A couple load calc questions

[paul32]

In the Mike Holt masters test online, a few didn't make sense to me but especially these two.

1) 400KVA connected load, what is the demand load for the service?

Huh? Need more information. As far as I know there is no generic demand factors, only for specific loads etc. What am I missing?

2) General lighting and receptacles for a 30,000 square foot bank. I got 135KVA but that wasn't one of the choices. Bank 3.5VA/sq ft, add 1VA/sq ft for recepts. 4.5X30K = 135KVA. It had 123, 151, 162, and 173 for choices.

Thanks much.

 

[bphgravity]

Re: A couple load calc questions

1. Are you sure the question didn't provide the type occupancy? It looks like an optional method for school demand.

2. I think you missed the added 125% for continuous loading for the lighting portion. 3.5 x 30K = 105kva x 125% = 131,250 + 30K (recepts) = 161,250kva. So, I guess the best answer would be 162.

 

[paul32]

Re: A couple load calc questions

1. Not totally sure, but I doubt it. I didn't write school down, and if it were the school it would have needed the sq ft, which I also didn't write down. I think if it had that info I would have found it, plus there was another question that involved the optional method for a school. I guess I'm not missing something in the code so won't worry about it.

2. That must be it. I'm assuming there's nothing that says something must be or doesn't have to be considered continuous, and just common sense to make commercial continuous. I understand nothing in a dwelling needs to be called continuous but I' m not sure I'd agree with it.

Thanks.

 

[jgriffin]

Re: A couple load calc questions

The first Problem requires more information. #2 Question---------------------------------------3.5 va X 30,000 sf.= 105,000 X 125% =131250 ------ 1 va X 30,000 sf.= 30,000 ---- take the first 10,000 va @100%---- other 20,000 va @50% = 20,000------ therefore 131,250va lighting + 20,000 receptacle load = 151,250 va total load.