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Thread: Double tap in tap block
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06-14-2011, 07:18 PM #1
Double tap in tap block
This is a single family home built in the early 90's. These taps are on the feeder cables in the service. The tap is supplying 2 different distribution panels. One for a detached garage, the other for a small panel beside the disconnect. The upper block is double tapped. This is a 100 amp service. Is this acceptable.
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06-14-2011, 10:30 PM #2
Re: Double tap in tap block
Matthew,
I would be concerned about the tap. The size of the tap looks to be smaller than the original feed. Is it properly sized? If copper connected to aluminum, has an approved connector been used? Can't tell with the tape on it.
Also, I don't see a utility tag/seal on the service entrance side of the panel.
Department of Redundancy Department
Supreme Emperor of Hyperbole
http://www.FullCircleInspect.com/
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06-15-2011, 06:07 AM #3
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06-15-2011, 06:23 AM #4
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06-15-2011, 07:37 AM #5
Re: Double tap in tap block
It is not tapped before the meter, the feeders are tapped. Could not see the blocks because of the tape but the feeders are al and one of the wires tapping is copper, not sure what the other one was. I have never seen 2 wires or cables in one tap block.
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06-15-2011, 08:40 AM #6
Re: Double tap in tap block
Matt, those are likely a split bolt connection.You can google for an image to see how they work. One conductor can be skinned and the tap laid alongside in the split bolt. Split bolts can also be used as similar to a wire nut at the ends of two conductors.
All answers based on unamended National Electrical codes.
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06-15-2011, 09:33 AM #7
Re: Double tap in tap block
what size are the tap conductors? where do they land in the panel? main lugs or circuit breaker?
what size circuit breaker?
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06-15-2011, 08:39 PM #8
Re: Double tap in tap block
The sparky went out and took a look, said its incorrect. Split bolts are not intended for that type of installation.
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06-16-2011, 01:09 PM #9
Re: Double tap in tap block
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06-16-2011, 05:59 PM #10
Re: Double tap in tap block
My assumption is that there are copper and aluminum conductors together at the tap. I don't know, but I suspect that the split bolt is not approved for copper to aluminum connection.
Of course, I could be wrong. I have been incorrect on one or two (thousand) occasions.
Department of Redundancy Department
Supreme Emperor of Hyperbole
http://www.FullCircleInspect.com/
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06-17-2011, 07:40 AM #11
Re: Double tap in tap block
This is all wrong!! for one, spliced wires are undersized for the 100 amp breaker. These circuits should be attached to the appropriately sized breakers in a separate service panel. Don't see any outer sheathing inside that panel either.
James Bohac
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06-17-2011, 11:53 AM #12
Re: Double tap in tap block
First things first,... need all conductor sizes, lengths of all conductors, in cable Assemblies or in conduits of what materials, and what/how/size of over current device the tap conductors terminate in (if any).
After the above info is determined, then one attempts to apply any of the tap rules provided in the code for that jurisdiction.
There are other concerns as stated (cu/al), (suitability of tapping mechanism),
and if the enclosure is listed for said tapping.
Note that enclosures need a required amount of space for taps and most manf. spec that they be made in a particular area of the enclosure (usually not in the gutter-space adjacent to over current devices and the like).
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06-17-2011, 08:06 PM #13
Re: Double tap in tap block
They do make "split-bolts" or "bugs" that are designed for connecting copper to aluminum. They have a divider inserted between the dissimilar metals.
However the tap conductors appear to be #10 and they feed what appears to a 60-amp disconnect. This does not meet the tap rule for this type of tap. The tap conductors can not have a rating that is less than the rating of the device they feed. So unless that is actually a 30-amp disconnect the tap conductors would have to be a minimum size #6.
Almost nobody uses split-bolts anymore with much easier and safer devices like Polaris taps (also called by many other names) which are basically insulated splice blocks.
Split-bolts may still be legal in some applications but they are not really feasible or cost effective any longer. What you might save in cost you lose 3-fold in labor to install them.
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06-17-2011, 09:08 PM #14
Re: Double tap in tap block
Tap conductors cannot have a rating of less than: (underlining and bold are mine)
(1) Taps Not over 3 m (10 ft) Long.
- (1) The ampacity of the tap conductors is
- - a. Not less than the combined calculated loads on the circuits supplied by the tap conductors, and
- - b. Not less than the rating of the device supplied by the tap conductors or not less than the rating of the overcurrent protective device at the termination of the tap conductors.
- (2) The tap conductors do not extend beyond the switchboard, panelboard, disconnecting means, or control devices they supply.
- (3) Except at the point of connection to the feeder, the tap conductors are enclosed in a raceway, which shall extend from the tap to the enclosure of an enclosed switchboard, panelboard, or control devices, or to the back of an open switchboard.
- (4) For field installations where the tap conductors leave the enclosure or vault in which the tap is made, the rating of the overcurrent device on the line side of the tap conductors shall not exceed 10 times the ampacity of the tap conductor.
- - FPN: For overcurrent protection requirements for panelboards, see 408.36.
The rating of the tap conductors must not be less than: (1)a) the combined calculated loads may be less than 30 amps (presuming #10 AWG conductors as you are estimating) ... AND ... (1)b) not less than the rating of the device OR not less than the rating of the overcurrent protection, and if the overcurrent protection is 30 amps, then #10 would be an okay size tap for that feeder tap no over 10 feet long ... AND ... (4) the overcurrent device on the line side of the tap conductors is not greater than 10 times the rating of the tap conductor (the service disconnect is not over 300 amps).
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06-18-2011, 07:39 PM #15
Re: Double tap in tap block
Jerry-
Seeing how the taps are on the exterior of the structure , would that eliminate to 10' in length restriction based on NEC section 240.21(5) Outside taps of unlimited length ?
Not that it matters in this case as the conductors appear to be well under 10'
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06-18-2011, 08:54 PM #16
Re: Double tap in tap block
Ken,
Based on the photos, the tap conductors do not meet the definition of conductors outside the structure, as such that subsection would not apply.
However, let's say those tap conductors were considered to be outside the structure and that subsection was applicable: (bold and underlining is mine)
- (5)(1) The conductors do appear to be protected from physical damage.
- (5)(2) This has not been clarified, it may or may not be the case. Conductor taps of unlimited length outside the structure must be protected at their ampacity rating. The 10 foot tap rule I posted above allowed for the greatest multiple of overcurrent protection over the rating of the conductors - and the conductors were obviously less than 10 feet in length. I was responding to Lou where he stated - incorrectly - "The tap conductors can not have a rating that is less than the rating of the device they feed.", tap conductors *are allowed* to have a higher overcurrent rated device and *are not required* to be protected at their ampacity rating - as that blanket statement made without representation that it was only applicable to one tap condition, it was incorrect ... and if we do apply tap rule (5) as you are asking about, then Lou's statement is incorrect as it stands as Lou stated "can not have a rating that is less than the rating of the device they feed" and the rule for option (5) is "The conductors terminate at a single circuit breaker or a single set of fuses that limit the load to the ampacity of the conductors."
- (5)(3) I would venture to say that the overcurrent device was a part of the disconnecting means.
- (5)(4)(a) Is the disconnecting means outside the structure? The disconnecting means is definitely *accessible from* outside the structure, but is it actually considered "outside the structure", the conductors are not (except that for this exercise we are saying the conductors are outside the structure).
- (5)(4)(b) Okay, if the disconnecting means is not outside the structure as needed for (a), then it would be inside the structure nearest the point of entrance of the conductors.
- (5)(4)(c) This takes us to the section defining whether or not the conductors are considered inside or outside the structure.
(The text in bold shows the difference between the statement being responded to and what the code says.)
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06-18-2011, 08:55 PM #17
Re: Double tap in tap block
.
Whenever I see something like this I often wonder whatever happened to taping skills. Proper taping skills for split bolts make a big difference in the quality and overall longevity of the splice. It's a shame that many electricians have not bothered to learn this skill.
The pictured splices are pretty bad IMO with improper wrapping of the vinyl electrical tape. You always use cambric (varnished series) tape for the first layer on a split bolt, then a rubber fusing tape then finish with a 3 rd layer of half wrapped vinyl tape of good quality.
IMO you could fail these splices based on 110.14(b) failure to cover the splice with insulation equivalent to the spliced conductors.
One split bolt has 3 conductors this likely is going to be incorrect if we could see the conductors and how they terminated in the split bolt and the split bolt itself.
And yes tap rules apply as other members have been discussing.
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06-18-2011, 10:40 PM #18
Re: Double tap in tap block
The original post indicated one of the taps is to a detached garage. I think it is fair to say that would indicate conductors in a length greater than 10ft.Mat,How the heck did you get that adjacent panel closed again? did it ever fully open? Looks like they mortared it in on all sides including the top.
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06-19-2011, 05:48 AM #19
Re: Double tap in tap block
OK - A multi person reply post !
Jerry-
We do agree ! The only sticking point is if the conductors are classified as inside or outside the structure. I guess technically the conductors are inside as they behind the finish of the structure and not completely outside the structure. I know some engineers,AHJs, among others that will say they are outside as they do not go into the interior of the home.
Roger-
I agree, taping skills have gone to the dogs. Everyone is starting to use those polaris type taps now - no taping involved. I guess given time the old fashioned split bolt will go the way of soldered splices.
As far as the splitbolts have 3 conductors - my money is on there are not 3 conductors, but rather the main feed cable has been stripped ( and not cut) and the split bolt used in the stripped part of the cable. Thus you have 1 cable passing straight through and 1 cable being tapped off - 2 cables.
HG-
You need to read the posts more carefully.
The detached garage panel ( disconnect) and the smaller disconnect to the side are in the photo. At most the tap conductors are maybe 5' at the most.
That smaller disconnect I'm sure opens as the cover fits under the top. thus the top does not move and the sides of the cover are exposed not restricting them from opening.
Closing is another story - how did you miss that?
My question is Will the cover close properly? It looks like the bottom of the disconnect is mortared tight thus not allowing the bottom of the cover to close 100%
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06-19-2011, 05:53 AM #20
Re: Double tap in tap block
HG from what I can see there is only one tap and it goes to the disconnect next to meter/mb. The other conductor appears to be the feeder to the main panel.
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06-19-2011, 11:54 AM #21
Re: Double tap in tap block
Wow. Quite a series of posts KH. Mixing imbibing with posting doesn't seem to work out too well for you.
Tapped Feeder to inside at top back wall of can. Tap to adjacent (Right) panel out right side wall of can, tap to detached garage out bottom side wall of can.
Where do YOU think the detached garage panel is pictured? Where has it been described to be...
There is one disconnect pictured that in the Combination equipment.
Mortar residue on the L side wall of the cover on the R. I made mention of the unclosed cover and the apparent not having been closed during the latest veneer project, and the apparent near-if-not impossible difficulty to close having been encased. Mat & and I have discussed in the past, and will continue to do so.
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06-19-2011, 12:28 PM #22
Re: Double tap in tap block
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Roger-
I agree, taping skills have gone to the dogs. Everyone is starting to use those polaris type taps now - no taping involved. I guess given time the old fashioned split bolt will go the way of soldered splices.
As far as the splitbolts have 3 conductors - my money is on there are not 3 conductors, but rather the main feed cable has been stripped ( and not cut) and the split bolt used in the stripped part of the cable. Thus you have 1 cable passing straight through and 1 cable being tapped off - 2 cables.
What I'm seeing is that the main feeder hot legs have been skinned. One of those has two tap conductors terminated to it (one going to the panel next to the combo service equipment and one out the bottom of the service equipment)... 3 conductors. The other hot leg of the main feeder has a single tap conductor going out the bottom of the SE...2 conductors.
I don't see 240 volts to the panel adjacent to the SE. It appears to me to be 120 volts going to that panel using a single tap to one of the feeder hot legs.. 120/240 going out the bottom of the SE.
I'm not seeing the detached garage panel in any of the pictures. I think it is the tap feeder going out he bottom of the SE that goes to the detached garage panel. The service equipment disconnect would remove power from the dwelling and the detached garage, however it would not be the detached garage disconnect as such, that disconnect must be located at the detached garage near the point of entrance of the feeder conductors.
Last edited by Roger Frazee; 06-19-2011 at 01:57 PM.
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06-19-2011, 04:46 PM #23
Re: Double tap in tap block
Roger,
If you look closely you can see there is a second #10 black running alongside of the bare ground going to the disconnect to the side.
Ken,
HG is right about the tap that runs down and out the bottom of the enclosure. Where does it go? What is the distance and does it meet any of the tap rules? This cannot be determined by the pictures that are posted and they are good and valid questions! They are a red flag that this needs further investigation.
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06-19-2011, 05:44 PM #24
Re: Double tap in tap block
[quote=Lou Romano;171091]Roger,
If you look closely you can see there is a second #10 black running alongside of the bare ground going to the disconnect to the side.
Yep saw that .. but if you look even closer you will see a #10 white grounded conductor next to that black and a bare ground. The wires your speaking of is a branch circuit coming from the adjacent panel. They are just sharing the same conduit with the 120 volt feeder to that small panel then going up and exiting the top of the SE.
Last edited by Roger Frazee; 06-20-2011 at 04:30 PM. Reason: corrected spelling error
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06-19-2011, 06:52 PM #25
Re: Double tap in tap block
[QUOTE=Roger Frazee;171097]I believe you are right Roger! Didn't catch that. Still I am more concerned with the wire coming from the tap and exiting the bottom of the panel without OCP.
This picture is not enough to go by. It would really help if the OP could post more or tell us more!
Have a nice night and Happy fathers day!
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06-19-2011, 08:09 PM #26
Re: Double tap in tap block
[quote=Lou Romano;171104]
Thanks Lou and the same to you.
Yep a little clarification would help. It is always hard to follow wires when viewing photos,
If the tap conductors land on an ocpd at their termination then it may still be ok. Jerry has been discussing the requirements to comply with the several tap rule options. But as Bob said earlier we need wire size and more information about those tap conductors at their termination to determine if they are in compliance with NEC tap rules. Even if the taps are permitted the splices fail IMO.
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06-20-2011, 05:59 AM #27
Re: Double tap in tap block
Lou & Roger-
You are correct - I missed that one, My bad -
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06-20-2011, 04:38 PM #28
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06-22-2011, 05:16 PM #29
Re: Double tap in tap block
When I happen upon a tap rule user while doing an inspection, I think to myself 'oh crapeth, now I have to look in the book'.
Even though I've performed numerous tap inspections, and in a few occasions installed them myself, I still cannot keep all the rules in my pea brain memory.
I cannot make an incorrect inspection in this regard, therefore I must resort to re-reading yet again, the flippen tap rules.
Someday I will make a cheat-sheet on TAPS as I have done on so many other code related issues. ugg
Do any of you HI types create your own cheat-sheets? Just wondering.
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