Many of the inverters I have seen, and
I have not seen them all...
The switch operates some 'stuff' in the inverter. The 'stuff' is of no consequence.
That tiny switch is not handling 500A from the battery!
The 'remote switch' can operated from a phone cord, on most.
The phone cord can not handle 500A either.
The dump controller can operate a very small relay, closing a switch... like the inverter remote control switch closes, turning on the dump load.
The hystersis between the dump load controller On and Off will need to be high.
A homebrew controller can do that easy enough.
I hear some inverters can NOT be turned On with a load connected, but I never saw one that I am aware of. (maybe the very large / expensive / 'sleep mode' style)
Really... What's the point of a remote control switch?
So I can turn the inverter on, then run to the inverter and plug in the load, then run back to where the inverter remote and the load are located, and then turn on the load?
A rapid cycling heating unit on an inverter can't be a great idea.
Hystersis should be 'quite high' I believe, and a 'On' timer (say 30, 60, or 120 seconds minimum per cycle) may be a good idea.
It would be as simple as turning on a LED for 30/60/120 seconds when the battery reaches a cetain voltage.
The LED would simply be replaced with a small relay, the relay would replace the inverter switch.
A basic and simple hack if the inverter and dump load controller are compatable with the concept, and each other.
G-