DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Electrical (http://www.diychatroom.com/f18/)
-   -   Number of wires under one neutral bus bar terminal screw? (http://www.diychatroom.com/f18/number-wires-under-one-neutral-bus-bar-terminal-screw-9845/)

Beren 07-12-2007 02:16 PM

Number of wires under one neutral bus bar terminal screw?
 
I was looking at our main panel today (residential, 100A service) with the cover removed. I noticed that in a couple of places, more than one neutral or ground is terminated under a single terminal screw on the neutral bus bar. Is this kosher? I don't know if there's a "one terminal, one wire" type rule regarding the neutral/ground bus bars.

HouseHelper 07-12-2007 02:31 PM

For neutrals, it's one wire per screw. For grounds it may be 1,2,or 3 depending on the panel manufacturer. There should be a label either inside the panel or on the door that will tell you how many are allowed on the ground.

Beren 07-12-2007 02:53 PM

Thanks House, I'll look that up!

johnny331 07-12-2007 09:37 PM

How did they use all the terminals up? They usually have enough for full capactity of the "skinny" breakers...

lhoney2 07-13-2007 06:55 PM

I put a new breaker panel in at at our house last weekend and I had to double encumber a few of the lugs because there simply wasn't enough slack in the wires to reach the next lug down. I thought it made more sense than making a splice inside of the panel.

HouseHelper 07-13-2007 07:13 PM

Better to put a splice than chance a loose neutral due to more than one wire under a screw. There is no restriction to wirenutting two wires together inside a panel as long as there is enough space to do so. Most modern panels have that space.

lhoney2 07-13-2007 07:50 PM

Househelper, thanks for the info. I'll wirenut them asap.

Beren 07-14-2007 08:43 AM

Quote:

Originally Posted by HouseHelper (Post 52842)
Better to put a splice than chance a loose neutral due to more than one wire under a screw. There is no restriction to wirenutting two wires together inside a panel as long as there is enough space to do so. Most modern panels have that space.

This might resolve my first issue. I was checking to see if there's space to swap out the bedroom breakers for AFCI breakers, and to swap two other breakers for a SSP. I know the pigtails for the AFCIs and the SSP /must/ be as short as possible. So, I could if necessary splice a few other lines together to make room? Or is it better to get a longer length neutral bus bar and install it?

HouseHelper 07-14-2007 10:16 AM

You do NOT want to be combining several neutrals under one wire nut with a pigtail to the buss: you risk overloading the pigtail. And most neutral bars are not replaceable.
For each AFCI breaker you add, you will be removing a neutral from the bus (it will now go to the breaker). If the breaker pigtail won't reach the now open hole, just add a short length of white wire to the pigtail to extend it.

Beren 07-14-2007 11:28 AM

Quote:

Originally Posted by HouseHelper (Post 52892)
You do NOT want to be combining several neutrals under one wire nut with a pigtail to the buss: you risk overloading the pigtail. And most neutral bars are not replaceable.
For each AFCI breaker you add, you will be removing a neutral from the bus (it will now go to the breaker). If the breaker pigtail won't reach the now open hole, just add a short length of white wire to the pigtail to extend it.

Right, what I meant was that if there is a ground wire in a spot I need on the neutral bus, I could move that ground wire into a shared spot with another ground wire. Assuming my particular panel allows more than one wire under a screw in the neutral bus, that is. The neutral wire coming from the AFCI breaker would not share a hole. The idea being that I could move a ground wire to another spot if doing so would allow the neutral wire from the SSP to be take the shortest path possible.

HouseHelper 07-14-2007 08:48 PM

Well when you put it that way, that is a good plan as long as this is a main panel (you said it was) and the neutral and ground buses are the same.

Beren 07-15-2007 03:07 PM

Would a licensed electrician be able to install a longer neutral bus bar if the existing one is already at safe capacity?

JohnJ0906 07-17-2007 03:56 AM

Quote:

Originally Posted by Beren (Post 53007)
Would a licensed electrician be able to install a longer neutral bus bar if the existing one is already at safe capacity?

Yes, but I think adding a ground bar and moving the grounds to it would be easier and cheaper. The end result (more room on the neutral bar) would be the same.


All times are GMT -5. The time now is 11:48 AM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved