Any telephone wiring experts here?

[D Skelton]

I have to replace a BT master socket and I'm replacing it with a modular master socket as I'm fitting dado trunking right across where the original master socket is sighted. I know technically I shouldn't be doing this because BT might get a bit aggy but needs must. I'm fully aware of the fact that what I'm doing may be a little naughty so no need to reiterate this, however if you're willing to help then please read on

As you can see in the pictures below the original master socket is wired as it should be with the two incoming cores at terminations 'A' and 'B'. As I'm sure you know the master socket allows for extensions via the IDC connectors on the consumers side. What I can't seem to see is a way to extend from the modular master socket. Would every extension from this master socket need to be a master socket also, surely extending straight from this to a slave would mean that there would be no surge arrester in place? Is it even possible?

Thanks in advance.

 

[UNG]

You can only piggy back off 2 & 5 where your incoming cable will be connected

It's not clear why you can't fit the BT NTE5 on your dado trunking after all it mounts on a standard socket box and provides a test point to split the extension wiring from the outside line should a fault occur. You could be leaving your customer open to a charge from BT for fitting a new NTE5 or delay repairs should they be called in on a fault

EDIT forgot to add that krone terminals only take two cables any more and the connection can be a bit hit and miss

 

[D Skelton]

It's not clear why you can't fit the BT NTE5 on your dado trunking

Facepalm

Thanks bud!

 

[D Skelton]

Mind you, whilst I'm here asking questions, by piggy backing off 2 and 5 on a modular master, if I did ever need to, would that mean that any extensions would have to be master modules too?

 

[UNG]

No they need to be secondary jacks you could use masters if that is all you have with you but you would need to remove all the components (capacitor etc) from it

 

[D Skelton]

I don't understand why? I thought the point of the master was because it contained a surge arrestor (among other things). Surely if you're simply daisy chaining from 2 and 5 to another socket it would need to be a master too? Essentially the extension would be part of the incoming line.

What am I missing?

 

[i=p/u]

Master A B, then 2,5 from back to next phone ponint and keep looping , if one phone ring they all ring= one line???

 

[D Skelton]

Master A B, then 2,5 from back to next phone ponint and keep looping , if one phone ring they all ring= one line???

I'm talking about the modular master sockets. They don't have 'A' and 'B'. You have to use 2 and 5 for incoming.

 

[UNG]

The A & B on the NTE5 are connected to 2 & 5 on the extension faceplate when it is plugged in, prior to the introduction of the NTE5 the old master socket connections were labelled 1, 2 ,3 etc and extensions were daisy chained from these.

The NTE5 was introduced when the wiring of telephone extensions was deregulated and was designed to provide a demarcation point between the BT PSTN and the customers wiring it being illegal to alter or add to the incoming connections (A & B ) the removeable lower faceplate allowed third parties to connect additional wiring


The components on the master are an out of service resistor, bell capacitor and a surge arrestor

 

[D Skelton]

Ahh, I see, it all begins to make sense now!

So hypothetically speaking what would be the result of replacing your master with a secondary jack? My guess = very little?

 

[UNG]

There is no reason why it would not work, an issue may arise with the automated line testing systems BT use and you would have no surge protection

Have a read of this for more info on phone sockets

 

[D Skelton]

The A & B on the NTE5 are connected to 2 & 5 on the extension faceplate

Are they connected directly or through the components?

Edit: Scrap that, seems by the diagram they are connected directly.