Panel Rewire - Opinions, Please

[big john]

I'm doing some work for my landlord, it's free of charge because of very generous room and board, and because some of it desperately needed to be done [E.g.: Flood lights dim - Turned out they were wired in series. Spot-lights not functional - Wiring was in such bad condition that from the sub-panel to the j-box there was a 33V drop with no load.] They had fire damage [read: damaged wiring] and the landlord did a lot of the wiring himself so it needed to be replaced. I was having such a time trying to remove old circuits/terminate new ones in the service panel that I decided to rewire the panel. I've done panel work before, all of it was checked afterwards by a mechanic so I know my terminating practices are sound.

However, this is the first panel were I have terminated everything in it with the exception of the service conductors (including GECs). To be honest, I don't think I came up with enough of a plan before-hand regarding where circuits would be placed in relation to where the conductors enter the box. It's a bit of a mess, and it might be a pain in the rear for someone to service in the future, neither of those am I too happy about. (Though, believe it or not, it's 1000% better than the rats nest the homeowner had crammed in there.)

Tell me what you think. Tell me what you would do differently. I'd like all opinions no matter how small or insignificant you think they are. What are some rules of thumb you try to follow when terminating a panel? Don't sugar coat it! (Though I wouldn't expect that from this bunch ) If it needs to be said, I'm all ears.



Thank you all for you input. And thank you for any help you've given by answering my questions in the past. I'm truly privilaged to be in the company of true professionals such as yourselves.

-John

 

[noxx]

Re: Panel Rewire - Opinions, Please

It's really late and I'm really tired, so only going to pose one question tonight.

It appears the feeders are aluminum, and I don't see any tell-tale smudges of noalox around them. Were the feeders treated at the terminations?

 

[big john]

Re: Panel Rewire - Opinions, Please

Tired? Having horrible insomnia is where it's at!

To answer your question, what you see is a trick of the light: Those feeders are copper.

-John

 

[iwire]

Re: Panel Rewire - Opinions, Please

Not that using noalox is a bad idea if listed for the purpose, noalox is not a NEC requirement that I know of.

John one thing I have to ask is why are white conductors landing on a equipment ground bar?

It is fine at the main to use the neutral bar for equipment grounds, but using the equipment ground bar for neutrals is at least a violation of the listing and I feel a violation of 310.2(B)

The way you have it set up you are using the steel of the enclosure as a full time conductor.

310 Conductors for General Wiring
310.2(B) Conductor Material. Conductors in this article shall be of aluminum, copper-clad aluminum, or copper unless otherwise specified.

250.118 specifies that the enclosure can be used as a grounding conductor.

That said I do not think it looks bad for a panel replacement.

On a how I would do it perspective, I like to keep the neutrals and grounds separate on all panels because IMO it looks neater and leaves more of the neutral bar free for the future, you are half way there as you installed a ground bar.

 

[iwire]

Re: Panel Rewire - Opinions, Please

Originally posted by big john:
Most of the original wiring came in the right-hand top or right-hand side, so the right-side of the panel was full of breakers. I tried to duplicate that to help avoid having to fill the bottom half of the panel with KO blanks if I spaced the breakers evenly on both sides.

This is fine you still have balance, the only wrong way would be to use only one bus.

Originally posted by big john:
The double pole breakers were originally spaced at random, with two of them at the bottom of the panel [30, 30, 40 and 50 amps, respectively]. Those were the first things I moved and terminated.

You could have left them where they where, if the loads on these breakers are drawing the voltage down and affecting the other branch circuits moving the breakers will not change this.

A few extra inches of 200 amp rated bus will not change voltage drop much.

Originally posted by big john:
None of the screws on the neutral/ground bus have more than one conductor under them, though they are listed for it.

Listed or not it is an NEC violation (408.21) to have more than one grounded conductor (neutral) under a screw. If listed for it you may put more than one grounding conductor under a screw.

John please take this in the spirit it was given, I think it is great that you are fixing this wiring and that you feel confident enough to ask questions.

You have chosen what I think is an interesting trade, one that you should never stop trying to learn new things.

I have been doing this awhile and it may sound like BS but the more I learn, the more I do not know.

Just when you think you have a handle on this trade things change or you find that you have been doing things wrong just because "we have always done it that way"

Take Care and Good luck, -Bob

 

[goldstar]

Re: Panel Rewire - Opinions, Please

John one thing I have to ask is why are white conductors landing on a equipment ground bar?

It is fine at the main to use the neutral bar for equipment grounds, but using the equipment ground bar for neutrals is at least a violation of the listing and I feel a violation of 310.2(B)

Bob,

This is a "main breaker" panel. The neutral bar and EGC are one and the same via the metal jumper strap going from one side to the other.

Big John,

I know this is an existing installation that you're just cleaning up "pro bono" but I would consider building some type of shroud around the steam pipes (especially since there's a union directly over the panel) to prevent possible water damage or leakage into the panel.

 

[david]

Re: Panel Rewire - Opinions, Please

There is a factory Main bonding Jumper between the two bus bars so I don?t see a problem with landing the grounded conductors on ether of these bus bars.

Is the service entrance installed using PVC?
Is the panel level?
Are your NM Cables secured with in 12 of the panel?
Are all unused openings effectively closed?
Are all the single pole breakers identified as suitable for this panel?
Is the equipment ground bonded to the junction box for the 8/3- WG?

 

[iwire]

Re: Panel Rewire - Opinions, Please

Originally posted by goldstar:
Bob,

This is a "main breaker" panel. The neutral bar and EGC are one and the same via the metal jumper strap going from one side to the other.

Phil, I am aware this is a main but I do not agree that the neutral bar and the equipment ground bar are the same thing even though they are electrically connected.

How would you feel about landing the service conductor neutral on the ground bar or the enclosure itself? (With correct lugs)

Do you think it is wise to pass continuous current through the steel of the enclosure?

Did you look at my code references?

Not trying to be a PITA, but IMO this is a big deal.

Bob

 

[david]

Re: Panel Rewire - Opinions, Please

Bob

Neither one of these bus bars are floating they are both factory bonded to the enclosure and there is a main bonding jumper in the form of a wire strap between the two.

 

[david]

Re: Panel Rewire - Opinions, Please

250.24(A)(4)
Main Bonding Jumper as Wire or Busbar. Where the main bonding jumper specified in 250.28 is a wire or busbar and is installed from the neutral bar or bus to the equipment grounding terminal bar or bus in the service equipment, the grounding electrode conductor shall be permitted to be connected to the equipment grounding terminal bar or bus to which the main bonding jumper is connected.

 

[goldstar]

Re: Panel Rewire - Opinions, Please

How would you feel about landing the service conductor neutral on the ground bar or the enclosure itself? (With correct lugs)

Bob,
Electrically speaking, it's the same point at the breaker panel via the jumper strap.

How would you feel about landing the service conductor neutral on the ground bar or the enclosure itself? (With correct lugs)

Although it's not directly landed onto the EGC bar it is the same point via the green bonding screw.

Do you think it is wise to pass continuous current through the steel of the enclosure?

The enclosure is not floating. If the EGC's from the ground rod and cold water main are properly installed (I usually use a metal NMC connector and strip the insulation where it enters the connector and bond it there and at the buss bar) the cabinet is bonded to ground.

Did you look at my code references?

I read the section but don't see where the violation is. Could you be more specific ?

Not trying to be a PITA, but IMO this is a big deal.

I'm still trying to figure out what a PITA is. Way down here in NJ it's a Syrian pocket bread. PLease explain.

Regards,

Phil

 

[david]

Re: Panel Rewire - Opinions, Please

How would you feel about landing the service conductor neutral on the ground bar or the enclosure itself? (With correct lugs)

___________________________________________________________________
Although it's not directly landed onto the EGC bar it is the same point via the green bonding screw.

Phil,

250.28(A) Material. Main bonding jumpers shall be of copper or other corrosion-resistant material. A main bonding jumper shall be a wire, bus, screw, or similar suitable conductor.

Be careful, though a screw is included in the material list in 250.28(A) it is left out of 250.24(A)(4) unless there is a main bonding jumper in the form of a wire or bus-bar you cannot say these are electrically the same points. You cannot land the service neutral to a lug that is bonded to the enclosure unless there is a main bonding jumper in the form of a wire or bus-bare tying the grounding electrode conductor to the grounded conductor. Also keep in mind by definition the main bonding jumper must tie the equipment grounds to the grounded conductor. For these to be the same points there needs to be a main bonding jumper in the form of a wire or bus-bar sized according to 250.66

250.28(D) The main bonding jumper, at times will have to be larger than the grounding electrode conductor

[ September 30, 2003, 07:40 AM: Message edited by: david ]

 

[rickcham]

Re: Panel Rewire - Opinions, Please

Big john

where is the EGC?? I do not see it in the panel.

 

[rickcham]

Re: Panel Rewire - Opinions, Please

Big John

hit the post buttom to fast, also wanted to add nice work overall

 

[hillbilly]

Re: Panel Rewire - Opinions, Please

Looking at the picture it appears that there is a aluminum bus between the two terminal bars. If there is, the install is OK in my opinion. If not, I don't believe any white wires should land on the left side (bonded) terminal.

 

[charlie]

Re: Panel Rewire - Opinions, Please

I have been doing this awhile and it may sound like BS but the more I learn, the more I do not know.

 

[charlie]

Re: Panel Rewire - Opinions, Please

BTW (By The Way) IMHO (In My Humble Opinion) PETA means Pain In The - - -.

 

[ryan_618]

Re: Panel Rewire - Opinions, Please

Originally posted by charlie:
[QB] BTW (By The Way) IMHO (In My Humble Opinion) PETA means Pain In The - - -.

Silly me...I thought PETA was people for the ethical treatment of animals. I think Charlie's definition is more accurate!

 

[big john]

Re: Panel Rewire - Opinions, Please

Originally posted by david:
Is the service entrance installed using PVC?
Is the panel level?
Are your NM Cables secured with in 12 of the panel?
Are all unused openings effectively closed?
Are all the single pole breakers identified as suitable for this panel?
Is the equipment ground bonded to the junction box for the 8/3- WG?

The service is in PVC conduit.
The panel is level.
The branch circuits will be secured within 12" of the can when I am done.
KO's will be sealed when I'm done.
All breakers are listed for the panel.
The EGC is not yet properly bonded to that j-box. That is a 30A feeder to a subpanel that I'm probably going to end up replacing. As it stands now it's cloth-insulated 10/3 going seventy feet to the subpanel. The rigid is the EGC but it comes into the sub through reducing washers and there's no bond-bushing. I'm probably gonna pull 8/4 or 8/3 and just put bond pushings on the conduit and use it as the EGC.

Originally posted by rickcham:
...Where is the EGC?

Maybe that was a mis-type and you meant GEC? If that's the case: In the upper right corner there are two brown-looking conductors that terminate on the neutral bus. Those are #4 bare copper, one goes to the ground rod and one goes to the cold and hot water pipes.

Regarding the neutral conductors on the grounding bus:
Both of those are factory installed steel busses with a steel bonding jumper between them.
I've seen panels wired with neutral conductors on the grounding/neutral busses and I've seen them wired with only EGCs on the grounding bus. I always thought it was a matter of preference. I couldn't find anything in code regarding objectionable current on a main bonding jumper, so I'm not sure what to do.

If the consensus seems to be that installing it like I have poses some sort of hazard, I'll certainly rewire it so that only EGCs terminate on the grounding bus.

Anything else?

-John

 

[noxx]

Re: Panel Rewire - Opinions, Please

Just a note. On your average residential meter-combo, the service grounded conductor terminates below the meter, and is connected to the grounded buss via the same type of strap across the can. It's designed to carry current, and if the system is properly grounded, presents no hazard.