Add a neutral bus bar?

[andyvh1959]

I'm close to wiring the detached garage 100 amp sub panel to the 200 amp main panel in my attached garage. I have the ground connected, and soon I'll install the 100 amp duplex breaker (on the open area on the main panel) that will feed the sub panel. My issue is the neutral. See the attached pics for the details in the Cutler Hammer Load Center main panel as it was wired back in 1973. Not impressed with the sloppy wire routing done back in 73 by a supposed "master electrician" as told to me by the original owners. But I've never had an electrical issue since I bought the house in 2002, other than finding live, unterminated Romex wires hanging under each deck, not in a box. This 200 amp main panel also feeds another 100 amp sub panel in the basement.

I just routed the conduit from outside the back wall of the attached garage into the main panel. My issue is I have a #2 AWG copper neutral coming into the main panel from the sub panel. Almost all the lug connections on the neutral bus bar are full, and none of them will fit a #2 copper wire. My question is can I add a separate neutral bus bar to which I can connect the #2 neutral?. From that extra bus bar I can run #10 white wire to a lug hole on the current neutral bus bar. If I can add a neutral bus bar does it have to be isolated in any way to the back of the panel, as in making sure it does not connect at another ground path to the panel and the panel ground bar? Or should I only use a crimp on cable lug which provides a #10 "pin" to go into an open lug hole on the neutral bus bar?

The panel has one ground connection that I can see which is routed out of the panel and down, so I assume it runs to a single ground rod. Again, the house was built in 1973 so there may only be one ground rod. My new detached garage has two ground rods six feet apart. Just want to make sure I am following any codes so when the final electrical inspection is done the end of this month I can pass with no issues. Hopefully the current 200 amp main panel passes inspection based on meeting code from the early 70's.

 

[brewchief]

Issues that I see, your new feed coming in needs to be in conduit the whole way. There are currently multiple neutral wires in each hole on the neutral bar, two grounds are normally allowed but only one neutral.

I would see if I could add a ground bar, there are normally some threaded holes in the panel and you might get lucky and have a current cutler hammer ground bar line up with those. I would then move as many grounds to the ground bar as possible to allow each neutral wire to have its own hole and hopefully enough room to add a lug designed to mount on the neutral bar that allows a larger wire. Same type of lug for the ground going most likely to the new ground bar.


I would also spend some time cleaning up that panel and routing wires as neat as possible without cutting them much shorter, at some time in the future I see a panel replacement and theres no sense having to extend a bunch of wires if you can avoid it.

Sent from my SM-T510 using Tapatalk

 

[andyvh1959]

Ok, good point about the conduit coming in. I assumed that once in the wall it could be routed to the panel without being in conduit. If that is required by code I'll change that right away. Glad I posted it here before the electrical inspector get his eyes on it.

I noted too about the doubled up neutrals in some of the lugs, thought about changing that. To do so I'll have to add onto the neutral and ground busses like you mention.

Would be nice to clean up the wire routing in the panel although I've had no issues. Not sure the electrical inspector would see it that way though. Also, if I clean it up, organize it better I bet I have better success getting my work approved.

 

[Bert_]

You have a major code and safety issue unless you are still planning on finishing that conduit run.

Looks like there is a lug up near the top that would take a #2.

 

[wyliesdiesels]

Add a ground bar and move all grounds over.

As said, neutrals cant be double up but grounds can be

If this is a subpanel, then there isnt a way to add another neutral bar unless you can find the risers that will insulate it from the enclosure. Do you have enough holes for all the neutral wires if you move the grounds over to new bar?

feeder definitely needs to be in conduit inside the wall.

 

[andyvh1959]

Thanks all, now I know what to do tomorrow. Finishing the conduit run for the feeder to the panel is not an issue, I can do that. Perhaps after I get the neutrals and grounds routing cleaned up I'll have more clearance to add a lug on the neutral bus bar to accept the #2 AWG neutral. With cleaning up the neutral wires routing I should have enough lugs to get each neutral into a separate lug hole. I can add a ground bus bar to clean up that routing also.

 

[TRWham]

Your existing ground electrode may be your water pipe with a single supplementary rod that was probably added later. If the incoming water pipe is still copper and the GEC connection is made within 5' of it entering the building that should be acceptable. If the pipe has been changed to plastic, then you can add another rod and connect the 2 rods into a system.

As for the existing neutral terminations, the code was silent on stacking neutrals in the 70s, however, UL was not and the panel mfgs did not support it. It was common (nearly universal in my experience) to land the neutral and ground for a circuit together but that was not really correct either. The explicit language requiring each neutral to have a separate terminal was only added to the NEC in the early to mid 90s as I recall. I agree that adding a ground bar and singling up the neutrals on the existing bar is probably a better solution. I have the same panel in a 30 space version and have to say the number of neutral bar terminations is barely adequate.

You need to mark those black conductors appropriately (neutral either white or gray and ground either green or bare) on both ends.

 

[Stuff]

Looks like there is a threaded hole on the neutral bar. If the threads are correct there is the Eaton NL20 neutral lug kit: https://www.homedepot.com/p/Eaton-125-Amp-Neutral-Lug-NL20/100198084

 

[andyvh1959]

Now that others have clarified what I need to do, perhaps the thread should be titled "Add a ground bus bar." So for that, is there anything particular (code wise) about adding a ground bar in an older load center? Does code allow for the ground bar to simple be screwed into the back of the panel after drilling some holes and using approved screws to connect the new ground bar to the panel? Again, I don't want the electrical inspector to tell me, "that's not to code and has to be corrected."

Update; passed electrical inspection yesterday. Green Bay inspector had been here a couple times earlier and I made the corrections he noted. Yesterday he did the final inspection, tested a bunch of circuits with a trip-tester. Everything passed.