bondingjumper

Status
Not open for further replies.
the senerio is, a mainpanel 100amp disconect connected to a subpanel with emt or rigid i didnt get a chance to look. its already feed with 3 conductors 4 awg but their just cap off right now. the work that needs to be done is the main panel has no room on the hotbusbars to place a 2pole ocp for the subpanel...so ill take out two of the brks put my 70i 2pole in and install the homeruns from the mainpanel in the subpanel..i know in a subpanel the grounded and grounding conductors should not be bonded so ill remove the scew thats bonding the bus bars together..ill run a 4awg grounding conductor from the mainpanel aswell.do i need to bond the emt to the subpanel with a jumper this might sound funny but i was reading in a book and it was showing a bonding jumper attached to a raceway and the panel..thanks for your time and sorry if this is a silly question..so i dont have to bring a grounding conductor to the sub panel but i will anyways..whats the smallest awg conductor i can use or is it you just use the same size as the ungrounded conductors
 
Last edited:
it sounds like EMTsoyou don't need an EGC but it is a good design and good practice.
its emt so you dont need to have a egc? bc the raceways is bonded to the main panel witch is bonded to the gec .but what would happen if their was a ground fault on one of the branchcircuits from the subpanel wouuld it find a path to ground through the raceway?
 
Emt is one of the EGC's listed in 250.118, the only places in the NEC that requires a bonding jumper from the raceway to the box or grounding bar is for service conductors, and GEC's, EGC's are sized in table 250.122 if you still think you want to run one, but it is not required by the NEC.

Remember before main service disconnect size in 250.66, after main service disconnect (except SDS's), size in 250.122, service disconnect and before it, bond race way, after locknuts do just fine.

This is only for voltages below 250 volts to ground.
 
Status
Not open for further replies.
Top