Joint between 16mm &1.5mm!

[rolyberkin]

A donut of a builder has helpfully run a piece of swa two core 16mm to a small feature fountain fitted with 1.5mm flex, suggestions on best way to join, couldn’t get the 16mm in a wago!

 

[Lucien Nunes]

providing its all tidy and insulated, could someone please explain why the suggestion of using a single strand into a wago would be frowned upon.

Electrically, of course, it would be fine. It's the ethics that are screwed up here. Leaving strands out of a termination violates a fundamental rule that is deeply imprinted in any (good) electrician's brain. Plus the Wago instructions would probably be disobeyed in two or three different ways.

A technically correct solution would be as suggested by Shaun1, to terminate the two cables into appropriate-sized DIN terminals and link them with commoning bars. Or to crimp on some suitable ring terminals (e.g. 6mm hole) and connect them via DIN-rail mounted insulated stud terminals. I have used that method before, for widely disparate cables sizes. There are all sorts of halfway house options, like lap crimps. Soldering, if done with skill, could make a nice job of it.

But I might still go for the 1-strand-in-a-Wago. In an outdoor terminal box, the less exposed metal and fewer things to corrode or create leakage, the better. From a purely engineering standpoint, provided the heatshrink job is well executed, it might be the most suitable technique. I leave for the reader the agonising consideration of inter-strand resistance after a few years of moisture ingress, vs. the equalisation of current between strands along the length of the cable.

 

[Deleted member 26818]

Conduit through box.
Gland the SWA to one side, plastic stuffing gland and flex the other side.
Choc blocks to make the terminations, fill with magic gel or resin.

 

[Devonchris]

Leaving strands out of a termination violates a fundamental rule that is deeply imprinted in any (good) electrician's brain

Thank you for the detailed reply. My quote above confirms my thoughts.

 

[DPG]

Anyone who just uses a couple of strands in a termination and cuts the rest off should be put on some sort of register.

 

[Deleted member 26818]

Anyone who just uses a couple of strands in a termination and cuts the rest off should be put on some sort of register.

Although it sounds terrible, if you stop and think about it.

 

[DPG]

Although it sounds terrible, if you stop and think about it.

It does indeed.

 

[w0z]

If the size of the conductor is going to be reduced from 16mm to 1.5mm then, leaving aside the IPxx rating, and providing its all tidy and insulated, could someone please explain why the suggestion of using a single strand into a wago would be frowned upon. To me it seems a practical way to reduce the conductor. What am i missing?

...because it would only work properly if the same few strands were connected at the other end...?

 

[Pete999]

...because it would only work properly if the same few strands were connected at the other end...?

No they will all be joined by close encounters, ohhherrrr

 

[pirate]

Clearly, as w0z said, you have to be sure the same few strands are connected at each end...
but somehow I don't think my new RJ45 crimper is going to be man enough for the job...

(nor the cat6 cable, to be fair)

 

[mydigitalhome]

I would agree with Midwest comment

 

[freddo]

Isn't an approved method to leave a strand long to terminate, then solder all the strands together, finally cover with heatshrink?

 

[DPG]

Isn't an approved method to leave a strand long to terminate, then solder all the strands together, finally cover with heatshrink?

Still sounds a bit bodgy to me that though.

 

[freddo]

Like this 16mm:

 

[Pete999]

Isn't an approved method to leave a strand long to terminate, then solder all the strands together, finally cover with heatshrink?

Don't think so

 

[freddo]

 

[Pete999]

View attachment 48418

Well I never did! goes against the grain though.