yesterlectric
Senior Member
- Location
- PA
- Occupation
- Electrician
Hate that this may be a duplicate but I searched some and didn't see this one answered on the forum.
This came up in a conversation about a design review recently and while I thought I knew the answer I felt I couldn't prove it. When applying 215.2 you perform 2 calculations and use the larger of the two:
215.2A1: ampacity for the non-continuous load plus 125% of the continuous load (unless the breaker/assembly is rated for operation at 100% continuous load).
215.2A2: ampacity for the maximum load to be served after the application of any adjustment or correction factors
My question is related to 215.2A1. It would make sense that we would not need to apply adjustment (derating) for bundling for this section 215.2A1 because the bundling does not so much occur in the panelboard but occurs more in the conduit, cable trench, wireway, etc. However, what about correction (derating) for ambient temperature? I think not just like we do not derate the panelboard but it doesn't seem to be concretely worded to remove all doubt.
This came up in a conversation about a design review recently and while I thought I knew the answer I felt I couldn't prove it. When applying 215.2 you perform 2 calculations and use the larger of the two:
215.2A1: ampacity for the non-continuous load plus 125% of the continuous load (unless the breaker/assembly is rated for operation at 100% continuous load).
215.2A2: ampacity for the maximum load to be served after the application of any adjustment or correction factors
My question is related to 215.2A1. It would make sense that we would not need to apply adjustment (derating) for bundling for this section 215.2A1 because the bundling does not so much occur in the panelboard but occurs more in the conduit, cable trench, wireway, etc. However, what about correction (derating) for ambient temperature? I think not just like we do not derate the panelboard but it doesn't seem to be concretely worded to remove all doubt.