Sizing bonding jumper

Looks like this is for a service so the bonding jumper is based on the size of the conductors in each individual raceway when using individual bonding jumpers. For 500 kcmil aluminum the bonding jumper is a minimum of #2 copper or #1/0 aluminum according to Table 250.102(C)(1).

For a single bonding jumper for all three raceways you would use 12.5% of the 3 sets combined or 500 kcmil*3*12.5%.
 
Cazelectric said:
so in your opinion is my interpretation of the 250.102 (C) (2) (1) correct ?
Click to expand...
No opinion. The minimum size for individual copper bonding jumpers for each raceway is in fact #2 copper but based on the answers #2/0 would be code compliant. I find the use of the term bonding jumper to be somewhat lazy. Since this is learning material the correct term Supply Side Bonding Jumper (SSBJ) should be used.
 
Last edited:
The question is misleading. They all work. The minimum size per raceway is #2 and 2/0 when bonding all of the raceways with one supply side bonding jumper.
 
infinity said:
For a single bonding jumper for all three raceways you would use 12.5% of the 3 sets combined or 500 kcmil*3*12.5%.
Click to expand...
For Al, 12.5% only applies over 1750 kcmil. For 1500 kcmil the table gives 2/0.

Agree that the answers provided seem to be based on all 3 sets in one raceway, while the diagram shows one set per raceway.

Cheers, Wayne
 
wwhitney said:
For Al, 12.5% only applies over 1750 kcmil. For 1500 kcmil the table gives 2/0.

Agree that the answers provided seem to be based on all 3 sets in one raceway, while the diagram shows one set per raceway.

Cheers, Wayne
Click to expand...
You're correct. I should have looked before answering. T250.102(C)(1) ends at 1100 kcmil for copper not aluminum.
 
You must log in or register to reply here.
Top