Enphase Combiner 6C Rapid Shutdown Question

[solarken]

Have any of you installed the 4th generation Enphase Combiner 6C and Battery 10C equipment yet? I have been trying to get a definitive answer from Enphase but no luck yet. They describe several scenarios for achieving Rapid shutdown in the install guide, but they all include interrupting either the PV breakers in the combiner, or the PV aggregate breaker in conjunction with opening the RSD terminals on a header on the controller. If the combiner is installed indoors, all the breakers in the combiner are not accessible to emergency personnel outdoors. They describe disconnecting the internal conductors from the aggregate breaker lugs, extending them with an insulated splice/tap device, and routing them outside thru a safety switch and returning to the lugs, so that the outdoor switch is in series with the PV aggregate breaker, using a 3-pole switch, so that the 3rd pole can interrupt the RSD terminals as well when the switch is off. The page from the manual is attached. When I look at photos and videos of the unit it does not look like there is enough room to fit two polaris devices in the little cavity in order to extend those 4AWG conductors to an outdoor safety switch and back.

I have a project where it will be difficult to route the 4AWG power conductors for the 80A aggregate current outdoors, and in addition, the cost of a 3-pole 100A N3R switch is not low. I am having a hard time understnding why RSD cannot just be achieved by interrupting the RSD terminals (shown at location 5 in the diagram). From the description, it seems those terminals, when not shorted, will initiate rapid shutdown, and the support tech says that is the case, but then they say you still need to route the PVA aggregate conductors outside and interrupt those as well. I have not bee successful in speaking to anyone on the engineering team, they seem to want us to interface only with the tech support team. Routing 12 or 18AWG conductors outside from the RSD terminals to a small lockable toggle switch would be an inexpensive, easy solution, and it is how I have done it with SolarEdge and Sol-Ark before. Does anyone have any experience with this detail on that product?

 

[solarken]

I mistakenly conflated two installation scenarios in my OP. If the extermal disconnect is in line with the PV Aggregate breaker, i.e. lifting the conductors from the PVA Breaker, extending them to the external disconnect, and returning back to the breaker terminals, only a 2-pole switch is needed. The 3-pole switch is needed if inserting the external disconnect between the backfeed lug (grid) terminals and the grid interconnection point. I just dont understand why opening the RSD terminals alone is not enough to meet achieve shutdown. I still have not heard back from Enphase.

 

[Zee]

I just installed 4 of these and planned 1.
Do whatever you can to install the Enphase Combiner 6C on the exterior.
It does not have to be next to the MSP.
Cannot be behind gate/fence.
Then you can print a label and affix it to the MSP directing someone (first responders) to the RSD in the Combiner.

I was going to place my Combiner next to the (E) SP in basement, as that SP is where I will tie the PV/battery system in...but I put it on exterior just to avoid installing an auxiliary RSD. That requires running big pipe, big wire and a new ACD. None of that is cheap, esp. now.

There is no way you can just run some small sensor wire to the header. There was so much thought put into this system, if that was remotely feasible, they would mention that which would be a huge labor saver and thus huge selling point.

 

[jaggedben]

I mistakenly conflated two installation scenarios in my OP. If the extermal disconnect is in line with the PV Aggregate breaker, i.e. lifting the conductors from the PVA Breaker, extending them to the external disconnect, and returning back to the breaker terminals, only a 2-pole switch is needed. The 3-pole switch is needed if inserting the external disconnect between the backfeed lug (grid) terminals and the grid interconnection point. I just dont understand why opening the RSD terminals alone is not enough to meet achieve shutdown. I still have not heard back from Enphase.

I think the answer is that they didn't design and list it that way. But I have also witnessed the conductors go dead when a breaker is opened in between the meter collar and the combiner, so I don't really get it either. It may be that some requirement in 690.12 isn't strictly met or that it doesn't meet the UL standard (rather than the NEC requirements) for rapid shutdown.