Solar Panel Circuit Breaker Size

Nec requires the breakers be sized at 125 of the inverter s rated output.

Solar panel circuit breaker size. This happens to be a standard breaker size. From there you d land your inverter s output into a 50a breaker and your done. This box accommodates 3 x 1 wide single pole or double pole tandem breakers. That requires a 40a breaker 32a x 125 40a.

A maximum output current of 16a multiplied by a 125 percent safety factor equals 20a. If the panels are connected in series the voltage of each panel is added but the amperage stays the same. So a 7680w inverter that outputs 240v outputs 32a 7680w 240v 32a. The general rule of thumb is that circuit breaker size should be 125 of the ampacity of cable and wire or the circuit which has to be protected by the cb.

This is defined as 20 of the overall home s service rating. This provides for a 30a input from the inverter and 3 x 15a 1 x 20a load circuits. 200a x 1 2 200a 40a in this example the maximum output of our pv system can be 40a or approximately 9 6kw. Two standard pv breaker examples.

The size of this fuse is dependent on how many solar panels you have and how they are connected series parallel or series parallel. There is a code rule nec 690 64 b 2 that s says you must not exceed a certain size circuit breaker for solar. Take 35 5a x 1 25 44 4a round up to the next standard trade size which will be 50a. Breaker box for ac distribution rated for 40a.

This would satisfy the busbar rating without an issue. In it we have a 200 amp main breaker. Our most popular selection is 30 15 15 20 15 15. If the utility requires a disconnect between the inverter and main panel board this could be a 60a fused or non fused disconnect dependig on their requirements.

So for example if you have a 200a service you cannot install more than 40a of solar circuit breakers 200 0 2.