Are mains surge protectors needed in the UK?

On Fri, 09 Jul 2004 12:07:50 +0100, Parish wrote:

Conor wrote:

In article , David Maynard says...
half_pint wrote:

How about using a plug with the correct sized fuse in it?

The proper fuse is always a good idea but fuses do not protect from power
line faults. They blow after your 'protected' device is fried and pulling
too much current as a result of it.

Or don't blow at all. Sister in Law is running a washing machine and
tumble drier off an extension. THe tumble drier developed a fault this
week. THe extension cable got red hot - too hot to touch. To get that
hot it had to have exceeded the plug fuse rating. Neither the fuse in
the extension chord or the fuse in the tumble drier mains plug blew.


The "fuse" isn't an M5x25 bolt is it? ;-)

Thats the Commodore 64 internal fuse replacement isn't it?

Conor wrote:

In article , David Maynard says...

half_pint wrote:


How about using a plug with the correct sized fuse in it?

The proper fuse is always a good idea but fuses do not protect from power
line faults. They blow after your 'protected' device is fried and pulling
too much current as a result of it.


Or don't blow at all. Sister in Law is running a washing machine and
tumble drier off an extension. THe tumble drier developed a fault this
week. THe extension cable got red hot - too hot to touch. To get that
hot it had to have exceeded the plug fuse rating. Neither the fuse in
the extension chord or the fuse in the tumble drier mains plug blew.



Yeah. That can happen. Obviously, since it did If it's not sized right
the wire resistance of the extension can act as a current limiter
'protecting' the fuse.

A wall receptacle safety ground is not earth ground. Yes,
safety ground and earth ground do connect. But when
discussing the earthing of destructive transients, then wall
receptacle ground is just too far away from earth ground.

Wire has impedance. 18 meters of 2.5 mm copper wire may be
less than 0.2 ohms resistance. But same wire would be maybe
130 ohms impedance to a surge. Wire impedance is why a
protector must connect less than 3 meters to earth ground. If
the plug-in protector attempts to earth a trivial 100 amp
transient down that 18 meter safety ground wire, then wall
receptacle would be at something less than 13,000 volts.
Where is the protection? Does not exist because wall
receptacle safety ground is not an effective earth ground.

Ineffective plug-in protectors such as Belkin fear you
might learn these facts. Belkin and others avoid all
discussion about earthing to make their sales. No earth
ground connection (using two wire or three wire plugs) means
they don't provide effective protection.

We install surge protector to earth direct lightning
strikes. Done routinely since before WWII. Your telco does
not shut down for every thunderstorm to protect their
multi-million dollar computer. 'Whole house' type protectors
with the less than 10 foot connection to earth ground have
been proven that effective for too many generations. And yet
today, still some recommend those ineffective plug-in
protectors such as the Belkin.

Every single wire (that is all AC wires and both phone
wires) must make a connection to earth ground. Some wires are
connected directly (ie AC neutral wire). Other wires must
make that earthing connection via a surge protector. But that
connection must be less than 3 meters and must be all wires to
same earth ground.

Defined is protection from direct lightning strikes because
lightning seeks earth ground. No earth ground (or earthing
wire too long) means no effective protection. What plug-in
protectors fear you might learn: a surge protector is only as
effective as its earth ground.

Properly noted is that protection is layered. That is not
layers of protectors. That is layers of earthing. Earthing
(not the protectors) is protection. Primary protection is
provided by the utility (see pictures cited below).
Secondary protection is the building's (service entrance)
'whole house' protector. So what is a plug-in protector?
Where is that plug-in protector's nearest earth ground?
Adjacent to 'whole house' protector. So where is the
layering by a plug-in protector? No layering exists because,
at best, it can only connect to same earth ground as the
'whole house' protector. Layering for protection - the earth
ground at pole and then the earth ground at building.

Again, protection is the earth ground - not inside a
protector. Layering is defined by the earth ground; and not
by protectors. Important pictures demonstrate why the
'Primary' protector can be compromised:
http://www.tvtower.com/fpl.html

Again, every incoming utility wires must be earthed to a
single point earth ground before entering the building.
Earthed directly or earthed via a 'whole house' protector.
Protection from direct lightning strikes is about earthing.

David Maynard wrote:
The article below is misleading. They talk of earthing "all
incoming utilities" but fail to recognize that any incoming
'utility' is not simply a single wire, as evidenced by their
stating "even the CATV wire drops down 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' should be 'earthed', as they describe, but the
others are not, or else your 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 that common earth ground which, hopefully,
arcs a lightning strike to earth at that point rather than
having it find earth through the devices, or you, in the
home so lucky you end up with only a few hundreds, or
thousands, of volts transients dancing around on the home
wiring and your home equipment
with the brunt going through the arc gap suppressors.

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

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

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

'Protection' is a multistage process. You have the
'protection' on the utilities themselves, meaning the power
company equipment/line outside the home, which absorb the
brunt of most faults. Then there is the protection going
into the home, which depends on the incoming line impedance
to limit the surge. And then you have protection (or lack
thereof) from the 'remnants' left on the interior wiring.

w_tom wrote:

Some deja vu. You're not in the States m8. In a densely populated
country like the UK, most of the risk are spikes from manmade
installations, induction from heavy machinery, fuse testing, outages.
A simple protector is well worth having and a once only investment.

In message , Lem writes
Are surge protectors on the main power supply actually needed in
the UK?

I've been running multiple home PCs in the UK for around 15 years and
have never had a problem with mains spikes, or ever heard from anyone
who has had a problem.

OTOH I've heard several reports of hardware losses in the US caused by
brownouts and spikes. The power distribution systems aren't as well
protected as in the UK, possibly because of the greater average distance
from substation to home, and poor earthing policies.

I've discussed internal wiring systems with US techies, some of them are
installing domestic wiring using uninsulated cables.



here in the UK we have few overhead mains power lines and have a
relatively steady mains power supply when compared to many other
countries (including the US).

However there seem to be very many surge protector products
advertised for sale in the UK (Argos, Maplins, etc).

I am quite sure it is not bad practice to use a surge protector but
in fact I have never known anyone who has has a problem from a
surge coming in through the power supply.

So personally I don't bother using a surge protector on my PC.

Am I being too complacent?

No.

I do have to report that I have recently had hardware damaged by 240v
power, but that was because the previous owner built a UPS system into
the garage and didn't mention it to the buyers. After blowing up some
kit I discovered that the garage supply does have lots of spikes, and a
square-wave waveform.

Ouch!


--
Bernard Peek
London, UK. DBA, Manager, Trainer & Author. Will work for money.

Somehow blackouts and brownouts are being confused with
destructive surges. The 'whole house' protector provides
protection from all types of surge. Plug-in protectors don't
even claim to provide equivalent protection. Blackouts,
brownouts, noise, and harmonic are not surges AND plug-in
protectors don't even claim to protect from them.

But let's assume a nearby heavy machine is creating frequent
transients every day. That plug-in protector is typically so
undersized that it is degraded within week or month end.
Review datasheets from MOV manufacturers for life expectancy
charts. They are selling devices for infrequent and more
destructive events. Furthermore, many plug-in manufacturers
grossly undersized internal components. How would you know?
Manufacturer even fails to discuss life expectancy. So again,
the plug-in protector still does not provide effective
protection.

Johannes H Andersen wrote:
Some deja vu. You're not in the States m8. In a densely
populated country like the UK, most of the risk are spikes
from manmade installations, induction from heavy machinery,
fuse testing, outages. A simple protector is well worth
having and a once only investment.

On Thu, 08 Jul 2004 22:24:22 +0100, Stormsinger
wrote:

However.....

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.

I use my own home made over voltage arrestors for my telephone line
http://w1.857.telia.com/~u85710476/d...kydd_tel_1.png
(swedish) I use one set at the incoming of the line,
and another set near my ADSL modem and computer.

This week we have a thunderstorm and my fuses blown,
se the blown fuses here
http://w1.857.telia.com/~u85710476/d...ample/fuse.jpg

My over voltage arrestors works very well. This is the fourth time.

In article , w_tom
drooled:

Your reputation would be much enhanced and your posts would be far more
legible if you stopped top-posting and replied to each point raised,
quoting context, instead of rambling in a long, top-posted, hand-waving
rant.

Furthermore, many plug-in manufacturers
grossly undersized internal components. How would you know?

Many good quality European surge protectors illuminate a warning lamp to
indicate when the protective devices have degraded such that they are no
longer effective and that the protector should be replaced. Some,
including Belkin devices, also illuminate a lamp to indicate that the
protector has been connected to an outlet with a good earth.

Given that you in the USA tend to use for your electrical accessories
the cheapest and nastiest **** from China, it comes as no surprise that
your "surge protectors" do not carry even this basic feature.

So again,
the plug-in protector still does not provide effective
protection.

Complete crap. As usual.

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

http://w1.857.telia.com/~u85710886/d...sient_11.jpgOn
Thu, 08 Jul 2004 22:24:22 +0100, Stormsinger
wrote:

However.....

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.

I use my own home made over voltage arrestors for my telephone line
http://w1.857.telia.com/~u85710476/d...kydd_tel_1.png
(swedish) I use one set at the incoming of the line,
and another set near my ADSL modem and computer.
My telephone lines are buried in the ground the hole way (750 meters)
from the telephone station to my home.
This week we have a thunderstorm and my fuses blown,
se the blown fuses here
http://w1.857.telia.com/~u85710476/d...ample/fuse.jpg
My over voltage arrestors works very well. This is the fourth time.
This is a double line model I built myself
http://w1.857.telia.com/~u85710886/d...ansient_11.jpg

It does not matter whether you top post or bottom post.
Your repeated intolerance is demonstrated both by your
difficult to read bottom posts, your need to pervert others to
your inferior posting method, your repeated intolerance to
those who disagree with your unsubstantiated opinions, and the
fact that you still cannot challenge technical facts - and
must then insult. BTW I still have not returned to you some
of your very first words. Let me start with one you posted to
me in your very first post - you twit.

I have posted as professional papers and technical
application notes are posted. New information up front.
Background information and references at the end. I am not so
intolerant as to bring up the silly top post / bottom post
nonsense that only the emotional would do.

You reputation would be enhanced if you could even challenge
the post demonstrating wire impedance. You cannot. So
instead you again start this silly top post / bottom post
nonsense. Do you like it when someone attacks you as you
attack others - by questioning your character?

Back to technical fact. And this makes it obvious how
little you know about surge protectors. In scary pictures are
more expensive surge protectors even with the MOVs removed -
and the "Protection Working" LED says protector still works
OK. How? Why? Why is the "OK" light still lit on an
obviously non-functional protector? You tell me since you
recommend those silly plug-in surge protectors. Little hint:
the light can only report when the protector is defective but
cannot report if the protector is good. You should have known
that:
http://www.zerosurge.com/HTML/movs.html

Second little hint - the protector cannot tell when MOVs have
degraded. They can only report when MOV was so grossly
undersized as to vaporize - as so many grossly undersized
plug-in protectors do.

This 'light' feature is so old in America that it was even
on surge protectors tested in PC Magazine in the 1980s. So
now you insult the US for importing Chinese 'junk'. Where in
that insult is a technical fact? How does that light work?

"So again, the plug-in protector still does not provide
effective protection." Your technical response? Another
insult:
Complete crap. As usual.

Mike. When are you going to challenge the example of wire
impedance. Remember that wire impedance that leaves a surge
protector at 13,000 volts when it is suppose to be earthing a
trivial 100 amp surge? Why, Mike, do you repeatedly avoid
facts by posting more insults? Do your routinely ignore
things you don't like?

So now Mike. Please enlighten us. How does that "warning
lamp to indicate when the protective devices have degraded"
work? Show us how that light can measure let-through voltage
of an MOV. You ignore the impedance in 18 meters of wire to
lie about plug-in protector effectiveness. So maybe just
once, provide us with good technical knowledge. How does that
light know the let-through voltage of MOVs? Spread your
wisdom.

Feel free to top post or bottom post. Impart your
comprehension on how all this stuff works. Show us how a
light can determine that the internal MOV has 'degraded'.
Also please explain what happened to that 130 ohms of
impedance to earth ground from the wall receptacle. Another
little hint: you cannot.

You seem to have so many personal insults that I think I
will keep the so many you have given me. After all, you are
going to show us how smart you are. You are going to show us
how that light reports that MOVs have degraded.

Mike Tomlinson wrote:
In article , w_tom
drooled:

Your reputation would be much enhanced and your posts would be
far more legible if you stopped top-posting and replied to
each point raised, quoting context, instead of rambling in
a long, top-posted, hand-waving rant.

Furthermore, many plug-in manufacturers grossly undersized
internal components. How would you know?

Many good quality European surge protectors illuminate a
warning lamp to indicate when the protective devices have
degraded such that they are no longer effective and that the
protector should be replaced. Some, including Belkin
devices, also illuminate a lamp to indicate that the
protector has been connected to an outlet with a good
earth.

Given that you in the USA tend to use for your electrical
accessories the cheapest and nastiest **** from China, it
comes as no surprise that your "surge protectors" do not
carry even this basic feature.

So again, the plug-in protector still does not provide
effective protection.