General Lighting Load

[EEVA PE]

For load calculations, does one add in 125% for general lighting load due to continuous duty. I looked in Article 220, but cannot find anything about adding 125% for general lighting load. The only thing I found is NEC 210.19 (1) for continuous load for branch circuits, but nothing pointed out about always using 125% for general lighting loads.

The reason I ask is I have an old sample exam that always shows adding 125% for general lighting loads, but I am having difficulty validating this solution. Is it possible the solution is wrong, or this was done using an older version of the NEC which was ok back then or am I missing something?

 

[Wildsoldier PE]

I would think is a continuous load because usually lighting can be on more than 3 hours most of the time.

 

[ElecPwrPEOct11]

I've always used the lighting loads straight from the NEC, and have never heard of adding 25% to them. I think it's more complicated if mixing lighting/motor loads on the same circuit.

I also believe this is covered by the provision that you can't load circuits to more than 80% of their overcurrent capacity, unless the overcurrent device is specifically rated for 100%. See NEC 210.19.

For residential, you certainly don't add 25% to the lighting load. Look at the examples in the back of the NEC in Annex D, specifically D3. Without studying it extensively I gather: for the feeder calc basically you use the lesser of 125% of the actual connected lighting load or the general lighting load calculated per Table 220.12. For the branch circuit calc it looks like you use 125% of the values per Table 220.12. Hope this helps.