Crimping Twin & Earth

[bigzed]

I'm sure I must be reading some of the posts wrong here but is it correct that's it permissible to through-crimp 2.5mm T and E ? I've already got a very good pair of ratchet crimpers bought from Vehicle Wiring Products that will handle up to 4mm cable but I just find it a little hard to swallow that it's allowable to use mechanical crimps on cable carrying mains voltage, especially when it's solid core, not stranded.

Coming from a BT background, I would've thought that there might be some form of heavy-duty IDC connector out there to fulfill the role ?

Can somebody give me a definitive answer to this please as if it's correct, it will make my new CU fitting a HELL of a lot easier for the two rings that won't reach the new CU position.

Also, are the connectors to be colour-coded. Brown - Live etc.

Thanks.

edit> forgot to add, is it OK to have these crimped joints inside plastic 1" trunking ? I want to lead all the cables through this trunking to make a better job.

 

[Taylortwocities]

Yes, you can use insulated through crimps and a rachet crimper made for the purpose.

You will need to use blue crimps for the phase & neutral join this is the correct size for 2.5mm² csa cable.
use red crimps for the earth -its a smaller size conductor.

The whole joint should be covered in heat shrink sleeving. Not strictly necessary if the joint is inside the trunking.

PS: I trust you are aware of the legislation that covers major works including changes of consumer unit?

 

[bigzed]

The whole joint should be covered in heat shrink sleeving. Not strictly necessary if the joint is inside the trunking.

What I would've liked to do is H/S each individual crimped conductor joint in three stepped positions then cover all three joints in one "overall" H/S. This is similar to how we use the Water Block H/S joints in BT cabling as below :-

PS: I trust you are aware of the legislation that covers major works including changes of consumer unit?

Yes TTC, this site has made me FULLY aware of all the procedures that I need to follow re: a job as big as this. I'm glad actually, because up to finding you guys on this board, I had been led to believe that just about all DIY Electrical was now prohibited.

What I am trying to do is pre-empt everything I need to know before calling up the LABC to get the Testing etc booked. By what I have picked up off this site up to now, it seems that because of the work I want to do, I will have to have all the original Cabling checked out by the inspector before I start to do ANY of the work I am proposing to do.

This is why I am asking all these questions first to make sure I don't come across anything that will be beyond me.

 

[RF Lighting]

It is not necessary to heat srink the individual crimps, but you can if you want.

This is a staggered crimped 2.5mm² t&e cable.

 

[bigzed]

Brilliant !! That's even less work for me to do Actually, I was going to use a low-temp H/S that we use that has a small amount of glue inside that helps to seal and strengthen the joint ( hence the term "Water Block" ). Do you reckon that this would be OK for the regs, or does T and E cable require VERY low heat H/S tubing ? ( i.e. Hair-Dryer stuff )

Sorry for all the Q's lads but I'm trying to make this as painless as possible

 

[RF Lighting]

Dunno what temperature the stuff I use shrinks at.

It's just what they sell at my wholesalers


I shrink it with my gas soldering iron.

 

[bigzed]

Dunno what temperature the stuff I use shrinks at, I shrink it with my gas soldering iron.

That sounds great to me because the tubing I have that I've used on bikes etc shrinks with the heat of a Hair Dryer but isn't particularly strong. The other tube I wanted to use requires a flame from a gas torch ( only just if you know what I mean ) but I wanted to make sure the T and E cable is up to it.

Thanks RF

 

[Taylortwocities]

The purpose of the heat shrink is to double insulate the live conductors.

I'm not aware of any particular specs that say what that outer layer of insualtion has to be. Other (wiser) contributors may be able to add other layers of complexity but I would say that the plastic trunking will serve to provide that. After all, its permissible to have single insulated live conductors in conduit.

 

[Softus]

...I just find it a little hard to swallow that it's allowable to use mechanical crimps on cable carrying mains voltage, especially when it's solid core, not stranded.

Hint: would you be happy to terminate a solid core conductor carrying 13 Amps by crimping it between a brass screw and a brass ferrule?

 

[bigzed]

would you be happy to terminate a solid core conductor carrying 13 Amps by crimping it between a brass screw and a brass ferrule?

Hmmm Point Taken Softus

 

[daytona]

in all honesty,i suspect the ones that struggle to crimp solid core conductors, are using sub standard crimpers and probably using a blue crimp for the cpc.