jcgjupiter
Member
I noticed a difference in Tom henry's books and Stallcup's master Electrician study guide on neutral calcs:
On page 11-40 Stallcup
120,000 sq ft office
Step 1
120,000 sq ft x 3.5 va = 420,000 with a check showing it is for neutral sizing
420,000 x 125 % =525,000 va for phase conductor sizing. (for continuous loading)
My dilemma is that in other notable books the neutral is sized based on the VA after multiplying by 125%.
Is the neutral sized based on 100 % va or 125% va even if it is like hallway or office lighting.
I know Tom Henry's calc book shows both the phase and the neutral conductors sized at 125%.
Mike Holt's Elect. Exam Prep. 2002 page 397
shows an office bldg. He used the 125% for the neutral.
I don't know why Stallcup's book does it differently.
Any know why?
Thanks
On page 11-40 Stallcup
120,000 sq ft office
Step 1
120,000 sq ft x 3.5 va = 420,000 with a check showing it is for neutral sizing
420,000 x 125 % =525,000 va for phase conductor sizing. (for continuous loading)
My dilemma is that in other notable books the neutral is sized based on the VA after multiplying by 125%.
Is the neutral sized based on 100 % va or 125% va even if it is like hallway or office lighting.
I know Tom Henry's calc book shows both the phase and the neutral conductors sized at 125%.
Mike Holt's Elect. Exam Prep. 2002 page 397
shows an office bldg. He used the 125% for the neutral.
I don't know why Stallcup's book does it differently.
Any know why?
Thanks