Neutrals and grounds doubled up on bus bar. Home Inspection

Fred B

Senior Member
Location
Upstate, NY
Occupation
Electrician
My Q is, are we supposed to be fixin' these older panels now?

~RJ~
In my area we are, in addition whenever installing either a new meter/service disconnect or an ATS the bond must be seperated. If you touch it, you own it. And YES in agreement to @Little Bill statement regarding multiple taps under one screw on neutral/ground bar, it's a no go.
 

flashlight

Senior Member
Location
NY, NY
In my classes, I wanted the students to understand the why behind the rule. When you open the neutral on a MWBC those parallel loads become in series. The $14 hair dryer will be fine at 80V, but that $300 TV will let the smoke out at 160V. This is one of my favorite graphics from Mike Holt. There is a similar rule for wiring receptacles on MWBC (IE pigtailing neutral)
That happened to me once, at a job at a design agency. Work had to be done at night, and there were some circuits we weren't allowed to kill.
One neutral on a MWBC got loose, and I think it was a TV or monitor that got fried. We worked it out with customer who just seemed to take it in stride.
Big lesson learned, and could have been much worse.
 

hillbilly1

Senior Member
Location
Atlanta,Ga
You don't want to accidently disconnect the neutral on another circuit, if it is a multi-wire branch circuit.
One of our guys did that years ago, he was cleaning up a 277/480 volt lighting panel. The project manger called me to investigate why around 150 ballasts suddenly went out. After interviewing the foreman, I knew exactly what he done.
 

kwired

Electron manager
Location
NE Nebraska
Home Inspection report:
"Noted ground wire and neutral wire under same bonding screw. This is not proper. Recommend licensed electrician
evaluate for repair
."
Note it says to have electrician evaluate for repair and not must be repaired.

It was mentioned here that this wasn't always in the code but was in the equipment instructions for some time, therefore it probably was always wrong.
 

Little Bill

Moderator
Staff member
Location
Tennessee NEC:2017
Occupation
Electrician
I've checked with two neighboring city elec inspectors about this, they both said I need to separate neutrals and grounds but ok to leave 2 neutrals and under one screw. ( For Home Inspection jobs)
Your inspectors missed the day they taught panel grounding/bonding!
It would make more sense to leave one EGC and one neutral under one screw than it would to have two neutrals under one screw. You could run into the same situation you would have taking the neutral off a MWBC if you had to remove one of the neutrals for some reason and the other neutral was part of a MWBC. Or you kill power to a regular circuit from loosening the screw, or cause arcing at the least.
 

kwired

Electron manager
Location
NE Nebraska
Your inspectors missed the day they taught panel grounding/bonding!
It would make more sense to leave one EGC and one neutral under one screw than it would to have two neutrals under one screw. You could run into the same situation you would have taking the neutral off a MWBC if you had to remove one of the neutrals for some reason and the other neutral was part of a MWBC. Or you kill power to a regular circuit from loosening the screw, or cause arcing at the least.
I used to put the N and G from same cable in the same terminal (at service panels), the logic being you probably would have the associated ungrounded conductor(s) off if you were loosening the neutral. Then came the NEC enforcement of one grounded conductor per terminal. After that I went with two EGC's per terminal and one grounded conductor per terminal. Usually the EGC's are associated with the two adjacent grounded conductors.

Then came plug on neutrals for GFCI/AFCI and not many neutral conductors even land directly to the bus bar anymore on especially new residential installations
 
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