Tapping into a main lugs connection .

[billybobbobrob]

I have a sub panel that is on a 30 amp breaker feed from the main panel. At this sub panel I have tapped into the main supply lugs to run a feed to an other sub panel that is 3 feet from the first sub panel . The 2nd sub panel is one breaker supplied for a hot tub at 30 amps ...Wire size and breakers is not in dispute, what a home inspector stated was to tap from the main l ugs was not ok I should have used a junction connection some were else othe r than the lug connections there was plenty of room in each lug connector a nd they tightened correctly and all the wiring passed , in dispute is the m ethod of connection for the 2nd sub panel. I had been told by a "electricia n" that junction connections simply have to be contained and were it is con nected it certainly is contained .Any thoughts? oh and the first sub panel is rated at 125 amps.

[wtf]

I would think an electrical inspector would trump a home inspector.

[David L. Martel]

So who is this "home inspector" and why does his opinion matter? Was he your county's building inspector or did the buiding inspector pass all of the wiork?

Dave M.

[dpb]

"NEC Code Quandary

Q1. Is it acceptable to terminate two wires on a single screw or lug?

Q2. Is it permissible to terminate two circuits on a single circuit breaker?

A. Sometimes. According to 110-3(b) "listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling" and 110-14(a) states "terminals for more than one conductor shall be so identified".

The only time two wires can be installed under a single screw or lug is when the terminal is identified for this purpose. Circuit breakers rated not more than 30 amperes are often identified for the termination of two conductors. This can be verified by reviewing the circuit breaker manufacture's catalog.

...

Note: Split-bolt lugs are only permitted for two conductors."

So, the definitive answer with the given information is "maybe, maybe not OK". :)

Does the panel list the feed terminals as suitable for more than one connection? If so, you're ok; if not then no.

[dpb]

On 09/14/2016 7:52 AM, dpb wrote: ...

...

That you wrote "electrician" in quotes reduces the importance of his opinion significantly it would seem; that this person only quoted the portion about being in an enclosure also seems to indicate incomplete familiarity with Code.

Normally, if it passed legitimate inspection I'd say that trumps NEC but while there many areas of more recent Code that are of marginal real difference imo, this one is pretty high on the list of potential for an issue if, indeed, the particular box terminals are not listed as suitable for the second conductor. I'd recommend to check that out and follow the manufacturer's listed procedure.

It's possible the home inspector did check the box and didn't see the above-mentioned labeling or it may be he just automatically flagged it just on general principles; the manufacturer's got the definitive answer yes/no and it's allowed for them to not have it on a label attached to the box but in the detailed catalog information for the device.

[DerbyDad03]

This reminds of the idiot that installed my new service panel a few years ago. I dealt the owner for the estimate but he sent 2 underlings to do the installation. They installed a panel with a ground bar kit on the right side of the panel, but not on the left. For the right side there was room for the neutrals and grounds to be on their own lugs, but he doubled up the neutrals and grounds on the left. I was pretty sure that that was wrong but when I called him on it, he said it was OK. I was sure he was wrong, so I called a buddy who is a licensed electrician who verified that it needed to be corrected.

When I called the owner back and told him that I verified the issue with a licensed electrician, he got pissed at me for not trusting him!

"Are you kidding me? Your guy wired the panel incorrecty and you're pissed at me for doing my homeowner and verifying that it is wrong? You either lied to me when you told me it was OK or you have no idea how to properly install a service panel. Either way, you better get someone over here to fix it ASAP or there will be hell to pay."

The next thing he tells me is that he will have to talk to his worker and find out when he can do it "on his own time" because "I'm not going to pay him to rewire it."

Holy crap! I told him that I don't give a crap about his business and how he deals with his employees but if this isn't fixed within a week I will be reporting him to the town and to anyone else that will listen.

The panel was fixed 2 days later.

[billybobbobrob]

home inspectors have no license in the state of California and far as being a contractor or licensed engineer . The local building inspector had signe d off on the installation. also at this panel the original permit was place d in plan view next to it. Home inspectors are used when real estate in bei ng sold and usually its the buyers agent that orders the home inspector...T he local building inspector said something about it being only 3 ft from t he first sub panel to the next and less than 25 ft, like that was the decid ing factor, possibly referencing some code? He seemed to feel that running the 4 main wires to a split lug junction would create a less desirable cond ition than to have them cleanly attached at the mains. Unfortunately that b uilding inspector is no longer around passed away several years ago. City b uilding inspectors do not revisit past inspections around here. They need n ew permit applications in order to get paid.

[billybobbobrob]

nia as far as being a contractor or licensed engineer . The local building inspector had signed off on the installation. also at this panel the origin al permit was placed in plain view next to it. Home inspectors are used whe n real estate in being sold and usually its the buyers agent that orders th e home inspector...The local building inspector said something about it be ing only 3 ft from the first sub panel to the next and less than 25 ft, lik e that was the deciding factor, possibly referencing some code? He seemed t o feel that running the 4 main wires to a split lug junction would create a less desirable condition than to have them cleanly attached at the mains. Unfortunately that building inspector is no longer around passed away sever al years ago. City building inspectors do not revisit past inspections arou nd here. They need new permit applications in order to get paid.

( corrected typos)

[gfretwell]

Well stated and I have never seen a main breaker lug rated for 2 conductors. A lot of panels do have a kit to add lugs at the bottom of the bus but you are still limited to the rating of the panel overall.

[gfretwell]

What size are the service entrance conductors?

[billybobbobrob]

On Wednesday, September 14, 2016 at 10:13:52 AM UTC-7, [e-mail] wrot e:

ing a contractor or licensed engineer . The local building inspector had si gned off on the installation. also at this panel the original permit was pl aced in plan view next to it. Home inspectors are used when real estate in being sold and usually its the buyers agent that orders the home inspector. ..The local building inspector said something about it being only 3 ft fro m the first sub panel to the next and less than 25 ft, like that was the de ciding factor, possibly referencing some code? He seemed to feel that runni ng the 4 main wires to a split lug junction would create a less desirable c ondition than to have them cleanly attached at the mains. Unfortunately tha t building inspector is no longer around passed away several years ago. Cit y building inspectors do not revisit past inspections around here. They nee d new permit applications in order to get paid.

main service at the meter is a 100 amp service. the line powering the the s ub panel 1 is 10 ga solid wire and is 220 on a 30 amp breaker at the main p anel the sub panel 1 is rated at 125 amps . it has its own earth ground at that sub panel. The sub panel feed wire is 10 ga 3 conductor with a bare wi re ground so technically there are 4 wires. so at the main lugs of this sub panel 1 wires were put in them and tightened to jump to another sub panel that is a 30 amp breaker sub outdoor rated box to connect a hot tub. the wi res going to the hot tubs sub panel run 3 ft from panel 1 to it . This was done because local code required the breaker to be within reach of the hot tub acting like a emergency main disconnect . This again was all done and s igned off by the local building inspector. The only thing in dispute here i s that I used the main lugs for this sub panel as a junction lugs to run th e feed wires for the hot tubs breaker/sub panel.

[dpb]

Is there documented evidence of this on hand or can you get same?

...

Didn't answer the pertinent question but it's bound to be at least 4 or

6 and there in is the rub...the much smaller wire in the single lug unless it's designed for it is a potential for loosening with time and becoming a hazard.

As far as NEC, see the previous answer; unless the panel lugs are specifically identified by the manufacturer as suitable for multiple conductors (and they'll specify the sizes, too) it is _NOT_ NEC-compliant to use it that way, inspector or no inspector.

Now, local Code can trump NEC and if you do have the documentation that it passed the local jurisdiction inspection you may be able to fall back on that and to sell the house (as it appears is the reason the issue has been raised) I'd start with that as my position.

But, the original question on NEC is still as is--it depends entirely on what the panel manufacturer says is the design-approved use of the lugs in question. That's in black and white in Code in location cited.

Have you looked at the panel itself to see if it is labelled therein or gone to the manufacturer's catalog to find out?

[dpb]

On 09/14/2016 12:11 PM, [e-mail] wrote: ...

Nor have I but I don't know that it isn't possible altho it would be highly unlikely methinks...particularly for the given application wherein the tap is #10 on a 4 or 6...

The original inspector may have let it go as "prettier" than the split-nut and I can see that as a point but doubt it meets the manufacturer's listing as you say since it would be so rare.

The cleanest solution probably would be to add the kit altho it's possible may be a difficult find owing to age as it is, after all, only

100A service which indicates it's got some age on it.

[clare]

My understanding of code here in Canada is only one conductor on a lug. What you need to do is replace the hot-tub panel with a multi-circuit sub panel and put the hot tup breaker in it - or feed the hot-tub panel from a breaker in the new sub panel (which really doesn't make ANY sense. Why do you need or want TWO sub-panels????

[clare]

You forgot ""terminals for more than one conductor shall be so identified". in the relevent code referenced previously. They DO need to be labelled in the box to be legal.

[David L. Martel]

Why do you care about the opinion of a "home inspector"? You say that this was inspected and passed by the local building inspector. Are you trying to sell this place? Does the home inspector work for the buyer? Tell the buyer that the wiring passed inspection, so they' ll be no money from your to fix this issue.

Dave M.

[clare]

OK - I understood the power from the main went to the hot-tub panel, and from THERE to the sub. In your case, just put another 30 amp 2 pole breaker in the Sub and connect the hot tub panel to that breaker

- that makes it all Kosher.

[clare]

I could have replaced my 100 amp fuse panel with a brand new 100 amp breaker panel last year, so the size meand absolutely nothig.. I could not put anything over 150 amps in (without paying to install a new underground cable back to the transformer vault)

[dpb]

On 09/14/2016 2:41 PM, [e-mail] wrote: ...

Excepting w/ 100A service, undoubtedly it was already full-up which is why couldn't do that before...

[dpb]

On 09/14/2016 2:44 PM, [e-mail] wrote: ...

Of course you could've; only it's quite unusual and has been for quite a long while for a new house installation to be only 100A...from which I simply infer it's likely an older house.

Maybe, maybe not, but reasonable inference for Californiay...