Ran out of grounds/neutral slots in my main breaker box.

[lzicc]

I installed a 50 amp sub panel in a garage and ran #6 aluminum wire to main breaker box to find out that I am out of openings on the ground/neutral bar. This is an older Murray box and only has 1 bus bar for both neutral and ground.

What I was going to do was double tap one of the existing openings that currently has 1 - #6 ground from a 220 line that is for my central ac on the bar which large enough opening to hold 2 #6 wires in it. I was going to then run that #6 wire to a small ground bar that I purchased. Then from there I can run both my #6 ground wire and my #6 neutral wire to new small ground bar. It seems like that might be ok to do, but wanted to get others opinions. If that isn't an option, I may need to upgrade the box, but I don't want to do that at this time.

 

[radioman]

you should be able to add on a grounding bar to have more room. they have extras at home centers. what i do is i combine couple or several ground wires and twist them together and put it in one lug. the whites i keep them separate (dont combine whites - ever- lugs on neutral bar.

 

[lzicc]

All the large enough openings on the ground the bus bar, which there is only 6, are being used for 220 grounds. So I can't double up the #6 neutral from the sub panel. The ground I can, since that is allowed, but neutral is not. That is where I am stuck.

I do have a second ground bar, just not sure of the correct way to connect it to the existing ground bar and since this Murray box is old, I just picked up a generic bus bar, so it will not be able to be mounted to the breaker box using pre tapped wholes since I can't the one specifically for this box. I'll have to use sheet metal screws to attach it.

 

[Budweiser John]

you should be able to add on a grounding bar to have more room. they have extras at home centers. what i do is i combine couple or several ground wires and twist them together and put it in one lug. the whites i keep them separate (dont combine whites - ever- lugs on neutral bar.

I think you contradicted your self. Only one wire under one lug bo matter where. If the panel in question is a sub panel and down stream from the main service entrance the neutral and grounding conductors must be separate at the sub panel. I.E. the feeder from the service entrance should be 4 wire and the sub panel have separate bus bars, one for the nuturals and one for the ground conductors serviced by that panel.
The natural and ground conductors can only be bonded at the main service entrance.
B. John

 

[lzicc]

You are correct. From the sub panel, I have 4 wires, 2 hots, 1 neutral and 1 ground. The neutral and the ground have their own bus bars in the sub panel. Those feed over to the main main panel. The main panel has only 1 bus bar for both neutral and grounds. There are not any large enough openings for the wire size I am using. What I thought about doing was double tapping one of the existing 220 grounds with a #6 piece of wire and run the other end of that wire to a new, 7 opening ground bar to complete that part of the ground/neutral circuit to the main bus bar. That would leave me 6 opening in the new ground bar to attach my ground and my neutral that is coming from the sub panel. It seems like that would work, but doesn't feel right to me.

 

[RNeumann]

You don't need to "double tap" from one bus bar to the other for the ground. The box itself conducts from one to the other and is grounded. As noted above the ground and neutrals should be separate and the neutral bar shouldn't be indirect contact with the panel box.

As a note- you know you can place multiple wires in one bus bar hole/slot. It's interesting that it's run out of space. That sends a red flag up.....

 

[lzicc]

RNeumann, in the sub panel, the neutral and ground are separate. In the main box, there is only 1 bar and both neutral and ground go to the same bar. If I mount the second ground bar in the box, you are correct about the box grounding once it is mounted, but since I have a neutral coming from the sub panel, I would need to put that in the new ground bar also along with the ground coming from the sub panel. Since the the original grounding bar is bonded with the box, in lack of better words, both neutral and ground are on the same circuit you could so in theory it should work. I've read about running a feeder from the new ground bar to the original ground bar.

The reason it is out of spaces is one, the bus bar handles both ground and neutral, when the newer boxes usually have 1 neutral bar and 1 bus bar. Also, some of these circuits have tandem breakers in them. I do have 2 open spaces, but they will only accept up to 10 gauge copper.

I do need to upgrade this box to a new one and I wanted to put that off for now, but I may not be able to. The big issue with swapping out the boxes is I need to have the power company pull the meter so I can swap out boxes, get it inspected, then have the power company put the meter back in. I live in the house, so I don't have the luxury of waiting for the inspector and power company. I could swap out the box in the matter of hours, but the inspection is what could hold me up.

 

[LD1]

Got any pics of your current main panel?

 

[lzicc]

Here are the pictures. The one is diagram on the door of the box.

Got any pics of your current main panel?

 

[RNeumann]

RNeumann, in the sub panel, the neutral and ground are separate. In the main box, there is only 1 bar and both neutral and ground go to the same bar. If I mount the second ground bar in the box, you are correct about the box grounding once it is mounted, but since I have a neutral coming from the sub panel, I would need to put that in the new ground bar also along with the ground coming from the sub panel. Since the the original grounding bar is bonded with the box, in lack of better words, both neutral and ground are on the same circuit you could so in theory it should work. I've read about running a feeder from the new ground bar to the original ground bar.

The reason it is out of spaces is one, the bus bar handles both ground and neutral, when the newer boxes usually have 1 neutral bar and 1 bus bar. Also, some of these circuits have tandem breakers in them. I do have 2 open spaces, but they will only accept up to 10 gauge copper.

I do need to upgrade this box to a new one and I wanted to put that off for now, but I may not be able to. The big issue with swapping out the boxes is I need to have the power company pull the meter so I can swap out boxes, get it inspected, then have the power company put the meter back in. I live in the house, so I don't have the luxury of waiting for the inspector and power company. I could swap out the box in the matter of hours, but the inspection is what could hold me up.

Ok easy enough. The main panel can accept the second bus bar and that bar should be grounded directly to box. It is ok (by code) to commingle neutral and ground in the main panel bus bars- however some would still separate the grounds and neutrals for future diagnosis and looks.

If you wanted to add a jumper between the two bus bars you can. It is a nice thought and shows your desire to do the best job possible and be conscientious about your work.

The separate ground and neutrals in sub panels helps with diagnosis. I know it's a bit strange having to run the extra wire and have separate locations for the neutral and ground in sub panels. But it is code.

 

[lzicc]

So would it be ok to double tap one of the existing 220 grounds so I can use that to link in the new bus bar? Since the 220 uses the 2 hot wires for power, the ground wire is simply a ground wire, there is no neutral wire involved on a 220 circuit. Just making sure on that part. I would double tap the existing 220 ground using a small length of #6 aluminum and the other end of that wire would go into the second bus bar. Then the second bus bar would only have the neutral and ground in it coming from the sub panel. And if I did it that way, I should be able to use sheet metal screws to attach the new bus bar so it is not just danging in the box.

 

[RNeumann]

So to be clear you are trying to hook up the neutral and ground wires that supply power to the sub panel in your main panel?

In the main panel you are adding a second bus bar?

I think you are asking if you can add a second bus bar in the main panel and add add a jumper wire between them.

The answer is yes you can do that.

I understand the desire to use sheet metal screws since the back of the panel isnt accessible. I'd recommend using the self tapping hex screws with fine threads (designed for grounding) instead. It will make for a higher quality install.

 

[LD1]

Hard to tell from the pics, but it looks like the top two large ground/neutral screws on the bar have a mere 10-12 ga wire in them. Can you relocate on the bar to a smaller hole. Didn't you say there were 2 open but only up to 10ga?

I see several openings that look like up to 6ga but sont see than many neutral/ground wires coming in the panel

 

[dstig1]

Save yourself the grief in the long run and upgrade it now. The PowCo and inspectors are usually pretty decent about this type of situation and will schedule same day service. Powco pulls the meter first thing, then you go to town on the box, then the inspector shows up in the afternoon, and the Powco comes back to reconnect. Get as much prepped as you can. Label all wires, loosen all cable clamps, have the new box already outfitted with a bunch of cable clamps and breakers, make sure it will all fit, etc. Then when it's dead, start pulling stuff out and go crazy. Heck, if you can disconnect a bunch (or even a few) circuits ahead of time that you can get by without, that will save time. And maybe borrow/rent a generator if you need lights to see the panel, if it is not near daylight. Or borrow some power from a neighbor if close enough.

You will be happy you upgraded now, as it will make your life much easier down the road.

 

[Rara Avis]

I installed a 50 amp sub panel in a garage and ran #6 aluminum wire to main breaker box to find out that I am out of openings on the ground/neutral bar. This is an older Murray box and only has 1 bus bar for both neutral and ground.

What I was going to do was double tap one of the existing openings that currently has 1 - #6 ground from a 220 line that is for my central ac on the bar which large enough opening to hold 2 #6 wires in it. I was going to then run that #6 wire to a small ground bar that I purchased. Then from there I can run both my #6 ground wire and my #6 neutral wire to new small ground bar. It seems like that might be ok to do, but wanted to get others opinions. If that isn't an option, I may need to upgrade the box, but I don't want to do that at this time.

You can add an insulated ground bar in the panel (you should be able to get one specifically designed for your particular panel, but here's what they look like):



.. and then connect it to the other ground bar using a piece of #4 AWG (solid bare copper, or stranded THHN insulated). This guarantees that the green bonding screw that's actually bonding your neutral on the other bar will affect both bars if it is removed. It's common to add these for isolated grounds, where they're connected to a different ground altogether instead of the other bar.

Note - the one you buy may come with its own bonding screw, and the appropriate tapped hole to receive it - so check for that prior to connecting the two together (IOW, read the installation notes that came with it).

 

[Tractor Seabee]

A lot of good advice here. The pictures show the normal rats nest of wires you encounter, makes it hard to work in there. Take the time to dress things up with neat bundles and bends at connections. Attach the new neutral/ground busses into the box using self drilling/tapping machine screws instead of SM screws. Haven't looked lately but I think the current code requires separation of the ground and neutral busses. Look at a new panel at a big box store for the latest scheme. Several lengths of bars are available. Connect two together with a #6 bonding wire. There are adapters available to expand the #6 size openings into two or three additional points. Might be the best solution for you most pressing point.

Ron

 

[lzicc]

Correct.

So to be clear you are trying to hook up the neutral and ground wires that supply power to the sub panel in your main panel?

In the main panel you are adding a second bus bar?

I think you are asking if you can add a second bus bar in the main panel and add add a jumper wire between them.

The answer is yes you can do that.

I understand the desire to use sheet metal screws since the back of the panel isnt accessible. I'd recommend using the self tapping hex screws with fine threads (designed for grounding) instead. It will make for a higher quality install.

 

[lzicc]

I'm going to call the power company to see what it would take to upgrade the box. I have to do it sooner or later. I really appreciate everyone's input. I can get the box, get the breakers needed and have it somewhat setup. I like the idea of renting a generator if needed. When I do this, if I get this setup with the power company and move forward on this, I will try to position the box so that all wires are long enough. Let's just I run into a few #12 or #14 wires that are not quite long enough, what would be the best way to splice a piece in or would that be against code? That shouldn't be an issue, but I want to run all options in my head prior to doing this.

 

[lzicc]

Also, which company has been around the longest, Eaton or Square D? I've used Square D in the past.

 

[GLyford]

The big issue with swapping out the boxes is I need to have the power company pull the meter so I can swap out boxes, get it inspected, then have the power company put the meter back in.

In theory, that is what happens here. In practice, the utility can't be bothered to do service calls. They instead give each electrician a bunch of seals. Electrician pulls the meter, swaps the box, re-installs and seals the meter, total down time is just the couple of hours to swap the box. I am not even sure the electrician tells the utility which seal they used, but the utility never rolls a truck or lifts a finger to a button.

Inspection happens after the fact whenever the inspector gets there, with the box live.