Pv breakers and NEC 408.36D

wrobotronic

Senior Member
Location
Colorado
Do PV breakers need to comply with 408.36D or is there something in 690 that allows the use of a regular breaker? Thank you as always.
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Do PV breakers need to comply with 408.36D or is there something in 690 that allows the use of a regular breaker? Thank you as always.
We don't need fasteners because adherence to UL1741 guarantees that if you pull a breaker out of a panel while the inverter that is backfeeding it is running, the inverter shuts down and the load side of the breaker is de-energized. The NEC reference is not in 690 but 705.12(D)(5).
 

Carultch

Senior Member
Location
Massachusetts
Do PV breakers need to comply with 408.36D or is there something in 690 that allows the use of a regular breaker? Thank you as always.
As mentioned, UL1741 overrides this because of the inverters automatically shutting off upon loss of stable grid voltage.

408.36(D) is not necessarily about backfeeding a breaker and having current flow in the opposite direction than normal (even though it uses that word for lack of a better word). The intent of that rule is to prevent you from energizing the load-side terminals of a stab-on breaker, and having those terminals and the breaker stabs remain energized when the breaker is removed.

It is more about the direction from which it is energized via voltage sources, than the direction of current flow.
 

wrobotronic

Senior Member
Location
Colorado
We don't need fasteners because adherence to UL1741 guarantees that if you pull a breaker out of a panel while the inverter that is backfeeding it is running, the inverter shuts down and the load side of the breaker is de-energized. The NEC reference is not in 690 but 705.12(D)(5).
Awesome. Thank you for that reference.:thumbsup:
 
Top