Are mains surge protectors needed in the UK?

Lem wrote:

Stormsinger wrote:
=20
=20
modems are different. If the strike hits a telephone pole then
the resulting surge down the phone line can easily take out a
modem, and if you're unlucky your mobo as well. Usually though
your modem will act as a very expensive fuse.=20

Buy a surge protection device that also protects modems and
you should be okay. IMHO Belkin are the best, but others may
have a different view.=20

Look at it this way. A couple of years ago we had a massive
storm in our area - apparently there were 30,000 odd
lightening strikes over the county. (according to the
electricity people). Over a two week period, I replaced
several dozen modems for people who "suddenly couldn't get
online". My supplier ran out of stock! Even the local PCWorld
ran out (someone from there even phoned my business to see if
we had any modems left in stock that they could buy!!).

You can save =A330 or so and take the risk - its up to you in
the end.=20

=20
=20
=20
See this posting to a second thread started with the same posting=20
as this one.
=20
It says the following.

The article below is misleading. They talk of earthing "all incoming=20
utilities" but fail to recognize that any incoming 'utility' is not simpl=
y=20
a single wire, as evidenced by their stating "even the CATV wire drops do=
wn=20
to earth ground." It's a coax cable folks, not a 'wire', and the wire in =

the middle is not 'earthed' or else there's be no signal. It IS however, =

'protected', to some degree, by the shield, which is what's earthed.

Power lines are more problematic. True, the incoming power line 'earth'=20
should be 'earthed', as they describe, but the others are not, or else yo=
ur=20
incoming power would be a direct short to each other through this common =

'earth' point.

The 'protection' for power and signal lines is an arc gap suppressor to=20
that common earth ground which, hopefully, arcs a lightning strike to ear=
th=20
at that point rather than having it find earth through the devices, or yo=
u,=20
in the home so lucky you end up with only a few hundreds, or thousands, o=
f=20
volts transients dancing around on the home wiring and your home equipmen=
t=20
with the brunt going through the arc gap suppressors.

Now you, as a human being, are probably safe from those remaining=20
transients, unless you have your finger stuck in a socket, but electronic=
=20
devices are not as they ARE plugged into the socket. And it is those=20
transients that an in-house transient/surge suppressor is meant to deal=20
with, not 'lightning strikes' per see.

It is true that small in-house 'protectors' are essentially useless if th=
e=20
home utilities AREN'T properly protected (earthed) but the implication=20
derived from the small snippet that if the home has 'proper' incoming sur=
ge=20
suppression that it's then 'safe' for electronic devices (I.E. they're=20
sufficiently 'protected') is simply hogwash.

It should also be obvious that if the surge protector has no path to eart=
h=20
then it's function is lost, which means the outlet(s) it's plugged into=20
must have the proper earth, or it's own wired earth. I.E. Using a '3 wire=
=20
to 2 wire adapter' on a surge suppressor disables the majority of it's=20
protection.

'Protection' is a multistage process. You have the 'protection' on the=20
utilities themselves, meaning the power company equipment/line outside th=
e=20
home, which absorb the brunt of most faults. Then there is the protection=
=20
going into the home, which depends on the incoming line impedance to limi=
t=20
the surge. And then you have protection (or lack thereof) from the=20
'remnants' left on the interior wiring.



=3D=3D=3D=3D=3D=3D QUOTE =3D=3D=3D=3D=3D=3D=3D
=20
A plug-in surge protector is on the order of tens of times
more money per protected appliance. Furthermore it does not
even claim to protect from the typically destructive
transient. Protectors do not stop, block, filter, or absorb
destructive transients. Ineffective protector manufacturers
get one to wish that is how they work. In reality, the
protector is not protection. Protector and protection are two
separate components of a surge protection system. Effective
systems must include the protection. And the connection to
protection is either a hardwire (less than 3 meters) or a
protector (also part of a less than 3 meter connection).
=20
In short, the protection is called single point earth
ground. Destructive surges may enter the building seeking
earth ground. If not earthed (either by hardwire connection
or by surge protector), then the destructive surge may find a
path to earth ground via computer. One classic example is due
to a direct strike to lines highest on utility poles - AC
electric. Incoming on AC electric, through computer and its
modem, then outgoing to earth ground via phone line. Many
then *assume* the surge entered on phone line, damaged modem,
then stopped - a violation of even primary school science.
=20
Effective protection means all incoming utilities are
earthed before entering the building. All must be earthed to
the same single point earth ground. That means even the CATV
wire drops down to earth ground, connects ground block 'less
than 3 meters' to that earth ground, and only then rises back
up to enter building. Again, no surge protector required
because earthing is accomplished by a direct and short
hardwire connection.
=20
These concepts are explained further including some examples
of 'whole house' protectors for AC mains at:
"RJ-11 line protection?" on 30 Dec 2003 through 12 Jan 2004 in
pdx.computing at
http://tinyurl.com/2hl53 and
"strange problem after power surge/thunderstorm" in
comp.dcom.modems on 31 Mar 2003 at=20
http://tinyurl.com/2gumt .
=20
Additional information on how surge protectors work, how
they are rated, installed, etc was posted in:
"Opinions on Surge Protectors?" on 7 Jul 2003 in the
newsgroup alt.certification.a-plus at=20
http://tinyurl.com/l3m9 and
"Power Surge" on 29 Sept 2003 in the newsgroup
alt.comp.hardware at
http://tinyurl.com/p1rk
=20
One industry professional demonstrates how two structures
are protected. Notice every wire entering each structure
(building and tower) must first connect to single point
ground. Even the buried phone wire carries a potentially
destructive transient which is why even buried wires must
enter building at the service entrance with the 'less than 3
meter' connection to earth ground:
=20
http://www.erico.com/public/library/...es/tncr002.pdf
=20
How do we identify ineffective protectors? 1) No dedicated
connection to earth ground AND 2) manufacturer avoids all
discussion about earthing. A surge protector is only as
effective as its earth ground - the protection.
=20
Those ineffective protector manufacturers fear you might
learn about the essential earth ground AND discover that
plug-in protectors cost tens of times more money per protected
appliance.
=20
=20

On Thu, 8 Jul 2004 23:16:17 UTC, "AK" wrote:

My house (in England) was struck by lightening

Did it change colour - say from beige to white? :-)

--
Bob Eager
begin a new life...dump Windows!

On Thu, 08 Jul 2004 21:44:41 GMT, "JULIAN HALES"
wrote:

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Please post in the group to reply.

I had a house electrical check a few weeks back from the local council, 2
guys, well one guy and his chimp, while doing it i said i do not want any
testing or surges as i run a large lan, although pre powerd down, they said
it was a good job i told them as at the end its normal to do something and
shove a surge? of some kind around the system.

yep they usualty shove 20,000 volts around IIRC as a surge test. They
do it once in a while at work and we have to unplug all the kit from
the mains.

They said, and i knew before hand even tho switched off at the wall but
still plugged in it could have blown the lot, how true this is i dont know

Potentially yes, espesh if one of the sockets was suspect.

Never had a surge pretector in years, always thought about it but never got
round to it, ok the LAN i have is cheap old junk, but the data should i lose
it would be a proble

Strange Lad wrote:


a friend of mine has had a machine totalled by a surge following a
nearby lightning strike that shot up his phone line, in through the
modem and spaltted his mobo to hell and gone.



I thought BT master sockets, NTE5s, have a built in lightning arrestor?
Maybe they don't, or he has an old type?

Parish

Cuzman wrote:

"Lem" wrote in message
...

" Am I being too complacent? "


Think of this when you next take a ****.
http://news.bbc.co.uk/1/hi/england/s...re/3457965.stm



LOL!

Electrical fault my arse; eight pints of Stella and a Ruby more like :-)

Parish

In article , Lem writes


See this posting to a second thread started with the same posting
as this one.

It was posted by an idiot with a bee in his bonnet about "whole house
surge protection", a superficial understanding of his subject, who only
ever posts to threads like this one, and who goes remarkably quiet when
challenged to substantiate his claims or to provide technical detail. A
google.groups search for w_tom in various uk.* groups will provide much
entertainment.

Said idiot is American and refuses to acknowledge that UK/European
wiring, because of its superior earthing system, is not as prone to
surges as American installations. In short, ignore.

--
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Q. What's the most annoying thing on Usenet?

On 9 Jul 2004 06:46:06 GMT, "Bob Eager" wrote:

-On Thu, 8 Jul 2004 23:16:17 UTC, "AK" wrote:
-
- My house (in England) was struck by lightening
-
-Did it change colour - say from beige to white? :-)

I hear the whoosh of passing thuneder.

Thanks for the chuckle, Bob.


-Rob
robatwork at mail dot com

In article , w_tom
writes

[more crap from w_tom]

Therefore only TVs suffered a direct
lightning strike incoming and outgoing. Incoming and outgoing
are essential requirements for surge damage.

No ****.

No adjacent protector that will stop, block, or absorb the
transient.

There's a big difference between a direct lightning strike and a
transient arriving via the mains. As you've been told many times.

An effective protection must shunt (divert,
connect, short circuit) the direct strike to earth so that the
direct strike does not find a better path via TVs. In your
case, that solution was a lightning rod

Really? Care to tell me how a lightning strike is going to discriminate
between a roof-mounted lightning rod and a TV aerial? (hint: in the
UK, most houses have a roof-mounted TV aerial.)

(and not plug-in
protectors that cost tens of times more money per protected
appliance).

Absolute bull****. No-one claims that plug-in surge protectors will
protect against direct lightning strikes. They, however, because of the
decent earthing system available on UK and European mains wiring, do a
good job of shunting spikes and surges to earth, thus protecting the
equipment plugged into them. And they are cheap insurance; 4 to 10 UK
pounds per protector.

Concepts such as 'whole house' protectors and lightning rods
are long ago proven to be superior protection.

Here we go again. In the States, maybe. Not in Europe.

--
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Q. What's the most annoying thing on Usenet?

Surge protectors (be they capacitors, varistors, or anything else) must
absorb the energy they're dealing with. Anything physically small will
vaporise and give little protection against a direct lightning strike on
the building, though they may protect against surges from further away.

I would expect a suitable Uninterruptible Power Supply to provide
reasonable lightning protection -- some APC units guarantee this, though
you'd have to ensure that all computers, monitors, etc. on a network are
powered through the UPC for safest results (or use fibre optic cabling
or wireless networking).

Surge protectors are probably of some use. A lightning rod for the
building is important. Personally I unplug computer equipment from mains
and phone during electrical storms if possible, But, in a city
environment, I haven't come across lightning damage, though I've heard
of it.

Obviously there are differences between a building in the middle of a
city and a house on a lone mountaintop!

Best wishes,
--
Michael Salem

"Mike Tomlinson" wrote in message
...
In article , w_tom
writes

[more crap from w_tom]

An effective protection must shunt (divert,
connect, short circuit) the direct strike to earth so that the
direct strike does not find a better path via TVs. In your
case, that solution was a lightning rod

Really? Care to tell me how a lightning strike is going to discriminate
between a roof-mounted lightning rod and a TV aerial? (hint: in the
UK, most houses have a roof-mounted TV aerial.)

I'm never one to jump to the defence of w_tom's American based
opinions but I think his 'lightning rod' = our 'earth-spike' and thus he
is talking about the effective ground rather than the place where
the strike enters the system. AICBW 8¬)


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