Jerramundi
Senior Member
- Location
- Chicago
- Occupation
- Licensed Residential Electrician
Hey all. Trying to help a friend out who just bought a building and really not used to the grounding and bonding of multiple main breaker panels.
Single main breaker panel I got. Single main breaker panel and sub panel(s) I got. Multiple main breaker panels are not really something I deal with regularly... so any clarification you guys can offer would be extremely helpful.
THE SET-UP: It's a two family building. 3-wire, single phase system, 200A 3/0 AWG wire in a single riser going to a (3) triple meter bank.
From the (3) triple meter bank, they have (3) separate raceways, each containing 3-Wire, single phase, 100A #3 AWG wire and feeding (3) separate 100A main breaker panels (public, 1st floor, and second floor).
If my understanding is correct, I need...
(1) A #8 AWG Main Bonding Jumper in EACH Main Breaker Panel sized according to 250.28(D)(1-2)... which needs to be continuous in bonding (1) the enclosure, (2) the EGC's, and (3) the ungrounded/neutral bus bar.
What I'm thinking about doing is starting an MBJ at the EGC bus bar, feeding it through a bonding bushing on the service entrance raceway to the neutral bus. Does this sound correct? I'm working with older, existing Challenger panels so there is no green screw to bond the neutral bus to the enclosure.
(2) A #6 GEC from the street side water main, bonding bushing on both ends of the raceway, to each individual neutral bus bar.
This is where I get somewhat confused because I'm not used to running a the GEC to multiple main break panels. Would I terminate this in the first panel and run a second wire run through a raceway to the 2nd and 3rd panels and their respective neutral buses? Or does it also have to be continuous? Would each intermittent raceway also require a bonding bushing on both ends?
Thanks in advance all! Stay safe.
Single main breaker panel I got. Single main breaker panel and sub panel(s) I got. Multiple main breaker panels are not really something I deal with regularly... so any clarification you guys can offer would be extremely helpful.
THE SET-UP: It's a two family building. 3-wire, single phase system, 200A 3/0 AWG wire in a single riser going to a (3) triple meter bank.
From the (3) triple meter bank, they have (3) separate raceways, each containing 3-Wire, single phase, 100A #3 AWG wire and feeding (3) separate 100A main breaker panels (public, 1st floor, and second floor).
If my understanding is correct, I need...
(1) A #8 AWG Main Bonding Jumper in EACH Main Breaker Panel sized according to 250.28(D)(1-2)... which needs to be continuous in bonding (1) the enclosure, (2) the EGC's, and (3) the ungrounded/neutral bus bar.
What I'm thinking about doing is starting an MBJ at the EGC bus bar, feeding it through a bonding bushing on the service entrance raceway to the neutral bus. Does this sound correct? I'm working with older, existing Challenger panels so there is no green screw to bond the neutral bus to the enclosure.
(2) A #6 GEC from the street side water main, bonding bushing on both ends of the raceway, to each individual neutral bus bar.
This is where I get somewhat confused because I'm not used to running a the GEC to multiple main break panels. Would I terminate this in the first panel and run a second wire run through a raceway to the 2nd and 3rd panels and their respective neutral buses? Or does it also have to be continuous? Would each intermittent raceway also require a bonding bushing on both ends?
Thanks in advance all! Stay safe.
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