Branch circuits through 4" j-boxes

mstrlucky74

Senior Member
Location
NJ
If you have mc cable entering and leaving a 4" j-box box in a ceiling is the ground wire not spliced together but rather terminate to a ground screw in the box?
 

John120/240

Senior Member
Location
Olathe, Kansas
So a wire nut is used? Sorry there was a little debate today. Someone saying that they are only bonded to the box and no wire connector was needed.....
Would it suffice to bond both the incoming and out going grounds to the box ? You could save one wire nut at the expense of one ground screw and a ground clip. Spend a dollar to save a quarter.
 

GoldDigger

Moderator
Staff member
Would it suffice to bond both the incoming and out going grounds to the box ? You could save one wire nut at the expense of one ground screw and a ground clip. Spend a dollar to save a quarter.
Well, the language quoted says that all of the grounds must be connected either to the box or to each other and that at least one of them needs to be connected to the box.
I am not sure whether it is a convenience, a money saver or not, but it seems to be permitted by the code.
But you do have to throw in the requirement (if it will be device box) that one ground conductor has to be available to be attached to the ground terminal of the device.
 

infinity

Moderator
Staff member
Location
New Jersey
Occupation
Journeyman Electrician
If you have mc cable entering and leaving a 4" j-box box in a ceiling is the ground wire not spliced together but rather terminate to a ground screw in the box?
If you had two MC cables and two ground screws you could eliminate the splice. The box would also require two 10-32 threaded holes. Since you mentioned a JB in the ceiling you would not need a tail for a device presumably because there wouldn't be one.
 

Joe Villani

Senior Member
If you had two MC cables and two ground screws you could eliminate the splice. The box would also require two 10-32 threaded holes. Since you mentioned a JB in the ceiling you would not need a tail for a device presumably because there wouldn't be one.
I couldnt use a machine screw & nut through a hole in the box?:roll:
 

mstrlucky74

Senior Member
Location
NJ
Thanks guys my question is when you have multiple grounds coming together in a 4" junction box(without a device) how do you commonly attach them? Spliced, wire connection connector?
 
Last edited:

qcroanoke

Sometimes I don't know if I'm the boxer or the bag
Location
Roanoke, VA.
Occupation
Engineering
Thanks guys my question is when you have multiple grounds coming together in a 4" junction box(without a device) how do you commonly attach them? Spliced, wire connection connector?
Spliced together with an approved "for ground connections" wire nut with a pigtail to connect to the box for bonding purposes.
 

Bang

Member
If you have mc cable entering and leaving a 4" j-box box in a ceiling is the ground wire not spliced together but rather terminate to a ground screw in the box?
If the conductor is only entering and exiting the J-box, could it be bonded without using a splice? Again, assuming this is only one MC cable entering and exiting the box without connection of a device.

2011 Handbook EXHIBIT 250.53
 

GUNNING

Senior Member
If you have mc cable entering and leaving a 4" j-box box in a ceiling is the ground wire not spliced together but rather terminate to a ground screw in the box?
you going to have to cut the wire to terminate the MC cable. When you do you are going to have to splice the ground and bond the box. Are you really trying to figure out how not to spend .17 on a wire nut or is this a mental exercise? The jacket for mc is not considered suitable for a bond, AC cable has an equipment grounding conductor integrated into its sheath. You might want to look up 250.118 and reevaluate materials.
 

hbiss

EC, Westchester, New York NEC: 2014
Location
Hawthorne, New York NEC: 2014
Occupation
EC
I don't know what the question is. You treat MC ground wires the same as you would Romex ground wires. The only difference is that because MC ground conductors are insulated, you can't wrap one around the ground screw and use it to pigtail the others. You have to use a premade pigtail (or make them yourself).

-Hal
 
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