Help.

[sparky723]

Heres the question, straight from Mike Holt's 2005 Master/Contractor simulated exam book. (Part 3-#20)

Each unit of a 20 unit apartment building is 990 sq. ft. What is the calculated load for the general lighting, small appliance,and laundry loads for the building?

a) 74,700 VA
b) 149, 400 VA
c) 51,300 VA
d) 105,600 VA

So that ya'll don't have to do the math, the answer key says c) 51,300 VA.

I have no problem with this, but I can't figure out how Mike came up with the answerALL the way through the problem. I got the total connected load of 149,400. The demand factors in 220.42 state First 3,00 at 100%, leaving 146,400. Then it says From 3001 to 120,000 at 35% and so on.

Well, in the answer, on this second step, (after the 100% is applied), it says
Next 117,000 VA at 35%.

Now here's my question...FINALLY:

Where in the world does 117,000 come from??

AM I really that dumb!!! AUGH!!!
Thanks, sparky723

 

[JohnJ0906]

3001 to 120000 va is 117000 va.

It is just stated a little different from the code book.

 

[sparky723]

??

??

3001 to 120000 va is 117000 va.

What?

Explain like I'm a third grader...

 

[JohnJ0906]

OK

Portion of lighting load to which demand factor applies.
First 3000 or less 100%
From 3001 to 120000 35% <-- This is the "next 117000"
Remainder over 120000 25%

First 3000 at 100%, Next 117000 at 35%, remainder at 25%