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Wiring main panel box for dedicated 20amp line.

I'm getting ready to install a dedicated 20 amp line and came across something I wasn't expecting. I have a single GE main panel box that's about ten years old. When I opened the box I was expecting to see neutral wires at one bus bar and the ground wires attached to the other, with the black wire - of course - attached to the circuit breaker.

Instead, I found the neutral and ground wires for each outgoing wire attached to the same bus bar on adjacent screws. I've since read that this is common practice and apparently up to code on a main panel.

To install a new 20 amp line, I could duplicate this setup with adjacent vacant spots on one of the bus bars and a new breaker, but I'm wondering if using a common bus bar for both the neutral and ground wires is suitable for a hi-fi application? The whole idea is, of course, to have a dedicated, properly grounded circuit for my gear. Also, if it's not ideal, would a small sub-panel be a desirable solution?

I'd be grateful for anyone's expertise. Thanks!
grimace
jadem6's avatar
jadem6
1,074 posts
 
Your right Yogiboy that the mains come in as a single line, but for some reason you can get more noise from one side of the panel verses the other. For this unexplained noise issue, a sub panel might be quieter I guess it would depend on where the sub panel was pulled from, certainly either the dedicated line or the sub panel should be pulled from the opposite side of the panel as motors are on. On my panel I moved all the motors, refrigerator, boiler, dishwasher, washing machine and well pump) to one side of the panel. My dedicated circuits come from the other side. I don't have a sub-panel, but if I did, I would pull it from the quite side and consider using fuses vs switch breakers.
The reason why noise does not filter equally across the panel in that it's all connected is beyond my knowledge. I do know in my house things got quieter when I switched all the noise to one side.
gvasale's avatar
gvasale
99 posts
 
The electric panel is an extension of the great parallel connected network. You really don't want all of the breakers on say the left, & nothing on the right. Each side is fed from one of the pair of live wires in the feed. You're better off, if you really need another 20 amp circuit to do it on the opposite side.
yogiboy's avatar
yogiboy
5,717 posts
 
Jadem6,You are lucky that that works for you. The only problem with that is that having all high current stuff on one side can trip the main breaker. The main panel is 240 volts,120 on each side! Like I said it's great that it works for you!
tls49's avatar
tls49
1,351 posts
 
You're better off, if you really need another 20 amp circuit to do it on the opposite side.
The breaker box should balanced on both sides, however dedicated lines for audio need to be on the same side. Searching the forums about this, dedicated lines on opposite sides is said to cause phase problems and increase the chance for ground loop hum.
grimace OP
624 posts
 
Thanks for the responses. I only needed one outlet and I placed the ground and neutral wire in adjacent spaces on the right bus bar. I chose that one only because it's the one the main ground wire attaches too. Seems to be working fine. The far bigger issue was wishing the wire through the wall, but even that wasn't too bad.

Regards,
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