Using MF Junction Boxes

[Nemo2000]

In part of some alterations in my hall, I've had to relocate a power socket that is in the ring main. In its new location one 'leg' of the ring main would still reach the socket, but not the other, so I've had to inset a new length of 2.5mm T&E and a new JB to connect to the old ring.

As I'm introducing a new JB into the circuit and it will be 'inaccessible' under the hall floor (once the new laminate flooring has been laid over the existing T&G floorboards), I thought I'd better do it 'properly (?) and use a Maintenance Free JB, so I've fitted a Hager J803.

First time I've used a MF JB and although I got the L and N cores into the terminal block with no trouble, how are you supposed to push in the ECC once it has been fitted with the obligatory Y/G sheath? As the sheath is loose, you can't just grip the outside with pliers, as the sheath just slips on the conductor. I managed eventually by forcing back the end of the sheath and griping the bare conductor with fine-nose pliers, but is there not a better way of doing this ?

 

[sparkwright]

I've used those before, though not lately, and didn't have any problems.

Is there a lever that you push down before pushing the wire in?

 

[bhm1712]

it’s quite simple, you push the earth sheathing out of the way and grip the CPC and push it in. Once done the earth sheathing will spring back into place. If you can’t, then the sheathing is too long.

 

[Nemo2000]

Well, that's just what I did, but I just wondered if there was 'another way' that I'd not thought about.

 

[Nemo2000]

I've used those before, though not lately, and didn't have any problems.

Is there a lever that you push down before pushing the wire in?

There is, but only for use with flexible stranded cable - for solid-core the instructions state simply to push in without depressing the lever..

 

[EFLImpudence]

There is, but only for use with flexible stranded cable - for solid-core the instructions state simply to push in without depressing the lever..

Yes, but you are allowed to use the lever if you want to remove the resistance.

 

[333rocky333]

If the box can be laid on a flat surface , i push the lever Down with a screwdriver, I assume that's why the slots are moulded into them.
I also use 2mm sleeving, it's a lot neater.

 

[bernardgreen]

Yes, but you are allowed to use the lever if you want to remove the resistance

When a solid core conductor is pushed into the connector there is some abrasion that removes any corrosion of the copper at the point of contact between conductor and spring. If the lever is used then there is little or no abrasion and the contact may be affected by corrosion.

A very thin layer of copper oxide ( corrosion ) can affect the joint by increasing the contact resistance and this contact heating.

New cable is unlikely to have significant corrosion but older cables may have a layer that is thick enough to affect the joint,

 

[EFLImpudence]

WHAT?

 

[bernardgreen]

WHAT in deed

replace "copper oxide" with "tarnish"