Telephone cabling help please

[Melter]

I'm trying to add a new phone point in our lounge. I've bought some four core cable to daisychain from the existing point and following instructions attached the wires to both points using the correct insertion tool. The new point doesn't work.

One thing I do find unusual about the existing wires in the first point (having read that cable should either be 6 core or 4 core) is there are 10 wires and they were wired as follows:

The two green and white wires were fixed in other slots and not 1 and 6 so I moved those.

Slot 2 has a blue wire
Slot 5 has an orange wire (the blue and white wires you'd expect in these slots are unused crammed into the box).

Slot 3 has a brown wire and the orange with white ring wire.
Slot 4 has a green wire and the white with orange ring wire.

What's happening here then, does this sound right? Any suggestions for where I might be going wrong? Btw the existing point works fine.

 

[Lectrician]

Dont look at the existing colours - just the termination.

Link terminals 2345 from the existing to the new - simple.

Strictly speaking, just 235 would do, but simpler to do the lot.

FORGET the other colours - concentrate on numbers!!

There is no strict code for colours on phones.

 

[Melter]

That's what I thought. So apart from the obvious, that is the new point is faulty, any thoughts on why it won't work?

 

[SparkyTris]

The new one may be faulty, but probably not. Most likely problem is that the new wires you have put in with the little tool are not making good contact with the blade connectors in the box. the blades in the connector slots serve the purpose of cutting the insulation and forming an "electrical connection" onto the copper within.

You've got the extension box, and presumably you have only one set of wires going into it, so the chances are good that these wires are making contact. It's probably the wires in the master unit that are causing the problem, because you are trying to double-up the connections on the slot's blades.

If I was you, I'd bare the wires, and push them firmly down into the blades with a bluntish knife.

As Lectrician says, you need:

Master unit connected to extension unit
2 - 2
3 - 3
5 - 5

 

[SparkyTris]

Don't worry about dealing with the bare copper of the telephone lines. there is never a lethal voltage on it by design. You may get a fingertingle if someone rings in and you are holding onto the wrong wires though.

 

[zoltron]

Right here is the correct wiring guide for BT & Cable Telephone services.

Pin 1 - Solid Green with White Stripes
Pin 2 - Solid Blue with White Stripes
Pin 3 - Solid Orange with White Stripes
Pin 4 - Solid White with Orange Stripes
Pin 5 - Solid White with Blue Stripes
Pin 6 - Solid White with Green Stripes

Pins 1 & 6 do not need connecting, however many believe pin 4 should also not be connected. This is untrue pin 4 should always be connected. Why might you ask? well simple really have you ever picked up your phone on an extension socket but your answering machine beat you to it? well if pin 4 is not connected the answering machine will not disconnect and will continue to play the greeting message while you are trying to say hello to the caller.

now to do a simple test if you have no electrical test equipment, if your extension does not work when you run from the NTE5A try this. Disconnect extension from the NTE5A (Master Socket) connect two wires to pins 2 & 5 on the socket and run them out of the bottom of the socket and replace the lower front socket of the master now take the two wires and strip them down to the copper cores, take 1 finger and wet it with saliva, place the 2 wires on the finger wet with saliva but do not short the cores across one another now if there is no problem with the socket you should see the copper on the saliva starting to fizz at the edges, if there is not fizzing then there is a problem with the master socket get your telco provider to replace. Now try the same thing where your extension socket is going if you see the fizzing there is no problem. You should be using the blue pair to do the fizz test, if all was okay at the master but not at the extension try changing the pair colour to green, or if you were using 4 or 5 pair use brown or slate.

When doing the fizz test I guaruntee you will not get an electrical shock, I promise, I used to be a telecoms network engineer. However do not do the fizz test on the tongue as that is most unpleasant.

 

[Melter]

Cheers guys. I have no problem with what wire goes where as there was a very useful sheet that came with the new phone point. I did wonder if I might be better baring the wire as my extension cable has added a third wire to the contact in some slots. I'll give it a go in the morning and let you know.

 

[securespark]

If I was you, I'd bare the wires, and push them firmly down into the blades with a bluntish knife.

Unfortunately the quickest way to wreck the IDC terminals.

However, I will agree with you on one thing - the conductors are probably not making contact - my guess is you are using a plastic insertion tool.

STOP! For a few quid, buy the real thing - they are the pro's choice and far better for connecting - plus they also cut off any excess.

According to my old mate who worked for GPO up to 70's, the colours most commonly used in the old code are Blue, Orange and Brown.

Blue = term 2 = Blue/White in new money

Orange = term 5 = White/Blue

Brown = term 3 = Orange/White (ringer connection)

Don't take this as gospel though, as Lec said, look at which terms they goto.

 

[Melter]

Wahey! As y'all suspected it was the connections on the existing point that was causing the problem. Swapped the existing point for the new one as this has screw terminals rather than slots and holds all the wires better. I'll get another new point to replace the old one.

Securespark: Your comments now make more sense to what I have here. There was indeed two cables (4 core and a 6 core) running to the existing point. The four core has the colours you mention and a green so this must be an old style cable.

Interestingly though the blue and whites from the six core weren't used so I took out the old colour wires from the terminals and wired the point up as it should be and it wouldn't work. It only seems to work if I use a combination of the old 4 core and the newer 6 core. Must be that the blue and whites aren't connected at the business end but can't think why someone would put in a new cable then not wire it up correctly.

Anyway all is good and I'm not tampering any further. Cheers all.

 

[plugwash]

Wahey! As y'all suspected it was the connections on the existing point that was causing the problem. Swapped the existing point for the new one as this has screw terminals rather than slots and holds all the wires better. I'll get another new point to replace the old one.

carefull

if the original point was a master socket you will need to keep a master in the system or your phones will not ring.

 

[Paul_C]

According to my old mate who worked for GPO up to 70's, the colours most commonly used in the old code

Yes -- Blue, orange, green, and brown were the standard colors for quad station wire used by the GPO until the early 1980s. Blue and orange were the line pair, with green and brown used in various ways depending upon the configuration of the phones, whether it was a party-line etc.

Some of these old cables were then just reterminated when the new modular jacks were introduced around 1982. At the same time, the standard method of wiring bells was also changed. The hybrid wiring which results in such a modified installation can be confusing to anyone not familiar with the old configurations.

Melter, glad you're up and running now, but another point for anyone else experiencing difficulties is that you can find some sockets which have been numbered backwards, i.e. you need to swap over 2-5 and 3-4.

This was due to a monumental lack of communication when the standard was drawn up which resulted in the plugs and sockets being numbered the opposite way round , and it seems that some manufacturers use the original plug numbering on their sockets.

A typical sympton of such a misnumbered socket is that a phone plugged into it will give you dialtone but it will not ring on incopming calls.

 

[SparkyTris]

Unfortunately the quickest way to wreck the IDC terminals.

I know what you mean! but in my opinion, these terminals were on a hiding to nothing right from the start!

I read somewhere that the new style modular equipment was designed to allow subscribers to add their own extensions - is this correct?
what was the point of going to this rather gimcrack IDC connection system? The old GPO stuff has really nice screw-down terminals, and I hang on to it wherever I can. I do a lot of telephone fixing for family & friends and virtually all of the problems have been down to a bad IDC connection.

incidentally I have just "resurrected" a GPO external bell that has been screwed to an outside wall ever since it was installed in 1964. I say "resurrected" because all I did was connect up the terminals that a BT man had snipped in about 1980. It still works perfectly.

 

[plugwash]

there are two types of master socket for current style plugs

with the older simple master sockets you are supposed to use a plug in adaptor (though many people don't for neatness reasons)

with the nte5s there is a seperate lower section for easy disconnection of customer wiring.

the idc terminals are fast if you have a decent tool and know what you are doing and similar terminals are used on pbx systems and networks with no real trouble but i agree they aren't really good for diy phone wiring.

 

[SparkyTris]

the idc terminals are fast

Yes, somehow I thought this was the reason...

 

[securespark]

One more point.

Re the fizz test.....

It is quite possible for there to be 50 VAC on a phone line. Also, if a call comes in when you are fizz testing, be prepared!