Rapid Shutdown requirements

[JoeNorm]

Have new rapid shutdown rules been adopted? I am specifically in Washington State.

A friend of mine told me he thought everything had to be module level as of January, but the code says 1 foot of the array field.

thanks for clearing this up

 

[jaggedben]

The new requirements went into effect on January first only if you are on the 2017 NEC or some version of it. If you are still on an older code cycle you'd have more time.

I think that with the new requirements the voltage limits within the array boundary effectively limit you to module level shutdown, even if they're not explicitly written that way. That is if you are using typical modules.

 

[Carultch]

Have new rapid shutdown rules been adopted? I am specifically in Washington State.

A friend of mine told me he thought everything had to be module level as of January, but the code says 1 foot of the array field.

thanks for clearing this up

1 ft from the array, it has to be brought down to 30V and below. Essentially 24Vdc power for the power electronics, and communication/control circuitry.
Within this boundary of the array, it has to be brought down to 80V and below. This provision allows for the module's own voltage to comply, in most cases.

In practice, this means module level shutdown, since few (if any) modules are low enough in cold VOC to be connected in series and still comply. It only indirectly prescribes module-level shutdown. You could in concept, connect all modules in parallel to be less than 80V, but in practice, you most likely won't do that, because design tradeoff of voltage vs current.

The 1 ft from the array rule existed, to allow 2014 solutions to continue for another couple of years prior to 2019, with combiner-level shutdown immediately adjacent to the array. It tightened the limit from 10 ft to 1 ft.