cable jointing

[cctbreaker]

OK guys, what jointing method do you recommend for inaccessible joint that will be in a chased out wall ie plastered over? Is crimping and heat shrink sleeving ok? or do you use the compound liquid jointy things? or summat else?

 

[assured elec]

pulled by who ? yellow are for 4-6mm cable . blue 2.5 mm and red for 1.0/1.5mm

 

[isitintheregs]

I'm of the old school on this one. Crimps, regardless of size should be used on multi-strand cables. I base this on having seen many loose crimps on single stand cables. I am led to believe that the push fit connectors that are becoming available are deemed to be acceptable in non accessible areas but they are not exactly an in line device.

This is from the Hagar website.
When installed in accordance with manufacturer’s instructions in a circuit complying with BS 7671, the Ashley Maintenance Free Junction Box does not require further inspection, testing and maintenance and therefore enables compliance with regulation 526.3.
In addition to the above tests the Ashley Maintenance Free Junction Box complies with BS EN 60670-22 which covers Junction boxes.

 

[mazolaman]

Interesting info about the Ashley jb's.Ill look into them.

I was pulled on the crimp rating issue on my elecsa inspection,appparently blues are rated at 20amp,which seems odd,as we all know,2.5t+e is rated at max 27 amp.

so is a ceiling void regarded as accessable?Ill have a look in the regs.

 

[OilBeDamned]

You should really be raggling out a box and using chocolate block or some other form of screw connector.

As some others have said never crimp a solid core as it can work loose or if incorrectly crimped you can shear the solid core, cause arcing and ultimately an electrical fire.

If stranded and your using crimps, please make sure your crimp correctly.

The bain of my life is replacing incorrectly crimped crimps

 

[Spudnik]

Correctly applied crimps applied with a ratchet crimping tool do not 'work loose'.

Why do you think they are used extensively i this industry?

Screw connections should not be used where the joint will not be accessible for inspection.

I have never found a loose crimp, however i have found plenty of loose screw connections.

 

[dazza69]

Well said jasons6930. I have used and inspected through crimps on single core cables and (as yet) have never encountered any problems! I would like one of the "old school boys" to answer the question on how they would repair or extend any cable which has to be buried into plaster work. Are they saying that they would rerun the entire circuit?

 

[OilBeDamned]

Correctly applied crimps applied with a ratchet crimping tool do not 'work loose'.

Why do you think they are used extensively i this industry?

Screw connections should not be used where the joint will not be accessible for inspection.

I have never found a loose crimp, however i have found plenty of loose screw connections.

First off IMO this joint should be made with srewed connections in a raggled out box with blanking plate to allow inspection. Straight through crimps do not allow this and do not allow the remaking of the crimp if improperly done.

Correctly applied crimps used with a ratchet crimping tool can work loose, especially in an enviroment with vibration.

Iv found quite a few loose crimps as well as loose connections.

Also in the industrial side of things you should never connect bare terminals into screwed connections that arent clamped, and even then it is good practise to use crimps.

The crimps im referring to are pins, forks, spades and 1 holed crimps like these. I prefer bootlaced crimps when using flexible stranded cable.


Polycarbonate Insulated Terminals

 

[davisph]

OK guys, what jointing method do you recommend for inaccessible joint that will be in a chased out wall ie plastered over? Is crimping and heat shrink sleeving ok? or do you use the compound liquid jointy things? or summat else?

I work for 3M and we have a solution for you that provides effective insulation without the need to use a heat gun to shrink heat shrink tubing or indeed have handle messy compound resins. It's called Cold Shrink and is basically a pre-stretched rubber/silicone tube loaded onto a coiled plastic core that is easily removed in seconds.

Here is a data sheet for the product:
http://multimedia.mmm.com/mws/mediaw...666OYrCOrrrrQ-

Here is the link to the RS site where you can purchase it:
Welcome to rswww.com Your search for cold shrink

Let us know how you get on

 

[OilBeDamned]

I work for 3M and we have a solution for you that provides effective insulation without the need to use a heat gun to shrink heat shrink tubing or indeed have handle messy compound resins. It's called Cold Shrink and is basically a pre-stretched rubber/silicone tube loaded onto a coiled plastic core that is easily removed in seconds.

Here is a data sheet for the product:
http://multimedia.mmm.com/mws/mediaw...666OYrCOrrrrQ-

Here is the link to the RS site where you can purchase it:
Welcome to rswww.com Your search for cold shrink

Let us know how you get on

Once you figure out how to get your coiled plastic core to uncoil without snapping or snagging unecissarily will it be recommended.

Have to use these all the time at work and you need to order almost 1 1/2 - 2 times what you require due to the fact that these "easily removed" cores aint so great.

Maybe its just a bad batch we get all the time but hey.

Also provide a better copper spring or even better 2 different sizes as not all cables fit inside your 1,2 and 3 box sizes.

 

[misterfranki]

Seems the link appears to be broken -
Oops! This link appears broken.

Maybe I'm not clicking my mouse button properly. Lol. I am intrigued in the product though.

I have always been told that cables been sunk into a wall should be run in conduit or capping. Maybe that is more of a recommendation than anything else.

 

[CUDABOY]

ived soldered solid core cables<propper soldering iron> .....

 

[davisph]

Once you figure out how to get your coiled plastic core to uncoil without snapping or snagging unecissarily will it be recommended.

Have to use these all the time at work and you need to order almost 1 1/2 - 2 times what you require due to the fact that these "easily removed" cores aint so great.

Maybe its just a bad batch we get all the time but hey.

Also provide a better copper spring or even better 2 different sizes as not all cables fit inside your 1,2 and 3 box sizes.

Thanks for the feedback. While we sell 1000's of these products annually, we are always looking to make improvements to our products and your comments have been taken on board. Can you confirm you are using the 3M ''LC'' Range of LV Cold Shrink joints? If that is the case then I would be interested in receiving a more comprehensive account of the problems you encounter when using our products, perhaps off line in the form of a separate email / telephone call / personal call. If you would be happy to do this then please let me know.

Thanks

Seems the link appears to be broken -
Oops! This link appears broken.

Maybe I'm not clicking my mouse button properly. Lol. I am intrigued in the product though.

I have always been told that cables been sunk into a wall should be run in conduit or capping. Maybe that is more of a recommendation than anything else.

Don't know what happened there

Try this link: http://multimedia.mmm.com/mws/mediawebserver.dyn?6666660Zjcf6lVs6EVs666OYrCOrrrrQ-

If that still doesn't work then visit 3M Electrical Supplies and Components and go to 'Technical Data Sheets' in the 'Document Download Centre' on the left hand navigation

Any Q's please shout

 

[Des 56]

Heres my old school comment on crimping

Whilst I personally would find some means of fitting a box with a blanking plate for inspection
I find the comments on crimping stranded cores only, to be probably true, with regard to being loose or vibration affecting them, but if the crimp is carried out correctly with the correct ratchet type tool then I defy any of you to loosen detatch or disturb the joint of any solid core crimping that I carried out
There is absolutely nothing wrong with crimping solid cores. the problem exists only when the person doing the work is at fault

 

[terry451]

Not seen anything about not crimping solid core. Also thought crimping was only alternative to inaccesable joints. eg under flooring anybody got any sources for this ??

Point of intrest Maplins do a heat shrink with internal glue. {heat activated} thier spec suggestes this makes the joint moisture tight.

 

[Mac]

Tried these things that City's(CEF) were giving away.They are like the scotch locks that BT use,filled with silicone,to terminate cables and they seem great and they're permanent connections allowed to be buried in walls,17th edition apparently