This is sometimes confusing
I will describe two line setups
Inverter----EMS(Surge Protector)----RV
Park Pedistal---EMS(As above)----RV--Sub branch--Inverter--Sub panel--Sub-sub loads
The first is a DO NOT, (With exceptions) the second is the proper way
In short DO NOT plug the EMS into a MSW inverter.. It won't pass MSW and may be harmed by it.
With TRUE SINE inverters.. I am withholding comment other than the fact is. it is not needed.
The EMS is supposed to protect you against High/low Voltage or frequency or bad waveform (MSW inverters) in some models.
With an TSW inverter all it is going to do is waste power.. So do not use it, The reason for this is the frequency is set by a very solid reference (likely crystal) and likely will be as good as or better than a good power company.
Likewise if the voltage goes out of range the inverter itself will shut down (or should). So the EMS is just going to sit there and suck a few watts.
However none of that really applies as we do not normally plug our RV's into an inverter (Unless it is an INVERTER generator and those are TSW) (And some models do not have that good a voltage regulation) . Inverters INSIDE the RV you won't be plugging the EMS into, you will be plugging them (Via the RV's shore cord) into the EMS. That is allowed.
