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Discussion Starter · #1 ·
Is it okay to put multiple ground wires in one hole in the ground block and multiple neutral wires in one hole in the neutral block in the main panel?
 

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If it is the main panel without any disconnect ahead of it, both neutral and ground wires can go on the same bar. If you have to put 2 wires under 1 screw, be sure both wires are the same size. If not, the larger wire will hold the setscrew away from the smaller.
 

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What would be the reason to have two under a single nut? Usually there’s sufficient space for each neutral to have its own terminal. If you can’t reach an open one just pigtail another wire to reach an open spot.


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A "Handy Husband"
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What would be the reason to have two under a single nut? Usually there’s sufficient space for each neutral to have its own terminal. If you can’t reach an open one just pigtail another wire to reach an open spot.


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Some panels (especially older ones) have a limited number of neutral/ground bar slots. Doubling ground wires is compliant, doubling neutrals is not.

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Can you put a second neutral/ground bar in a main panel to add more space?

Can you put similar size wires in a wire nut and then run a jumper to the bar?

Can you use a "Greenie" for ground wires to have one single run to the bar?

Just asking some questions that I am sure others want to ask. And so I can learn more.

And, I understand that some of it depends on the AHJ. (Which means what again?

Thanks, Dan
 

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You can add a additional ground bar to make more room but the easiest way is to take several ground wires and wire nut them to a pigtail and use a single space on the bar. You can use any color wire nut. The pig tail must be the size of the largest ground wire. You can't do this with neutrals.

BTW, the reason you cannot have 2 neutrals in one slot is that if you open a neutral inadvertantly, you can cause issues with the other circuit. If you do this with a MWBC, you will fry electronics.

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Multiple neutrals on one terminal in a breaker box is against code and dangerous - even life threatening. I am astounded that anyone here would condone the practice, even if they have seen it done. The reason:
Say you are working on a circuit and have opened the breaker to ensure the circuit is safe to work on. However, the neutral of this circuit is doubled with that of another - still hot. If you happen to remove the neutrals from the neutral bar, the neutral of the hot circuit is now hot, possibly lethal, and the person doing the work is likely not aware of it. 'Voltage' is feeding from the hot breaker through any lights, appliances, etc. that are turned on and appearing at that disconnected neutral, now at a 120V potential. There is no current flowing unless something or someone touches this hot neutral and a neutral/ground. Bingo! Crispy critter. So no, it is not safe.
 

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Discussion Starter · #17 · (Edited)
You can add a additional ground bar to make more room but the easiest way is to take several ground wires and wire nut them to a pigtail and use a single space on the bar. You can use any color wire nut. The pig tail must be the size of the largest ground wire. You can't do this with neutrals.

BTW, the reason you cannot have 2 neutrals in one slot is that if you open a neutral inadvertantly, you can cause issues with the other circuit. If you do this with a MWBC, you will fry electronics.

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Aha! This is why I posed the question in the first place, to find out if an electrical problem could be created by it. So, it's not that having multiple neutrals in one hole is the problem (because the electricity is all lumped together on the neutral bar), but that causing a disconnect (voltage surge?) in one of the other circuits in the same hole, especially if the juice is still on while loosening the set screw. I hope I got that right...

Stuff like this intrigues me.

*Adds Neutral Bar extension*
 

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Discussion Starter · #18 · (Edited)
Multiple neutrals on one terminal in a breaker box is against code and dangerous - even life threatening. I am astounded that anyone here would condone the practice, even if they have seen it done. The reason:
Say you are working on a circuit and have opened the breaker to ensure the circuit is safe to work on. However, the neutral of this circuit is doubled with that of another - still hot. If you happen to remove the neutrals from the neutral bar, the neutral of the hot circuit is now hot, possibly lethal, and the person doing the work is likely not aware of it. 'Voltage' is feeding from the hot breaker through any lights, appliances, etc. that are turned on and appearing at that disconnected neutral, now at a 120V potential. There is no current flowing unless something or someone touches this hot neutral and a neutral/ground. Bingo! Crispy critter. So no, it is not safe.
Awesome! I reckon stuff like this is why there's an Electrical Code. Even if it looks like it makes sense to do something a certain way, it may not be correct/safe.

Any chance oldelectricguy's above post (not mine) could be pinned? He probably just saved me and others a nasty shock/surprise.
 

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So, it's not that having multiple neutrals in one hole is the problem (because the electricity is all lumped together on the neutral bar), but that causing a disconnect (voltage surge?) in one of the other circuits in the same hole, especially if the juice is still on while loosening the set screw. I hope I got that right...
No, Rj is talking about a MWBC which is 2 hot legs sharing a common neutral (most commonly found as a kitchen circuit). If that 2nd neutral you disconnected and left the breaker on happens to be a MWBC, there is no normal return path for the neutral current. So power from the black hot will attempt to return through the red hot and vice versa.

It back feeds up the neutral of the opposing leg. Since they are 180 degrees out of phase with each other, when they meet at the device you have 240v accross the device. Since more and more kitchen appliances have digital clocks and other electronics (120v), when you put higher voltage and larger current through them, you fry those clocks and any other control boards that are turned on.

There is no power surge involved, you just accidentally put 240v across a 120v device.
The risk with the 2nd circuit having its own neutral is the 1st case. Making the 2nd circuit a MWBC with a shared neutral, adds a 2 risk on top of the 1st.
 

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Sure, add another acronym. What is MWBC?

A greenie is not just a different color of wire nut. It is meant to join ground wires and allow one of them through to be connected to a box, fixture, outlet, and hopefully a bar in a panel.

And, I know you can't have neutrals and grounds in the same bar in sub-panels.
 
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