During a recent home inspection of a 1980s-built house, I came across an electrical panel where most of the neutral conductors were terminated on a single side of the neutral bus bar, despite the panel having multiple available slots. Some of the terminals had more than one conductor under a single screw.
The panel was a Square D QO load center (200A main service), and there were no subpanels. The grounding conductors were properly separated, but I’m concerned about the neutral bus being overloaded on one side. I checked for signs of overheating but didn’t see any visible damage or scorching. However, I did notice some loose connections when gently tugging on a few conductors.
My questions:
Is there a specific NEC code violation for multiple neutral conductors under a single screw in a main service panel?
Could this cause an unbalanced load issue or overheating over time?
Should I recommend an electrician to redistribute the neutrals evenly across the bus bar?
Would love to hear from more experienced inspectors on how you typically report this issue in your inspection findings.
Yes only one neutral is permitted in a hole in the neutral bar. {408.41}
If you’re asking about all of the neutrals being on one side then no. There is no unbalanced load so there is no overheating. The entire neutral assembly is rated to have conductors terminated at any place on the neutral bar.
No. If the neutrals are loose or there is more than one per hole those need to be corrected. Nothing needs to be moved from one side to the other.
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.
I’ll definitely note NEC 408.41 in my report regarding the multiple neutrals under a single screw. Good to know that having all the neutrals on one side of the bus bar isn’t a concern for load balancing or overheating.
Since I did find some loose connections, I’ll recommend that an electrician properly secure those and ensure each neutral is correctly terminated. Appreciate the insight!
Would you suggest calling out the issue in a general manner (e.g., “improper neutral terminations found”) or specifically citing NEC 408.41 in the report? Curious how other inspectors approach it.
Ugh… never what a home inspection was intended to be and you’re walking yourself into the lion’s den.
Obviously, you’re free to do inspections as you please. I’ve personally completed 8,000+ and overseen another 25,000+ going through my company and have never cited a code section or even mentioned a code in my/our reports. All this code stuff is so misdirected within our industry.
I agree, unless you’re also a licensed electrical professional citing code sections should be avoided.
In this example how would you report the code violation of more than a single neutral conductor within a hole in the neutral bus without mentioning electrical code?
“The neutral bus had two or more neutral wires terminated under one lug. This is a safety concern. Recommend correction by a qualified licensed electrical contractor.”
One might add, modern building standards typically do not allow this configuration. But why complicate things?
And to be complete: two GROUND wires don’t create the same concern.
The neutral concern is specifically that one or the other neutral could come loose, perhaps during service, and create problems. For example a technician drops power to one circuit, but the other neutral wire is a multiwire branch circuit that gets loose at the same time.
The code in many cases tries to protect undertrained and unaware workers from their own actions.
Good stuff. It is important for the inspector to know WHY it is a safety concern. How much is disclosed in the narrative is up to the inspector. Sometimes more is good, sometimes not.
