Neutrals and grounds doubled up on bus bar. Home Inspection

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Stevenfyeager

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United States, Indiana
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electrical contractor
What year did NEC start requiring neutrals not doubled up with grounds in busbars? Recent years Elec inspectors are requiring neutrals by themselves with only one wire in each hole
 
IMHO, this is not an NEC issue but a manufactures issue. 110.3(B) has been in the NEC for a long time. It is the Manufacturer who determines how many conductors are allowed per terminal. :)
 
This was added to the NEC because it has been a listing standard and manufacturer's instruction for many decades, but electricians were not following those requirements.
 
And this was a UL requirement for some time, but few electricians knew it, so was added to the NEC.
Why is it a requirement?
 
Note that, IF allowed by manufacturer, the NEC does allow two EGCs from different circuits to share a single terminal hole.
There is no immediate hazard from momentarily interrupting the EGC of a live circuit.
 
In case anyone goes looking for the 408.21 section... it has changed.

2020 NEC 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."
 
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Rock86 said:
In case anyone goes looking for the 408.21 section... it has changed.

2020 NEC 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."
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"Grounded conductor" means neutral And not EGC correct ?
 
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)
 

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Homeowner didn't want me to take time to change the doubled up neutrals. He said he researched the year the house was built 1994, and it wasn't required. I called the city elec inspector to ask what I should do, he said I need to separate the neutrals to individual holes. I did that, but am now looking in my 1993 NEC and can't find a similar paragraph like 408.41 2020 NEC. Help. Thanks.
 
Stevenfyeager said:
Homeowner didn't want me to take time to change the doubled up neutrals. He said he researched the year the house was built 1994, and it wasn't required. I called the city elec inspector to ask what I should do, he said I need to separate the neutrals to individual holes. I did that, but am now looking in my 1993 NEC and can't find a similar paragraph like 408.41 2020 NEC. Help. Thanks.
Click to expand...
Is this a job where you've been wiring, or a real estate inspection?
 
480sparky said:
As stated, the Code didn't require it, but the manufacturer probably did. Realistically, how much time is it going to take? 15 minutes?
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It can take up to a couple of hours. The reason they're doubled is usually all the holes are full.

The last one I did it was only a week ago, and it took about 45 minutes to remove some neutrals, add a ground bar, jumper with bare #4, make up neutrals and grounds again

Sometimes the neutral and ground from each circuit are together in one hole. Got to remove all of them and make up all over again.

Many times, the multiple wires under one screw have been twisted together, and the wires aren't long enough to just cut the Twisted part off and re-strip
 
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