Are mains surge protectors needed in the UK?

w_tom wrote:

Yes, utility switching does cause transients. But nothing
that should overwhelm internal protection in household
appliances.

Except that it can and sometimes does.

If switching transients were so destructive, then
we all would be replacing RCDs, dimmer switches, and clock
radios weekly. Once numbers are applied to those switching
transients, then those transients become irrelevant.

That's as illogical as saying if lightning strikes were so destructive we'd
be replacing RCDs, dimmer switches, and clock radios every time it rained.

Neither are 'destructive' till the relatively infrequent occurrence when
they are.


Bob Eager wrote:

On Thu, 8 Jul 2004 23:41:08 UTC, w_tom wrote:

The frequency of destructive surges is about once every
eight years. What is that frequency in your neighborhood?

Lightning isn't the only cause of surges. I've seen excessive
voltage several times over the last few years. Switching
transients, etc.

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 article , David Maynard
writes

You mean a separate earth.

I do, yes.

Neutral is, of course, earthed.

This is the distinction made in the wiring code between the "grounded"
and the "grounding" terminal... which causes confusion all of its own


No, they expect an earth ground too.

I've been over this with w_tom at considerable length in the past (feel
free to have a google.) Because American electrical outlets can't be
guaranteed to have an earth terminal (for example, in older construction
as you point out), the makers of surge protectors for the American
market have to wire them to the lowest common denominator, so that a
surge on phase is shunted to neutral using one MOV.

In the UK and Europe, two MOVs are used - one to shunt phase to earth,
and another to shunt neutral to earth. This makes surge protectors made
for this market much more effective.

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In article , Graham
W writes

I'm never one to jump to the defence of w_tom's American based
opinions

Quite wise, IMHO.

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¬)

You miss the point. If you have a lightning rod and a TV aerial on the
roof of a house, the lightning rod, even if it is higher than the
aerial, is not going to save your TV set from a direct strike. Your TV
will blow up regardless.

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In article , w_tom
writes

Wall receptacle is safety ground; not earth ground

Please explain the difference. I could do with the laugh.

- as
explained in another post in this thread.

I see no explanation elsewhere.

However let's
assume the plug-in protector does earth a destructive
transient via wall receptacle.

Which it does in the UK and Europe.

Now that transient is on a
wire bundled with other wires.

So? The transient is shunted to earth via a low impedance path.

Induced transient is now
created by that plug-in protector.

Induced on what? The earth wire? That's what it is there for!

By earthing on safety
ground wire, we have now induced transients on all other
adjacent wires.

Absolute crap. There are three wires - phase, neutral and earth. A
transient on the phase wire is shunted to earth by the surge protector.
What do you mean by "all other adjacent wires"? If you mean low voltage
cabling, for example twisted-pair Ethernet cabling, any electrical
installer worth his salt (i.e. not you) knows that you /do not/ run low
voltage cabling in the same conduit as mains power. It's called
segregation.

What kind of protection is that?
Ineffective.

Very effective.

One well-known maker of surge protectors in UK and Europe, Belkin, gives
a free £10,000 warranty on equipment connected via any of its products.
If the surge protector fails and the equipment is damaged, you can claim
the cost of a replacement. If their products were that ineffective, do
you think they'd offer the warranty?

Same problem applies to the service entrance and single
point earth ground. All earthing wires must be installed from
each utility wire to earth ground separated from all other
wires.

In your American Mickey Mouse electrical installations, yes. In the UK
and Europe, it's unnecessary.

Too many installers want to be neat. They make clean
sharp bends and nylon ty-wrap all wires together. IOW they
compromise the protection 'system'. Even sharp wire bends
increase wire impedance. Earthing wires must be shorter (less
than 3 meters)

Why less than 3 metres? This is another of the claims you frequently
make without a shred of evidence to back it up. And remember, we are
discussing this in relation to UK and European wiring practice. I
sincerely doubt you have ever worked on an electrical installation
outside the US (thank god for that too.)

Just more reasons why plug-in protectors are so
ineffective.

What reasons? Where? I see only more hand-waving from you.

I've come to the conclusion that you must work for a maker of these
"whole house" surge protectors that you constantly advocate. Your
opinion is therefore biased, not objective, and worth **** all.

HTH. HAND. FOAD.

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On Fri, 9 Jul 2004 16:39:26 UTC, Mike Tomlinson
wrote:

In the UK and Europe, two MOVs are used - one to shunt phase to earth,
and another to shunt neutral to earth. This makes surge protectors made
for this market much more effective.

Indeed. I think (can anyone confirm?) that sometimes three MOVs are
used, with one between phase and neutral...

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begin a new life...dump Windows!

"Bernard Peek" wrote in message
...
In message , w_tom
writes

Concepts such as 'whole house' protectors and lightning rods
are long ago proven to be superior protection. Why? They
(unlike the ineffective plug-in protector) make a superior
connection to earth ground so that lightning does not find
earthing via TVs or computer.

That's not how lightning protectors work. They create a corona discharge
around the building, dissipating charge buildup immediately around the
site. That means that a strike is more likely to happen elsewhere.

The copper strap has a cross section of less than an inch, nowhere near
enough to safely shunt a real strike to earth. If the building does get
hit the strike will still do nearly as much damage as if it was not
there.



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

I know a Russian who was killed while rewiring his house, his name was Sergi

"w_tom" wrote in message
...
Assumed is that lightning confronted everything inside the
house equally. Just not true. Based upon your description,
the circuit from cloud to earth borne charges found a good
path via those TVs. Therefore only TVs suffered a direct
lightning strike incoming and outgoing. Incoming and outgoing
are essential requirements for surge damage. If the computer
only had an incoming path and no outgoing path, then lightning
currents did not pass through nor damage computers. That
complete electrical path to earth ground is the essential
requirement for surge damage. Clearly other household
appliances did not make that same "complete electrical
circuit" connection; therefore were not damaged.

I don't really care about the Physics........all I know is that I wont take
the chance anymore

Mike Tomlinson wrote:

[...]

I've come to the conclusion that you must work for a maker of these
"whole house" surge protectors that you constantly advocate. Your
opinion is therefore biased, not objective, and worth **** all.

This explains w_tom's surge of mains FUD surge protector posts...

"Mike Tomlinson" wrote in message
...
In article , Graham
W writes

I'm never one to jump to the defence of w_tom's American based
opinions

Quite wise, IMHO.

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¬)

You miss the point. If you have a lightning rod and a TV aerial on the
roof of a house, the lightning rod, even if it is higher than the
aerial, is not going to save your TV set from a direct strike. Your TV
will blow up regardless.

No, I haven't missed the point - what you say is right. It is just that
his faltering English is difficult to read and it makes more sense if
referred to the earth spike than a lightning conductor over the roof.
But he seems to mean the latter in what he has subsequently said.
I'll go away now! 8¬)


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