On page 35 of “Wiring Unlimited”, there is a note about not breaking the negative connection between 3 phase and/or parallel inverters when there is a VE Bus comms cable still connecting the inverters. The reason for this is that “it will cause a current in the negative signal of the data cable. This current can damage the inverter/charger’s communication chip.”
Wiring unlimited offers this diagram of how wire, and how not to wire inverters in this scenario:
In Australia, it is common practice to offer an isolator for each inverter, as well as a main battery isolator. To meet Australian standards, this isolator must be double pole, breaking both the positive and negative.
One suggestion I have heard is to independently connect the negatives of each inverter before the isolator, with a small inline fuse:
I’d like to get people’s opinion on this workaround. Can you see any problems with this approach, either from a functional or standards point of view?