Surge Protector

[Kevin Martin]

Sally wrote:

Yes, useless. The tiny air gap left when a GPO switch is opened is quite
useless for the near end results of a spark many hundreds of metres long.
Agree about the "if you are at home" bit though. In high risk areas (eg
Florida) many computer users routinely unplug when going out.

But don't forget to unplug the phone line or cable modem too.

Kevin Martin

--
To Reply, delete what is "Not Required" in abbreviated form

 

[Sally]

Ah yes, I missed that point as so much misinformation about lightning was
being bandied around. Switching off would certainly be enough for most non
lightning disturbances, except the bigger ones. Such as in the UK one day
when a 132 Kv line fell across 240v lines. It blew fuseboxes and switches
clean off the walls of nearby homes.

"David L. Jones" <altzone@gmail.com> wrote in message
news:1183984068.821678.148400@o11g2000prd.googlegroups.com...

On Jul 9, 9:48 pm, "Sally" <m...@anon.net> wrote:
Yes. Direct copper connection is obviously worse, and so switching off
does
improve protection. But the GPO air gap (typically 1-2 mm) for 240V is
still
far too small for a direct lightning strike (already perhaps 5 km).

Of course, and that's all I was saying, glad you agree.
The thread is about "surge protection" in general, not just lightning
strikes.

Dave.

 

[Trevor Wilson]

"Sally" <me@anon.net> wrote in message news:4691e732$1@dnews.tpgi.com.au...

Well, I certainly won't be buying anything from rage audio. The website
link is engineered with similar care...

**Feel free to list all the known examples of where a standard, off the
shelf surge protector has protected equipment. If you want snake oil
products (over-priced surge protectors) then you'll need to shop elsewhere.

Learn about 'top-posting' and try to refrain from doing so. It is poor
netiquette. Let Google be your friend.


--
Trevor Wilson
www.rageaudio.com.au



--
Posted via a free Usenet account from http://www.teranews.com

 

[Franc Zabkar]

On Thu, 5 Jul 2007 08:12:50 +1000, "Tim" <tim45@yahoo.com> put finger
to keyboard and composed:

Is it recommended for my new TV and sound system, or just another rippoff.?

I think the term "surge" is a misnomer in this case. "Surge
protectors" (aka metal oxide varistors) will soak up spikes, but not
sustained overvoltages, which is how I perceive the term.

While I have no faith in these devices, I do agree that it may be more
economical to purchase a Belkin surgeboard (ie, a lifetime insurance
policy bundled with a power board) than to upgrade an existing
household contents policy, especially when amortised over several
years.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Sally]

I owe you an apology dmm! You were in error but I could have corrected it
more politely. I fell into the usual trap of ng posters in demolishing a
point with a steam roller instead of gently righting the wrong. Please
accept my apology.

On the point I corrected, fusion (in Australia and UK anyway) is defined as
I described it (burning out of the windings of an electric motor) and is not
the same as lighting damage. Most policies cover lightning damage (some
require visible evidence, which IMO is silly, because with masonry there is
often no visible sign). Most also cover fusion which is usually invoked in
the case of a fridge compressor tripping due to a power event and then
restarting (or trying to) under load. In another thread (can't remember
which one now) the poster spoke of extending the normal household cover. In
most cases it will not need extending. Lightning is a traditional cover
usually offered because back in times gone by it was perceived as a
particularly frightening event and yet the individual (or catastrophe, for
that matter) risk was in fact statistically very low. That was before the
days of solid state electronics, or course. Them there slowing bottles were
very transient resistant owing to their thermal inertia.

"Sally" <me@anon.net> wrote in message news:46921fba@dnews.tpgi.com.au...

Absolute rubbish! Fusion is defined as the burning out of the windings of
an electric motor and has nothing whatsoever to do with lightning.

"dmm" <dmmilne_REMOVE_@ozemail.com.au> wrote in message
news:gh54935kt4ajhnv0l2iaf4uvnh17h46cg3@4ax.com...
On Thu, 5 Jul 2007 08:12:50 +1000, "Tim" <tim45@yahoo.com> wrote:

Is it recommended for my new TV and sound system, or just another
rippoff.?


You would probably be better served by checking that your insurance
covers
damage caused by "fusion".

 

[Sally]

....and one more thing, in view of the thread topic. The notorious "power
surge" (not lighting) often claimed by "repairers" who are just computer
salesmen, when there is not the slightest reason to suspect it and when
random breakdown is probably the cause of loss, *is* excluded from many
household policies precisely because it has been abused by the greedy and/or
ignorant so much in the past.

"Sally" <me@anon.net> wrote in message news:46932976@dnews.tpgi.com.au...

I owe you an apology dmm! You were in error but I could have corrected it
more politely. I fell into the usual trap of ng posters in demolishing a
point with a steam roller instead of gently righting the wrong. Please
accept my apology.

On the point I corrected, fusion (in Australia and UK anyway) is defined
as I described it (burning out of the windings of an electric motor) and
is not the same as lighting damage. Most policies cover lightning damage
(some require visible evidence, which IMO is silly, because with masonry
there is often no visible sign). Most also cover fusion which is usually
invoked in the case of a fridge compressor tripping due to a power event
and then restarting (or trying to) under load. In another thread (can't
remember which one now) the poster spoke of extending the normal household
cover. In most cases it will not need extending. Lightning is a
traditional cover usually offered because back in times gone by it was
perceived as a particularly frightening event and yet the individual (or
catastrophe, for that matter) risk was in fact statistically very low.
That was before the days of solid state electronics, or course. Them there
slowing bottles were very transient resistant owing to their thermal
inertia.

"Sally" <me@anon.net> wrote in message news:46921fba@dnews.tpgi.com.au...
Absolute rubbish! Fusion is defined as the burning out of the windings of
an electric motor and has nothing whatsoever to do with lightning.

"dmm" <dmmilne_REMOVE_@ozemail.com.au> wrote in message
news:gh54935kt4ajhnv0l2iaf4uvnh17h46cg3@4ax.com...
On Thu, 5 Jul 2007 08:12:50 +1000, "Tim" <tim45@yahoo.com> wrote:

Is it recommended for my new TV and sound system, or just another
rippoff.?


You would probably be better served by checking that your insurance
covers
damage caused by "fusion".

 

[a t e c 7 7]

Franc Zabkar wrote:

On Thu, 5 Jul 2007 08:12:50 +1000, "Tim" <tim45@yahoo.com> put finger
to keyboard and composed:

Is it recommended for my new TV and sound system, or just another rippoff.?

I think the term "surge" is a misnomer in this case. "Surge
protectors" (aka metal oxide varistors) will soak up spikes, but not
sustained overvoltages, which is how I perceive the term.

While I have no faith in these devices, I do agree that it may be more
economical to purchase a Belkin surgeboard (ie, a lifetime insurance
policy bundled with a power board) than to upgrade an existing
household contents policy, especially when amortised over several
years.

- Franc Zabkar
We have a "protector" fitted to the 60 telly "

with a close ground strike recently it tripped and I assume helped
save things as the same boards also serves the sounc system and I was
delighted to see the survival even though the rooms incadecant was blown
, I expect the induction from a strike only 4 metres away was severe ?
( it was LOUD)

 

[dmm]

On Tue, 10 Jul 2007 16:38:44 +1000, "Sally" <me@anon.net> wrote:

I owe you an apology dmm! You were in error but I could have corrected it
more politely. I fell into the usual trap of ng posters in demolishing a
point with a steam roller instead of gently righting the wrong. Please
accept my apology.

Apology accepted. I should probably point out too that I'd had about 3 glasses
of red wine when I wrote my reply. I shouldn't have mentioned fusion, but lightning
damage as pointed out instead.

On the point I corrected, fusion (in Australia and UK anyway) is defined as
I described it (burning out of the windings of an electric motor) and is not
the same as lighting damage. Most policies cover lightning damage (some
require visible evidence, which IMO is silly, because with masonry there is
often no visible sign). Most also cover fusion which is usually invoked in
the case of a fridge compressor tripping due to a power event and then
restarting (or trying to) under load. In another thread (can't remember
which one now) the poster spoke of extending the normal household cover. In
most cases it will not need extending. Lightning is a traditional cover
usually offered because back in times gone by it was perceived as a
particularly frightening event and yet the individual (or catastrophe, for
that matter) risk was in fact statistically very low. That was before the
days of solid state electronics, or course. Them there slowing bottles were
very transient resistant owing to their thermal inertia.

"Sally" <me@anon.net> wrote in message news:46921fba@dnews.tpgi.com.au...
Absolute rubbish! Fusion is defined as the burning out of the windings of
an electric motor and has nothing whatsoever to do with lightning.

"dmm" <dmmilne_REMOVE_@ozemail.com.au> wrote in message
news:gh54935kt4ajhnv0l2iaf4uvnh17h46cg3@4ax.com...
On Thu, 5 Jul 2007 08:12:50 +1000, "Tim" <tim45@yahoo.com> wrote:

Is it recommended for my new TV and sound system, or just another
rippoff.?


You would probably be better served by checking that your insurance
covers
damage caused by "fusion".

 

[Sally]

Thanks dmm! I actually had a bout of conscience over that! I am only saved
from the red wine syndrome by the fact that I usually post in the very early
hours and have my red wine (usually white) much later!

"dmm" <dmmilne_REMOVE_@ozemail.com.au> wrote in message
news:ipr6931o4f06m9vl8ad2hsp69ntsvnvf84@4ax.com...

On Tue, 10 Jul 2007 16:38:44 +1000, "Sally" <me@anon.net> wrote:

I owe you an apology dmm! You were in error but I could have corrected it
more politely. I fell into the usual trap of ng posters in demolishing a
point with a steam roller instead of gently righting the wrong. Please
accept my apology.

Apology accepted. I should probably point out too that I'd had about 3
glasses
of red wine when I wrote my reply. I shouldn't have mentioned fusion, but
lightning
damage as pointed out instead.

On the point I corrected, fusion (in Australia and UK anyway) is defined
as
I described it (burning out of the windings of an electric motor) and is
not
the same as lighting damage. Most policies cover lightning damage (some
require visible evidence, which IMO is silly, because with masonry there
is
often no visible sign). Most also cover fusion which is usually invoked in
the case of a fridge compressor tripping due to a power event and then
restarting (or trying to) under load. In another thread (can't remember
which one now) the poster spoke of extending the normal household cover.
In
most cases it will not need extending. Lightning is a traditional cover
usually offered because back in times gone by it was perceived as a
particularly frightening event and yet the individual (or catastrophe, for
that matter) risk was in fact statistically very low. That was before the
days of solid state electronics, or course. Them there slowing bottles
were
very transient resistant owing to their thermal inertia.

"Sally" <me@anon.net> wrote in message news:46921fba@dnews.tpgi.com.au...
Absolute rubbish! Fusion is defined as the burning out of the windings
of
an electric motor and has nothing whatsoever to do with lightning.

"dmm" <dmmilne_REMOVE_@ozemail.com.au> wrote in message
news:gh54935kt4ajhnv0l2iaf4uvnh17h46cg3@4ax.com...
On Thu, 5 Jul 2007 08:12:50 +1000, "Tim" <tim45@yahoo.com> wrote:

Is it recommended for my new TV and sound system, or just another
rippoff.?


You would probably be better served by checking that your insurance
covers
damage caused by "fusion".

 

[Sally]

Yes, if it was a crash rather than a rumble it was close. The equipment will
have experienced EMPs through induction on both the aerial and power lines,
and probably a little through space as well. The zapping of an incandescent
lamp indicates a very powerful effect as those devices are much more
resistant to lightning EMPs than solid state devices in electronic domestic
equipment. However, not as bad as the alleged problem suffered in a case I
dealt with some years ago. The "victim" claimed that his lamps had been
"blown out of their sockets". A somewhat tall order (either for bayonet caps
or Edison screw fittings!). In fact I would suggest that in your case the
possibility that the strike concerned caused a major disturbance to power
lines and transformer gear and maybe the lamps suffered from that (the
intermix piggyback syndrome)

"a t e c 7 7" <"atec 77 at hotmail dot com"> wrote in message
news:46934477@dnews.tpgi.com.au...

Franc Zabkar wrote:
On Thu, 5 Jul 2007 08:12:50 +1000, "Tim" <tim45@yahoo.com> put finger
to keyboard and composed:

Is it recommended for my new TV and sound system, or just another
rippoff.?

I think the term "surge" is a misnomer in this case. "Surge
protectors" (aka metal oxide varistors) will soak up spikes, but not
sustained overvoltages, which is how I perceive the term.

While I have no faith in these devices, I do agree that it may be more
economical to purchase a Belkin surgeboard (ie, a lifetime insurance
policy bundled with a power board) than to upgrade an existing
household contents policy, especially when amortised over several
years.

- Franc Zabkar
We have a "protector" fitted to the 60 telly "
with a close ground strike recently it tripped and I assume helped save
things as the same boards also serves the sounc system and I was delighted
to see the survival even though the rooms incadecant was blown , I expect
the induction from a strike only 4 metres away was severe ?
( it was LOUD)

 

[Sally]

Incidentally, how did you know it was 4 metres away?

"a t e c 7 7" <"atec 77 at hotmail dot com"> wrote in message
news:46934477@dnews.tpgi.com.au...

Franc Zabkar wrote:
On Thu, 5 Jul 2007 08:12:50 +1000, "Tim" <tim45@yahoo.com> put finger
to keyboard and composed:

Is it recommended for my new TV and sound system, or just another
rippoff.?

I think the term "surge" is a misnomer in this case. "Surge
protectors" (aka metal oxide varistors) will soak up spikes, but not
sustained overvoltages, which is how I perceive the term.

While I have no faith in these devices, I do agree that it may be more
economical to purchase a Belkin surgeboard (ie, a lifetime insurance
policy bundled with a power board) than to upgrade an existing
household contents policy, especially when amortised over several
years.

- Franc Zabkar
We have a "protector" fitted to the 60 telly "
with a close ground strike recently it tripped and I assume helped save
things as the same boards also serves the sounc system and I was delighted
to see the survival even though the rooms incadecant was blown , I expect
the induction from a strike only 4 metres away was severe ?
( it was LOUD)

 

[w_tom]

On Jul 10, 4:34 am, a t e c 7 7 <"atec 77 at hotmail dot com"> wrote:

We have a "protector" fitted to the 60 telly "
with a close ground strike recently it tripped and I assume helped
save things as the same boards also serves the sounc system and I was
delighted to see the survival even though the rooms incadecant was blown
, I expect the induction from a strike only 4 metres away was severe ?
( it was LOUD

Incandescent bulbs will not be destroyed by lightning strikes.
However a massively higher energy source can cause that problem.
Lightning may construct electrically conductive paths where none must
exist. That path constructed by same process that starts a
fluorescent lamp. That surge finished in microseconds. But the
plasma path remains.

For example, lightning formed a circuit from utility transformer
primary to secondary. Now AC utility 13,000 or 33,000 volt primary is
connected directly into your building. That high voltage applies high
energy. What might explode? Well which items completed that
electrical path? Not necessarily everything.

Demonstrated is why utility earth ground is critical to surge
protection. Surges that may overwhelm protection inside all
electronics should not be permitted inside the building. Then
electronics internal protector circuits are not overwhelmed.

How might a ground strike be a direct lightning strike to telephone
equipment? Yes, I said direct strike. Strikes to earth or a nearby
tree can also be direct strikes to a human, cow, or building that does
not have effective protection. An application note from Polyphaser
discusses a failure and what provides protection:
http://tinyurl.com/38v2dv

Lightning strikes somewhere across the street close to the below
grade West cable vault. ... The first line of defense is the telco
protection panel, but the panel must be connected to a low
resistance / inductance ground. There was no adequate ground
available in the telephone room.

Polyphaser app notes are considered industry benchmarks for
understanding the principles:
http://www.polyphaser.com/technical_notes.aspx

Did surge enter on earth ground? Then building's surge protection
'system' is defective. Destructive surges enter via ground when an
earthing system - what provided protection - is improperly installed.
Begin with some of those Polyphaser app notes.

Every electronic device - powered on or off - in home or business -
is connected to the equivalent of a radio antenna system. Principles
pioneered by Franklin in 1752 on churches and by early 20th Century
Ham radio operators are also installed by Telstra so that their
switching computer (connected to overhead wires all over town) is not
destroyed (for four days due to surge damage). Direct lightning
strikes (via overhead or ground strikes) without damage are that
typical.

Appreciate why each telephone switching center can suffer hundreds
of surges during each thunderstorm - and no damage. First they earth
each surge before it can enter the building. Then protection already
inside electronics is not overwhelmed.

 

[a t e c 7 7]

Sally wrote:

Incidentally, how did you know it was 4 metres away?

A tree stopped existing

"a t e c 7 7" <"atec 77 at hotmail dot com"> wrote in message
news:46934477@dnews.tpgi.com.au...
Franc Zabkar wrote:
On Thu, 5 Jul 2007 08:12:50 +1000, "Tim" <tim45@yahoo.com> put finger
to keyboard and composed:

Is it recommended for my new TV and sound system, or just another
rippoff.?
I think the term "surge" is a misnomer in this case. "Surge
protectors" (aka metal oxide varistors) will soak up spikes, but not
sustained overvoltages, which is how I perceive the term.

While I have no faith in these devices, I do agree that it may be more
economical to purchase a Belkin surgeboard (ie, a lifetime insurance
policy bundled with a power board) than to upgrade an existing
household contents policy, especially when amortised over several
years.

- Franc Zabkar
We have a "protector" fitted to the 60 telly "
with a close ground strike recently it tripped and I assume helped save
things as the same boards also serves the sounc system and I was delighted
to see the survival even though the rooms incadecant was blown , I expect
the induction from a strike only 4 metres away was severe ?
( it was LOUD)

 

[Sally]

OK. It was either on the tree or within about 1 metre of it. The sap
literally explodes the tree, due to the sudden heat. (= energy, unlike the
suggestion of someone on here who contended that there was no energy in a
lightning strike!) For those keen to learn more Frydenlund makes interesting
reading. And Dr Steven Gumley, who survived despite what I think is
foolhardy stuff in taking his VW Combi into storm activity to do
experiments! Although both gentlemen were involved with various products
they were somewhat above keen salesmen! In fact Steven was a Rhodes Scholar
(but on the other hand so was Bob Hawke!)

"a t e c 7 7" <"atec 77 at hotmail dot com"> wrote in message
news:46942110@dnews.tpgi.com.au...

Sally wrote:
Incidentally, how did you know it was 4 metres away?


A tree stopped existing

"a t e c 7 7" <"atec 77 at hotmail dot com"> wrote in message
news:46934477@dnews.tpgi.com.au...
Franc Zabkar wrote:
On Thu, 5 Jul 2007 08:12:50 +1000, "Tim" <tim45@yahoo.com> put finger
to keyboard and composed:

Is it recommended for my new TV and sound system, or just another
rippoff.?
I think the term "surge" is a misnomer in this case. "Surge
protectors" (aka metal oxide varistors) will soak up spikes, but not
sustained overvoltages, which is how I perceive the term.

While I have no faith in these devices, I do agree that it may be more
economical to purchase a Belkin surgeboard (ie, a lifetime insurance
policy bundled with a power board) than to upgrade an existing
household contents policy, especially when amortised over several
years.

- Franc Zabkar
We have a "protector" fitted to the 60 telly "
with a close ground strike recently it tripped and I assume helped save
things as the same boards also serves the sounc system and I was
delighted to see the survival even though the rooms incadecant was blown
, I expect the induction from a strike only 4 metres away was severe ?
( it was LOUD)

 

[Sally]

Spot on w_tom! And I had given you up as a pontificating politiciser. Just
shows how wrong one can be...

"w_tom" <w_tom1@usa.net> wrote in message
news:1184112755.227078.19770@r34g2000hsd.googlegroups.com...

On Jul 10, 4:34 am, a t e c 7 7 <"atec 77 at hotmail dot com"> wrote:
We have a "protector" fitted to the 60 telly "
with a close ground strike recently it tripped and I assume helped
save things as the same boards also serves the sounc system and I was
delighted to see the survival even though the rooms incadecant was blown
, I expect the induction from a strike only 4 metres away was severe ?
( it was LOUD

Incandescent bulbs will not be destroyed by lightning strikes.
However a massively higher energy source can cause that problem.
Lightning may construct electrically conductive paths where none must
exist. That path constructed by same process that starts a
fluorescent lamp. That surge finished in microseconds. But the
plasma path remains.

For example, lightning formed a circuit from utility transformer
primary to secondary. Now AC utility 13,000 or 33,000 volt primary is
connected directly into your building. That high voltage applies high
energy. What might explode? Well which items completed that
electrical path? Not necessarily everything.

Demonstrated is why utility earth ground is critical to surge
protection. Surges that may overwhelm protection inside all
electronics should not be permitted inside the building. Then
electronics internal protector circuits are not overwhelmed.

How might a ground strike be a direct lightning strike to telephone
equipment? Yes, I said direct strike. Strikes to earth or a nearby
tree can also be direct strikes to a human, cow, or building that does
not have effective protection. An application note from Polyphaser
discusses a failure and what provides protection:
http://tinyurl.com/38v2dv
Lightning strikes somewhere across the street close to the below
grade West cable vault. ... The first line of defense is the telco
protection panel, but the panel must be connected to a low
resistance / inductance ground. There was no adequate ground
available in the telephone room.

Polyphaser app notes are considered industry benchmarks for
understanding the principles:
http://www.polyphaser.com/technical_notes.aspx

Did surge enter on earth ground? Then building's surge protection
'system' is defective. Destructive surges enter via ground when an
earthing system - what provided protection - is improperly installed.
Begin with some of those Polyphaser app notes.

Every electronic device - powered on or off - in home or business -
is connected to the equivalent of a radio antenna system. Principles
pioneered by Franklin in 1752 on churches and by early 20th Century
Ham radio operators are also installed by Telstra so that their
switching computer (connected to overhead wires all over town) is not
destroyed (for four days due to surge damage). Direct lightning
strikes (via overhead or ground strikes) without damage are that
typical.

Appreciate why each telephone switching center can suffer hundreds
of surges during each thunderstorm - and no damage. First they earth
each surge before it can enter the building. Then protection already
inside electronics is not overwhelmed.

 

[Sally]

BTW, ISBN 0-442-01338-8

"Sally" <me@anon.net> wrote in message news:46942e34@dnews.tpgi.com.au...

OK. It was either on the tree or within about 1 metre of it. The sap
literally explodes the tree, due to the sudden heat. (= energy, unlike the
suggestion of someone on here who contended that there was no energy in a
lightning strike!) For those keen to learn more Frydenlund makes
interesting reading. And Dr Steven Gumley, who survived despite what I
think is foolhardy stuff in taking his VW Combi into storm activity to do
experiments! Although both gentlemen were involved with various products
they were somewhat above keen salesmen! In fact Steven was a Rhodes
Scholar (but on the other hand so was Bob Hawke!)

"a t e c 7 7" <"atec 77 at hotmail dot com"> wrote in message
news:46942110@dnews.tpgi.com.au...
Sally wrote:
Incidentally, how did you know it was 4 metres away?


A tree stopped existing

"a t e c 7 7" <"atec 77 at hotmail dot com"> wrote in message
news:46934477@dnews.tpgi.com.au...
Franc Zabkar wrote:
On Thu, 5 Jul 2007 08:12:50 +1000, "Tim" <tim45@yahoo.com> put finger
to keyboard and composed:

Is it recommended for my new TV and sound system, or just another
rippoff.?
I think the term "surge" is a misnomer in this case. "Surge
protectors" (aka metal oxide varistors) will soak up spikes, but not
sustained overvoltages, which is how I perceive the term.

While I have no faith in these devices, I do agree that it may be more
economical to purchase a Belkin surgeboard (ie, a lifetime insurance
policy bundled with a power board) than to upgrade an existing
household contents policy, especially when amortised over several
years.

- Franc Zabkar
We have a "protector" fitted to the 60 telly "
with a close ground strike recently it tripped and I assume helped
save things as the same boards also serves the sounc system and I was
delighted to see the survival even though the rooms incadecant was
blown , I expect the induction from a strike only 4 metres away was
severe ?
( it was LOUD)

 

[Ross Herbert]

On Sun, 8 Jul 2007 17:18:28 +1000, "Doug Jewell" <noone@nowhere.com>
wrote:

"Trevor Wilson" <trevor@SPAMBLOCKrageaudio.com.au> wrote in message
news:468c10f2$0$32552$88260bb3@free.teranews.com...

"Tim" <tim45@yahoo.com> wrote in message
news:468c1b67@dnews.tpgi.com.au...
Is it recommended for my new TV and sound system, or just another
rippoff.?

**Rip-off.
Until the first electrical storm, or the power company has a
transformer go
arse-up.

There is absolutely no way that a normal surge protector can protect
against such things as a transformer going "arse-up". By this I assume
you mean that a higher than normal voltage will be connected towards
your premises.

One day several years back I was sitting in the family room about 20
feet away from my old Panasonic Genius microwave oven, which has a
small printed board in it which is fitted with the usual surge
protection components as found in your everyday anti-surge powerboard.
Suddenly I heard this enormous bang and smoke issued forth from the
oven.

Upon investigation I discovered the anti-surge varistors had been
blown to smithereens and some copper track acting as a fuse had
vaporised from the board. I asked the power authority what had caused
it and they informed me a tree-lopper had managed to bring a high
voltage power line into contact with the normal domestic power lines
feeding my area. This produced a similar situation to that of a
transformer going "arse-up".

Antisurge power boards will protect only from relatively minor over
voltage situations where low currents are a by-product. Anything which
is capable of producing high current along with over voltage
sufficient to activate the anti-surge devices will simply overwhelm
them and blow them to the shit-house. In my case the real protection
was offered by the copper track on the pcb which acted as a fuse,
although I suppose the varistors may have provided a microsecond of
delay before they vaporised.

 

[Franc Zabkar]

On Tue, 10 Jul 2007 18:34:01 +1000, a t e c 7 7 <"atec 77 at hotmail
dot com"> put finger to keyboard and composed:

Franc Zabkar wrote:
On Thu, 5 Jul 2007 08:12:50 +1000, "Tim" <tim45@yahoo.com> put finger
to keyboard and composed:

Is it recommended for my new TV and sound system, or just another rippoff.?

I think the term "surge" is a misnomer in this case. "Surge
protectors" (aka metal oxide varistors) will soak up spikes, but not
sustained overvoltages, which is how I perceive the term.

While I have no faith in these devices, I do agree that it may be more
economical to purchase a Belkin surgeboard (ie, a lifetime insurance
policy bundled with a power board) than to upgrade an existing
household contents policy, especially when amortised over several
years.

- Franc Zabkar

We have a "protector" fitted to the 60 telly "
with a close ground strike recently it tripped and I assume helped
save things as the same boards also serves the sounc system and I was
delighted to see the survival even though the rooms incadecant was blown
, I expect the induction from a strike only 4 metres away was severe ?
( it was LOUD)

Maybe I'm being unfair.

For example, Belkin's 4-way Surgeboard (the cheapest) boasts the
following specs:

Part # F9A402au2M
Protection: Level 1
Joules: 714J
Maximum Spike Current: 19,500A

Assuming that a 100W incandescent lamp experiences a cold current of
10 times its operating current for 2 mains cycles, then its energy
dissipation would be only 100W x 10 x 20ms x 2 = 40 Joules.

Comparing the two figures (714J vs 40J), is it any wonder that your
lamp failed while your MOV survived?

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Sally]

Yes, it's a matter of degree. But a good surge board, properly earthed, is
certainly better that nothing.

"Ross Herbert" <rherber1@bigpond.net.au> wrote in message
news:llu893puctp4s7s4vsng3dbqdnkr0ckmnk@4ax.com...

On Sun, 8 Jul 2007 17:18:28 +1000, "Doug Jewell" <noone@nowhere.com
wrote:


"Trevor Wilson" <trevor@SPAMBLOCKrageaudio.com.au> wrote in message
news:468c10f2$0$32552$88260bb3@free.teranews.com...

"Tim" <tim45@yahoo.com> wrote in message
news:468c1b67@dnews.tpgi.com.au...
Is it recommended for my new TV and sound system, or just another
rippoff.?

**Rip-off.
Until the first electrical storm, or the power company has a
transformer go
arse-up.


There is absolutely no way that a normal surge protector can protect
against such things as a transformer going "arse-up". By this I assume
you mean that a higher than normal voltage will be connected towards
your premises.

One day several years back I was sitting in the family room about 20
feet away from my old Panasonic Genius microwave oven, which has a
small printed board in it which is fitted with the usual surge
protection components as found in your everyday anti-surge powerboard.
Suddenly I heard this enormous bang and smoke issued forth from the
oven.

Upon investigation I discovered the anti-surge varistors had been
blown to smithereens and some copper track acting as a fuse had
vaporised from the board. I asked the power authority what had caused
it and they informed me a tree-lopper had managed to bring a high
voltage power line into contact with the normal domestic power lines
feeding my area. This produced a similar situation to that of a
transformer going "arse-up".

Antisurge power boards will protect only from relatively minor over
voltage situations where low currents are a by-product. Anything which
is capable of producing high current along with over voltage
sufficient to activate the anti-surge devices will simply overwhelm
them and blow them to the shit-house. In my case the real protection
was offered by the copper track on the pcb which acted as a fuse,
although I suppose the varistors may have provided a microsecond of
delay before they vaporised.

 

[w_tom]

On Jul 11, 3:23 am, Franc Zabkar <fzab...@iinternode.on.net> wrote:

...
For example, Belkin's 4-way Surgeboard (the cheapest) boasts the
following specs:

Part # F9A402au2M
Protection: Level 1
Joules: 714J
Maximum Spike Current: 19,500A

Assuming that a 100W incandescent lamp experiences a cold current of
10 times its operating current for 2 mains cycles, then its energy
dissipation would be only 100W x 10 x 20ms x 2 = 40 Joules.

Comparing the two figures (714J vs 40J), is it any wonder that your
lamp failed while your MOV survived?

Your post is based in some assumptions. For example, a lamp
filament absorbs nearer to zero energy when cold. Bulbs fail after
filament gets too hot - vaporizes. Typical surges are microseconds.
Filament never gets hot enough fast enough to increase resistance,
then vaporize.

For example, a 'whole house' protector rated for 50,000 amps will
have wires how large? 2 or 2.5 mm diameter copper. A wire rated for
20 amps constant current is also sufficient to shunt 50,000 amps surge
current because that surge is not constant; typically in
microseconds. Same reason why short transients surges would dissipate
so little energy in a light bulb.

To have sufficient energy to blow a bulb, that current must conduct
longer. Source of higher energy and source of current long enough may
be utility supplied electricity.

Confused is how light bulbs dissipate energy verses what joules
measure for an MOV. Same units measure different parameters.

Joules for MOVs is a measure of how conductive the MOV may be and a
ballpark measurement of its life expectancy (size, pulse width, and
number of transients). Joules for MOVs is equivalent to measuring
gauge of a wire from Ben Franklin lightning rod to earth. If that
wire is too thin, then it will vaporize. If MOV has too few joules,
then it will degrade. MOV vaporizes only when current massively
exceeds what manufacturer intended - well beyond Maximum Permissible
parameters.

More joules in an MOV mean MOV absorbs even less energy. More
joules for a light bulb means a bulb dissipates more energy. For a
constant current, higher joules in an MOV means more conductive; high
joules for a light bulb means less conductive.

Conductivity of a wire is measured in amperes. Conductivity of MOVs
is measured in joules. The difference between wire and MOV: wire does
not degrade with use. MOVs degrade with use. Wires are for
continuous current. MOVs are for rare and short current transients
that are typically measured in microseconds. Whereas necessary wire
size is measured by wire gauge; MOV size is measured by joules and
lamp energy dissipation is measured in joules. Joules for a lamp and
joules for an MOV are measuring two different parameters.

What happens when an MOV is better - more joules? Then it absorbs
even less energy. MOV function is not to absorb energy. It's
function is to shunt (connect, divert, clamp, bond) that electricity
elsewhere.