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Discussion Starter #1
Looking inside the electrical panel in the house I bought, I was surprised to see the neutral bus bar crowded right up next to the ground bus bar, so much so that it seems the ground bus bar is virtually impossible to access in order to secure grounding wires to it.

Here's a photo:



The neutral bus is to the left of the ground bus, and it stands slightly forward of the ground bus. You'll notice that the neutral bar is loaded with double-taps - including both neutral and ground wires. I'm not even certain there are ground wires actually connected to the ground bus (it's pretty well hidden) - though as you can see in the lower right corner of the photo, the very thick service ground wire that connects the ground bus to the plumbing and grounding electrode.

The bus bars and double-taps are seen more clearly here:



Looking at this next photo - the handling of the ground wires pictured has me asking if this is wrong and needs to be corrected?



Here, ground wires terminate outside the panel box, though bonded to it.

As well, a couple ground wires inside the panel box are kind of twisted together, with at least two wires wrapping around a couple of others that are connected at the neutral bar.

The panel box is an old Murray Class CTL Load Center, Cat. No. LC 240 PS that may date back to the 70's, when the former owners bought this house. The only information I've been able to find about what it's original intended configuration was supposed to be is a diagram on the panel door that actually shows two vertical columns of screw heads/lugs (side-by-side) that appear to represent those bus bars, numbered like the breaker spaces.

Questions, questions! Were these bus bars installed correctly? How was/is someone supposed to access that ground bus with it being so tight against both the neutral bus and the inside of the panel box? Also, I mentioned the numbering of the bus bar lugs to correspond with the breakers numbering, and so I wonder does it really matter in what order neutrals and grounds are connected to their bus bars?
 

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The grounds for the lower bar will slide under the upper bar.
 
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The panel is probably okay for now due to grandfathering.

The ground wires twisted together outside the box may have been properly installed at the time the panel was installed but nowadays simple twisting is not enough. Wire nuts or in some cases certain kinds of clamps are needed.

One of the clusters pictured would need to be completely untwisted and twisted the other way (clockwise with the wire ends pointed at you) just before the wire nut is screwed on.

Two ground wires of the same size can share a hole. Each neutral wire needs its own hole.

Suggest turning off the main breaker, then unhooking all the neutrals and all the grounds. Then insert the grounds, as many as possible, two per hole, into the lower bar. Then insert the rest of the wires including the neutrals into the upper bar.

Two wires entering a hole should be symmetric about the screw shank and not touch each other.

The order of the wires does not have to match the (numeric or physical) order of the breakers.

You can put fairly sharp L bends in the wires to get them into the holes better but the bends should not be sharper than would be the case if you were curling the wires around an imaginary wire or screw shank three times the diameter of the wire you are bending.
 

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Firstly, I don't suspect anybody relocated the ground bar from it's manufactured location. Although the location is poor, when the panel is wired from scratch, the grounds (bonding conductors) can be connected with free open access. True, additional wiring added to the panel will be difficult to ground as the ground bar in now concealed by the frontal neutral conductors. Its just something you/they will have to deal with.

Secondly, while connecting the grounds to the neutral bar is against code practice, it's not a safety issue. The neutral is grounded at the service anyways. Your reference to a "very thick service ground wire" is used to accomplish just that.

Thirdly, the external open ground wiring (above the panelboard) is also disapproved by codes. However, by way of function....it works. While the past homeowner/s may have done things wrong, at least they took the time to bond the branch circuit wiring to ground! I would suggest you move those external grounds, that is, destine them to the panelboard's interior. Loosen the existing Romex cable-clamp connectors, pull each cable's ground into the panel where it belongs. If their long enough to reach the ground bar, terminate them there.
 

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Discussion Starter #5 (Edited)
Thank you to all of you for the helpful info and suggestions!

These next two photos show both the full panel of breakers, and the door-mounted diagram of the breaker spaces and bus bars.





Given how the breaker space numbering (1 - 40) matches the bus bar numbering - which seems to suggest there are only 40 slots at the entire bus bar complex - then how would it ever be possible to fit, say...34 neutrals, and lets say, an equal number of grounding wires? The neutrals must be one to a slot, and the grounds can be doubled and even tripled(?). Perhaps I could do some pig-tailing of some of the grounding wires? It seems odd to me that the panel maker allowed so much room for breakers, but not the connection space for the neutrals and grounding wires that would also be necessary.
 

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@ HouseIsBoss:

"...then how would it ever be possible to fit, say...34 neutrals..." = Good question to ask.....I suspect is because the manufacturer knows that some of those breakers are going to be 2-pole (range, dryer, garage, AC, etc.....) occuping two (2) breaker spaces but only one neutral conductor requires connection.

"...grounds can be doubled and even tripled..." = more than one ground is permitted under the same compression set-screw......However, this is not recommended for neutrals.
 

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The NEC requires the neutral to be in a dedicated hole. It is not to be shared.
 
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Discussion Starter #8
Exactly, @Jim Port. Which is why it seems my panel comes up woefully short in supplying dedicated holes for neutrals in comparison to the number of breakers the panel actually holds. I'd certainly love to explore putting in a large ground bar extension to free up the current bar configuration to hold all of the current neutrals - one per hole, and place most of the ground wires in the extension. My concern is that the age of the panel may make it impossible to find the correct-fitting ground bar extension. Anyone have any thoughts on that? I included the make and model of the panel in the original post, and haven't been able to find anything on the internet about it. Would it be worth a stop at a supply house to try and find the correct ground bar extension? Or would something made for today's panels sold at a big box possibly fit?
 

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You would use a ground bar. See picture below.

I was surprised, but Home Depot does actually have them. Home Depot's are Square D. So they're not identical to that shown below.....but in principle, their the same.

Model# PK23GTACP

When/if you install this into your panelboard, you'll see two (2) screws (self tapping are fine) are needed to mount it to your panelboard's interior. It's a good practice to grind off the panelboard's grey paint before screwing the ground bar in place. This way, there are no dielectric materials between the grounded panel chassis and your new supplementary ground bar.
 

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Which is why it seems my panel comes up woefully short in supplying dedicated holes for neutrals in comparison to the number of breakers the panel actually holds.
Murray panels have always been, shall we say, 'economical' solutions. If it didn't need it, it didn't come with it. There's nothing wrong with that until like minded electrical contractors start installing them improperly. Why spend a couple of dollars for a ground bus now when there is sufficient space for what I am doing? Leave it for the next guy. Then the next guy starts doubling up the lugs since none are free. You get the idea.

My concern is that the age of the panel may make it impossible to find the correct-fitting ground bar extension. Anyone have any thoughts on that?
Murray was acquired by Siemens and are still made by them. Most of their ground bar kits are listed for use in Murray panels. Even Home Depot and Lowe's should have them. Look for the models with the L bracket attached and it will state it is suitable for use in Murray panels.

Your situation is actually not that bad. A ground bar or two, maybe some Greenies, will let you clean things up to snuff for less than $30 in materials.
 

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Discussion Starter #12
@Power- Thanks for the product suggestion. I quickly plugged the model # into Google and it came up with hits at both Home Depot and Amazon that look like this:


It's a closeout item on Amazon (but available). If you don't mind me asking (because I've seen a bewildering amount of these kits available for so many different panel brands - enough that I was ready to throw my hands up w/o any forthcoming help from the original manufacturer), what is it that makes this the correct fit for my particular old panel?

Being that this version differs from the picture you showed me, does that change your recommendation in any way?

I'd love to get one of these installed and properly bonded to the existing neutral-ground buses, and to the main ground connection.
 

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Discussion Starter #13
@Fishbulb28: Thanks for the background on Murray panels, and for pointing me in the direction of the "L" bracket bus bars. I did see something like that, but as I lamented in another post, there's just so much available that I really didn't know which way to go without an expert's knowledge, manufacturer help - or pulling all the wires to really get a really good look at the bus bar ( but that would mean going through the process twice). I'll consider this along with @Power-'s suggestion.
 

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I am understanding your putting considerable thought into this.

We're not building a piano here.....this is just a ground bar. While they mechanically look different, they all electrically perform the same thing. I think the ground bar I pictured for you earlier was Burndy, but the one I referenced at Home Depot was Square D. True, they are from different manufacturers, but in principle, they're identical.

You simply screw these to a location accessible for you in the panelboard....there is no pre-drilled or pre-determined location for adding supplemental ground bars. Like I mentioned before, ensure the paint is removed (grind it off with a Dremel or manually with sandpaper) under your prospective location. Then screw it down with two self-tapping (self-drilling) screws.
 

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I'm not going to go into all the nuances but instead I'll state you need to install a ground bar from the panel's manufacturer for two reasons:

1. It will fit without modification to any equipment.
2. The combination has been tested by a national reliability test laboratory, which is a requirement.

So you're left with two choices for the ground bar kit:

1. Murray branded kit. They're still made and still available. But you won't readily find them in stock at home improvement centers or hardware stores. Electrical supply shops or Internet sources will have them.

2. Siemens branded kit which is listed for use in the Murray panels. Siemens makes more than one line. Look for the ones which have an integrated L bracket. These kits will plainly state they are for use in Murray equipment as well as Siemens. You'll find these kits in stock everywhere.

The outermost holes in the bracket will align with prepunched holes in the panel. You'll find a pair of these prepunched holes in two to four places. I see one pair on the left side in your photo. There will be a corresponding pair on the right side in the same location and possibly more pairs. Use the supplied screws to attach the bracket and the installation is done. The bars are bonded through the screws to the equipment panel.

These kits come in a few sizes. Which size(s) to get is up to you. More spaces mean less bundling or eliminating bundling the grounding conductors altogether. But the larger buses will take up more room.
 

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I am understanding your putting considerable thought into this.

We're not building a piano here.....this is just a ground bar. While they mechanically look different, they all electrically perform the same thing. I think the ground bar I pictured for you earlier was Burndy, but the one I referenced at Home Depot was Square D. True, they are from different manufacturers, but in principle, they're identical.

You simply screw these to a location accessible for you in the panelboard....there is no pre-drilled or pre-determined location for adding supplemental ground bars. Like I mentioned before, ensure the paint is removed (grind it off with a Dremel or manually with sandpaper) under your prospective location. Then screw it down with two self-tapping (self-drilling) screws.
I know it is done but a violation to use self tapping screws for the ground bar. Not enough metal to metal contact
 

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I'm not going to go into all the nuances but instead I'll state you need to install a ground bar from the panel's manufacturer for two reasons:

1. It will fit without modification to any equipment.
2. The combination has been tested by a national reliability test laboratory, which is a requirement.

So you're left with two choices for the ground bar kit:

1. Murray branded kit. They're still made and still available. But you won't readily find them in stock at home improvement centers or hardware stores. Electrical supply shops or Internet sources will have them.

2. Siemens branded kit which is listed for use in the Murray panels. Siemens makes more than one line. Look for the ones which have an integrated L bracket. These kits will plainly state they are for use in Murray equipment as well as Siemens. You'll find these kits in stock everywhere.

The outermost holes in the bracket will align with prepunched holes in the panel. You'll find a pair of these prepunched holes in two to four places. I see one pair on the left side in your photo. There will be a corresponding pair on the right side in the same location and possibly more pairs. Use the supplied screws to attach the bracket and the installation is done. The bars are bonded through the screws to the equipment panel.

These kits come in a few sizes. Which size(s) to get is up to you. More spaces mean less bundling or eliminating bundling the grounding conductors altogether. But the larger buses will take up more room.
Scroll up and look at the age of the OP's panel! Any grounding kit that is endorsed by Murray and/or Siemens is going to be a ground bar, perhaps some mounting brackets, and two self drilling screws......and of course, a "SIEMENS" sticker.

Like I said before.....the OP is not building a piano. It's just a ground bar.
 

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Square D does have drilled and tapped holes for the ground bars.
 

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Discussion Starter #20 (Edited)
Thanks to all, gentlemen! Your explanations really helped me to understand what the configuration is in this old panel box, and what was missing, as well as what was needed with wiring "clean-up". I've decided to use this Murray ground bar kit, which I found at both Home Depot and Amazon:


It's a Siemens 28 Terminal Position Kit from Home Depot, Model# ECLX075M - though it's listed at Amazon by the same model number, but under the Murray name. I chose it because the bracket elevates it, allowing easier access to the wire slots, and because the bracket holes align 2" OC with the pre-drilled holes at the lower left side of the Murray panel box.

Because the Grounding Electrode Conductor is #2 (aluminum) wire, I'll bond this new ground bar to the original neutral bar using #4 copper. I've determined that the original neutral bar was installed in an insulating framework - but this being the main (and only) panel - the neutral bar was required to be bonded to the panel. (This panel is the service disconnect, and there is only a service meter outside the house.) If the aluminum GEC didn't do this (where it exits the panel box through a clamp) then I must assume some other means (hidden from view behind the wires) was used to bond the neutral bar to the panel. I'll look to confirm this.

Anyone see any issues with this setup, or does all seem well as newly configured?
 
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