article 250

[surf more]

if i have 8-500 kcmils thw copper conductors entering a commercial steel building then using 250.66 how do i come up with the answer??

my answer is wrong,and trying to figure this out.

 

[chris kennedy]

if i have 8-500 kcmils thw copper conductors entering a commercial steel building then using 250.66 how do i come up with the answer??

my answer is wrong,and trying to figure this out.

MBJ or GEC?

 

[surf more]

electrode conductor to be bonded to steel building

 

[raider1]

Do you have 8 paralleled conduits or 8 total conductors?

Chris

 

[surf more]

8 total conductors

 

[raider1]

8 total conductors

So Let me get this straight,

2 paralleled conduits with 4-500 Kcmil conductors in each conduit.

So according to Table 250.66 Note 1 when more than one set of service entrance conductors are run, you take the equivalent area of the largest service entrance conductor.

So that would be 1000 Kcmil (2 X 500).

Table 250.66 requires the GEC to be sized at 2/0 copper.

Chris

 

[surf more]

my answer key says 3/0,and here it is so we on same page because i need your help.

minimum required size gec to be bonded to steel building.it is fed with se conductorsof 8-500kcmil copper in parallel per phase.

 

[augie47]

semantics... I read that to be (8) 500's PER PHASE well over the "over 1100" column in 250.66, thus a 3/0 (maximum required for GEC)

what did you get and how ?

 

[surf more]

2/0 copper,note 1 multiplied 2 sets.can you explain how you came up with your answer.

 

[augie47]

again we are playing "word games". to me "8-500kcmil copper in parallel per phase. " litersally means that EIGHT 500's per phase or (8 x 500) or 4000 kcmil.

 

[surf more]

gottcha --that simple--sometimes i make it harder on myself than it is.

 

[infinity]

semantics... I read that to be (8) 500's PER PHASE well over the "over 1100" column in 250.66, thus a 3/0 (maximum required for GEC)

what did you get and how ?

I agree, 8 sets of 500 kcmil in parallel equals #3/0 from 250.66.

 

[surf more]

thanks for yall's help!!!!