Are mains surge protectors needed in the UK?

[Jonathan Buzzard]

You have now...
I too have been running a bunch of computers in my home/office (in SE
England) for many years without any problem, until a couple of months
ago when one Saturday morning we had a surge that blew up the PSUs of
2 (of 5) computers running at the time. It also destroyed my
neighbour's TV, and reset all the clocks on VCRs etc. There was no
lightning around at the time, so it must have been mains borne. Since
then I've put UPSs or surge protectors on at least some of my gear.

Cannot be, because according to w_tom such surges don't exist

JAB.

 

[Jonathan Buzzard]

GDTs and MOVs are paired both for faster response time and
for the lower conductive voltage provided by a GDT. However
GDTs alone were fast enough. At £2 or $3 per GDT, then GDTs
also are too expensive. MOVs wholesale on the order of $0.10
each. Which is more profitable when even a 160 joule UPS is
considered by consumers to be more than sufficient protection?

Also the higher surge current capacity of the GDT. They continue to be
used with avalanche diodes as well for the same reason. My point is that
if a GDT costs 1.75GBP retail at RS in quantities of one, then wholesale
in quantities of say 10,000 they will cost at least half this. So you are
saying that a 80p device is two expensive to put in a surge protector?

The problem is w_tom, that it has already been demonstrated to you that
plug in surge protectors sold in the UK do indeed have GDT's in them.
So whatever your protestations about them being to expensive might be, you
are clearly wrong, and should accept this fact.

If they were trying to make a faster and superior protector,
then MOVs would instead be replaced by avalanche diodes that
are faster, do not degrade as MOVs do, and can shunt at a
lower threshold voltage. But again, avalanche diodes cost
closer to $1. Also too expensive when selling plug-in
protectors only for the massive profits.

Not really, a 1500W bidirectional (i.e. ac application) transient voltage
suppression diode in the RS catalogue is 57p in quantities of 100.
Personally I would put it down to ignorance.


JAB.

 

[usenet]

No I did not say the back EMF causes the circuit breaker to trip. I simply
pointed out the fact that most readers of the post will be aware of; that
a bulb that goes pop when you turn it on frequently trips the MCB. This
means that there is serious amounts of excess energy in the circuit.
Something that you have denied repeatedly as being possible.

What on earth do you mean by "serious amounts of excess energy"?

The phenomenon of an MCB tripping when a filament bulb fails is well
documented and explained, it's nothing to do with "excess energy".
What happens is that when the filament breaks an arc is struck across
the ends. The arc has a low impedance and as the rest of the filament
burns away the arc ends up effectively shorting the circuit to the
lamp and the MCB trips. If the circuit is protected by a wire fuse
then the arc usually breaks before the fuse blows but MCBs (in the UK)
are fast enough to trip before the arc stops.

 

[half_pint]

See above, if you handle computer components without observing ESD
precautions you probably have, just you don't realize it.

Well may conputer works just fine, I have touched the circuit
boards many times whilst changing memory and drives etc...
I dont wear an anti static band rtc..
It appears to be working perfectly well.

Maybe it will fail in 10 year time due to the damage I have caused?

 

[VWWall]

What on earth do you mean by "serious amounts of excess energy"?

Some U.S A. measurements: (Halve or double to get 230 V values.)

100W 115V incandescent lamp: Cold 9.6 ohms Hot 132 ohms

Starting current ~ 12 A. Running current ~0.86 A

At least a dozen of these on a standard U.S. 15 A lighting circuit can
be turned on at once without tripping a 15 A branch circuit breaker.

The phenomenon of an MCB tripping when a filament bulb fails is well
documented and explained, it's nothing to do with "excess energy".
What happens is that when the filament breaks an arc is struck across
the ends. The arc has a low impedance and as the rest of the filament
burns away the arc ends up effectively shorting the circuit to the
lamp and the MCB trips. If the circuit is protected by a wire fuse
then the arc usually breaks before the fuse blows but MCBs (in the UK)
are fast enough to trip before the arc stops.

This sounds like a very plausible explanation. I have never seen this
happen on a U.S. circuit. Perhaps the lower voltage will not sustain
the arc long enough, or the gas ionization is different, or our 15 A
breakers aren't as fast as the MCBs.

Someone mentioned in-rush current to an ATX PC power supply. Most have
some form of input current limiting. There are two 480 mfd capacitors,
(typical), in series connected to the line through a rectifier. The
charging current would need to be limited. The ATX spec is vague on this.

Virg Wall

PS: I've worked in the UK with the USAirForce in UK MOD buildings
installing satellite tracking equipment. The only thing that bothered
me was remembering that UK switches are "up" in the "off" position.

 

[half_pint]

[snip pointless attempt to reason with half_pint]

David, you're wasting your time arguing with half_wit.

I'm beginning to see your point.

Rather amazing, actually. I mean, even when one points to authoritative
sources he simply declares everyone else ignorant or just plain dumb.

Thats utter wank and you are a wanker.

 

[David Maynard]

Well my Bettaware magazine is selling silicone mats for resting
hot pans on.

I would imagine it's made from one of the 'solid' formulations I mentioned.

Which, of course, says nothing about the liquid or gel formulations. Nor,
for that matter, does it necessarily say anything about the other, many
varied, solid formulations.

 

[David Maynard]

Mike Tomlinson wrote:

[snip pointless attempt to reason with half_pint]

David, you're wasting your time arguing with half_wit.

I'm beginning to see your point.

Rather amazing, actually. I mean, even when one points to authoritative
sources he simply declares everyone else ignorant or just plain dumb.

Thats utter wank and you are a wanker.

I posted to you links on ESD damage and you proclaimed the people ignorant.
Case closed.

 

[w_tom]

If a warranty was really a measure of product quality, then
Hyundais are clearly much more reliable than Hondas and
Toyotas. After all Hyundai promotes their vastly superior
warranty.

Especially with surge protectors, the larger a warranty,
then the protector is typically less effective. A benchmark
in protectors is Polyphaser. They offer no warranty. But
then we have repeated testimony from those who learned about
that warranty first hand:
Newsman on 10 Sept 2002 in the newsgroup alt.video.ptv.tivo
entitled "SONY TiVo SVR-2000"

I got a Belkin surge protector with phone line protection
soley for Tivo purposes.
Yet my Tivo's modem still failed. And the '$20,000
connected devices warranty' did not help me. I jumped
through many hoops, including finding the original recept
for the surge protector (just under a year old) and I
sent my surge protector to Belkin (paid for shipping), and
was denied my warranty. They gave me a ton of crap,
including that it was null and void b/c the Tivo was also
connected to the coax line for cable (this was not
mentioned as a thing in the warranty that can nullify it).
Eventually it boiled down to a line in the warranty that
said "Belkin at it's sole discretion can reject any claim
for any reason".

Try reading the fine print attached to that warranty before
jumping to conclusions. They did provide that long list of
exemptions with the Belkin protector. Oh? They forgot to
provide that information? How curious.

 

[w_tom]

If a surge was not due to lightning, then it would have
been one of those other often rare type of events - that the
'whole house' protector also would have protected from. One
protector - properly sized - to protect all machines from the
incoming surge. Or lots of undersized protectors, at greater
costs, that only claim to protect from one all but nonexistent
type of surge.

Jonathan Buzzard guy is still trying to explain how
impedance in wire and the inductance in a light bulb can
create massive surges when power switched.

Mains borne surges are why we use 'whole house' protectors
that are properly sized and that typically cost tens of time
less money per protected appliance.

 

[usenet]

This sounds like a very plausible explanation. I have never seen this
happen on a U.S. circuit. Perhaps the lower voltage will not sustain
the arc long enough, or the gas ionization is different, or our 15 A
breakers aren't as fast as the MCBs.

Your MCBs are different I believe. Your MCBs only have thermal
overload tripping, ours have both magnetic and thermal tripping. The
thermal tripping is slow but the MCB will trip on overloads only a
little above the rating, the magnetic tripping is very fast but needs
an overload several times the rating.

 

[w_tom]

Of course not. I have no affiliation with any of those
companies. Why would I mention the competition so often? But
this is
basic and essential information when doing anything that
requires reliable operation such as aerospace work and
semiconductor factories. Ever see all computers damaged just
before a space launch because the facilities were not properly
earthed?

Over the years, I have had some mysterious failures and
spectacular successes. Most early lessons were on friends
homes. Have seen MOVs completely vaporized so that only two
lead exist - an eerie scene. Have seen everything - literally
every electronic device - damaged except on one circuit
protected by (what I now know to be) an undersized but
properly located MOV. That MOV, earthed by less than three
foot connection, shunted a surge so large as to partially
damage the electric meter. All other circuits exposed to that
strike suffered complete damage. This one protected circuit
with such a short earth ground connection suffered not one
failure - except where the surge passed through electric meter
to get to earth ground.

That one experience got me heavily into questioning surge
protectors. Discovered myths all but promoted by plug-in
protector manufacturers AND the highly rated products from
real world protector companies such as Polyphaser.

 

[Bagpuss]

If a warranty was really a measure of product quality, then
Hyundais are clearly much more reliable than Hondas and
Toyotas. After all Hyundai promotes their vastly superior
warranty.

If I want to take your methods of proving a point, I have never seen a
broken down Hyundai. They may be ugly and have a cack brand name but
they keep running.

Especially with surge protectors, the larger a warranty,
then the protector is typically less effective. A benchmark
in protectors is Polyphaser. They offer no warranty. But
then we have repeated testimony from those who learned about
that warranty first hand:
Newsman on 10 Sept 2002 in the newsgroup alt.video.ptv.tivo
entitled "SONY TiVo SVR-2000"

Try reading the fine print attached to that warranty before
jumping to conclusions. They did provide that long list of
exemptions with the Belkin protector. Oh? They forgot to
provide that information? How curious.

In which case the exemptions won't apply as they are not listed in the
warranty.

Of course if the device is not fully isolated by the surge protector
how can you proove that it was the surge protector that failed?

The point is that with £20,000 insurance and the device being pretty
simple to isolate from other power (e.g. mains input and phone line)
they would be pretty quickly out of business if the devices were
regularly failing. But then the UK mains supply seems to be vastly
different to whay you have to deal with.

 

[David Maynard]

If a warranty was really a measure of product quality, then
Hyundais are clearly much more reliable than Hondas and
Toyotas. After all Hyundai promotes their vastly superior
warranty.

In the first place, we're not talking about a warrantee on the 'product',
we're talking about an insurance of devices protected by it.

The is a modicum of truth to pointing out that warrantee alone is not a
'perfect' indicator, however...

Especially with surge protectors, the larger a warranty,
then the protector is typically less effective.

that statement is patently absurd.

A benchmark
in protectors is Polyphaser. They offer no warranty. But
then we have repeated testimony from those who learned about
that warranty first hand:
Newsman on 10 Sept 2002 in the newsgroup alt.video.ptv.tivo
entitled "SONY TiVo SVR-2000"

Of course, because it, the surge protector, can't protect something it's
not connected to: I.E. the cable connection.

Belkin offers protectors with modem protection as well as protectors with
cable connection protection but he apparently had the wrong one on it.

(this was not

This person apparently didn't read the warrantee because it IS explained fully.

Try reading the fine print attached to that warranty before
jumping to conclusions.

I DID read it, and it's obvious you haven't a clue. Not that that stops you
from spouting garbage about it anyway.

They did provide that long list of
exemptions with the Belkin protector. Oh? They forgot to
provide that information? How curious.

What isn't curious are your perpetual innuendoes and attacks on
manufacturers you have no clue about, terms and conditions you have no clue
about, and technology you have no clue about.

 

[Bagpuss]

I DID read it, and it's obvious you haven't a clue. Not that that stops you
from spouting garbage about it anyway.


What isn't curious are your perpetual innuendoes and attacks on
manufacturers you have no clue about, terms and conditions you have no clue
about, and technology you have no clue about.

As we all know about the perpetual motion engine (buttered toast
strapped to the back of a dropped cat) perhaps we could generate a
stasis device by pluging 4 of w_toms exploding LED clocks in to a
belkin surge protector. It should result in a set of LED clocks
permenantly in the state of breakdown due to the expected surge, but
the surge never quite arriving at the clocks. The result, I theorise,
is a destructive spark suspended in time somewhere inside the belkin
unit or one of 4 clocks resulting in a set of 4 clocks that will never
breakdown.

Much like like the Asphyx suspended in the box lit by a flash compound
in the film The Asphyx.

 

[usenet]

In the first place, we're not talking about a warrantee on the 'product',

What on earth is a "warrantee"?

Sort of half guarantee and half warranty I suppose.

 

[usenet]

damage the electric meter. All other circuits exposed to that
strike suffered complete damage. This one protected circuit

'complete damage', as opposed to 'incomplete damage' no doubt.

 

[usenet]

If a surge was not due to lightning, then it would have
been one of those other often rare type of events - that the

How the #@$£"&^ can something be "often rara"!?

 

[usenet]

How the #@$£"&^ can something be "often rara"!?

.... or even "often rare", oops!

 

[VWWall]

Your MCBs are different I believe. Your MCBs only have thermal
overload tripping, ours have both magnetic and thermal tripping. The
thermal tripping is slow but the MCB will trip on overloads only a
little above the rating, the magnetic tripping is very fast but needs
an overload several times the rating.

As a Registered Professional Engineer, (CA), I have signed many
electrical installation plans. I never thought about the tripping limit
of the most common circuit breakers. (15 A, #14 AWG wire branch
circuits, 20 A, #12 AWG wire branch circuits. Not "ring" wired!) I
recently looked at NEMA AB-3-2001-p36, which has some typical circuit
breaker ratings: (They *are* both magnetic and thermal.)

15A "instantaneous" open: 180-220 A 5X15 A (75 A) 2.5-7.0 seconds

Seems like our lamps don't draw 200 A arcs! The cold start current for
18 100 W lamps, (maximum circuit capacity), of about 215 A would be
marginal, depending on the definition of "instantaneous".

Virg Wall