NEC question - General load calculations

#1 joshtrevino

joshtrevino

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Posted 27 March 2011 - 11:36 PM

I have some old NEC practice problems.

Problem:
What is the general lighting load for a 4000 square foot bank?

From table 220.12 the general lighting load by occupancy of a bank is (3.5 va/sqft)*(4000 sqft)*(1.25) = 17,500va.

My question:
In NEC article 210.19(A)(1) it states to take 125% of all continuous loads when calculating general loading. Is this always the case? Would you agree with the solution? These examples use the 125% factor for several other load calculations including signs and track lighting. Thoughts?

#2 Guillaume

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Posted 28 March 2011 - 05:10 PM

The article 210.19(A) is for sizing the branch cricuit conductor, not to calculate the load. In this problem, you have to calculate the general lighting load, so the solution is correct (per table 220.12). If now, you were asking for the ampacity of the conductor feeding this load, you will have to use article 210.19(A) and look at all the other loads on the branch circuit.

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