Extending Cable to BT Master Socket

[jdw]

Hi

I need to extend the wiring from the internal BT80B junction box where drop wire comes in to the master socket. Currently there is a very old 4-core cable linking the junction box and master socket (brown, orange, green, blue) with only the blue and orange cables in use. I have a CW1308 6-core cable to extend this and I'm wondering which colour I should connect to the blue cable and which to the orange cable?

Any help would be greatly appreciated.

 

[Spark123]

I don't think you are supposed to tamper with anything on the BT side of the master socket, can you run the new cable from the master socket? Is it an NTE5 type socket with a plate which can be removed from the bottom where you can connect into?

 

[breezer]

that is correct.

but as for colours, makes no difference, so long as they are the same at both ends

 

[TicklyT]

Use two wires with the same colours in. They are the twisted pairs.

The old cable was a twisted quad. The colours used were blue = 1, Orange =2, Green = 3, Brown = 4.

New cables are twisted pairs. Blue = pair 1, Orange = pair 2, Green = pair 3, Brown = pair 4, Grey = pair 5.

 

[Space cat]

For a fully functional extension which will work with any phone you need three wires. Connect these from pins 2, 3 and 5 in the master socket to the matching pins in your extension(s). Unless your 6-core cable has colours that match the ones in the master socket there is little point worrying about it. They will be non-standard whatever you do and, somewhere down the line (no pun intended), some underpaid BT monkey will be totally flummoxed.

More important than the colours are the cores. Those IDC connectors are designed for a particular size of SOLID core wire. Stranded core wires make unreliable connections. This will cause you much grief 'further down the line' - literally!

And finally, a word of warning: When you're wiring up phone sockets, NEVER TRUST THE NUMBERS! I once spent hours trying to work out why some phones wouldn't ring at a particular socket. I eventually realized that its connectors were numbered BACKWARDS!!! Pins 2 and 5 are interchangeable but 3 and 4 are not. Without a wire on pin 3, older phones won't ring. Ever since that day I've ignored the numbers and worked backwards from the spring leaves in the socket.

 

[jdw]

Thanks for the replies so far.

Just to clarify, currently the drop wire comes in the bathroom window where it meets the junction box. The cable then runs along the wall, out into the hall and disappers into the wall before it comes out at the master socket. I'm getting the walls in the bathroom plastered (tomorrow!) and need to extend the part of the cable that's in the bathroom so that it can run along the floor.

Unfortunately extending after the socket isn't an option and neither is paying/waiting for BT to come out to do the work.

TicklyT - does it matter which of the twisted pairs I use for connecting? (colours in the new cable are blue with white stripe, white/blue, orange/white, white/orange, green/white white/green)

 

[breezer]

nope, but most common is blue white, white blue

 

[Space cat]

There are standard colours for phone extensions and you have them in that cable of yours. Sorry, no time to look them up for you right now. Got to get some work done.

 

[ugjointer]

JDW,if you are having your bathroom plastered wrap the bt 80 b up in some clingfilm and keep it out of the way of the plastererus,when they have done then extend the wiring ,which is technically BT s as its before the NTE but thats another thing.The bt 80 will have numbered terminals and terminals 2 and 5 should be the only two used if it is before the NTE 5.