I have a Reliance ProTran2 manual transfer switch plugged into my Bluetti AC300 battery backup system which has a floating ground.
The AC300 is supposed to be used as a UPS backup system and pass grid power through the AC300 and then when grid powere goes off, it switches over to the battery. The AC300 has a switch to turn on AC output.
PROBLEM: If I plug the AC300 into grid power, with the AC output turned off, it charges up the batteries with no problem. As soon as I turn on the AC output, the GFCI circuit breaker that I have the AC300 plugged into pops. This happens no matter how I have the Transfer switches set in the ProTran2. They can all be set to Grid, neutral or Gen with same result.
If I unplug the AC300 from the grid, I can switch any or all of the ProTran2 switches to GEN and have power with no problem.
I have seen others who did the same thing without pluggibg into the grid without using a GFCI plug actually fry their AC300. The talk is that a different type of manual transfer switch is needed but no definite brand or model is specified.
We are not wedded to the transfer switch but are to the Bluetti AC300 battery backup system. I have asked the manufacturer to give me the name of a transfer switch that will definitely work and I'm waiting for a response.
The transfer switch was installed by an electrician specifically for the backup system and the backup system is supposed to be used as a UPS backup system with grid power being passed through and when grid goes out, the system is supposed to switch over to the battery.