On Sat, 15 Dec 2018 15:23:28 -0000, trader_4 wrote:

On Saturday, December 15, 2018 at 9:52:09 AM UTC-5, Kristy Ogilvie wrote:
On Sat, 15 Dec 2018 14:43:50 -0000, Harry Bloomfield wrote:

Kristy Ogilvie brought next idea :
Where is this protective ground? There certainly isn't one in any BT master
socket I've seen, just a couple of twisted pairs coming through a plastic
tube to the socket.

Some service lines would be fitted with a ground connection in the
early GPO days, but I doubt any are now. Most likely there will be a
ground at the pole or the cabinet.

I assume this is only for overhead lines anyway, mine are underground.

Strangely some newer houses in the next block have overhead phone wires (but underground mains wires). Did they forget them when building or something?

Here in the US all phone lines I've seen had a surge protector installed,
bonded to ground, at the house, whether over head or underground.

You maybe get more storms there? I've not actually heard of any lightning problems in UK phone lines.

There might be surge protectors within the main socket, but they're not earth bonded.

I don't know why you have them protected if they're underground though.