Double tap bus bars - is this too code?

[wazzabie]

The neutral and ground bus bar in the main panel has double taps.

This is not my panel but it is representative of what I see. At most there are two taps wires per hole.

Should this be a concern?

 

[slow]

look and see what the panel rates the number of conductors for a ground/neutral.

 

[wyliesdiesels]

Definitely not for the neutrals. that needs to be fixed.

I just fixed an old zinsco panel last month that had the same problem.

Some panels allow 2 grounds per hole. check the listing and labeling on the panel

 

[wyliesdiesels]

look and see what the panel rates the number of conductors for a ground/neutral.

code does not allow grounded conductors/neutrals to share a lug. one neutral per lug.

equipment grounding conductors/grounds on the other hand, depends on listing and manufacturer

 

[Norcal]

The neutrals must be terminated one conductor to a screw, many ground bars are listed 2 sometimes 3 grounding conductors per hole, but must be the same size and material, which means no mixing 12 & 14 AWG & cannot mix copper and aluminum conductors.

 

[slow]

code does not allow neutrals to share a lug. one neutral per lug.

grounds on the other hand depends on listing and manufacturer

Thanks for the info

 

[wazzabie]

Here is a photo of what I have on the bus. It is a joint neutral and ground bus.

Should there be some documentation on the panel on as to if I can use more then one wire in a hole?

 

[wyliesdiesels]

Is there a label on the panel door?

The neutrals MUST be one per hole.

The max number of grounds per hole depends on listing on label.

But cannot have more than one neutral per hole nor a neutral and a ground on the same hole.

 

[wyliesdiesels]

Easy and fairly inexpensive to buy an auxiliary ground bus bar and move the duplicated neutrals to it. Seems I remember it's about $8 to buy one at the hardware store. Then, just jumper from the new bar to the panel bus with a #6 bare copper. A couple of hours of sorting out and moving the neutrals, and neatening up the wires so it looks professional. Sort out and move the ones that reach the best.

Looks like there's some open slots on your existing bar also to spread them out.

Theres no need for the jumper between the bars.

 

[wyliesdiesels]

The neutral and ground bus bar in the main panel has double taps.

This is not my panel but it is representative of what I see. At most there are two taps wires per hole.

Should this be a concern?

Just to confirm- theres no panels or disconnects ahead of this panel? Just a meter?

 

[AntonLargiader]

Just to confirm- theres no panels or disconnects ahead of this panel? Just a meter?

That is not his actual panel.

 

[mm08822]

Easy and fairly inexpensive to buy an auxiliary ground bus bar and move the duplicated neutrals to it. Seems I remember it's about $8 to buy one at the hardware store. Then, just jumper from the new bar to the panel bus with a #6 bare copper. A couple of hours of sorting out and moving the neutrals, and neatening up the wires so it looks professional. Sort out and move the ones that reach the best.

Looks like there's some open slots on your existing bar also to spread them out.

Relying on the mount screws and the can for conductor? On a neutral bar, I much prefer a solidly connected copper conductor! Even if you use a bonding screw to the can.

And, of course, if it's a secondary panel, code doesn't permit the neutral bar to be bonded to the can.

I think the confusion results b/c you said install grd bar and move neutrals to it.

If I were adding a ground bar, I would move the grds to it and keep all the neutrals together on the factory installed neutral bar.

 

[mm08822]

i haven't found a section of code the explicitly addresses this, but continuity of path and appropriate conductor sizing sections as well as panel listing requirements would cover it indirectly.

250.8 a(5) & (6)

 

[mm08822]

That addresses individual equipment grounds and bonding jumpers, but doesn't explicitly address establishing a grounding path for a ground bar. It definitely wouldn't apply to a current carrying neutral bus bar, in my opinion.

I've seen a wide range of interpretation of this by inspectors over the past few years.

Screws into enclosure are only for gnd bars, no neutral bars.

Listed accessory ground bars from a mfr typically rely on two fasteners to mechanically secure and bond it to the already grounded enclosure. The instructions for installation require nothing further. If you want to add an additional jumper between bars there shouldn't be an issue. I would at least use the min size required for that service/feeder egc. And its purpose is for gnds only.

A neutral bar is sold as a different part # for a different purpose. I would think a ground bar used as a neutral bar could fail inspection as it is being used for a different purpose. (No I don't have the listing details for either.)

If there was a second neutral bar field installed (and not excluded in mfr instructions), I would think the same conductor supplying neutral to the panel would be required to jump between neutral bars unless the mfr supplies a jumper. Anything less alters the mfr's rating of the neutral bar "system".

I have yet to ever add a second neutral bar to a panel. Only replaced one, once.

 

[wazzabie]

Definitely not for the neutrals. that needs to be fixed.

I just fixed an old zinsco panel last month that had the same problem.

Some panels allow 2 grounds per hole. check the listing and labeling on the panel

Did you replace the Zinsco panel?

 

[wyliesdiesels]

Did you replace the Zinsco panel?

No.

It was still in good shape and customer doesnt have the money.

 

[wazzabie]

No.

It was still in good shape and customer doesnt have the money.

How did you know the Zinsco was in good shape?

 

[wyliesdiesels]

Bus bars were clean, no corrosion no arcing no melting.

No corrosion on the enclosure

Neutral bus bar looked good. Lugs still turned

Main disconnect was smooth with no hang ups or rattling.

Ive seen my share of zinsco panels in poor and very bad shape.

 

[wazzabie]

The first pic is of my Sylvania panel which has a Zinsco main breaker. The other breakers are not of the zinsco design and can be found as the Sylvania breakers at home depot.

The second pic is not my panel but it has the same design. I find that the metal clip that I rectangle in yellow is loose. When I put the panel cover back on the clip fell down and I was not able to move the main from the off to the on position.