Grid tie PV with Generator back up/

Sierrasparky

Senior Member
Location
USA
Occupation
Electrician ,contractor
What is the proper way to add a portable generator to a home with PV grid tie Don't want the PV back-feeding the genny. Someone said add a Normally closed relay on the PV tie to the main panel that opens when the Generator is run?
 
We put the PV connection on the utility side of the transfer switch, so when the generator is connected, there is no connectivity to the utility or PV.
That works of you are using a transfer switch, if a interlock device is use then ?
 
Are you saying ok to use a interlock device? If so how do you prevent a back-feed if the PV is fed through a back-feed breaker. In this instance I am not getting involved in changing how the PV feeds the house panel.
Grid down, pv inverter shut down pv, no supply in pv breaker
Home owner switch off main breaker, pv breaker
 
Are you saying ok to use a interlock device? If so how do you prevent a back-feed if the PV is fed through a back-feed breaker. In this instance I am not getting involved in changing how the PV feeds the house panel.
IF you have a backfed breaker and want to make it idiot proof, you either have to change it to a supply side connection or put some sort contactor on the inverter output circuit. If provided, I wonder if you could trigger the rapid shut down function somehow.
 
That works of you are using a transfer switch, if a interlock device is use then ?
Got two inspected this year, using load-side interlock.

The portable generators void SolarEdge inverter warranty, so solar DC must be opened with main, at same time geny DC is closed.

AHJ's have no clue, not aware of inverter listing violation with generators, and never seen interlock listed for 3 switches.

Interlock OEM had to produce NRTL letter, but recalcitrant AHJ's stand firm, citing NEC 110.3(C) due to NTRL no longer certified.

Passing inspection requires proof that NRTL was certified at time test results were issued to interlock manufacturer (OEM).

Among 141 UL research documents, and correspondence related to certification status of NRTL in question, only 2 sentances provide relavant proof. It was a needle in the haystack, but I got the proof.

Orange County Public Works AHJ remained none responsive, until legal proof settled NRTL certification at specific dates indicated, and was provided to the Building Official at the State capital in Sacramento.
 
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