Splices: Is Twist & Tape a permitted "splicing device identified for the use"?

[peterpaulw]

Is twisting multiple wires together and then taping them with electrical tape a splice permitted by the NEC? - This is not an April fools joke. The country I live in uses the NEC 2017 copied verbatim into the Philippine Electrical Code (PEC 2017). The NEC/PEC 110.14(B) states: "Splices. Conductors shall be spliced or joined with splicing devices identified for the use ... " (and I am not asking about soldered connections). - I am asking about connections made by twisting wires together (without wire-nuts) which I see all the time in most residential and business installations, usually inside PVC junction boxes and sometimes right on wooden beams. Commonly between 2 and 5 stranded or solid copper wires of AWG 14 to AWG 10 are twisted together with lineman's pliers carrying up to 30A of 240V current. Recently an electrician came to our house from the local POCO. He made multiple new live-wire twist-and-tape connections to repair and reconnect the insulated aluminum wires that go across the street feeding our meter on a 100 ampere residential mains connection. We still have power - for now

They all act as if this is permitted by 110.14(B). What is puzzling to me, is that experienced Philippine electricians continue to teach this method today (in numerous videos) and leading Philippine electrical engineers who are familiar with the code do not even mention it as a potential risk. Proper "splicing devices identified for the use" such as UL listed wire-nuts are actually available, but are not used widely. Therefore, I am wondering, if I may have misunderstood the code? Where does the code explicitly forbid such splices? Could NEC/PEC 110.14(B) or another part of the code actually be interpreted as endorsing "twist-and-tape"?

On a practical level, what are the disadvantages and risks of using twist-and-tape as the primary method of wire splicing? Often I encounter splices made with cheap Chinese electrical tape which start to unravel after only a short time, whereas splices taped with higher quality tape such as 3M electrical tape tend to look much better even many years later. In my observations here during the past 30 years, these connections can actually hold up quite well, if the initial mechanical connection created by the twisting of the wires was done by an experienced electrician, but at other times I come across splices which are barely held together by the minimal pressure of the electrical tape.

Having answers to these questions would really help to explain to local electricians we hire, why we want them to use wire-nuts instead of twist-and-tape.

The last two photos are from a recent video about wiring an outlet by an electrician whose popular channel has 7 million views

 

[LarryFine]

Welcome to the forum.

No, tape is not a spicing device.

 

[augie47]

FYI 110.14(B) Splices. Conductors shall be spliced or joined with splic‐ ing devices identified for the use or by brazing, welding, or soldering with a fusible metal or alloy

 

[zbang]

Utilities are usually covered by different codes (in the USA, it's NEC vs NESC) so splicing the drop wires that way might be acceptable if they own that wire. Not saying it's a good method, only that it might be allowed in that location.

 

[peterpaulw]

Welcome to the forum.
No, tape is not a spicing device.

Thank you Larry for the welcome and the clear answer!

Utilities are usually covered by different codes (in the USA, it's NEC vs NESC) so splicing the drop wires that way might be acceptable if they own that wire. Not saying it's a good method, only that it might be allowed in that location.

Right, that's an interesting point. I will try to find out which code applies here.

 

[peterpaulw]

FYI 110.14(B) Splices. Conductors shall be spliced or joined with spliing devices identified for the use or by brazing, welding, or soldering with a fusible metal or alloy

Exactly the one which I quoted in my original post, noting that these connections are not being soldered, merely twisted together, then taped. Therefore, would interpret 110.14(B) as prohibiting twist-and-tape as a splicing device?

As an electrical inspector, have you ever seen twist-and-taped wire connections in your state? What problems did they cause or which issues would you expect?

 

[winnie]

This is one of those 'I never really questioned it' sort of things. In the US, twisted and taped splices are not accepted. They are a sign of hack work and would fail inspection .

I think one could make an argument that it is hypothetically permissible to make a twisted and taped splice, but even so there is no practical legal way to do so.

Tape is a device, and clearly proper twisting can create a suitably mechanically and electrically solid connection. (Remember the requirements for a soldered connection...it has to be mechanically and electrically sound before the solder.) So with good enough twisting and proper tape, the splice would pass muster.

But you won't find any tape that has been 'listed' as a splicing device. You won't find tape with any of the instructions that come with splicing devices. (Little things like permitted wire size combinations, length to strip wires, number of wraps of tape, etc.)

Short of having a listed product with instructions for use, you have no way of verifying if the splice is good enough.

In the US, twisted and taped splices are considered code violations, and if this was a matter of practical debate I'd be advocating for a code change explicitly prohibiting them.


Jon

 

[paulengr]

Exactly the one which I quoted in my original post, noting that these connections are not being soldered, merely twisted together, then taped. Therefore, would interpret 110.14(B) as prohibiting twist-and-tape as a splicing device?

As an electrical inspector, have you ever seen twist-and-taped wire connections in your state? What problems did they cause or which issues would you expect?

What you are referring to sounds very much like a “Western Union” splice BUT those were also soldered and intended for communication circuits. Google it and you will find documentation for it. WU splices technically if you do it as per say the American Electricians Handbook because of the solder are legal but again it’s the context.

Solder is NOT in and of itself mechanically strong. It is little more than the mechanical equivalent of “hot glue”. It won’t hold anything heavier than say an electronic component. It does not “weld” (fuse to the base metal). It does not improve resistance. It hardens and destroys the underlying malleability properties as well so it can’t be used on flexible components, only things that are supposed to be fixed in place.

It is common in overhead lines to use soft drawn aluminum jumpers. You land the cables properly with tension eyes and lag bolts. Then jumper from there to whatever the load is. The jumper is not under mechanical load except it’s own weight. This depends on load. Think for instance about the load on a 4160 line feeding a residential transformer.

Today I rarely see this done. Mostly we use crimp on or mechanical connectors for reliability reasons. Generally speaking in the US utilities are exempt from “codes” since it is all a privately owned system. The NE:SC (IEEE C2) is a standard, not “law”, used a lot by utilities. Another one are the “RUS standards”. NEC does not cover utilities (see scope section).

 

[peterpaulw]

Utilities are usually covered by different codes (in the USA, it's NEC vs NESC) so splicing the drop wires that way might be acceptable if they own that wire. Not saying it's a good method, only that it might be allowed in that location.

I was able to find the relevant national regulations for utilities which state, that the power company is actually required to abide by the Electrical Code according to the Philippine Distribution Code (2016 edition) section 3.6.1.1 and 2 "The Distribution Utility shall develop, operate, and maintain its Distribution System in a safe manner ... In this regard, the Energy Regulatory Commission adopts the Philippine Electrical Code (PEC) Part 1 and Part 2. ... The PEC Parts 1 and 2 shall govern the safety requirements for electrical installation, operation, and maintenance. Part 1 of the PEC pertains to the wiring system in premises of End-Users. Part 2 covers electrical equipment and associated work practices employed by the Distribution Utility. Compliance with these codes is mandatory." PEC Part 1 is a word-for-word copy of the NEC 2017 (merely excluding AFCIs), but I could not find any details though about PEC Part 2 or a copy of Part 2 and can therefore not draw any firm conclusions.

I have looked for suitable overhead crimp compression connectors such as LINKIT or HYSPLICE, but found none available in this country. We do have brass solderless split-bolt connectors available which would provide a better connection. Overall availability is limited for splice connectors that are listed for aluminum wire and for those that are insulated and suitable for a wet environment hanging overhead.

The Electrical Code is applied very selectively here and usually not consistently checked or enforced. Decades of sloppy traditions, poor training and lack of local availability of suitable connectors leads to such poor solutions even though our local power company actually owns and operates new state-of-the-art power plants which certainly need to import specialized parts for maintenance. They could easily import HYSPLICE type connectors and crimp tools, but they just do not bother. Sadly they also do not bother to supply their low voltage linemen (who are twisting the live wires) with properly maintained class 00 insulating gloves as can be seen in the photo above.

As the shown overhead wire is still considered a "construction connection" which will need to be officially changed for the final connection and approval before we move in, they just keep patching it every time it fails, which happened a few times already due to the large welding machine used on-site, which was able to overload a 60 A circuit breaker in the past. We will certainly request that they change this poorly patched wire for the permanent connection.

 

[peterpaulw]

What you are referring to sounds very much like a “Western Union” splice BUT those were also soldered ...

It is common in overhead lines to use soft drawn aluminum jumpers. You land the cables properly with tension eyes and lag bolts. Then jumper from there to whatever the load is. The jumper is not under mechanical load except it’s own weight. This depends on load. Think for instance about the load on a 4160 line feeding a residential transformer.

Today I rarely see this done. Mostly we use crimp on or mechanical connectors for reliability reasons.

True, the splice can be similar to a “Western Union” splice, if done well (pictured below on a neutral service drop wire), but they are never soldered or welded. Yet most splices here are done by merely twisting the wires in parallel (in the second photo) which can easily crack the brittle aluminum wires that are usually used for the mains connection.

On the photo above (in the original post) only one of the splices is under the load of the wire hanging across the street, while six of the seven visible splices are indeed in the jumpered portion and not under mechanical load. Those six splices could have been reduced to two, if the electrician or lineman had just replaced a few yards of wire going to the meter mounted 10 feet down the post. - I am still looking for easy to use approved aluminum wire connectors here, but they seem to be unavailable.

“Western Union” style splice

Typical Twist-and-Tape

 

[Hv&Lv]

True, the splice can be similar to a “Western Union” splice, if done well (pictured below on a neutral service drop wire), but they are never soldered or welded. Yet most splices here are done by merely twisting the wires in parallel (in the second photo) which can easily crack the brittle aluminum wires that are usually used for the mains connection.

On the photo above (in the original post) only one of the splices is under the load of the wire hanging across the street, while six of the seven visible splices are indeed in the jumpered portion and not under mechanical load. Those six splices could have been reduced to two, if the electrician or lineman had just replaced a few yards of wire going to the meter mounted 10 feet down the post. - I am still looking for easy to use approved aluminum wire connectors here, but they seem to be unavailable.

We use them every day for service drops. look at Hubble power systems. They have tension barrel sleeves, service sleeves, automatics for full tension distribution lines, etc..