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wrong socket wiring

vetterlein
Grafter
Posts: 68
Registered: ‎11-01-2008

wrong socket wiring

1st I have BT as my phoneline (Plusnet/force9 for the broadband)
Last Wednesday (4 days ago) OpenReach came out and installed my FFTC connection.
(so I got a big box where the NTE5 was previously)
Before Wednesday. I had an NTE5 with the front phone socket used (for an answerphone(+DECT) & emergency phone)
and out of the back came two sets of cables ... a filtered and an unfiltered phone line.
These travelled over Cat5 and came out in my office on an RJ45/RJ11 plus a Phone Socket.
The RJ11 (unfiltered) went to the Modem
The phone line (filtered) went to my office phone ( extension socket, NO Capacitor)
So to install FFTC , I lose the unfiltered line (and the modem) an instead keep the Filtered line.
When the engineer tested this, with replacement for NTE5, using my original extension socket, the office phone did not ring  (emergency phone did ring).
After much scratching of head he eventually gave me a 'BT socket (bulk of a an NTE5 by the looks) .. this does not allow my other socket to fit in the box so is only a stopgap**.
I had assumed he had simply mis-wired the socket in my study (confused, because it was 6 pin socket and modern BT seem to just have 2 (A & B)
However having taken the new socket off the wall. I see what he has fitted is a 'Master socket'  ..ie it has a big yellow capacitor in it  (Labelled MKT-82 1u8k250v)
So what is going on here? ... I'm pretty sure my office should have an 'extension socket' (no capacitor)  ... so my only guess is that he has mis-wired the NTE5 replacement box (what are these called?) ... so I suspect the capacitor here is compensating for this mis-wire ?

[** FYI the cat5e and the phone sokets are the modular style ... so bot in  one box ... hence I cannot use  standard BT socket]
14 REPLIES 14
vetterlein
Grafter
Posts: 68
Registered: ‎11-01-2008

Re: wrong socket wiring

Seem to have solved my own problem 🙂
Looking here ==>http://www.wppltd.demon.co.uk/WPP/Wiring/UK_telephone/uk_telephone.html
The short answer is "pin 3" (aka Orange)
The BT guy kept saying "you have 4 wires" (between master and slave socket)  you only need two ... and in anycase
we only have three!
Turns out you need three, four are often wired just to make it neater (which looks like what I did many years ago)
Anyhow manage to coerce it into working (ring & phone) using existing socket, but it had become quite damaged
with all the connect/disconnect cycles ... so bought a new modular socket at screwfix (seem to be better mechanical construction)
and we are away ... extra capacitor is gone  , rings and phones just fine.
Looking at the kit BT install .. a series of plugin boxes with connectors marked A & B ... really have dumbed down from the days
when these could make a working phone line with wet string and multimeter !
HPsauce
Rising Star
Posts: 6,769
Thanks: 18
Fixes: 1
Registered: ‎02-02-2008

Re: wrong socket wiring

There's a simpler way round your problem.  Wink
You DO only need 2 wires for a phone, however some older types (what type is the one that didn't ring?) do require a "ring signal" in order to ring properly.
Typically this is generated in the master socket and carried on the 3rd (bell) wire to extensions if you have them.
This 3rd wire causes problems for ADSL and is regularly disconnected these days, normally with no impact on the phones.
IF you do have an old phone plugged into an extension, that won't ring the solution is simple:
- Unplug phone from socket.
- Take a spare plug-in ADSL filter and plug the phone lead into it.
- Plug the filter into the socket
The phone will now work normally.  Cheesy
Anotherone
Champion
Posts: 19,107
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Registered: ‎31-08-2007

Re: wrong socket wiring

As HP has mentioned you need the ring wire for some older phones, in many respects what the BT eng said was right and in an ADSL situation the bell wire must be filtered or disconnected, hence why you tend only to connect the unfiltered A&B throughout (unless you have central filtering).
So in a standard ADSL installation using filters at all used sockets, the reason all phones will ring is because each filter has it's own capacitor and bell wire (filtered), that's why the trick that HP suggested will work (the only potential downside is that the phone is double filtered and depending on filter quality some Caller Display units won't work).
In a centrally filtered situation, you need to feed the bell wire to all filtered phone sockets or have a local capacitor (ie.an LJU master socket). This is acceptable in a centrally filtered situation.
FTTC is centrally filtered. The NTE5 is fitted with a vDSL filtered plate that sits between the back plate and the plug-in front plate whose socket is now filtered with a filtered bell wire and all extension phone sockets should be connected with the 3-wires. In your case it seems the engineer only left the two connected and ended up providing an LJU master having a local capacitor.
The vDSL filtered plate has the RJ11 socket where the Modem can be plugged in (or a Data extension kit - 2 pair Cat5e cable with an RJ11 socket on the end) but the plate also has 2 IDC terminals for a hard wired Data extension.
FYI the modern BT socket/plug is 6-way but for normal residential use there are only 4 in an NTE5a. Depending on source/spec. LJU's can come with 4 or 6 fitted. Plugs fitted to phones etc can have 2 or 4 fitted depending on the need or source. 6-way plugs are available for (rare) specialist installations
It wasn't clear from you post where the FTTC modem ended up and how it was wired, out of curiosity could you complete the picture?
HPsauce
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Posts: 6,769
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Registered: ‎02-02-2008

Re: wrong socket wiring

Quote from: Anotherone
potential downside is that the phone is double filtered and depending on filter quality some Caller Display units won't work

An unlikely combination - a phone old enough to need a bell wire but having caller display.  Wink
vetterlein
Grafter
Posts: 68
Registered: ‎11-01-2008

Re: wrong socket wiring

The phone is a BT converse 1300 ... not particularly old .. in fact this unit is less than a year old (took a while to find as newer version lack some facilities I use, like headset)
I've always used central filters, never filter on the phone socket .... I used to run a filtered (4-wire) connection out to the phones and an unfiltered pair just for the thomson 585v8  (via rj11 socket)
...so never used socket level filters, always had 4 wire extensions , ringing always worked ... reasonably modern phone.

(I draw an picture of the layout)
Anotherone
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Posts: 19,107
Thanks: 455
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Registered: ‎31-08-2007

Re: wrong socket wiring

No need to draw any pictures, totally familiar with what you are saying.
@HP
If I can find it I have a broken one of those I could flog you  Grin  Grin  Grin
vetterlein
Grafter
Posts: 68
Registered: ‎11-01-2008

Re: wrong socket wiring

I have a broken one as well (this is the replacement)  ... damm about the pictures ... I've been exercising my bamboo stylus & GIMP .... so you can damm well have the pictures 🙂
HPsauce
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Registered: ‎02-02-2008

Re: wrong socket wiring

If you'd wanted to save running a 2nd cable you could have just used 4 cores (2 pairs) of the Cat5 for ethernet - that's all you need up to 100mbps.  Wink
Anotherone
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Posts: 19,107
Thanks: 455
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Registered: ‎31-08-2007

Re: wrong socket wiring

Ah well. I did ask what the final setup was  Grin  Grin
By the way, if you want keep 2 separate cables and to neaten up your wiring, I presume you know you can use CW1308 cable for the phone extension - less bulky than Cat5, but I suppose your existing cabling will give you greater flexibility for possible future changes.
HPsauce
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Registered: ‎02-02-2008

Re: wrong socket wiring

The converse is also that you can use CW1308 for 100mbps LAN - and I do!  Grin
Anotherone
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Posts: 19,107
Thanks: 455
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Registered: ‎31-08-2007

Re: wrong socket wiring

Tut, tut, not much cop on a long run and prone to more interference unless you luckily live in a very quiet electrical environment!
HPsauce
Rising Star
Posts: 6,769
Thanks: 18
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Registered: ‎02-02-2008

Re: wrong socket wiring

Well I'm not running it 100 metres in a factory that's for sure.  Grin
vetterlein
Grafter
Posts: 68
Registered: ‎11-01-2008

Re: wrong socket wiring

Well the 1st cable was 8 wire ... because I shared it between two 'lines' (filtered and un-filtered)
2nd cable exists , because it starts at a different place (modem , rather than NTE5) and is 8 wire because all the CAT5 in my house is 8 wire ... several just in locations which might be useful one day ...over the years they have been phone extensions, network points and  baby alarms, proving very flexible. I'd recommend it to anybody moving into a house.
HPsauce
Rising Star
Posts: 6,769
Thanks: 18
Fixes: 1
Registered: ‎02-02-2008

Re: wrong socket wiring

Quote from: vetterlein
several just in locations which might be useful one day

Yes, I do that when SWMBO isn't looking.  Grin
The CW1308 I ran when I needed a LAN cable in a hurry and there was no redecorating or similar in the offing, but there WAS a redundant phone cable along much of the obviously visible part of the route (which I removed and replaced). It wasn't ever noticed or commented on.  Lips_are_sealed