Anode
Member
- Location
- Washington, USA
Simple question. Does the feeder from the inverter output circuit, either single or combined, always have to match the rating of the back feed ocpd installed in the main panel or switchboard?
I know that we can oversize the back feed ocpd breaker for the inverter output circuit, beyond the 125%. For example:
Have a commercial project where EC installed larger breaker in the switchboard 250A, our plans for the pv system show 200A. We are most likely going to either ask them to provide the smaller breaker, or upsize our conduit and conductors between panelboard collecting inverter output circuits and the main switchboard to match the 250A breaker that is now existing.
So, my question is hypothetical in nature, as we are going to work with the circumstances. Regardless, your input is appreciated. I should note that I searched this forum, and couldn't find a thread dedicated specifically to this.
I know that we can oversize the back feed ocpd breaker for the inverter output circuit, beyond the 125%. For example:
if you have a residential sized pv array where the ocpd would equal say 35 Amps, it is commonly upsized to a 40Amp common trade size breaker.
In this example, my question again rephrased would be; in any case could the wire still be sized to 35 Amps, which again is adequately oversized for the max continuous output rating of the inverter, when the back feed ocpd is 40Amps.
Have a commercial project where EC installed larger breaker in the switchboard 250A, our plans for the pv system show 200A. We are most likely going to either ask them to provide the smaller breaker, or upsize our conduit and conductors between panelboard collecting inverter output circuits and the main switchboard to match the 250A breaker that is now existing.
So, my question is hypothetical in nature, as we are going to work with the circumstances. Regardless, your input is appreciated. I should note that I searched this forum, and couldn't find a thread dedicated specifically to this.