Sizing grounded conductor? per Note 1 under Table 250.102(C)(1) with 12.5% rule

[housemoney]

If your total Equivalent area of Ungrounded parallel conductors is over 1100 kcmil copper or 1750 kcmil AL (example 4 parallel runs of 500s= 2000kcmils) are you *required* to use the 12.5% rule for Sizing your minimum grounded conductor and *not to* use table .102 c / 1 ?

 

[augie47]

See Note 3 to the Table. For the grounded service conductor it depends on there being in one raceway or multiple raceways.
If you have (4) 500s in (4) separate raceways, each would have a 1/0 unless larger is required by load
(Your MBJ would still require tye 12-1/2%)

 

[housemoney]

See Note 3 to the Table. For the grounded service conductor it depends on there being in one raceway or multiple raceways.
If you have (4) 500s in (4) separate raceways, each would have a 1/0 unless larger is required by load
(Your MBJ would still require tye 12-1/2%)

“required by the load” synonymous with what’s found in said table?

 

[augie47]

“required by the load” synonymous with what’s found in said table?

Not necessarily... There are some factors to consider: The neutral must be sized to carrry the calculated load per 220.61; it serves as the ground fault return path to the service supply so it must be sized per 250.102(C); and, when parallel conductors are involved, it can't be smaller than 1/0 per 310.10. You have to look all three of those requirements and determine the size required.

 

[housemoney]

Thanks for the summary