breaker, so the Gateway would never be able to sense any energy consumed by the HPWC. It just makes more sense to get the EV in before the PV+ESS to avoid this weird hiccup.

 

[charlesj]

...

PS. before you approve this design, see if they can replace the conductors with the (8) circle to #8 AWG instead of #10 AWG. @h2ofun would be pleased.

He must have had a long run of wire to be concerned with IR drop in wire.

 

[VickiSoCal]

Yes, sorry I think I did not update, when I finally got someone on the phone, and discussed the current design they said a whole house backup would be a redesign and I should be getting revised schematics.

 

[holeydonut]

Huh I wonder how the previous/old design was not a whole house backup. It's a good thing you did the work to make sure you're getting the system that you want.

 

[dareed1]

The original layout in the OP looks like whole house backup to me. One possible way to find out the reason for the redesign (or to find out that they aren't in fact redesigning) is to ask them to delineate, using the original design, which circuits would be energized by the PWs during a grid outage and which will not. That avoids the jargon of "whole house backup".

 

[VickiSoCal]

We are up and running. They left everything turned on, so we have not purchased any electricity from the grid in 5 days. Hoping inspection and PTO goes smoothly.
They are supposed to be sending a guy to reinstall our rain gutter downspout.

 

[SMAlset]

We are up and running. They left everything turned on, so we have not purchased any electricity from the grid in 5 days. Hoping inspection and PTO goes smoothly.
They are supposed to be sending a guy to reinstall our rain gutter downspout.

Congrats! It's so nice to run your house on solar power during the day and battery at night and refill the battery when sun starts coming up again. We've been charging our cars as well. BTW what did you do about a future EV load?

An aside, love the stacked brickwork on your house!

 

[arnolddeleon]

We are up and running. They left everything turned on, so we have not purchased any electricity from the grid in 5 days. Hoping inspection and PTO goes smoothly.
They are supposed to be sending a guy to reinstall our rain gutter downspout.

I see Tesla painted your conduits as they did mine. My sister's install which was done 2 days ago doesn't have painted conduits (don't know if they're coming back for it).

 

[VickiSoCal]

I had paint on hand from a previous project. Not sure what they would have done if not.
They said it would be easy to add EV later?