"Mike Tomlinson" wrote in message
...
In article , bud--
writes

Not clamping phone wires to earth is a major surge suppression flaw.

It's simply not necessary in towns and cities in the UK. Occurrences of
damage caused by surges on phone lines are practically unheard of.
There are reports of damage caused by direct or nearly lightning
strikes, but of course nothing is going to protect against that.

Houses in villages and remote locations would probably benefit most from
additional protection. You can be sure that critical installations
(hospitals, data centres, etc.) will install additional protection.

British Telecom fit NTE (network termination equipment), also known as a
master socket, which does have surge arrestors built in, but they don't
clamp to earth, they're just across the line:

http://www.buzzhost.co.uk/nte5.php

has a circuit diagram of the NTE, and an interesting photo of damage
caused by a direct lightning strike further down the page (which, of
course, none of w_'s equipment would have prevented.)

An additional factor is that adding further surge protection devices can
affect the line characteristics, causing ADSL sync speeds to drop.

A service panel
suppressor doesn't help the voltage difference at all.

Obviously.

Surprising since the UK seems to be very good on electrical protection
in general.

As I said in an earlier post, a calm, intelligent assessment (not w_'s
level of hand-waving, gibbering hysteria) of each situation is needed
before deciding on the level of protection required.

It's clear that it's simply not needed for most UK domestic phone lines;
this will have been borne out by years and years of experience, looking
at the number of insurance claims, etc. I should think BT's attitude is
that if the customer wishes to install additional protection after the
demarc (NTE), that's up to them.

In the end, It's all about assessing risk and mitigating it.

I found this webpage rather amusing:

http://www.satcure.co.uk/tech/phonesurge.htm

but will leave it to others to comment

--
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Wow, it says phone lines there can have as much as 180 [ringing] volts on
them, interesting.