You are supposed to turn the EMS unit off when using inverters.
That is now in Progressives manual, it was not in my manual and I had a circuit board go bad because I tried an inverter with the trailer.
What is not in the manual, and I did not get an answer from Progressive, is why can't I use traditional DC battery supplied inverter but I can use a gasoline powered inverter generator.
Generators work by using mechanical rotation with magnets and wire to produce AC voltage, which gives us 120 volts AC providing the rotation is a constant 3600 RPM, regardless of load (there are a couple of units out now that will run at 1800 RPM). The output may be filtered to clean it up.
Inverter generators produce more electricity per revolution the standard gennys. This raw output is unusable as we know it so it is transformed into DC power. This DC power is then inverted to the 120 AC as we use it. Because the initial output is significantly higher, the engine does not need to spin at 3600 RPM, so it spins only as fast as is needed for the current load. This makes the inverter gennys more fuel efficient and because of design, quieter.
Still doesn't explain though why I can use my Honda 3000IS but not use my Heart Interface 3000 through the Progressive EMS.
My Yamaha inverters weren't throttling up quick enough and the relays in the EMS would chatter like mad. Once in a while I still get that just a little.
I occasionally get the chattering with my 3K Honda inverter generator
Maybe you could rewire the transfer switch and EMS places in the incoming power system to allow power from the generators to bypass the EMS. By this I mean the shore power connection feeds the EMS, which outputs into the transfer switch. The transfer switch would also have a separate input connection from the generators. Power on the generator line would initiate the transfer and disconnect shore power via the EMS. Output from the transfer switch goes to the circuit breaker panel. Then generator power would not be going through the EMS.
The Progressive EMS simply uses a cut out switch on the panel to allow portable generator use, if needed.
I don't see a need though, I have used my Honda 3K many times with the trailer, initially in the bypass mode and now using the full protection of the EMS by bonding the neutral and ground of the generator.
The EMS would not allow the generator to pass through as it saw the open neutral ground bond.
