250.24(C)(2): Do I Use 12.5% Grounded Conductor in Parallel Runs?

[George Stolz]

My question started out (as I was writing this) as to whether you need to use the 12.5% rule given in 250.24(C)(1) when in a (C)(2) scenario, since (C)(2) references (C)(1).

Now, after trying to contrive a situation that would call for this and failing to create one resulting in a greater-than-3/0 grounded conductor, is there even a way to reasonably get a result bigger than 3/0? :huh:

 

[Volta]

My question started out (as I was writing this) as to whether you need to use the 12.5% rule given in 250.24(C)(1) when in a (C)(2) scenario, since (C)(2) references (C)(1).

Now, after trying to contrive a situation that would call for this and failing to create one resulting in a greater-than-3/0 grounded conductor, is there even a way to reasonably get a result bigger than 3/0? :huh:

I am not sure if I understand- if one pulled 1500 kcmil hots, for whatever reason, wouldn't 12.5% require a 4/0? Am I on the right track here?

 

[George Stolz]

What pipe would you stick that in?

 

[LEO2854]

What pipe would you stick that in?

6"RMC


Table C.8? Maximum Number of Conductors or Fixture Wires in Rigid Metal Conduit (RMC)
(Based on Table 1, Chapter 9)

 

[Volta]

Yeah, or 6" PVC. But I sure do see what you're saying. All that work for 625 amps, not likely. Parallel 500 kcmil in 4" EMT with a 1/0 EGC and you get 688 amps....