Store calc standard panel sizes.

[stonecold]

I have a store caculation they provided the answers for the panel size and the feeder size. My question is is why the feeder size says its 200 amps due to the panel size? Are these questions worded correctly.

1. What is the 208 volt panel board size?
18766.6 / 120 volt= 156.39. (200 amp panel) feeder size

2. What is the feeder size to panel board?
75 x 1000/ 208v x 1.732= 208.18 amps (200 amp due to panel size)

Does anyone know where to get the standard panel board and transformer sizes?
Is the feeder size the conductor size.
NEED HELP!!! TESTING 5/29/09

 

[Smart $]

I have a store caculation they provided the answers for the panel size and the feeder size. My question is is why the feeder size says its 200 amps due to the panel size? Are these questions worded correctly.

1. What is the 208 volt panel board size?
18766.6 / 120 volt= 156.39. (200 amp panel) feeder size

2. What is the feeder size to panel board?
75 x 1000/ 208v x 1.732= 208.18 amps (200 amp due to panel size)

Does anyone know where to get the standard panel board and transformer sizes?
Is the feeder size the conductor size.
NEED HELP!!! TESTING 5/29/09

I'm having a slight problem making heads or tails out of the questions and answers supplied.

Is there supplemental information which precedes these questions? One obviously cannot pull a value of 18766.6 (VA?) out of thin air.

Also, are the two questions related? Question 1 appears as though it is for a 120/208 1? 3W panel. The calculation is wrong regardless of 1? or 3?!!!

Question 2 appears to deal with a 208/120 3? 4W supply from a 75kVA source... but that is judging from the answer and not the question. Once again, the values appear to pulled out of thin air.



One thing I can answer for certain is: yes, feeder size is—essentially—conductor size.