Are mains surge protectors needed in the UK?

David Maynard wrote:

Hehe. true. But 'neutral' and 'ground' are separate wires in 3 prong
plugs even though 'neutral' is earthed at the entry, as is the 'ground'
wire. The 'ground' is really 'protective (as in human safety) ground'.
Aside from the voltage and U.S. wall outlets being one phase of 230/240
(for 115/120), the U.S. and U.K grounding scheme is essentially the
same. FUSING and ring vs star wiring is another matter.

Just a small correction. U.S. wall outlets are on opposite "sides" of a
230/420 volt circuit, with respect to their neutral. They are both on
the same phase. There are very few U. S. domestic units supplied with
more than single phase power. Two different sets of outlets can, and
often do, share the same neutral wire. This can lead to a "wild
neutral", if an open in the neutral circuit back to the entry
distribution point leads to two, (sets), of outlets becoming in series
across the entire 230/240 power. They will split the voltage between
them in accordance with the loads connected to each side. If one is
lightly loaded, and the other side is heavily loaded, the light load
side can have much higher than its normal 115/120 volts. I've seen
cases where "surge protectors" prevented damage. I suspect it was the
low amperage circuit breaker in the outlet strip that protected the
equipment, perhaps aided by the protector's MOVs drawing a high current
because of the over-voltage. The MOVs in a local protector can't stand
an overvoltage for more than a few milliseconds.

A single computer power supply is a small load if, the other "side" is
connected to a refrigerator starting up. I recall a microwave oven
which had its own internal MOV destroyed in this way. Most new U.S.
codes require things like refrigerators to be on "home run" individual
circuits, but many homes still have them on common kitchen outlets.

This is a problem UK protectors would not have to contend with.


Virg Wall
--
A foolish consistency is the
hobgoblin of little minds,........
Ralph Waldo Emerson
(Microsoft programmer's manual.)

VWWall wrote:

David Maynard wrote:

Hehe. true. But 'neutral' and 'ground' are separate wires in 3 prong
plugs even though 'neutral' is earthed at the entry, as is the
'ground' wire. The 'ground' is really 'protective (as in human safety)
ground'. Aside from the voltage and U.S. wall outlets being one phase
of 230/240 (for 115/120), the U.S. and U.K grounding scheme is
essentially the same. FUSING and ring vs star wiring is another matter.

Just a small correction. U.S. wall outlets are on opposite "sides" of a
230/420 volt circuit, with respect to their neutral. They are both on
the same phase. There are very few U. S. domestic units supplied with
more than single phase power. Two different sets of outlets can, and
often do, share the same neutral wire.

If it's not wired according to code I suppose they could. But code has
separate runs back to the entry panel.

This can lead to a "wild
neutral", if an open in the neutral circuit back to the entry
distribution point leads to two, (sets), of outlets becoming in series
across the entire 230/240 power. They will split the voltage between
them in accordance with the loads connected to each side. If one is
lightly loaded, and the other side is heavily loaded, the light load
side can have much higher than its normal 115/120 volts. I've seen
cases where "surge protectors" prevented damage. I suspect it was the
low amperage circuit breaker in the outlet strip that protected the
equipment, perhaps aided by the protector's MOVs drawing a high current
because of the over-voltage. The MOVs in a local protector can't stand
an overvoltage for more than a few milliseconds.

A single computer power supply is a small load if, the other "side" is
connected to a refrigerator starting up. I recall a microwave oven
which had its own internal MOV destroyed in this way. Most new U.S.
codes require things like refrigerators to be on "home run" individual
circuits, but many homes still have them on common kitchen outlets.

This is a problem UK protectors would not have to contend with.

I really don't know *what* problems a UK protector would have to contend
with if someone broke code and ran wire just any old way they felt like.



Virg Wall

w_tom wrote:

Long before computers existed in homes, why were LED clocks
and radios replaced daily?

Must be some odd problem of yours as I've never had one fail.

Because switch generated
transients were and remain destructive?

Just below you said they weren't. Make up your mind.

Why are RCDs and
dimmer switches - things more easily damaged and without any
external protection - also failing daily?

Couldn't say as mine all work.

Because again those
transients from switching are so destructive.

Then why did you say they weren't?

Put some
numbers to those switch generated transients. Some who
promote utility switching as a source of destructive transient
never provide numbers and ignore those above real world
examples. They are promoting junk science made obvious by
their fear of numbers and a shortage of weekly examples. We
can see from dialy damaged electronics equipment that those
transients are so destructive.

For one who critiques a 'lack of numbers' they are notably missing from you.


You are replacing RCDs daily because of daily utility
switching and the resulting transients? We also don't put
umbrellas over that RCD because rain also does not damage the
RCD. Why install protection when sufficient protection
already exists?

Now you're back to saying they don't matter. Do you always talk in babble
circles or is this a special occasion?

Utilities are reconfiguring their grids every month for
maintenance, reconfiguring loads, and adjusting voltages.
Transients from such events can be seen sometimes as often as
daily. So where are all those damaged refrigerators?
Transients are well below what all appliance must be designed
to withstand without damage.

No one said routine 'daily' switching was necessarily a problem.

Now show me there can NEVER be ANY kind of utility, or industry, or
construction, or by any thing else, generated destructive power surge.


We install surge protection for a so destructive surge more
typically known as lightning.

I've never had any of the above mentioned devices fail from a lightning
surge either so, using your (il)logic of 'colloquial non failure
observation', I guess I don't need your stuff either.

Other far less frequent events
do occur.

You just tried to claim they don't.

Unfortunately some people confuse blackouts and
brownouts with surges.

Speak for yourself, paleface.

Surge protectors do nothing for a
blowing fuse or a utility line snapped by a construction
machine. Furthermore, destructive transients of all types
are made irrelevant by the less expensive and more effective
'whole house' protector.

Except most reputable 'whole house' protection manufacturers recommend
'plug in' surge protectors on sensitive electronic equipment, such as
computers, in addition to their 'whole house' devices.


David Maynard wrote:

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.

David Maynard did not have an LED clock fail because
utility switching does generate typically destructive
transients. Why do we need surge protectors? Because the
destructive transients are from truly destructive events such
as lightning. Plug-in protectors don't even claim to protect
from such transients. For protection from destructive
transients, we require properly earthed 'whole house'
protectors. Protectors that would also and even protect from
insignificant or extremely rare transients such as those due
to utility switching.

Which then returns to the original question. Do we need
surge protectors in the UK? That depends, in part, on the
frequency of CG lightning in that neighborhood, and how much
inside the building requires protection. 'Whole house'
protectors and earth ground are quite inexpensive as well as
more effective. If the house has computers, RCDs, kitchen
appliances, touch on-off lights, alarm system, smoke
detectors, digital timer switches, etc; then by all means the
'whole house' protector protects so much for so little money.

In the meantime if anything else should strangely cause a
destructive transient, then still everything remains protected
by same 'whole house' protector. So much more protection for
less money per protected appliance.

What is the alternative? Plug-in protectors on each and
every appliance? Rather foolish for too many reasons. Costs
are so excessive many times over. Product is typically
undersized. Product does not even claim to provide effective
protection.

The costs and advantages of 'whole house' protectors and
single point earth ground make a mains surge protector quite
reasonable protection even for the UK where lightning is not
as frequent.

David Maynard wrote:
w_tom wrote:
Long before computers existed in homes, why were LED clocks
and radios replaced daily?

Must be some odd problem of yours as I've never had one fail.

Because switch generated transients were and remain
destructive?

Just below you said they weren't. Make up your mind.

Why are RCDs and dimmer switches - things more easily
damaged and without any external protection - also
failing daily?

Couldn't say as mine all work.

Because again those transients from switching are so
destructive.

Then why did you say they weren't?

Put some numbers to those switch generated transients.
Some who promote utility switching as a source of
destructive transient never provide numbers and ignore
those above real world examples. They are promoting junk
science made obvious by their fear of numbers and a
shortage of weekly examples. We can see from dialy
damaged electronics equipment that those transients are
so destructive.

For one who critiques a 'lack of numbers' they are notably
missing from you.

You are replacing RCDs daily because of daily utility
switching and the resulting transients? We also don't put
umbrellas over that RCD because rain also does not damage the
RCD. Why install protection when sufficient protection
already exists?

Now you're back to saying they don't matter. Do you always
talk in babble circles or is this a special occasion?

Utilities are reconfiguring their grids every month for
maintenance, reconfiguring loads, and adjusting voltages.
Transients from such events can be seen sometimes as often as
daily. So where are all those damaged refrigerators?
Transients are well below what all appliance must be designed
to withstand without damage.

No one said routine 'daily' switching was necessarily a
problem.

Now show me there can NEVER be ANY kind of utility, or
industry, or construction, or by any thing else, generated
destructive power surge.

We install surge protection for a so destructive surge
more typically known as lightning.

I've never had any of the above mentioned devices fail from
a lightning surge either so, using your (il)logic of
'colloquial non failure observation', I guess I don't need
your stuff either.

Other far less frequent events do occur.

You just tried to claim they don't.

Unfortunately some people confuse blackouts and brownouts
with surges.

Speak for yourself, paleface.

Surge protectors do nothing for a blowing fuse or a
utility line snapped by a construction machine.
Furthermore, destructive transients of all types are
made irrelevant by the less expensive and more
effective 'whole house' protector.

Except most reputable 'whole house' protection manufacturers
recommend 'plug in' surge protectors on sensitive electronic
equipment, such as computers, in addition to their
'whole house' devices.

w_tom wrote:

David Maynard did not have an LED clock fail because
utility switching does generate typically destructive
transients.

I'd be truly stunned if you ever said anything that made sense.

snip of w-tom babble

In article , w_tom
writes

'Whole house'
protectors and earth ground are quite inexpensive as well as
more effective. If the house has computers, RCDs, kitchen
appliances, touch on-off lights, alarm system, smoke
detectors, digital timer switches, etc; then by all means the
'whole house' protector protects so much for so little money.

I'll repeat my earlier question. Do you work for, or otherwise have an
interest in, a manufacturer of these whole house "protection" devices?
If the answer is yes, you should declare your interest each time you
recommend them.

What is the alternative? Plug-in protectors on each and
every appliance?

It's simply not necessary in the UK. Electricity feeds to homes are
underground, not overhead, so are less prone to surges caused by
lightning strikes. It's more cost-effective to buy individual surge
protection devices for more expensive devices (stereo systems,
computers.)

The costs and advantages of 'whole house' protectors and
single point earth ground make a mains surge protector quite
reasonable protection even for the UK where lightning is not
as frequent.

Nonsense. If that were the case, such surge protectors would be
recommended by industry professionals designing new construction. I
accept they're installed in commercial enterprises and in datacentres,
where the effects of a surge would impact on the organisation's
business, but for the typical UK domestic home, they're simply not
needed.

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

In message , Lem writes
I don't have a surge protector on my TV or my stereo. So, do I need
one on my PC?

Not until the power company stuff up - then its wise to go buy one - of
course nothing works for weeks whilst replaced etc.. But why waste a
fiver to prevent it!


--
Nigel J Carron

On Thu, 08 Jul 2004 19:41:08 -0400, w_tom wrote:

The frequency of destructive surges is about once every
eight years.

It might be in the USA where lightning strikes are much much more frequent
than the UK. However as with all your advice it is based on the situation
in the USA where everything is different and renders your advice almost
completely wrong.

JAB.

--
Jonathan A. Buzzard Email: jonathan (at) buzzard.me.uk
Northumberland, United Kingdom. Tel: +44 1661-832195

On Fri, 09 Jul 2004 09:02:44 -0400, w_tom wrote:

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

I wondered how long it would be before you spouted rubbish again.

You point blank refuse to accept that when a kettle lead shorted out
at work, the HD15 input of a very expensive 21" monitor stopped working.
It was working fine right until the MCB and RCD tripped. When turned
back on it was not working. The building had whole earth grounding
as you claim gives all the protection you need. In reality internally
generated transients can prove fatal to equipment.

You have also failed to answer why the British Standard says that whole
building grounding is insufficient for full protection, and that sensitive


You also claim that lightning strikes are not physically destructive.
Despite many reported incidents in the press to the contrary.


The reality remains that the utility companies in the U.K. (that is
electric and telephone) do a very good job of doing proper earth grounding
of there facilities. The upshot of this is you only need to provide
sufficient extra impedance to encourage any earth seeking surge to use the
earth grounding provided by the utility companies. As such plug in surge
protectors do a sufficiently good job in the U.K.

In fact as the *vast* majority of people in the U.K. have their
electricity supply delivered underground from the substation any surge
protection on the electricity supply is entirely pointless in most cases.

Even telegraph poles are earthed, if you want I can take a photograph of
one erected recently near me, and you can clearly see the shinny copper
wire running down the side and into the ground. Even then a large
percentage of people have their telephone come in entirely underground
from the exchange so again in those cases any grounding is entirely
pointless.


JAB.

--
Jonathan A. Buzzard Email: jonathan (at) buzzard.me.uk
Northumberland, United Kingdom. Tel: +44 1661-832195

On Fri, 09 Jul 2004 09:39:10 -0400, w_tom wrote:

Wall receptacle is safety ground; not earth ground - as
explained in another post in this thread.

Wrong again, the earth wire in that by law must follow all wiring in
the house is earthed at the consumer unit to earth ground.

However let's
assume the plug-in protector does earth a destructive
transient via wall receptacle. Now that transient is on a
wire bundled with other wires. Induced transient is now
created by that plug-in protector. By earthing on safety
ground wire, we have now induced transients on all other
adjacent wires. What kind of protection is that?
Ineffective.

Perfectly satisfactory. Any earth seeking surge will find the lowest
impedance path to ground. All a plug in surge protector does is increase
the impedance at that point. So the surge arives at the plug in surge
protector seeking earth ground. It has two choices, it can take the path
to earth ground provided by the surge protector at a fraction of an ohm.
Alternatively it can decided to find some other path to ground at a *much*
higher impedance (typically thousands of ohms if not more).

Basic 101 physics here, it takes the lowest impedance path to earth ground,
that is through the surge protector, job done. Surge protector might be
stuffed afterwards, but that is not the point, the valuable data on your
hard disk is safe.

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. 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.

Rubbish, you will only effect the impedance if you wire it in a coil.

Earthing wires must be shorter (less
than 3 meters), no splices (which wall receptacle safety
ground wires violate), not inside metallic conduit, and
separated from all other wires.

Again you spout rubbish. The length does not matter one jot. Neither do
any joins. The only thing that counts is the impedance. As a point of note
how do you propose joining your earth wire to the grounding spike without
a join?

Just more reasons why plug-in protectors are so
ineffective. Therefore plug-in protectors avoid all
discussion about earthing. They fear you might learn about
the less than 3 meter necessity.

As pointed out many if not most plugs in an average British house are
within 6 metres of earth and due to the standard ring main wiring in
the U.K. have a much lower impedance than you would have in the U.S.A.

Further the actual impedance does not matter, provided it is sufficiently
lower than an alternative destructive route through your equipment. Again
this is 101 physics. Oh sub 1 Ohm route through the plug in surge
protector to earth ground or 10,000 Ohm route through the equipment. Your
claim is that they take the 10,000 Ohm route through the equipment because
the sub 1 Ohm route is not close enough to ground. Really w_tom you do
talk some utter and total rubbish.

So they avoid all discussion
about earthing. They would even encourage the consumer to be
confused about safety ground verse earth ground.

Wrong indeed, they talk about earthing all the time. In fact the typical
one generally talks about safely dissipating surges to earth. Then again
as you don't live in the U.K. it is not surprising that you would not know
what they say on the box.


JAB.

--
Jonathan A. Buzzard Email: jonathan (at) buzzard.me.uk
Northumberland, United Kingdom. Tel: +44 1661-832195