Backfeed Breaker Solar

690 10 e plug in type back fed circuit breakers connected to a stand alone inverter output in either stand alone or utility interactive systems shall be secured in accordance with 408 36 d.

Backfeed breaker solar.

The main purpose of the fuses and breakers are to protect the wiring. Energizing wiring systems far from your setup like this can damage your equipment and the appliances being powered as well as potential for electrocution to technicians repairing power lines. The nec allows adding a back feed breaker so that the current supply is up to 120 of the rating of the bus bar. The transfer switch or interlocked backfeed breaker acts to prevent the connection of the generator while the main breaker for the panel is closed.

Article 690 requirements apply to solar pv systems. When setting up a generator to backfeed your house power can be pushed out through the main breaker to the transformer and cause unexpected high voltage. The problem is the backfeeding only happens when battery is fully charged. From there you d land your inverter s output into a 50a breaker and your done.

We sometimes see people adding a 60 or 80 a breaker instead. In my case i have 1 6kw solar but 9 6kwh golf battery system it will never get fully charged unless i choose so. So you always want to be sure your sizing your wire to handle the output of each circuit in the system. The sizing of back feed breakers is another point of difficulty.

Nec705 12 b 2 3 b states that where there are two power sources the grid and the solar inverter the sum of their breakers cannot equal more than 120 of the busbar rating of the breaker box. As noted in sec. If a 200 a busbar has a 200 a main breaker the code allows adding a up to a 40 a backfeed breaker. According to the manual backfeeding is a real grid tie system once the grid is off the backfeeding stops.