This is probably a dumb question that I should know, it is whether I should use a jumper from the neutral bus to the ground bus in an old 100 amp. service? There is a ground rod with a #6 wire connecting it to the ground bar and its a 2 phase with bare neutral going to neutral bar. Do I use a jumper to connect them inside the service or leave them seperate? Me confused.
residential grounding question.
- Thread starter ipso
- Start date
- Status
- Location
- New Jersey
- Occupation
- Journeyman Electrician
They should be already connected via an old ground screw or strap from the neutral bar to the metal panel back box. If not you would need to connect them together using a conductor based on 250.66.
Just for the record this would not likely be a two phase system but a single phase, 3 wire system. Welcome to the forum.
Just for the record this would not likely be a two phase system but a single phase, 3 wire system. Welcome to the forum.
jwelectric
Senior Member
- Location
- North Carolina
250.24(A)
(4) Main Bonding Jumper as Wire or Busbar. Where the main bonding jumper specified in 250.28 is a wire or busbar and is installed from the grounded conductor terminal bar or bus to the equipment grounding terminal bar or bus in the service equipment, the grounding electrode conductor shall be permitted to be connected to the equipment grounding terminal, bar, or bus to which the main bonding jumper is connected.
(4) Main Bonding Jumper as Wire or Busbar. Where the main bonding jumper specified in 250.28 is a wire or busbar and is installed from the grounded conductor terminal bar or bus to the equipment grounding terminal bar or bus in the service equipment, the grounding electrode conductor shall be permitted to be connected to the equipment grounding terminal, bar, or bus to which the main bonding jumper is connected.
Thank you for the quick replies. The panel is a 100 amp square D home line series, and looked as if the grounded conductor bus bar was isolated from the panel by a plastic spacer , unless it was bonded under the black plastic and I just couldnt see the connection to the back of the panel. Anyone know about this panel? If not I will jump a piece of # 6 between each bar just to be safe. Code is Code.
Psychojohn
Member
- Location
- Oshkosh, Wisconsin
There should be a screw, usualy green, screwed through the neutral bus bar and into the case behind it.
A #4 wire between the neutral and ground bar works also.
A #4 wire between the neutral and ground bar works also.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
ipso said:
Sounds as if the EG bus is not connected directly to the panel can because of the plastic mounts. You can simply install a #8 copper jumper or a #6 if you so choose.
keesha
Member
- Location
- North Of Boston/So.NH
Is this a main or sub-panel? Where is the main breaker/disconnect located?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
keesha said:
The op is calling it a service. I assume it is but could be wrong.
I think the point Mike is making is that unless there is a wire or a bus bar connecting the ground bar and the neutral bar (A screw into the panel doesn't count for this purpose) the grounding electrode conductor will need to be moved from the ground bar to the neutral bar. Even if the grounding electrode is moved, a main bonding jumper will need to be installed. If the grounding electrode conductor is moved, then the bonding screw will suffice.
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