Do my panels need Double Pole breakers? If so, why?
So for some years now, I've had all my parallel panels on my van, protected against a short circuit dump by running the positive of each through their own 10A breaker, just before the controller
Today, I had someone inform me however, that this is a No No - all floating panels (ie negative not grounded) in strings of 3 or more must have Double Pole breakers (ie on + and - ).
When I pressed him on why, got the usual "Er....um...safety...best practice...regulations say so", but nothing in terms of a technical explanation as to WHY you need both lines cut?
I've been hunting all day and can't find anything conclusive, jut a lot of equally vague references about how this is the done thing with 'ungrounded' panels.
Can anyone explain the actual hazard mechanism behind having only a single breaker per string, on the positive line?