Rapid shut down

624

Member
Location
Fresno ca
Between arrays if it is 20 ft or less of exposed conduit on roof do I need rapid shut down. I have sunny boy rapid shut down between inverter and first array. I think between arrays it is 20 feet Inspector thinks i need RSD between arrays cause it’s more then 10. I think 10 feet each array Equals 20 feet
 

ggunn

PE (Electrical), NABCEP certified
Location
Austin, TX, USA
Occupation
Electrical Engineer - Photovoltaic Systems
Between arrays if it is 20 ft or less of exposed conduit on roof do I need rapid shut down. I have sunny boy rapid shut down between inverter and first array. I think between arrays it is 20 feet Inspector thinks i need RSD between arrays cause it’s more then 10. I think 10 feet each array Equals 20 feet
IMO, you are correct; when we were governed by that language in the code, several times we were able to show the AHJ that at no point were there DC conductors more than 10 feet from an array when the arrays were 20 feet apart, and they approved it. We even had a couple of cases where there were DC conductors in conduit running alongside arrays for much longer distances than ten feet but staying closer than ten feet from the array, and they were OK as well.
 

GoldDigger

Moderator
Staff member
All interpretation. If a trunk runs halfway between the arrays, then there is no point that is more than 10 feet from the source array.
But if the arrays are daisy chained, the 15-5 point is only 5 feet from the nearest array, but 15 feet from a potential source of DC.
I think that an AHJ could justify either interpretation.
 
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