Inverter overload - strange problem

[Simonbr]

I have an Aims 24v 3000w inverter charger with a 420ah battery bank. Everything works great either in inverter mode or when the inverter is in charge/bypass mode with my Yamaha 3000efi inverter generator.

When I use my air conditioning unit (it has a hard start kit) in inverter mode the system works well, pulling about 64 amps. When I start my generator, my inverter kicks out and goes shows "Over load Alarm" and resets back into inverter mode. Of course since my generator is still running, after a few seconds it goes back into charge/bypass mode and does it over and over. If I connect my generator directly to my RV, the AC runs no problems.

Any thoughts of what can be causing this? I’m in contact with Aims but they aren’t too sure either and are suggesting things for me to try, which I`ve already performed.

 

[DIYrich]

Turn off eco mode on your Generator? Also, the rated output of your generator is 2.8kW continuous.

How does it work if the generator is on, and then you turn on the AC?

 

[Simonbr]

If the generator is on straight to the camp and I turn the ac on it works. If it’s on feeding the inverter in bypass/charge mode, that’s when the inverter trips. I tired to turn off eco mode too, same results. The generator doesn’t trip or anything, it’s the inverter that goes into overload for a second, if it was the gen wouldn’t it trip?

 

[740GLE]

What size AC? 64a at 27v 15-1600w, but what’s the inrush of the unit?

My guess is the inverter charger is looking to the Genset to help with inrush, and the Genset takes a second or two provide good suply then repeats. The inverter charger just needs a slightly longer delay to deal with that inrush.

How long can you run the AC on battery alone? With an undersized generator for inrush it might be just battery or Genset only.

 

[Vigo]

I believe most inverters which have an ac ‘passthrough’/bypass function have some version of this silliness, which is to say it will be picky about the AC input on initial switchover, but once switched over will be very tolerant of imperfection. So, for example, i can set my Growatt inverters to either ‘appliance’ or ‘ups’ mode and the main difference is how ugly it will let the ac input get before it abandons it and switches back to battery. I believe on appliance mode my 240v inverter will let the ac input sink to something like 90v before giving up on it! But it will NOT switch over to it in the first place unless it is pretty close to 240v/60hz. Thats just an example but its probably what your inverter is doing, being picky about a sudden change in the waveform that occurs when you dump load instantaneuously on the generator. If you dont have some kind of equivalent ‘applicance/UPS’ setting then you’re stuck with the picky programming youve got and the only practical solution is to manually reduce load during the switchover.

 

[Solar Guppy]

You need a soft start, not hard start kit. Hard start actually make it worse in these conditions you describe.

This explains why

 

[740GLE]

If the generator has an eco or quiet mode make sure and disable it for this. For example if an inverter generator is ‘idling’ it will be spinning the engine at a low rpm that can probably support no more than 1/4 of its peak watts rating. When you suddenly present it with a large load it has to increase

Ours (Wen open frame 3k) on eco mode can support almost full load it just takes more time to ramp up. This ramp up time is prob what’s messing with the inverter charger ATS.

Also I’m curious at how the ATS handles a large load with a Genset, is it still trying to charge the battery? Is the grid support draw adjustable?

 

[seneysolar]

I have an Aims 24v 3000w inverter charger with a 420ah battery bank. Everything works great either in inverter mode or when the inverter is in charge/bypass mode with my Yamaha 3000efi inverter generator.

When I use my air conditioning unit (it has a hard start kit) in inverter mode the system works well, pulling about 64 amps. When I start my generator, my inverter kicks out and goes shows "Over load Alarm" and resets back into inverter mode. Of course since my generator is still running, after a few seconds it goes back into charge/bypass mode and does it over and over. If I connect my generator directly to my RV, the AC runs no problems.

Any thoughts of what can be causing this? I’m in contact with Aims but they aren’t too sure either and are suggesting things for me to try, which I`ve already performed.

Did you get this to work?
I have a similar setup, but with a 4k Aims and Yamaha 3000.
That inverter has a small adjustment screw for charge rate right on the face. With a small generator you will need to turn it down or un load the inverter. The inverter witll try to pass through the loads to the generator AND try to charge batteries. 3k inverter and 3k generator, theres not enough power left for the charger if the rate is on max.