Subpanel

**Farmhouse1890** · 05-01-2012, 06:38 AM

I am installing a 50 amp subpanel to my second floor to tie in numerous circuits that have resulted from a gut rebuild of all of the rooms. I am running 6/3 wire with ground to the subpanel. There is more than enough capacity for mostly 15 amp lighting and receptacle circuits. I plan to use AFCIs on the 10 or so new circuits that will tie into the subpanel. I understand that on this GE panel it is typical to separate the neutral and ground bus bars and use a screw to ground the ground bus bar to the panel. However in using two columns of AFCIs, it would then be necessary to have the white wire from the AFCIs on the column near the grounding bar run over the AFCIs on the other side to tie into the neutral bar. My plan is to keep the two bars connected as neutral and not ground to the panel so that the white wires from the AFCIs can tie into the bar closest to them. I would feed the ground wires into the separate grounding bus bar that is already part of the panel. Any problem with doing it this way or suggestions for a better way? Thanks

**jadnashua** · 05-01-2012, 09:35 AM

To pass code, a subpanel needs the neutral and ground buses separated. How you do that, depends on the panel. Many offer add-on bus bar extensions.

50A might be pushing it if this includes a bathroom(s) and maybe a computer room or some TV's. Probably okay, but maybe not. If it truly is mostly just some lighting, it should be fine. But, some people end up with some big current hogs, like maybe a window a/c unit or two, a small refrigerator, etc. A laser printer can pull a fair amount when the heater element turns on. It all adds up.

**ActionDave** · 05-01-2012, 09:42 PM

There is nothing wrong with adding a separate buss for the equipment grounds.

Make sure everything you do gets inspected.

**Farmhouse1890** · 05-02-2012, 06:37 AM

Originally Posted by ActionDave

There is nothing wrong with adding a separate buss for the equipment grounds.

Make sure everything you do gets inspected.

Thanks. I will get the permit and inspection.

**Farmhouse1890** · 05-02-2012, 06:41 AM

Originally Posted by jadnashua

To pass code, a subpanel needs the neutral and ground buses separated. How you do that, depends on the panel. Many offer add-on bus bar extensions.

50A might be pushing it if this includes a bathroom(s) and maybe a computer room or some TV's. Probably okay, but maybe not. If it truly is mostly just some lighting, it should be fine. But, some people end up with some big current hogs, like maybe a window a/c unit or two, a small refrigerator, etc. A laser printer can pull a fair amount when the heater element turns on. It all adds up.

Thanks for the response. I went through load calculations and came up with less than 30 Amps, but am doing 50 Amps just in case since there is only a little more cost for wire. The AFCI's will be the biggest cost, but if anything went wrong it would be hard to live with knowing they could have prevented it.

**ActionDave** · 05-02-2012, 07:07 PM

For what it's worth, If you hired me I would not use anything less than a 100A feed for your sub-panel, but that is because I do not anything to sneak up and bite me. But the chances of you drawing more than 50A are greater than winning the next Power Ball lottery.