Question about .5A Breaker

Re: Question about .5A Breaker

As vtMaps says--The 0.5 (or 1-5 amp) breaker is between Battery Return (typically negative lead) and Earth/Safety/Green Wire Ground.

If there is a Hot to Safety Ground short, the 0.5 amp breaker trips which then opens the ganged 63 amp breaker too which is connected to the + to the solar array (or in newer Outback drawings, I understand the 63 amp breaker is between the charge controller and the battery bank).

The intent was to reduce the chance of Arc Faults in the solar array (short circuits in PV circuits tend to produce steady arcs instead of "popping a breaker or a fuse). This was a first past NEC attempt at "solving" the Arc Fault problem in solar arrays.

Personally, I think a fuse/breaker between DC Return and Safety Ground (+earth ground rod) is not a safe thing to do.

There are some devices (such as newer Midnite Classic MPPT controllers) that have Arc Fault detection circuitry that can shut down the current flow if there is an Arc Fault detected--But this is not widely implemented at this time, nor a 100% fix either.

-Bill