Identify BT Drop Box Wires

[pauldk]

My BT drop cable has a grey sheath and 8 wires, BLUE, BROWN, ORANGE, GREEN and 4 WHITE wires. Which wires which go to A/B on an NT5 Master socket?

As 4 of the wires are white, can I identify them using a multimeter?

 

[plugwash]

Are any of the wires twisted together?

 

[Handymanjo]

Use multimeter to fine pair with 50v dc on.

 

[bernardgreen]

Those colours are the colours of CAT5 ( data wiring ) and not any type of telephone drop wire ( at least not in the lists I have ).

You will ( should ) find each white is twisted with one of the coloured wire to make 4 pairs.

Most likely the active pair will be either the Orange/White pair or the Blue/White pair ( but it depends on who connected it and their choice of colour.

As mentioned you could use a voltmeter to find which pair has 50 volts between its two wires.

 

[Diver Fred]

What colour is the outer sheath?
(Off) White or Cream then that cable is likely to be CW1302 internal '8 wire' in which case each colour is paired (and twisted) with a white wire. 1st pair is Blue with its paired white. 'B' leg is the colour. (8 wire in domestic properties is so very rare that it could be a bodge.)
Black then it's 'new' type Drop wire in which case the white wires are the steel suspension wires. But the colours do not sound correct.

 

[pauldk]

They say there are no stupid questions, so, do I need an active telephone account/line for there to be voltages running across the wires?

 

[Diver Fred]

Is the cable a 'Drop Wire' or 'Internal Cable'.
If it's internal cable if the wire colours are solid it should be Blue and Orange as the line pair. If the wire colours are colour/White & White/Colour banded then it should be the Blue/White - White/Blue pair.
If its external cable/drop wire see https://britishcablescompany.com/wp-content/uploads/2018/06/Dropwire-15-a.pdf