Wiring for UK Telephone Sockets Author - Peter Parry - WPP Although pin 4 has no function in a domestic installation it is usually connected for the sake of neatness. The quality of wiring carried out by many older BT wiremen is often approaching art in its perfection. The BT Drop Cable (The cable coming from the outside world) This often has Orange, White, Green and Black wires. Usually (but.. Since most telephone extension wiring consists of two pairs, you may find this information particularly useful if you need to use a particular run of pre-installed cable for both a filtered and unfiltered signal (However Cat5e/Cat6 has that extra pair remember?).
Installation & Connection To Telephone Lines It is important to follow these instructions carefully to ensure telephone extension sockets and cabling do not damage public telephone networks and will give trouble-free service. The telephone service provider (eg British Telecom) is entitled to check and inspect any sock-et (or wiring) connected to their exchange lines.. If you have underground wiring with a small grey connection box by the door the internal cabling will usually be the same type and colour as the extension cabling.