No, it's "earth" for earth recall.
The bell wire is the anti-tinkle/ring wire. Bells (sounders) should be connected from it to the A wire. When a phone goes off hook the bell wire is shorted to the A wire.
You don't really want to stick an unbalanced ring wire down your cat5 for reasons of noise immunity/generation. Hence its much better to run structured wiring using 2 cores for phone.
yup, true.
You don't need to *run* the third wire - you run two wires from hub to socket, and fit a ring cap at the socket - so the third wire exists only for the length of the phones cable.
No, that was used for earthed (rather than timed break) "recall" facilities. Generally not wired these days.
Just coming back to report the outcome of my wiring experiment after absorbing the various contributions on this thread.
I took a two-wire connection from BT master terminals 2 and 5 and connected these to pins 5 and 4 of four patch panel sockets (wired in parallel).
I used Cat5e patch leads to connect the four patch panel sockets to the kitchen, dining room, bedroom and study. I inserted the Comlynx PSTN adapters into the corresponding jacks in those rooms and plugged the phones in.
It worked fine.
[Footnote: I have since bought a Panasonic TEA308 PABX and four Panasonic hybrid phones. Once I've worked out the wiring on these, I'll install them instead of the PSTN phones.]HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.