Is there a electrical reason for two+ PowerWall 2s vs PV system size?

[3laine]

Peak PW output is 7,000 watts or less than 30A at 240V. Keep in mind that is for all loads , so your AC inrush (LRA of compressor and fan) plus all other loads would need to less than that 7kW.
https://www.tesla.com/sites/default.../Powerwall 2_AC_Datasheet_en_northamerica.pdf

Thanks! I guess I'll just try to keep the A/C at ~20A or less so if I'm running the fridge and a few LED lights, it will still be able to start up.

 

[mongo]

Thanks! I guess I'll just try to keep the A/C at ~20A or less so if I'm running the fridge and a few LED lights, it will still be able to start up.

There are AC system with variable compressor speeds and even inverter drives that are more solar/ power wall compatible. That would be my suggestion if you are getting new. There may also be a compatibility list out there somewhere...

 

[NuShrike]

Bringing this back from the dead, but hoping you can answer my question!

I'm about to buy a new AC system, but want to make sure I could run it with a single PW2. Problem is, I can't find the actual specs for max LRA for a single PW2. I know it's ~30A, but want to find a definitive number and haven't had luck with that.

Thanks!

As Mongo already replied, just do the math for max 7000 watts at voltage. The HVAC compressor is probably running at 204V, which needs some amperage translation to 240V, or just check the wattage.

Just absolutely stay below 7K watts. Subtract some watts for safety buffer.

 

[3laine]

As Mongo already replied, just do the math for max 7000 watts at voltage. The HVAC compressor is probably running at 204V, which needs some amperage translation to 240V, or just check the wattage.

Just absolutely stay below 7K watts. Subtract some watts for safety buffer.

Thanks. I'm working with my AC guy, now, to make sure I get something that will work with a future single powerwall if necessary.

 

[JHellow]

I have two PW2s, but also two AC systems. The 4t compressors (Carriers) are the newer variable type and have very low initial draw. No problems so far running them off the PW2s.

 

[JohnRatsey]

"Inverter" may be the keyword in the AC spec. This means variable frequency drive which both enables the system to build up speed progressively and avoid any initial power spike but also, as the actual temperature converges on the target, then the system slows down, reduces the output and avoids the off-on-off-on... behavoiur of older systems. I've only got a small A/C / heat-up with this technology but I've been impressed by it.

 

[NuShrike]

"Inverter" may be the keyword in the AC spec. This means variable frequency drive which both enables the system to build up speed progressively and avoid any initial power spike but also, as the actual temperature converges on the target, then the system slows down, reduces the output and avoids the off-on-off-on... behavoiur of older systems. I've only got a small A/C / heat-up with this technology but I've been impressed by it.

My new linear-drive LG fridge works like this. It draws half daily of what my old Amana fridge did, even though it's almost running constantly (at ~2x to 4x network-router wattage levels of < ~100w), while having more capacity (30 cu ft).

I'm sure variable-compression HVACs is the thing to get for on/offline full-compatibility with home-battery systems.