terminating a telephone cable

Dunpony

I'm having some building work done in my garden and the builder cut through the phone cable that leads to an extension in the shed. We no longer need the extension but need to 'cap off' the cable because it is causing problems with the phones in the house - I have had to plug into the test socket to get phone and broadband.

Is there a way to terminate the cable myself?

RS2000.

Yes, where is it connected in the house?

Owain_Moneysaver

Disconnect it where it connects to the rest of the house wiring.

robatwork

As Owain said forget the garden cable, just "unwire" it from where it terminates in the house - probably your main BT box. Should be a simple job.

I believe there's only 50V on a BT cable and bugger all Amps.

Mankysteve

Are you using any other telephone points? If not find you master socket.

If you've got other phone point you'll have to trace back the cable to where it joins in the chain.

zax47

robatwork wrote: »

As Owain said forget the garden cable, just "unwire" it from where it terminates in the house - probably your main BT box. Should be a simple job.

I believe there's only 50V on a BT cable and bugger all Amps.

50V DC was generated at the exchange (from lead acid batteries I believe) to power the bell/ringer (so only present on the line when ringing!) in old bell equipped telephones. Phones haven't needed/used this for ages now. You could currently (pun intended) find 70V between the incoming pair. Full PSTN line spec here; http://www.sinet.bt.com/sinet/SINs/pdf/351v4p6.pdf

Just disconnect that extension at it's source, almost certainly in the NTE5 ("Master socket").

robatwork

zax47 wrote: »

50V DC was generated at the exchange (from lead acid batteries I believe) to power the bell/ringer (so only present on the line when ringing!) in old bell equipped telephones. Phones haven't needed/used this for ages now. .

Noted.

My phone still has a bell though, as does my servant's quarters. Must give a quick pull on the rope now as I fancy some cucumber sandwiches.

DandelionPatrol

zax47 wrote: »

50V DC was generated at the exchange (from lead acid batteries I believe) to power the bell/ringer (so only present on the line when ringing!) in old bell equipped telephones. Phones haven't needed/used this for ages now. You could currently (pun intended) find 70V between the incoming pair. Full PSTN line spec here; http[://][***].sinet.bt.[***]/sinet/SINs/pdf/351v4p6.pdf

Just disconnect that extension at it's source, almost certainly in the NTE5 ("Master socket").

Link is broken.

50Vdc is not used directly to power the ringer. It is used to power a carbon microphone on phones which still have them and also to detect that the handset is on or off hook.

Ringing is 75V ac or thereabouts at 16 2/3 Hz to 25 Hz.

touching the wires while there is only DC is fairly much unnoticeable, but it is more exciting if the phone is ringing

Ectophile

If it's the only extension you have, then the easiest solution will be to simply pull the wires out of the removable faceplate that you will already have taken off the master socket.

If you have more than one extension, and know how they are wired, then go back to the one that the cut extension wire is connected into and disconnect it there. Otherwise, you may have to open up all the extension sockets to find out where to disconnect the cables.