Load Center Replacement-Neutral Wires Too Short!

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Old 04-30-08, 12:19 PM
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Load Center Replacement-Neutral Wires Too Short!

Hi all,,
I could use some expert opinions on my federal pacific load center replacement.
I got a new box and $200 worth of breakers (returning them to sutherlands, HD is a lot cheaper...).
But I have a problem. The old neutral/ground bus was at the bottom of the box, the new box has the neutral bus at the top and ground bus at the side, so the neutral wires are not long enough.
See the chopped up attachment. It is roughly to scale and relatively positioned like I plan to install it, the new box is a little bigger than the old. 27x11.5 -vs- 30x14.
I think I'm OK with the ground bus; my plan is to mount the new box slightly lower, so the top of the new box wil be where the old one was and it will hang down a bit lower. That will mean the new hole I will cut in the back for the loads will be a little higher in the new box and farther to the right. I will also cut a new hole for the feed wires just above the existing knockout on the left side.
The breakers will be relatively lower in the box, so I should have plenty of slack on the hot leads, and the grounds should reach the new ground bus, but I will need to replace the neutral feed wire from the meter socket and somehow extend the neutral load wires to reach the new neutral bars at the top of the box.
Is it OK to splice the neutral wires inside the load center? I would probably use copper barrel splices, crimp, solder and heat-shrink them.
Sound like a plan?
I suppose the alternative would be to knock out another brick above the main breaker and pull the wires into the box at the top. Then I would also need to reposition the ground bus...
Thanks in advance,
Walter
 
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Old 04-30-08, 12:32 PM
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Cutler Hammer and probably Square D make a panel for retrofit that has a neutral bus located very close to the top of the panel - and you can probably turn it upside down. Otherwise just use wire nuts, right pros?
 
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Old 04-30-08, 12:45 PM
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Originally Posted by wamcneil View Post
but I will need to replace the neutral feed wire from the meter socket
Check the spec sheet on your new panel. You can probably mount it main breaker down configuration so the feeder neutral is long enough to reach the lug.

Another options is to use a splitbolt or buttsplice connector to extend the feeder neutral. Look for Polaris brand connectors -- they make some nice ones that would work in this situation. Check your local electrical supply company.

http://www.polarisconnectors.com/370..._EXTRA_ISR.pdf

and somehow extend the neutral load wires to reach the new neutral bars at the top of the box.
Is it OK to splice the neutral wires inside the load center? I would probably use copper barrel splices, crimp, solder and heat-shrink them.
Just plain old wirenuts are fine for this purpose. It's very common in a panel upgrade.
 
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Old 04-30-08, 02:36 PM
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Thanks for the quick input!
So wire nut splices are OK inside the panel? That will make my life a lot easier.
I can't invert the front panel without hacking it pretty bad, so I think I'm stuck with the existing configuration.
BTW, if it is significant, this is a square d QO 20 space, 30 pole, 150A load center.
  • Feed Wires- The meter socket is only ~2" from the load center, so the feed wires are pretty short. A new neutral feed would just need to be ~3 1/2' long so I think I'll just replace it. I'm assuming it has a screw down attachment inside the meter socket similar to the ones inside the load center?
    The existing neutral feed is #4, where the hot feed wires are #1. Should they all be #1?
  • New holes-Anybody see a problem with my plan to cut a new hole for the feed wire conduit just above the existing (still intact) knockout at the lower left side?
    I could raise the box and use the existing knockout, but that would put the two lower mounting holes inside the load wire entrance hole in the brick. And it would make the ground wires too short.

    And are there any special concerns about the location of the hole in the back for the load wires to enter the house?
Thanks again!
 
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Old 04-30-08, 02:45 PM
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Originally Posted by wamcneil View Post
So wire nut splices are OK inside the panel? That will make my life a lot easier.
Yep.

just need to be ~3 1/2' long so I think I'll just replace it. I'm assuming it has a screw down attachment inside the meter socket similar to the ones inside the load center?
Usually it's a big #1 phillips screw or a hex drive lug (allen wrench). Replacing the neutral conductor creates a bit more of a safety issue, because the hot side of the meter can is always hot even when the POCO disconnects the meter. You'll have to ask the line technician to disconnect your service at the pole or to just make the connection in the meter can himself if he's willing to do that. It is too dangerous for you to do this on your own.

The existing neutral feed is #4, where the hot feed wires are #1. Should they all be #1?
The #4 is probably okay. In order to know for sure you can do a neutral demand load calculation. Given the very short distance it wouldn't be a big deal just to make it #1 and forget the calculation. The neutral wire should also be wrapped in a spiral of white tape to mark it.

Anybody see a problem with my plan to cut a new hole for the feed wire conduit just above the existing (still intact) knockout at the lower left side?
It's okay. Just make sure to use a fitting or bushing through all holes to protect wires from sharp metal edges.

And it would make the ground wires too short.
You could buy an add-on ground bar kit and drill/tap screw holes in a more convenient location for the ground bar. The ground wires can also be lengthened with wirenuts if needed.
 
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Old 04-30-08, 05:25 PM
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Thanks,
I'll make the call on the neutral feed once I have pulled the meter.
I had another idea: I could abandon the stock neutral buss alltogether and put another ground buss in the lower left side wothin reach of all the neutral branches can reach it. And it would be in reach of the existing short neutral feed.

Would that be cleaner/preferable to splicing the neutral branch wires and using the stock neutral buss?
W
 
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Old 04-30-08, 08:29 PM
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with the breaker box like that i useally turn the gut upside down and it is common for me to do that if you want go that route but keep your mind the cover door will be reversed.

and the other thing before you actally unhook any wire make a note of any circuit that is on 240volts so you will have to remark it properly otherwise you will be saying "what the heck i go wrong".

also you may end up putting in new ground rods and check the bonding connection at the water meter if you have copper supply pipe there.

Merci,Marc
 
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Old 04-30-08, 08:46 PM
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Maybe it is just the pictures (or the way I am looking at it) but something looks "funny" to me where those service (or feeder?) conductors are entering the new(?) panel and where the branch circuit conductors are entering the old panel.

I don't see any conduit connected to the box. It does kind of look like the new box has some sort of channel behind it where the conductors are coming up but...???

And in the old box it looks like the branch circuits were cable but the cables were never fastened to the box but just came through a hole in the wall and into the box.

Is this kosher?
 
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Old 04-30-08, 09:24 PM
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It's just the roughly photoshopped pictures. I altered the picture of the new box to represent where the wires will be running. The old box is still on the wall outside, the new box is pictured on the garage floor. I copied chunks of the picture on the right and pasted them on the left.
Yes, in the old box the branch circuits come through a hole in the brick wall and then into the load center through a hole inthe back.
 
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Old 04-30-08, 09:27 PM
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Originally Posted by french277V View Post
also you may end up putting in new ground rods and check the bonding connection at the water meter if you have copper supply pipe there.

Merci,Marc
I have been a little concerned about the ground; there is no ground rod. I assume the large black wire in the ground/neutral bus attaches to the plumbing somewhere inside the house. Should I supplement it with ground rods?
 
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Old 04-30-08, 10:12 PM
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Yes you will have to drive in new ground rods anyway.,,

the wire from ground rods to the main breaker is #6 [ if sized for 100 amp but for 150~200 amp you can stay with #6 as well ] but for bonding the 150-200 amp box sizes you have to run #4 bare or green wire to the copper pipe and make a new jumper as well.

the other thing if you bring in the wires in from the back you will need a bushing so that way the wires don't get cutted or nicked when you install the new breaker box.

as i will mention when you drive the ground rods keep them about little over 6 feet apart and make sure you don't hit water or sewer pipes along the way.

Merci,Marc
 
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Old 05-01-08, 08:51 AM
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I believe Sq D panels are designed to mount 'upside down' as well. Since the main breaker trips left to right (and not up/down), you can flip the whole panel over.

The front cover shouldn't matter as you'll mount that 'upside down' as well. Notice there's no writing on it that will end up being upside down - it's all written sideways intentionally. (the wonders of industrial design).
 
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Old 05-01-08, 07:25 PM
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The nipple coming into the panel with your feeder needs to have a plastic bushing installed on it per NFPA 70.
If you don't have locknuts on both sides, please install bonding bushings on both sides.
The large hole with all the branch circuits isn't right but if your inspector will allow it, at least use a bushed nipple.
Too many cables in one hole presents the possiblility of overheating.
 
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Old 05-01-08, 08:27 PM
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Hang on guys, Look at the picture closer. It is an outdoor panel and can't be flipped upside down because of the weathr proof cover design.

Also since that is your main panel, your grounds and neutrals are the same... meaning the ground and neutral bars should be tied together through the metal enclosure.

Your new panel should have came with a bonding screw (Green in color) use that to bond neutral and grounds together. in fact I see it in the picture on top left corner of neautral bar...make sure it is tightened down all the way, they ship it loose from factory.
 
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Old 05-02-08, 07:39 AM
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Thanks again for all of the input!
Right, the panel cannot be flipped without hacking the cover and drilling all new screws to mount the backplane. That's not goint to happen.
At this point I'm leaning toward just mounting a new neutral bus in the lower left. That way the neutral feed and the existing branch neutrals will reach. It may be a little crowded in the bottom of the box, but I won't need to splice anything. I have removed the neutral bus from the top of the backplane since it will not be used. The old box used a common bus for ground and neutral.
Originally Posted by dezwit View Post
The nipple coming into the panel with your feeder needs to have a plastic bushing installed on it per NFPA 70.
If you don't have locknuts on both sides, please install bonding bushings on both sides.
The large hole with all the branch circuits isn't right but if your inspector will allow it, at least use a bushed nipple.
Too many cables in one hole presents the possiblility of overheating.
What is a bonding bushing?
All of the existing wiring goes through the one hole in the back of the housing and there are only about 20 branches in use, does code specify that multiple conduits be used to exit the box? I will use a plastic bushing in any case. Where is a good place to get one? HD does not seem to have them.
I thought this was a more straightforward issue than it apparetnly is and people are calling my attention to aspects I had not considered, so here is a little (no, a lot!) more background to put it in context:
This is a 30 year old house with a largely unmolested 150A electrical system. My inspector called attention to the original Federal Pacific external load center as being a hazard and recommended replacement (this was the only issue he had with the electircal system) so I am just replacing it with another 150A Squar D QO series that I found in the clearance items at a sutherlands. It would have been a cheaper to put in a 200A load center (because that is all that the discount home centers stock now...), but service to the meter is not up to 200A.
Underground mains enter the meter socket from below. It is located 2" from the lower left of the load center where the feed wires enter the box. Hot feeds are #1 and the neutral feed is #2 (I misstated the neutral feed as being #4 earlier in the post).
All but one branch circuit exits the box through that hole in the back which is located over a brick that has been knocked out of the wall for that purpose.
A #4 ground wire exits the box through the hole in the back and re-emerges from the base of the wall where it is connected to a single grounding rod (just found that yesterday).
I do not believe that I need to pull a permit for this work because it is a replacement of existing components, not modification of the electrical system; I had to describe what I was doing before the power company would agree to remove the meter lock without a permit.
I do not intened to get a formal inspection when I am done and I am not neccessarily concerned with meeting the letter of the current code (eg- I do not plan to install a 2nd ground rod). The house is in great shape, but I am sure there are numerous aspects of this 30 year old house that would not conform to today's code.
My objectives, in order of importance are:
  • SAFE
  • A little better than every other house in the subdivision
  • I don't want to get dinged by the inspector when I sell the house like the PO did.
 
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Old 05-02-08, 08:42 AM
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New Plan

OK, Here's the new plan presented in a slightly more refined photoshop format.

I'll try to find some kind of 3" bushing to put around the exit hole and some kind of liner for the conduit coming in.
How does this sound?
 
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Old 05-02-08, 09:22 AM
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You probably will need a permit and inspections, especially since you will have to get the power company involved to pull the meter and open the meter base (if that is needed) and you will be modifying the equipment a bit.

A bonding bushing has a terminal to connect a grounding conductor to. You will probably need one for the meter conduit.

I have no problem with a supplemental neutral bus, if you can get one.

You may or may not have to make the new box meet current codes. You have to ask your local authority that question. Do not assume you do not have to.
 
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Old 05-02-08, 11:53 AM
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The new drawing looks ok, just make sure the bar use has a hole big enough for the #2 neutral to fit. If it doesn't they sell neutral adapter kits which basically screws into 2 of the smaller ground bar holes and turns it into a #1 Terminal.

Make sure your neutral bar is physically screwed into to metal of the box so that it is bonded.

The bonding bushing will go on the threads of conduit coming in from meter. It goes on after the locknut and will have terminal on it to accept a ground wire wire. The ground wire in your case will be #6 copper.

If you can get a close up picture of that pipe coming in the back we could probably give you a few ideas
 
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Old 05-02-08, 01:04 PM
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Originally Posted by rich3236 View Post
If you can get a close up picture of that pipe coming in the back we could probably give you a few ideas
I don't think I could get a picture that would convey any more info, I can't see much looking into it, just a crowd of wires.
There is no pipe; just a brick knocked out of the wall behind the box and a hole cut in the box to allow the branch circuits in. I'm hoping I can gain a couple of inches effective length on the branch circuits; the existing hole is on the left side of the brick opening and my new hole will be fairly centered over the brick opening and a little closer to the source of the branch circuit wire bundle.
I can't find a grounding bushing on the HD website. If I add lock nuts to the condiut coming into the box from the meter will that suffice?
 
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Old 05-02-08, 11:34 PM
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The Bonding bushings is a shelf item at HD, they may not have bothered to list on the site, they are around $3 and come in different pipe sizes. They are required for service equipment. You could also use what they call a bonding locknut ( Regualr locknut with a screw in it to bite metal)

the whole point of the bushing is so you are not relying on the locknut for a ground, Locknuts can become loose over time etc.. I have seen a loose locknut glow orange from being so hot after a short occurred since the locknut was loose not allowing the fault to go to ground.

It in effect caused the pipe and locknut to become a resistive load ( like coils of a toaster) instead of tripping the breaker.
 
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Old 05-03-08, 09:39 PM
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Done!!!

Ok, I got it done today.
I found a grounded bushing and put that on the service conduit. To bring the branch circuits into the box I got a 2 1/2" PVC conduit end, cut a couple of threads back and chamfered the end.
Here's what it looks like now. Anything I should rethink?
Thanks!
Walter




 
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Old 05-03-08, 11:54 PM
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Wow, Really nice job on that. Looks good. Only thing I see and I can't really tell from pic is the second screw of bonding bushing doesn't look tight all the way. It should bite into the threads of the connector if it isn't already.

Another thing you may want to think about if you are in an area that loses power is a generator interlock kit that will fit right on that new panel and allow you to feed gen power to all your circuits as needed. They cost around $70 for the square D panels
 
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Old 05-04-08, 02:25 PM
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Looks pretty good to me.

Is that black wire on the ground bus in the bottom right your #4 GEC to the water main or is an unmarked ground or neutral from a branch circuit?
 
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Old 05-04-08, 03:01 PM
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Not saying it is technically wrong, but I am unnerved by the service conductors running overtop the branch conductors. The bonding jumper seems a bit short. There could be a bit of slack in it.
 
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Old 05-04-08, 04:14 PM
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Thanks y'all!

The screw in the bonding bushing is pretty snug.
I'll keep the interlock in mind, but a generator is not currently in the budget!

The large black wire on the ground bus goes to the grounding rod just below the load center.

I don't have much choice but to run the service conductors over the top of the branches. That's the way it was originally done and to do otherwise would involve a lot more modification than I am willing to get into.
I may put a bit longer bonding wire next time I have the box open.


Walter
 
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