MechEdetour
Member
- Location
- NY, USA
Well, I've held off for a little while but figured I'd have to break the seal eventually as far as making my first post is concerned.
I understand this clause in the NEC is probably going to undergo some changes/adjustments in the near future, along with being incorporated into standards, etc. But I am curious how the case would apply to:
Say I have a string of arrays going into DC combiner, which is then feeding an inverter (oversimplified system but should suit the question I'm asking). Theoretically the DC combiner designed with a contactor, along with a remote control station should have the ability to satisfy the requirements of 690.12. However, in the case where the inverter cannot satisfy 690.12(2) due to say discharging capacitors, then the DC combiner "assembly" that can function as a solution to rapid shutdown no longer does because of the inverter that its being used with. And vice versa. An inverter that discharges in the required time, will still have live conductors feeding it if the DC combiner does not have a rapid shutdown feature.
To me it seems like the rapid shutdown requirements are heavily dependent on the integration of all the components. Is it not? In the system I presented, the DC combiner AND the inverter would need to be designed to satisfy the requirement. Additional to this it seems like a combiner or inverter can't be listed to satisfy the requirement of 690.12 in a PV system. How would this be incorporated into a standard so that just a combiner that meets rapid shutdown requirements doesn't create the illusion that the entire system will satisfy the requirement as well. Does it all come down to the installer satisfying 690.12 and not the manufacturer of listed equipment?
I guess I'm just looking for a discussion.
I understand this clause in the NEC is probably going to undergo some changes/adjustments in the near future, along with being incorporated into standards, etc. But I am curious how the case would apply to:
Say I have a string of arrays going into DC combiner, which is then feeding an inverter (oversimplified system but should suit the question I'm asking). Theoretically the DC combiner designed with a contactor, along with a remote control station should have the ability to satisfy the requirements of 690.12. However, in the case where the inverter cannot satisfy 690.12(2) due to say discharging capacitors, then the DC combiner "assembly" that can function as a solution to rapid shutdown no longer does because of the inverter that its being used with. And vice versa. An inverter that discharges in the required time, will still have live conductors feeding it if the DC combiner does not have a rapid shutdown feature.
To me it seems like the rapid shutdown requirements are heavily dependent on the integration of all the components. Is it not? In the system I presented, the DC combiner AND the inverter would need to be designed to satisfy the requirement. Additional to this it seems like a combiner or inverter can't be listed to satisfy the requirement of 690.12 in a PV system. How would this be incorporated into a standard so that just a combiner that meets rapid shutdown requirements doesn't create the illusion that the entire system will satisfy the requirement as well. Does it all come down to the installer satisfying 690.12 and not the manufacturer of listed equipment?
I guess I'm just looking for a discussion.