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Old BT wire colours

mikehale77
Newbie
Posts: 6
Registered: ‎14-03-2011

Old BT wire colours

My extensions were installed by BT using the following convention:-
2 solid blue
3 solid green
5 solid orange
They were taken off upstream of the master socket at a line block .
Can anyone tell me the likely installation year(s)?

Mike
1 REPLY 1
Nick_Russell
Grafter
Posts: 555
Registered: ‎10-05-2007

Re: Old BT wire colours

This site indicates "pre 1980" -

Quote
On older installations (pre-1980) cream or grey cables were used. They contained conductors coloured blue to pin 2, orange to pin 5, brown to pin 3 and green to pin 4 (if used), on some conversions green was used for pin 3 and brown for pin 4.
Additional Bells are wired between pin 3 (orange/white) and pin 5 (white/blue).

http://www.telephonesuk.co.uk/wiring_info.htm