One powerwall and ac compressor

[MrPeacock]

I’ve seen various answers on this topic so thought I would post for the latest.

My install is scheduled for next week (took almost 7 months). It’s a 9.6kw system with one powerwall. I would like to run one A/C compressor in the evening for a couple hours max. I’ve attached the compressor LRA and RLA specs below. According to Tesla’s website, my RLA (not LRA) is within 1 powerwall spec. Can I run my AC compressor off my single powerwall? Will it need a sure start and if so, will they supply and install?

Thanks!

 

[garrett5688]

I don’t think 1 PW can support anything 240v. Need at least 2, and even then HVAC is hit and miss.

 

[MrPeacock]

This page says otherwise in regards to ac compressors.

What Can Powerwall Back Up | Tesla Support

Learn more about the variety of home appliances and EV charging equipment that Tesla Powerwall can backup.

www.tesla.com

 

[jgleigh]

Your LRA is over what one Powerwall can handle. On-grid it should work fine, but off-grid it can't supply enough current to start the HVAC unit.

 

[MrPeacock]

Your LRA is over what one Powerwall can handle. On-grid it should work fine, but off-grid it can't supply enough current to start the HVAC unit.

From what I understand, the startup current is handled by the sure start device.

 

[ucmndd]

I don’t think 1 PW can support anything 240v. Need at least 2, and even then HVAC is hit and miss.

Powerwalls are most definitely 240v and can supply power to 240v circuits.

I don't think a single PW can back up a circuit greater than 30 amps though, which is more likely to be a problem here.


OP, I doubt a single PW will fire that thing up with any reliability. A sure start MIGHT help. But in any case, even if you can run it, you're probably not going to want to in an off-grid situation. 13kwh is not much storage and your AC will chew through that pronto.

It SHOULD start fine during the day when your solar is producing, even in an off-grid situation. Once the sun is down things get dicey.

 

[BGbreeder]

From what I understand, the startup current is handled by the sure start device.

Maybe it will maybe it won't. If you read enough posts here, it is clear that SureStart units don't work for many AC owners.

However, it only matters for off grid use, when you have other variables like what other power draws are present, and how much solar is active. The perhaps more pressing issue is that AC compressors are a huge, huge, energy sink and a single powerwall won't last very long.

TL;DR a non inverter AC unit on a single power is not a certain bet, and your particular unit is right at the RLA limit, and over the LRA limit (without the SureStart).

 

[cwied]

To add details to the good advice already given, check this page: Hyper Engineering | Single Phase

Sure start reduces 100A to 29A, 130A to 36A. That means your 117A LRA would be reduced to about 33A by the Sure Start, which is still over the maximum current one Powerwall 2 can deliver. Maybe a Powerwall+ would be able to handle it, but it's cutting it pretty fine.

If you realistically want to run AC during a power outage, you'd probably want at least two Powerwalls. Running your AC for two hours is pretty much going to empty the whole Powerwall, leaving you with nothing to run overnight.

 

[schettj]

I've got an AC w. LRA around 50 - it starts/runs fine on a single PW + solar (~3kw production) or PW + grid, but would not try to run it during grid outages.