Grounding and neutral

I know that you are allowed to place two wires of the same size in a buss bar terminal, but can you mix ground wires and neutral wires in the same buss and screw position?



The neutral must terminate under its own terminal/lug.

Grounding conductors may be doubled, only if the equipment listing allows for it.

Thank you Jeff would you tell me the nec code that I can get this information from? I have 408.40 and 408.41 but where else can I find this?


NEC 408.21

NEC 408.40 & 408.41 do not exist.

2005 NEC:

408.40 Grounding of Panelboards
Panelboard cabinets and panelboard frames, if of metal, shall be in physical contact with each other and shall be grounded. Where the panelboard is used with nonmetallic raceway or cable or where separate grounding conductors are provided, a terminal bar for the grounding conductors shall be secured inside the cabinet. The terminal bar shall be bonded to the cabinet and panelboard frame, if of metal; otherwise it shall be connected to the grounding conductor that is run with the conductors feeding the panelboard.

Exception: Where an isolated equipment grounding conductor is provided as permitted by 250.146(D), the insulated equipment grounding conductor that is run with the circuit conductors shall be permitted to pass through the panelboard without being connected to the panelboard’s equipment grounding terminal bar.
Grounding conductors shall not be connected to a terminal bar provided for grounded conductors (may be a neutral) unless the bar is identified for the purpose and is located where interconnection between equipment grounding conductors and grounded circuit conductors is permitted or required by Article 250.

408.41 Grounded Conductor Terminations
Each grounded conductor shall terminate within the panelboard in an individual terminal that is not also used for another conductor.

Exception: Grounded conductors of circuits with parallel conductors shall be permitted to terminate in a single terminal if the terminal is identified for connection of more than one conductor.

Although incorrect today, it was common practice in this area for many, many years to terminate the ground and neutral at the same terminal on the buss. Literally thousands of panels in this area are done that way, and it was just fine with the AHJ.

Same thing goes for areas that are not under the NEC.
In my area we are under a state code which does not directly address this subject.
AHJ’s allow it every day.

I myself do not do this though.

Always an exception to the proverbial rule…:wink:

True, but we can only parallel conductors 1/0 and larger, so this is rarely an issue residentially.

Except for in the 2005 NEC :roll:

I didn’t look that far ahead. . .

Todays sub panel??? Not quite on point, but grounds and neutrals combined.

Yet the bars are separate and the ground bar is bonded as it should be.
What geniuses.

It was a thing of beauty Speedy. Each sub in the rather new 5 plex was like this.:roll: :frowning:

In the nec 2005 408.21 has been deleted. :neutral: As I am new to the business this is the first nec book I have bought, and do not have the earlyer books. Thanks for all the replys. They have been helpfull.


I have a copy of the 2005 NEC as well. I just didn’t think to look at it as my area is still working from the 2002 NEC.

The subpanel usually is not bonded.
Combined neutral/ground a no-no.
Could not tell from picture, but was it a 3-wire or 4-wire feed?

I think you mean the sub is not usually bonded to the neutral. It MUST be bonded to the EGC.

4 wire