I have a Phoenix Inverter Compact 2kVA which I have been using satisfactorily for over two years and am now wanting to use my BMV-700 to provide auto cut-out to protect the batteries from excessive drain.
The short question is: can I directly wire the BMV-700 relay into the Phoenix remote switch terminals to achieve this or should I use a further external relay between the two?
The longer background to this is … I changed the DIP switches in the Phoenix to select remote switch operation and wired in a simple manual on/off switch to the terminals on the circuit board. Using this manual switch, the system continues to operate as it has done since 2017. When I replace the on/off switch with the BMV-700 relay, the Phoenix starts up ok (with minimal load of just my internet router), but when my fridge is turned on there is a large, prolonged power drain (c. 1kW) from the batteries (as observed on the BMV-700), the inverter fans start up for a couple of seconds and then the inverter auto powers off (the BMV relay remains on). If I revert to the manual switch everything is fine again (there is of course a very brief power surge when the fridge starts, but it settles to the 100W steady state within a second or so and the inverter fans have no need to activate). I have repeated this three times, each time the fridge causes this large power drain with the BMV but there is no problem with the manual switch. This makes no sense to me!
Any help or thoughts appreciated!