Connecting Photovoltaic Power into Building

[richanton]

We are testing some solar panels and are trying to backfeed about 600 watts of power into our system through an existing GFCI receptacle. The GFCI keeps tripping. Grounding is installed per manufacturer, but inverter is 240 volts AC output and is passed thru 240/120VAC transformer before connecting to receptacle. I wonder if that could be an issue.

 

[waross]

More likely your GFCI doesn't like the wave form of the inverter. I had issues with GFCI receptacles FED from an inverter. Worked fine on normal power but were liable to trip when the power failed and the inverter took over. The longer the conductors, the worse the effect was.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[richanton]

That's interesting. Our cable is pretty long, about 75' of extension cord.

 

[rasevskii]

It would be better, for test purposes only, to connect the 240V directly to a spare 2-pole breaker on your main panel, bypassing the GFCI. This is assuming that you are in N. America and have a 120/240V single phase supply. Of course this is not according to any code to connect an extension cord this way. A short circuit at the far end of the 75ft cord may not trip the 2-pole breaker, and you will have a fire on your premises, possibly.

The breaker would have to be only a 3 to 6A size, unlikely an available item. Fuses a better option. The risks involved are yours and not inconsiderable. It cannot be seen as any kind of permanent installation until redone according to the NEC which may require a GFCI on the circuit.

rasevskii