Help needed to work out what all these BT cables do

Discussion in 'Electricians' Talk' started by SmugDictator, Nov 8, 2019.

  1. SmugDictator

    SmugDictator Member

    Trying to get to grips with what is what with the BT cables coming into the house.

    I've attached some pictures

    1. BT Cables outside of house
    Here you can see two cables coming to the house. One goes down towards the front door and the other tracks alongside first storey of the house and seems to wind its way through the rooms to the box room.

    01. BT cables outside of house.jpg

    Question: Does the fact there are two cables mean the property had two separate telephone lines?

    2. Master socket in entrance hall
    The cable that runs from the front of the house towards the front door (let's say cable A) comes into the hall into what looks like a master socket given the relay and capacitor. However, it seems then to be linked back directly to another cable which goes back out the same way.

    02. Master socket in entrance hall.jpg

    Question: Is this a master socket? It doesn't appear to have the double plate thingy where by you can separate all of your internal wiring from BT's.

    3. Connection block in bedroom
    The other cable coming to the front of the house (let's call it B), after running along the first storey external wall comes inside the house and is joined in this box.


    Question: I presume that this is some sort of terminal connection box? Can I mess with it?

    4. Another master socket.
    That cable B then ends up here in what looks like another master socket in the box room. If I am correct about their being two lines, this would appear to be the 1st master socket for cable B.

    04. Another master socket.jpg

    Question: If I am correct, I guess I can't touch this socket and it's owned by open reach despite it being deep inside the house?

    5. Bedroom master socket
    This socket appears to originate from cable A. After it goes into the what I presume is a master socket in the entrance hall, it comes back out of the house, around the house and terminates in this box which does look like a master socket.

    05. Bedroom master socket.jpg

    Question: Is this a master socket? It looks like one and has the detachable part to remove my wiring from BT's.

    To my untrained eye I seem to have a lot of master sockets!

    Would welcome some opinions on what I have and what I can get rid of.
  2. KIAB

    KIAB Super Member

    Your house had two seperate phone lines at one time.

    And each line would have a single master socket,then any further sockets would be usually secondary.
  3. SmugDictator

    SmugDictator Member

    So the socket that is deep in the house that connects via that box on the wall I can't touch as it's Openreach's property by the sound of it?

    Why would the previous owners put master sockets on extensions? Any technical reason?

    Also, if Openreach came out would then just swap that old master socket on the hallway that seems to feed another extension?

    Thanks again.
  4. blarblarblarblar

    blarblarblarblar Active Member

    Why would the previous owners put master sockets on extensions? Any technical reason?

    Yes, if you were missing a 3rd wire, possibly due to a damaged cable. Ringing wire.
  5. blarblarblarblar

    blarblarblarblar Active Member

    2 is not a master, it’s a Line Jack 2 /1A.
    3 is a block 80A, with the pcb removed,
    4 is a master, but fed with internal cable.
    5 is a master and fed with the external drop wire, from the pole, or may come from the block 80.
    Wiring isn’t correct, or at least doesn’t make sense.
    Last edited: Nov 8, 2019
  6. SmugDictator

    SmugDictator Member

    Really frustrating these master sockets are where I don't want them and yet I can't touch them.

    Would you be able to explain what a Line Jack does please? I think the previous owners did have a phone at that point.
  7. blarblarblarblar

    blarblarblarblar Active Member

    Well, it’s your house, move it, but be prepared for BT to charge if it goes wrong.

    Move it to where you want it.

    The line jack unit, is kind of a main socket, but can be used for larger building to help with the loss of ring. REN used to be an issue, so too many phones, would require a LJU 2 or 3,

    The 2 piece master, was brought in to allow anyone to fit secondary/ extensions with having to disconnect the main incoming. Really doesn’t matter anymore.
    Alwaysworking likes this.
  8. blarblarblarblar

    blarblarblarblar Active Member

    Out of interest, why do you need more than 1?
  9. SmugDictator

    SmugDictator Member

    I don't actually need any at present as we have cable. I predict the cable provider will increase the price at the end of the contract so I want to be prepared to have the master socket near to the cable providers where there modem lives to feed my lan.

    Also I want to tidy up the internal and external wiring around the house. The external stuff goes all over the place as does the internal which I don't want to redecorate around.

    Could I extend the cable from the LJU with some sort of punch down terminal block then fit a new master?

    If I could take the extension out of the LJU that would also be a start.

  10. ajohn

    ajohn Screwfix Select

    They may pick up a line fault while you are changing things ;) on the other hand they may not if you do it sensibly.

  11. Alwaysworking

    Alwaysworking Active Member

    Yeah, that’s a joke right. No one will know. Or will they?
  12. SmugDictator

    SmugDictator Member

    Is there any way I could damage their equipment? e.g. if I shorted some wires?

    I'm planning to cut them off one by one, a bit like how they diffuse a bomb on tv ;)
  13. Mr Rusty

    Mr Rusty Screwfix Select

    If you've just bought the house, cut it all off as you want, and then when you are ready contact whoever and say you have inherited what you have and you would like a working line installed. They will come out, see what you've got and do a new install. You may have to pay for a new line or not depending. I had to do basically this with my house project, because I had to cut the line as I stripped the house. 2 years later all installed new organised by Zen Internet. I can't actually remember whether I paid for a new line or not.

    Technically you shouldn't touch BT equipment but......
    blarblarblarblar likes this.
  14. blarblarblarblar

    blarblarblarblar Active Member

    No. If you short it, anyone calling will get an engaged tone, do people still have house phones?
    Last edited: Nov 9, 2019
  15. blarblarblarblar

    blarblarblarblar Active Member

    Technically you shouldn't touch BT equipment but......

    Technically your master should be within 1 metre of drop wire In to the building. So as it’s not, move it where you want.
    If you phone BT, they will have A record stating a working line is present, but wont have a record of the socket location. If BT turn up as you have cut out the internals, they will reinstall a master, where your drop wire enters the building. No ones bothered, really.
    If it was my house, I’d be shouting at BT to get back and clip the drop wire to the house properly, and not as if Stevie Wonder was on call that day.
  16. Alf berwick

    Alf berwick New Member

    If you are having broadband, you should wire it to the proper bt method.
    Don't worry about touching the bt equipment, they will only charge you if they are out on a fault you have caused.
    So,follow in coming cable and put the proper nte5 socket on that. Then, if you are having extensions, either use the existing cables if they are proper phone cable, or run new PHONE Cable, not alarm cable,( it may be cheaper but will kill broadband signal,) and if you are having more sockets, you must run from socket to socket, not run two extensions from one socket, or that will also kill the broadband. Colour code is orange white on the thick drop wire, blue white on internal, to terminals 2 and 5, polarity is not important unless you are using very old bell phones from 30 years ago.
  17. peter palmer

    peter palmer Super Member

    John Ward has just done a skit on phone wiring.

  18. Mr Rusty

    Mr Rusty Screwfix Select

    Interesting. When they installed my new box it's 4m across and 5m down from the building attachment point. They put it where I wanted.
  19. Alwaysworking

    Alwaysworking Active Member

    It Didn’t say attachment, it said into the building. 1 mtr from entry point,
  20. Mr Rusty

    Mr Rusty Screwfix Select

    Yes that's what I meant. My cable entered the building at the attachment point and goes 5m down and 4m across internally, all nicely installed by Mr Openreach. The house was bare brick/open ceilings at the time and the cable was run through the ceiling space.

Share This Page