I’m running a new branch circuit for my garage (first, and hopefully last, time I’ll need to use 10 gauge) and have a question about the neutral-ground bus in my GE 200 amp service panel.
All of the slots on both buses are full. There are, however, some open slots on what look to be auxiliary buses mounted on either side near the edge of the panel. There are small stickers adjacent to these busses that read “equipment grounding only”. I note that there are both ground and neutral wires going to the main busses, but only grounds running to the “auxiliary” buses.
Is it permissible, and/or good practice, to run multiple wires into the same slot on the neutral-ground bus? I’m thinking “not”. If not, I assume I need to remove a ground wire from the n-g bus, re-rout it to the “auxiliary” busses, and use the now empty slot in the n-g buss for my new neutral?
Why would these “auxiliary” buses be appropriate for grounds, but not neutrals?
Thanks for any insight.
Replies
bump
Is your panel full? More than 42 breakers? It would almost seem that it would have to be.
His panel need not be full. Many manufactures still do not provide enough space to land 42 grounds and 42 neutrals in the panel.
To the original poster: You can move a ground wire from the N buss to the G buss and land your new neutral on the N buss.
The reason the auxilliary G buss is not sufficiant for neutrals is that the service neutral is connected directly to the neutal buss, but would by connected to the ground buss only through the bonding strap and the steel cabinet of the panel. By landing the neutral on the ground buss you would be using the steel cabinet as a circuit conductor-not good.There are no electrons! It is all made up. Don't believe it.
Electricity is made by GREENIES.
Thanks, Bosn! As you surmise, my panel is not full. I still have room for 6 breakers.
Also the neutral wires can only be one per hole.For ground wires, if the label approves it, you can have 2 wires per hole.
(A definitely wrong) WAG: Why not free up some real estate on the neutral bar by piggying a couple-three neutrals tightly together with a brass-collared marette, and running a single piggy under the neutral screw?
Disclaimer: I am not an electrician.
(Edit: See CAP's post below which explains why my WAG is NOT the way to go.)
http://www.costofwar.com/
Edited 11/26/2005 9:36 pm ET by Pierre1
Edited 11/26/2005 9:55 pm ET by Pierre1
You ask, why not pigtail two or three neutrals in the panel?
Because the single pigtail conductor could possibly carry the return current for all two or three circuits. It'll overload and that's bad.
Let's say that you had the neutrals of three, 15 amp circuits pigtailed to one 14 gage conductor that was terminated on the neutral bar. Let's assume that all the circuits are fed from the same pole or leg of the service.
At any given time, say the three circuits are running at 12 amps, 10 amps and 10 amps. As a consequence, that short length of #14 is carrying the sum of the currents--32 amps. Thes gives you overload, overheat, insulation meltdown (eventually), and very likely a loose connection at the terminal bar (with the wire heating up considerably more than design spec, it'll loosen quicker).
On the other hand, you could splice two or three equipment grounding conductors (EGCs) together and take a pigptail (of the same gage wire) to the ground bar. This is because the EGC only carries current when there's a fault, and then only long enough to trip the breaker
Thanks for the correction and explanation.http://www.costofwar.com/