Telephone - 2 masters?

[adiwillow]

Hi all. I've got a small prob with the telephone cabling.

I've got an underground feed which comes to the house via a small box outside the front door. Now, from what i understand i should have 1 cable with a master socket on the end (in the house) coming from this box, and subsequent extensions coming from this master socket.

what i've actually got is 2 cables coming from the outside box up the wall into the house into two different locations, with a master socket on one (downstairs) and a normal socket on the other one (upstairs). I'm guessing this isnt right.

Anyway, i had to remove the master socket on the downstairs due to a bit of decorating and movnig sockets. Anyway, afer removing the wires and refitting the master socket it now wont work. (i've got the cables right and they're making contact). The socket upstairs still works.

Can anyone help? i'm unsure what to do next. I'm thinking i may have broke the cable internally when moving it, or perhaps the master socket has gone. Aside from this obviously my main issue is why i've got two cables coming into the house from the outdoor box, and why one had a master and one didnt?

thanks
adi

 

[Lectrician]

If the upstairs is a BT installed extension, it isn't uncommon to find that they spur from before the master socket.

They will usually fit a secondary, and use spare pairs in the cable to run the ringer back from the master to the box con and then to the second socket (if that makes sense).

Are you sure it is a secondary upstairs?

Do you have broadband?

Does the phone RING upstairs?

 

[bathjobby]

my main issue is why i've got two cables coming into the house from the outdoor box, and why one had a master and one didnt?

You only need one master and it contains the termination circuit for the line, so what you describe is fine.

 

[adiwillow]

They will usually fit a secondary, and use spare pairs in the cable to run the ringer back from the master to the box con and then to the second socket (if that makes sense)

yep i get you.. but i dont think they've done that as there was only the normal three wires connected in the master.

You only need one master and it contains the termination circuit for the line, so what you describe is fine.

okay thanks.. so any idea what may have happened as to why its not working now? I ran just the upstairs one for a while with the downstairs master completely disconnected. Now, when i go back to refit it, its dead. I guess i could try a replacement master to rule that out.

And yep, i'm using the upstairs socket for broadband, and yep the phone rings upstairs.

 

[Steve]

2 wires is normal in a master. 3 wires means they have taken the ringer back along the wire to the junction box, as someone said earlier!

 

[securespark]

It was common practice to convert hard-wired points to sockets by just replacing the main point with a master and any others with secondaries, unless any cores were damaged in which case BT used to fit a master - that way you can get a ring at each point with only 2 wires.

 

[bernardgreen]

http://www.wppltd.demon.co.uk/WPP/Wiring/UK_telephone/uk_telephone.html

 

[Lectrician]

Phone upstairs will still ring with out the master due to the DSL Filter.

Cordless phones and many newer phones also do not need a ring circuit to generate ringing.

Sounds like you have not made a good enough connection to me, or have muddled the cables/terminals.

 

[adiwillow]

i followed the standard wiring code.. and i'm99% i made the connection right as i'm used to using IDC anyway.

I'l try again at the weekend..

 

[adiwillow]

PS is there any way i can meter the wires out to make sure they are what they should be coming in?

 

[bernardgreen]

PS is there any way i can meter the wires out to make sure they are what they should be coming in?

In the sockets there should be about 50 volts between pins 2 and 5 when all phones are on hook ( not in use ), This will drop to about 10 volts when a phone is picked up.

Pin 2 positive Pin 5 negative is the usual polarity. All sockets should have the same polarity.

The 50 volts can vary between 48 and 55 and that is OK. less than 48 suggests a leak due to damp between the wires

NOTE if someone rings you the voltage is 50 volts DC PLUS 80 volts AC so the voltage across pin 2 and pin 5 is alternating between - 30 and +130 which can be un-pleasant on the fingers and mechanical meters.

The voltage between pin 3 and pin 5 should be zero. ( it may take a few seconds to settle as a capacitor is involved ) If it is not zero then there is damp or other leakage between the wires 2 and 3.

The ADSL ( broad band ) signal has been known to work when one of the wires A or B is open circuit.

One problem may be a reversal of the wires to pins 2 and 5 at one of the sockets where a ADSL filter is fitted.



Bernard

Sharnbrook

 

[adiwillow]

thanks .. very helpful . I'll try it later on.