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Double tapped


Mark P
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This is a sub-panel in a garage. AL wire running off a 60 amp breaker from main panel.

I could not read the AWG markings on the wire, therfore I'm vague in my report about the ratings. Anyway, would one of you electrical gurus please take a look and see if I'm using the correct verbage or if I'm missing something here. Thanks in advance.

Mark

"Garage sub-panel: The main lug is double tapped. There is a second, smaller (red), wire attached to the main lug. The larger wire appears to be rated for 60amps, the smaller wire is rated at around 20 amps, both are connected to a 60 amp breaker in the main panel in the house. In the case of an electrical short or other problem the red wire may melt down and cause a fire before the 60 amp breaker trips. A qualified electrician needs to make appropriate repairs, to this sub-panel's wiring."

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Looks like the black conductor probably is double tapped to the other hot lug.

"the red wire may melt down and cause a fire". I think I would change "may" to "will" or "is likely to".

You probably know this, but you have also got equipment grounds on the grounding bus and double lugged grounding conductors. No grounding of the panel that I can see.

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I'm not exactly sure what you've got there Mark. You're saying both the larger feeders for that panel and the small red wire run back to the same 60 amp breaker at the main panel? Double-lugged at both ends?

You may be better off being more general in a multi-messed-up case like this. Off the top of my head, I'd say something like this:

"This sub panel is wired wrong and is potentially hazardous. Among the errors I saw were 3 wires instead of 4 (no separate neutral and equipment ground wires), double-lugging at the main lugs, double-lugging of neutrals at the neutral bar, and neutrals and equipment grounds terminated on the neutral bar together. Potential hazards related to these wiring mistakes include over-heating, fire, and accidental shocks. You should have an electrician check all of the wiring related to this panel and make whatever changes and repairs are needed to make it safe and National Electric Code compliant."

Or you can go with the shorter, Kurt-inspired version:

"The wiring in this panel is messed-up and dangerous. Have someone who knows what they're doing fix it." [:D]

Then there's the fantasy version:

"Wow, some idiot really screwed this wiring up badly, and if the right/wrong conditions lined up with this crummy wiring, the results could be injured or dead people (maybe even a burned-down house to go with that). Find an electrician who actually understands how to wire a sub panel and have him straighten this mess out as soon as possible."

And last but not least, the "friendly" version:

"It was observed that the wiring in this panel could use a little...tweaking. Hey, nothing big you understand, just a few minor things that should be no problem at all to take care of. What a great house!"

Brian G.

Take Your Pick [:P]

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Looks to me like it may be a 'multi-wire' branch circuit (red coming off the top of the left 110V lug, black off the right 110V lug?).

The red (and black guy at right) have no 'dedicated overcurrent protection' and are only protected by the 60A disconnect 'upstream of here'. It is an improper 'tap' with no dedicated overcurrent protection. Of course, the 60A disconnect is 'too big' to protect that wire (or wires...). Photo is tough to discern exactly what is going on. Looks like no 'equipment ground conductor' in that feeder as well..

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Originally posted by AHIS

This is a sub-panel in a garage. AL wire running off a 60 amp breaker from main panel.

I could not read the AWG markings on the wire, therfore I'm vague in my report about the ratings. Anyway, would one of you electrical gurus please take a look and see if I'm using the correct verbage or if I'm missing something here. Thanks in advance.

Mark

"Garage sub-panel: The main lug is double tapped. There is a second, smaller (red), wire attached to the main lug. The larger wire appears to be rated for 60amps, the smaller wire is rated at around 20 amps, both are connected to a 60 amp breaker in the main panel in the house.

Hold it right there. When I first read this, I thought, as Brian did, that you meant that one end of the red wire is connected to the sub panel lug and the other end is connected to the 60-amp breaker in the main panel. After looking at the picture, I think you're simply saying that the only overcurrent protection for the red wire is the service panel's 60-amp breaker. You need to make that clearer.

In the case of an electrical short or other problem the red wire may melt down and cause a fire before the 60 amp breaker trips. A qualified electrician needs to make appropriate repairs, to this sub-panel's wiring."

What's the red wire for anyway? Is is part of a multi-wire circuit as Rob speculated?

Of course you're also going to mention the lack of ground-neutral separation, the doubled up neutrals, the four grounding wires under one lug, and whatever other sins are present outside the photo.

-Jim Katen, Oregon

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Thanks everyone, your correct the the only overcurrent protection for the red wire is the service panel's 60-amp breaker, I did not word that very well. I have no idea where it ran after it left the box. Yes I had all the grounding problems addressed, even though I don't understand the why behind it all.

What i would like is some education on why is doubling up the neutrals or grounding wires under 1 screw a no no. I understand why the two have to be seperated in the sub-panel, but I don't know why the grounds can't share the same lug. I see it all the time, (I know that does not make it right). If you could recommend a good educational source, electrical wiring for dumb a@@es, or something it would be appreciated.

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Hi,

The schematic and labeling on the box will often tell you what size conductors can be used under those bus lugs. As far as I know, there isn't any prohibition against multiple equipment-grounding conductors (grounds) under a single terminal, as long as the maximum number of conductors for that terminal is not exceeded. However, grounded conductors (neutrals) may not be doubled.

ONE TEAM - ONE FIGHT!!!

Mike

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Originally posted by AHIS

. . . What i would like is some education on why is doubling up the neutrals or grounding wires under 1 screw a no no. I understand why the two have to be seperated in the sub-panel, but I don't know why the grounds can't share the same lug. I see it all the time, (I know that does not make it right). If you could recommend a good educational source, electrical wiring for dumb a@@es, or something it would be appreciated.

The white wires can't be doubled on the neutral terminal bar because the terminals were not tested for (and are not listed & labeled for) more than one current carrying conductor. The problem with putting two white wires under one lug is exactly the same as putting two black wires under one breaker lug (unless that lug was designed for two wires); the connection might overheat or arc.

As for the grounding wires, the label will allow either two or three wires per lug, usually depending on the size of the wires. I've never seen a panel that allowed four grounding wires (or more) under a lug. The problem here is that, with that many wires, some of the wires might not have an adequate connection to the lug to clear a fault.

The code reference is 110.3(B). It says that the equipment has to be installed in accordance with its listing & labeling.

- Jim Katen, Oregon

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Why are there seven nuetrals, and seven grounds, with only four breakers in the box? The doubled up mains are probably because they already tripled up the breakers? I think that this photo should be part of the Licensing exam, ie-find the problem(s) in this picture.

Thank you all for your informative and entertaining answers. I have learned a lot in the past year from you regular guys, and it is very appreciated.

Mel

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The grounded white conductors "neutrals" can only terminate with one conductor per terminal and the EGC's may take two or more of the same size under a terminal when the instruction so state that fact per 110.3(B).

If that picture is a sub panel then the problems get worse and the reports expanded, see 408.40 and 41 in the NEC.

Let me know if you need a copy.

PS: This forum is a breath of fresh air!

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Originally posted by electricalinspector

The grounded white conductors "neutrals" can only terminate with one conductor per terminal and the EGC's may take two or more of the same size under a terminal when the instruction so state that fact per 110.3(B).

If that picture is a sub panel then the problems get worse and the reports expanded, see 408.40 and 41 in the NEC.

Let me know if you need a copy.

PS: This forum is a breath of fresh air!

Hi Joe. We're pleased to have you here. Please contribute as often as you can.

For those who don't know, Joe's a genuine guru.

- Jim Katen, Oregon

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