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Topic Title: Phone connections
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Created On: 06 March 2013 11:19 AM
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 06 March 2013 11:19 AM
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tomgunn

Posts: 3182
Joined: 25 May 2005

Hi... got some wiring to do on Friday plus sort out a telephone problem, not been there yet, but I cannot find my info on the terms thats required, ( I have them saved somewhere... duh! dont know where though ), so; is it terms 2 and 3 at the box and I think I am right in saying that the bells no longer required any more?

Thanks...

Tom

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Tom .... ( The TERMINATOR ).

handyTRADESMAN ... haha

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 06 March 2013 11:27 AM
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AJJewsbury

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Off the top of my head I thought it was 2 & 5 for the A & B lines (blue/white). 3 I think was the ringer (orange) - probably still worth connecting - I think that many approved phones used the ringer line for the "bell" rather than re-derrive it from the A/B lines to avoid tinkling when dials were used.
- Andy.
 06 March 2013 11:54 AM
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sparkiemike

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Joined: 24 January 2008

Sometimes the 3rd wire is disconnected if there are broadband (ADSL) problems, especially if every extension has it own ADSL filter, each filter might have its own circuitry (capacitor) to generate the ring signal. This means if there is no 3rd wire even phones without that circuitry will ring because they go through the filter.

EDIT: I have alsways found this resouce useful - UK Telephone Extension Wiring - there are many others if you google it.
 06 March 2013 01:08 PM
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mikejumper

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Originally posted by: tomgunn
is it terms 2 and 3 at the box and I think I am right in saying that the bells no longer required any more?

2 and 5 using the blue pair and 3 using one of the orange pair.

I think 3 was originally connected to stop bell tinkle although I've never been entirely sure why it's used. I always connect it and have never had any problems.
 06 March 2013 01:27 PM
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AJJewsbury

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I think 3 was originally connected to stop bell tinkle

As I understand it, the bell line (3) carries a low frequency a.c. signal, derived from the A & B lines from the exchange using a capacitor. Old rotary dials put pulses on the line, which which look a bit like the a.c. signal the bells are expecting, so causing them to ring a little bit (tinkle). To stop this, the rotary dials have an additional contact that closes when the dial is anywhere other than its rest position - this is used to short out the ringer line, so stopping the bells tinkling when the dial is moving. When you have several phones (or independent bells) on one line you needed the dial to short out the bells on all of them - hence they needed to share a single ringer line - so the signal is created in the master socket and available to be shorted out everywhere. Approved phones (even DTMF ones) needed to use the ringer wire, rather than listen directly on the A&B lines, to ring their bells in case there was a rotary dial phone somewhere else on the line.

As sparkiemike correctly says, often the 'master sockets' role of generating the ring signal as been usurped by ADSL filters.

So if you leave off a connection to 3 (and don't have a ADSL filter or another master socket downstream) then chances are the phone won't ring.

- Andy.
 06 March 2013 02:06 PM
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tomgunn

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Well thanks to you all... brill replies as per usual!! I know I have all the info in my office... afely stored away... but I dont know where! Ahhh! haha!

I've altered them many times before but the olde grey matters going me thinks!

Great - now I'll pop along on Friday and try and look intelligent! Hope it works!

regards....

Tom

-------------------------
Tom .... ( The TERMINATOR ).

handyTRADESMAN ... haha

Castle Builders

Why did Nick Clegg cross the road? Because he said he wouldn't!

I can resist anything..... except temptation! ( Karl Gunn ).
 06 March 2013 07:32 PM
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stateit

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A one-line mini-rhyme for you Tom as a memory aid::

"Blue to Two"

And:

If the BT master socket is an NTE5 socket - the one with the removeable faceplate (ie nearly ALL installations, introduced in 1991) - You Do Not need to connect Orange to Teminal 3.

Nothing to do with ADSL filters - it's been that since before broadband had even been thought of !

-------------------------
S George
http://www.sg-electrical.com
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