Two AC300s in Split Phase not able to run my central air

Yeah, so… Not sure what’s up. Maybe I wasted twenty thousand dollars for a giant paperweight that I eagerly waited 6+ months to arrive.

I have 2 AC300s and 8 batteries. All the accessories. Etc, etc…

So, I tried powering my central air today in 240 volt mode. Turns out when I try, the Fusion Box shuts down (I assume due to too many watts). Shouldn’t I have like 12,000 watt surge? And 6,000 watts continuous?

I should be able to run central air, right? Nothing else was running (all other breakers flipped off).


How large is your AC? I don’t think a typical home AC should exceed 6000W. The 12000W surge is for a fraction of a second only, not all that useful. The instruction has the specs, but I think it can take like 8000w for a few seconds.

Sometimes when an AC is powered and shut down, it is under pressure and will take more to start. Maybe wait 15 min and then try again?

Still I would expect 6000w to start it even with startup surge.

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I once measured the inrush current on one leg of my homes heat pump and it was over a 100 amps. No idea how long the surge lasts since my clamp meter only keeps the highest reading but its long enough to notice the lights in the house briefly dim as the compressor kicks in.

I started looking into a soft start module but found out they won’t work with my Carrier unit.

It might be worth checking out for your system. The EasyStart 368 Soft Starter For Residential Home Units By Micro-Air, Inc.


You may need to get a soft starter device for your AC so it doesn’t have that surge required to startup.