Lighting loads - additional options
I like the recent addition of the general lighting loads, but there are a couple of additional things that I would like to see related to that.
- I think that the calculated load should include the greater of the general lighting load or the connected lighting load. The NEC states that the values for the general lighting loads are minimum values and that they may not be adequate.
Ok, so this is probably a low priority because the NEC values are pretty conservative. With the increased adoption of energy conservation codes it becomes less likely that the connected lighting load would be more than the NEC values. But it would still be nice to be able to do this automatically.
- I would like to see the Connected kVA column include only the connected lighting load and the Calculated kVA column include only the General Lighting load (or preferably, the greater of the General Lighting load x 100% or the connected lighting load x 125%).
For me there is a pretty good reason for doing it this way. There is a situation that I have all the time. Let’s say that I have a 10,000 sq. ft. retail building. The General Lighting Load at 3 VA/sq. ft. is 30,000 VA (125 amps @ 240V). The connected lighting load may only be 10,000 VA (42 amps @ 240V) if I use energy efficient lighting.
Now let’s say that I have a distribution panel and two sub panels. I could easily have a 100 amp lighting panel, but how do I allocate the General Lighting loads? If I put it all on the lighting panel it looks like the panel is overloaded when it really is not. If I put it on the distribution panel the lighting panel has no lighting load – which is not accurate.
Of course there are a lot of things that I can do manually. I can allocate just the right amount to the lighting panel and put the rest on the distribution panel. That works perfectly, but it requires me to do it manually. It would be easier if it could be done automatically.