am I the only one double over tails

[beaver74]

Hi all

more and more I am come across new fuse boards with the mains tails stripped and terminated with out doubling over.yes I know it is a bi**ch to get a doubled over 25.00 in these new isolator but there is room and I dont feel there is any issue with it.tails which are not doubled over, in time the strands seperate and after a day or so you can generaly get another half turn on the terminal

Am I the only one now thet is making the effort

 

[Amp David]

Are domestic CUs designed to take anything larger than 35mm?

Spread the strands with pliers first then they never settle further and come loose. Have never doubled over tail or even seen it before

 

[Andy78]

I would never double tails at 25mm either. And yes Amp David, I think domestic main switch terminals are designed for a max of 35mm stranded or 50mm solid.

 

[Darkwood]

I fit crimps on so no splaying of conductors, this should be the practised method as terminal lugs grind into the core strands when tightening effectively damaging them unless you have a decent brand of main switch which uses a clamping chamber.

 

[vernam616]

Id love to see that acheived, over the top completly, never ever heard of doubling a stranted cable of them sizes

 

[Silly Sausage]

.............Am I the only one now that is making the effort

Yes. .

 

[rich.250]

There is no need to double over stranded cable at all. It spreads when tightened to fill the terminal.
I can see that crimping them may be a good idea, especially if tri rated.

 

[Darkwood]

To mention another point here; whe you clamp stranded cores no matter how tight you get them or if you double them over their is an initial period where you get copper settlement as the pressure is effectively pushing the cores around trying to equal and reduce the pressure..... this can take hours, days or weeks before they find their seating positions. Schneider i believe have a patent on a clamp terminal that avoids this situe' keeping the termination as tight as the day it was made - ive seen them use it on their larger contactors etc where coil vibration can enhance this copper creep.

 

[Deleted member 26818]

It is a requirement to protect fine stranded cables at terminations.
This can be achieved by crimping, doubling over, or using terminals designed for fine stranded cables.

 

[Darkwood]

It is a requirement to protect fine stranded cables at terminations.
This can be achieved by crimping, doubling over, or using terminals designed for fine stranded cables.

Regarding fine wire, doubling over isnt acceptable, they can be tinned only if screw terminals are not used or alternatively a crimp ferrule can be used and are often the preferred method. see 526.8

 

[Deleted member 26818]

Nothing in the old 256.8 or the new 256.9 prohibits the method of doubling over.
Tell me, how do you connect light pendants, do you tin them (which is not allowed if normal screw terminals are used), or do you crimp the ends?
Or do you like most of us do, twist and double over?

 

[Darkwood]

Nothing in the old 256.8 or the new 256.9 prohibits the method of doubling over.
Tell me, how do you connect light pendants, do you tin them (which is not allowed if normal screw terminals are used), or do you crimp the ends?
Or do you like most of us do, twist and double over?

Yes sorry red book in house green in van so quoted old code.... but in response if you buy a pre-made 9" pendant or a appliance with a removable plug top, youll usually find the flex is crimped as the manufacturers have to comply but agree its practiced by almost all sparkies to do as you said including me that ferrules are not fitted and in 13amp plugtop main reason is because you cant fit them in anyway.... but i was pointing out it is required and if i fit industrial plugs on flex etc yes i do crimp ferrules on, and as i make control panels i do ferrule all my fine wire cables.

 

[MarkieSparkie]

You may like to read the article "Installing Smart Meters: ESC campaigns for checking tightness of meter tail connections in consumer units." in the Spring 2012 ESC Switched On magazine which reviews preliminary tests carried out on 7 and 19 strand conductor tails.

http://www.esc.org.uk/fileadmin/user_upload/documents/public/switched_on/Issue_24_Spring_2012.pdf

 

[Edd]

Hi all

more and more I am come across new fuse boards with the mains tails stripped and terminated with out doubling over.yes I know it is a bi**ch to get a doubled over 25.00 in these new isolator but there is room and I dont feel there is any issue with it.tails which are not doubled over, in time the strands seperate and after a day or so you can generaly get another half turn on the terminal

Am I the only one now thet is making the effort

Any Chance of a Photo Of this being acheved please..

 

[malcolmsanford]

What you can do if your terminating into a screw terminal with a smallish cable, and what I was taught to do, strip the tail as normal and wind horizontally along the conductors a piece of single core 2.5mm, in essence your using the 2.5mm to bind the cables together and increasing the CSA on the termination.

This gives you a snugger fit, and stopped the splaying on the cable.