I find both EGCs and neutral conductors connected at the neutral bus bars in the main panel. And then there is also a ground bus bar. I thought the equipment grounding conductors and neutral conductors could be attached to either the ground bus terminal bar or the neutral terminal bar at the main service panel.
Neutrals cannot be attached to a “ground bus” under any circumstance. Grounds can be attached to the neutral bus as long as grounds and neutrals are not required to be separated in the panel, such as in a sub-panel with a 4-wire feed.
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Ok thank you. So if the main disconnect is at the meter then grounds and neutrals would be separated at the “main” service panel and a subpanel?
Sometimes, lol. It’s not quite that easy though. A newer code change allows a 3 wire feed from the exterior disconnect to the main distribution panel, as long as the exterior disconnect is labeled as an emergency disconnect. In that case, with a 3-wire feed to the main distribution panel, then ground and neutrals need to be bonded in the main distribution panel.
If your situation is not under newer code, then there should be a 4 wire feed from the exterior main disconnect to the main distribution panel and grounds and neutrals should be separated.
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I appreciate the help!
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Terminology will help. Main disconnect is kind of meaningless. The proper terms are service disconnect, or emergency disconnect which may or may not be the service disconnect. Once you determine exactly what the disconnect is then that will dictate whether or not the neutrals and EGC’s are required to be on separate buses.
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Found this at the service panel the other day on a six year old home, is there ever a circumstance where double lugging is allowed on the neutral bus in a Square D panel?
There is no panelboard that would permit more than one neutral per hole in the neutral bus. There are terminals that allow two conductors (see photo) but that wouldn’t be applicable to the neutral bus in the panel.
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But in that scenario those two conductors MUST be the same size correct?
I believe that is correct.
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Thanks Robert! Always on it once again… You are the best man!
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Although ground wires terminations are allowed to have up to three conductors if my memory serves me well, per lug at a ground bus bar, neutral wires are more likely to carry current and experience problems. One per termination point.