NEC 220.5(B) Fractions of an Ampere and PV OCPD

D

DTran86

Member
Location
Houston
Occupation
PV + ESS Inspection
Hello, everyone!

I wanted to get their input on NEC 220.5(B) and if it's applicable for PV OCPD? If we have lets say 50.25A calculated with 125% included, are we safe to use a 50A OCPD? Any code references would be very much appreciated.
 
The only place I know of where the code refers to this is 220.5 and it's unclear if that can be applied to article 705. It really ought to be, be a strict reading would say it doesn't and a 50A breaker and 50A rated wiring is too small and you must upsize.

Power Control Systems could also potentially be quite useful here.
 
The first draft of the 2026 code adds the word "load" before calculations to make it clear the rounding only applies to load calculations.
There was a proposal to put the rounding rule in Article 110 so it would apply throughout the code, but that was rejected.
 
You must log in or register to reply here.
Top