Regarding commercial buildings, lighting branch circuits: we add up the lighting fixture wattages and always use 125% for demand factor for the load because lighting is continuous load. Is this wrong? I'm trying to have it proved that it's right by NEC, but....Looking into NEC 2014 210.20(A), 125 percent is required for the overcurrent protection and not for load. NEC 2014 table 220.42 shows the lighting load demand factors, where for a commercial office building the demand factor would be 100%. Is there any other section of the NEC which tells us that commercial office building lighting load demand should be at 125%? Thank you!
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Originally posted by curious101 View PostRegarding commercial buildings, lighting branch circuits: we add up the lighting fixture wattages and always use 125% for demand factor for the load because lighting is continuous load. Is this wrong? I'm trying to have it proved that it's right by NEC, but....Looking into NEC 2014 210.20(A), 125 percent is required for the overcurrent protection and not for load. NEC 2014 table 220.42 shows the lighting load demand factors, where for a commercial office building the demand factor would be 100%. Is there any other section of the NEC which tells us that commercial office building lighting load demand should be at 125%? Thank you!Ethan Brush  East West Electric. NY, WA. MA
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Looking for some clarification... So lighting demand factor is 100%. Continuous loads are 125%. Lighting fixtures that are used in everyday operation are considered continuous loads so essentially get a 125% demand factor applied right? So the only 100% demand factor for lighting would be like lamps or plug in fixtures?
I'm trying to piece these two threads together. https://forums.mikeholt.com/forum/ac...innec?t=52496
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Originally posted by WA_Sparky View PostLooking for some clarification... So lighting demand factor is 100%. Continuous loads are 125%. Lighting fixtures that are used in everyday operation are considered continuous loads so essentially get a 125% demand factor applied right? So the only 100% demand factor for lighting would be like lamps or plug in fixtures?
I'm trying to piece these two threads together. https://forums.mikeholt.com/forum/ac...innec?t=52496
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