MOD Micro-Air EasyStart for RV air conditioners

[texskeet]

Yes just fine. Both shore and generator .

 

[Chuggs]

Yes just fine. Both shore and generator .

Seems you've isolated the problem.

I would check the wiring between the breaker and the switch. Specifically the inverter breaker and selector switch for selcting Inverter v Main AC.

If this is good...then something is happening, and probably too quickly to catch.

Loads? Neutral?

If you have the Precision Circuits panel...with the Inverter sub bus...I would leave the Inverter 30A on...and the Air Conditioner 20A on...and flip the rest of the breakers. You're just checking to see if the Inverter can power the A/C when it's the only thing. If it runs...you may be getting the drop out on the A/C because the inverter sees itself as overloaded.

Would be nice to measure amps on the 12v Inverter feed...and the 120v air conditioner Inverter powered LINE. Also check Inverter settings...maybe something is misconfigured.

The last item I can think of is something we avoided...so I haven't witnessed it. Did you use a double poled switch? I worried the Inverter might misbehave IF the Netral Line isn't switched along with the HOT. The distribution panel has two buses for A/C Line distribuition... One for main AC and one for Inverter. Each have thier own specific HOT rail and Neutral Rail. There is a combined ground bus. The neutrals aren't joined...nor should they be.

For your AC to complete a circuit...if you let the Neutral stay on the main AC neutral rail, it can't complete the loop without coming from the AC in supply side of the inverter. I don't think the Inverter likes this. Kinda acting as a ground fault...but on the Neutral line. If yours is wired with just the 120V LINE (hot) being switched...I would try wiring it with the LINE (hot) and Neutral both being switched...so each source to air conditioner maintains continuity... Main AC or Inverter...but not half and half.

That's all I can think of now...

 

[texskeet]

I will check all of that and see Thanks

 

[Golfer Guy]

The previous owner had the soft start wired to the middle AC so it will run off the batteries. Last summer in the heat it was a very nice addition to keep the coach comfy when boondocking.

 

[Chuggs]

The previous owner had the soft start wired to the middle AC so it will run off the batteries. Last summer in the heat it was a very nice addition to keep the coach comfy when boondocking.

I'm interested...I realize temperature, sun exposure, and battery capacity all factor in...but how long could you run the A/C without hitting 50% SOC?

 

[Golfer Guy]

Good question Charlie, I really don't know. I will have to take a look at that as things warm up. I watch the battery levels in the coach closely and don't remember a time where the AC was bringing the batteries down to a critical level. With the 1200 amp hours of lithium batteries it was never an issue. Usually if its that hot there is also plenty of solar for me to use. I suppose the dometic has a chart that shows how much draw it pulls when cooling but not sure where to find that.

 

[Chuggs]

Good question Charlie, I really don't know. I will have to take a look at that as things warm up. I watch the battery levels in the coach closely and don't remember a time where the AC was bringing the batteries down to a critical level. With the 1200 amp hours of lithium batteries it was never an issue. Usually if its that hot there is also plenty of solar for me to use. I suppose the dometic has a chart that shows how much draw it pulls when cooling but not sure where to find that.

Yep...1200aH of LiFePO4 is sweet!... You don't waste as many aH to resistance at high amp draw and have more useable aH by a massive margin.