grounding

[mjh324]

? one what minimum size Cu GEC required for 120/208 volt 3phase 4 wire service with 3 kcmil Cu conductors per phasemy answer was 2/0 is this correct 250.102(c)(1) 3x300=900 250.24(c)(1) note 1 12.5% then chap 9 table 8

? two Determine the minimum number and minimum size AL EGC"s required for installation which consists of two parallel 2" RNMC's each of which has the conductors backed up by a 225 OCPD My answer is 250.122(f) minimum number in each pipe is 1 250.122 minimum size #2 AL

? Three what size bonding jumber load side EBJ 110 amp 4" FMC My answer 250.64(E) 250.102(D) 250.122 answer #6 Cu

 

[mjh324]

grounding

? one what minimum size Cu GEC required for 120/208 volt 3phase 4 wire service with 3 kcmil Cu conductors per phasemy answer was 2/0 is this correct 250.102(c)(1) 3x300=900 250.24(c)(1) note 1 12.5% then chap 9 table 8

? two Determine the minimum number and minimum size AL EGC"s required for installation which consists of two parallel 2" RNMC's each of which has the conductors backed up by a 225 OCPD My answer is 250.122(f) minimum number in each pipe is 1 250.122 minimum size #2 AL

? Three what size bonding jumber load side EBJ 110 amp 4" FMC My answer 250.64(E) 250.102(D) 250.122 answer #6 Cu

Well never put on here want to know if theses answers are right thanks

 

[don_resqcapt19]

1)...You do not have enough information...you need to know what the grounding electrode is. The absolute minimum grounding electrode conductor size would be #6 to a ground rod. The maximum ever required for where the service conductors are three sets of 300 kcmil woud be 2/0. See 250.66

2)Yes, each raceway needs an EGC sized based on the 225 amp OCPD

3) Don't know what you are asking.

 

[augie47]

Took me a few minutes to "cipher", but #1 yes..depending on what electrode you are connecting to, #2 I think we have to assume 300kcmil from your math, not your question, but yes, 2/0. You didn't need all the math. 250.66 shows 2/0 for 900 kcmil. #3 yes.