Meter Tails Splice for EV Fitters

[Dustydazzler]

What do we think..?

 

[Petej999]

What do we think..?

not a fan maybe use Henley blocks? rather than some sort of line tapping bodge

 

[Julie.]

Looks familiar

 

[loz2754]

They're not meant for this application. Especially insulated and sheathed tails.
Bit of a bodgina, if you ask me!

 

[7029 dave]

Have seen these used on cannabis farms when making safe, bloody crude looking

 

[Dustydazzler]

A mate of mine set fire to his old vauxhall nova after a bodged stereo install using splice wire splitters

I can see some advantages to using pinch / stab connectors on meter tails if the EV guys are not confident pulling the main fuse but if you are messing with electrics then pulling a fuse shouldn't be a big issue ?

 

[freddo]

Their video seems to suggest they are unsuitable for use for a number of reasons! I think I'll pass.

 

[snowhead]

Can't see any problems with them apart from;

They were not designed and tested for use internally.
The B.S probably doesn't cover that.
They are likely to be fitted by persons who are not trained to do so, unless that person is ex DNO in which case I doubt they would use them.
As they are not fixed they could put additional strain on the termination into the meter or Henley / Service connector if above, or the DNO service head connections.
Having gone to the trouble of introducing metallic consumer units and similar gear to contain fires, the introduction of this type of connector could potentailly put an installation back into to worse position re safety that a few years ago.

It will be interesting to see how people who do EICR's deal with these.

 

[7029 dave]

Long live the henley block

 

[Zerax]

Long live the henley block

...although, talking to a meter fitter the other week... they're being told to remove the hard 'bakelite' type ones and fit the Proteus PBT type ones. He had no idea why !

 

[HappyHippyDad]

What do we think..?

I reckon you should get admin to attach a poll to this one @Dustydazzler .

Although, it's perhaps looking a little one sided already.

My vote would be 'No', although it does have potential!

 

[freddo]

they're being told to remove the hard 'bakelite' type ones and fit the Proteus PBT type ones

Those proteus blocks are crap.

 

[Lucien Nunes]

The concept of IPC (insulation piercing) and IDC (insulation displacement) connectors is fine, no issues about that if correctly installed. Much of the world runs on IPC / IDC now in many different scenarios. E.g. we often use IDC DIN terminals when connecting up rows of 72 circuits in 2.5 or 4.0 for theatre lighting. As mentioned in the video, this very type of connector is popular with DNOs for overhead work.

But like crimps, IPC / IDC connectors only work to spec when used on the specified cables. So if a particular IPC line-tap is specced for XLPE or ABC or whatever but not PVC/PVC tails, then it is a complete no-go to install them on tails. The radial thickness of the insulation and sheath are highly critical to the IPC process and an excessively thick or low-modulus insulation could render the connection unreliable and prone to decreasing contact pressure and therefore overheating.

Then there are the IP and mechanical durability issues also highlighted in the video, but for me the cable incompatibility is the important one, because even if you solve the other problems with an enclosure, you might still have bad joints that will start cooking 18 months down the line.

Full disclosure: I invented / designed a version of this 30+ years ago. I am generally a fan of IPC and IDC.

 

[Gavin John Hyde]

In theory these make work a lot easier - however as demonstrated in the efixx video the single insulation covering the added tail is a concern and would need an enclosure, by the time you have done this you may aswell use henley blocks as routing tails etc through a plastic box isnt always easy.
Im wondering how long until somebody messes up and cuts too far through a live tail?
The attraction is time and space saving.... That said it only takes minutes to drop the tails out of the meter and fit a henley block.
Of late on some installs I have used 4 pole isolation switches with a piece of busbar to link out the terminals so 2 poles are L the other 2 N. it saves a lot of space, you then have 1 input from the meter and upto 2 outgoing terminals for cables on each of the tails you are also incorporating DP isolation for the whole installation - existing board. and small ev board.
With some adaptations and added insulation these could become more main stream but for now I have doubts. I would want a manufacturer I trusted and had confidence in to first develop them further and show the compliance and stand behind the product. Otherwise you run risk of knock off chinese version flooding the market and who knows how they will stand up under a constant 32A load.

 

[Gavin John Hyde]

...although, talking to a meter fitter the other week... they're being told to remove the hard 'bakelite' type ones and fit the Proteus PBT type ones. He had no idea why !

Some of those bakelite henleys crack at slightest tough. Mind you Some of the ones in suppliers at moment are awful- try removing the knockout for a new tail and the whole thing can crack...The proteus ones are not too bad, you can remove the little insert to give access to terminals without bashing the thing to oblivion. That said I aint going to CEF to buy them unless I have another order as CEF are a bit pricey!

 

[Lucien Nunes]

The Henley block and its derivatives are very much a UK thing, not surprising as the generic name comes from a UK company (W.T. Henley's Telegraph Works.) The original product is branded either Henley or AEI, there were equivalents by Lucy etc, and of course lots of modern copies from overseas.

We haven't been so much into the line-tap idea for this application, it's more common in other countries. The advantage being that the main run of conductor is unbroken so that only the current taken by the tap cable actually flows through the connector. Although, curiously, our UK-specific round phenolic junction boxes with slotted terminals were originally designed with that in mind, e.g. with a 30A 3-terminal box you can spur off a ring without breaking the ring conductors provided you are happy with tape on the main run CPC instead of sleeving.

I use Legrand screw-down line taps as a handy problem solver, e.g. Line tap - non-shear - with feet - capacity per tap 2x16 mm² - hexagonal head - https://www.legrand.com/ecatalogue/034042-line-tap-non-shear-with.html
They are available in a range of sizes, can accommodate a selection of different conductor types and clamp them very tightly without damage. Obviously where IP is important an enclosure is needed but it's not hard to arrange an unbroken slotted path through a box.

Another device I quite like although don't actually use is the Russian «ореx» i.e. nutshell, which clamps the conductors separately between plates a bit like a flat busbar joint and then encloses them between the two half-shells. Pics some way down this page: Russian 'nut' tap connectors

 

[Simon47]

It strikes me that it should be hard to device something along the lines of a Henley, but which allows the insertion of an uncut main run - just strip the insulation. ISTR there are joints (designed to go into potted joints tapping off a street distribution cable ?) where one part is U shaped with grooves that a bar slides into to make it closed - and then the clamp screws can be tightened.

 

[pc1966]

I use Legrand screw-down line taps as a handy problem solver, e.g. Line tap - non-shear - with feet - capacity per tap 2x16 mm² - hexagonal head - https://www.legrand.com/ecatalogue/034042-line-tap-non-shear-with.html
They are available in a range of sizes, can accommodate a selection of different conductor types and clamp them very tightly without damage. Obviously where IP is important an enclosure is needed but it's not hard to arrange an unbroken slotted path through a box.

Handy for some things, recently used them to attach SPD to some 25mm tri-rated cables. Didn't realise Legrand also make them.

Another device I quite like although don't actually use is the Russian «ореx» i.e. nutshell, which clamps the conductors separately between plates a bit like a flat busbar joint and then encloses them between the two half-shells. Pics some way down this page: Russian 'nut' tap connectors

They look good, reminds me a lot of the clamping plates used to cross-join lightning conductor tapes.