Irish Math needs updating. The blinking neon bulb had
ZERO to do with surge protection! Surge protectors,
usually varistors, are solid components and NOT subject
to aging the same as a bulb or an electrolytic
capacitor. That stip's surge protection, which is
minimal in most power strips anyway, is 99.9999% likely
to be just fine!
Please don't use irish math that costs people money
when it's not warranted.
Give that man a cigar!!!
The varistor in them surge strips is a protection device, usually a one-shot
deal, and is wired in parallel with the protected load--in theory, if line
voltage ever goes over at certain definate set point, they short
out.....thus tripping the circuit breaker or blowing the fuse to the branch
circuit feeding the unit.
Having relatively high dollar computerized equipment in our machine shop, we
always add a set of them just downstream from the mains fuse block whenever
the machine wasnt already equipped with a set as supplied from the factory.
Sort of, but not exactly. They also "clip off" short transient overvoltage
pulses. Each time they do, they take a little "hit" and degrade a bit.
DAMN tax cuts! They're letting money trickle down to people who spend it!
WASHINGTON, July 13 (Reuters) - The U.S. government posted a larger-than-
Thats why I said "in theory"..........
Since you want to be specific:
No, very specifically and emphatically, the blinking neon
bulb has ZERO to do with the condition of the surge
protection, which was my original point.
Additionally, varistors et al have a "knee" or breakdown
area where they begin to conduct. That "knee" does vary
within percentages with age, but it does NOT negate the
protection afforded; the full breakdown point is stable to
wihin 5% as a rule, of the specified voltage, over the life
of the component,
The unfortunate and uniknown state of the varistors in
the surge protection however, plus how the protection is
installed, is, in the cheaper strips, completely and totally
unknown unless there are monitor LEDs to indicate their
condition. Once stressed, a varistor DOES lose its ability
to dissipate the amount of joules it was rated for at
manuifacture. When overtstressed, the varistor opens up
completely, and there is no protection form the OPEN
Usually there are 3 varistors: One from hot to earth,
one from neutral to earth, and one from hot to neutral. IF
one if hit hard enough to cause it to go short , after which
the normal 120V ac current burns it out and it opens up, you
still have the other two in place, BUT for practical
purposes, protection is compromised, although not lost,
because of the triad of components. Even with one gone
there is still SOME protection left, in all three
directions. It's non-intuitive, but is the case.
For those who might be interested, surge protection is
measured in joules; the higher the number of joules it can
handle, the better the protection. Current and/or voltage
are NOT an indication of how MUCH surge protection is being
provided. So look for the joule ratings; it's sort of like
watts, but more indicative of the strength of the protection
at any current or voltage combination.
I didn't read Mr. Meehan's post to link the light and the surge protector.
In addition, my computer specialist says:
1. Power strips become less reliable surge protectors with age.
2. Power strips aren't very good at surge protection in any case,
not withstanding money back guarantees.
Item 2: Correct. Literally, a "power strip" only has a
switch and some outlets. It says nothing about any kind of
surge protection. A few lo-joule varistors is NOT very good
surge protection for anything but everyday inductive load
switching, etc as in motors, xfmrs, and so on. They do
little to nothing for outside surges coming into a house
mains or telephone line.
Most, not all, damaging surges to computer equipment
comes in on the phone line anyway, not via the mains where
there is a stepdown xfmr to help limit them, and more
Item 1: Isn't really a very mean ingful statement. Coming
from the MTBF and failure compliance world, "age" is
relative, and without a reference, meaningless. How much
aging? How long does it take for surge protectors to become
less reliable? Etc.
I think, if htat guy knows what he's talking about, he's
actually saying not to trust them because the surge
protection can be "used up" if you will, and no longer
present, after a surge, and the user never gets any kind of
indication that such an event has occurred. So, if it
happensw again, Blammo! And the surge protector didn't
work! Not the second time, anyway.
Shelf life of varistors, tridacs, etc., is in the order
of decades, and useful, non-surged life is nearly
equivalent. The -problem- is not being able to tell WHETHER
any damage/loss of protection has occurred. They're not
very useful, but at the same time, very important to have.
The life of a computer is so short that a new surge switch
with any new computer is more than en ough to keep things
current. Obviously, as you said, if it really matters,
spend the $50 or so to get a good one or better yet an UPS.
Thanks, I'm disabled and like to talk "shop".
Which is true, as I tried to indicate. However there is a type of
relationship. A flickering neon light is a good indication that it is old.
All authorities I have read, with the exception of you have indicated that
age and use of surge protectors does tend to point to a greater likelihood
of reduced protection.
I offer no personal or verifiable objection to your arguments that
appear to suggest that age is not a factor in the reliability of surge
protectors. I only note that others have appeared to offer different
As others noted, it's just the bulb. The power strip is likely aging,
though, and if it makes you feel better you can move it to a place where
it's serving lesser-value equipment. Think of it a little like the
"penny test" for tires.
You didn't note if it has built-in surge protection; usually a "power
strip" so named does not. It may not be offering you any equipment
protection to begin with.
A computer, for instance, should be on a high-quality surge arrestor
such as those made by ADP or Tripp-Lite, ideally isolating different
parts of the system from each other. Every time you turn on your
printer, for example, you could be adding a surge to the line that is
damaging your computer. Personally, I think the added peace of mind from
buying a $50+ surge device is worth it, considering the value of my
computer equipment. But not everything needs that kind of protection.
Pop Rivet accurately describes how MOV protectors must
fail. MOVs degrade as intended and as speced by charts in
manufacturer data sheets. That is 'degrade' which is
completely different from a catastrophic failure also known as
'vaporize'. A vaporized MOV has operated well beyond what the
manufacturer requires and does not even appear on those data
sheet charts. A vaporized MOV is so ineffective as to be
called grossly undersized and completely ineffective.
There is good reason to grossly undersized a protector. A
properly sized protector with more joules will earth a surge.
Human should never know the surge even existed. But with
grossly undersized (and overpriced) protectors, then the naive
will *assume* a protector failed to protect an adjacent
appliance. In reality, protection that already exists inside
appliances was not overwhelmed by the same tiny surge that
catastrophically (unacceptably) destroyed a grossly undersized
protector. With or without the adjacent protector, that
appliance internal protection would never have been
overwhelmed by that tiny surge. But now a misinformed human
is recommending a grossly undersized and overpriced
protector. How to increase profits (get the naive to
recommend a product) without installing sufficient MOVs.
Any protector damaged by one surge was grossly undersized
and should have never been purchased - too few joules. And
yet that is what so many naive will recommend only because it
vaporized - was grossly undersized. The only acceptable
failure mode for MOVs is degradation. Vaporization means the
human bought a defective protector. Not just undersized.
Grossly undersized. Too few joules. Grossly overpriced and
There is no difference between a *high quality* protector
from ADP, Tripplite, or Monster and the $5 protector if all
have same joules rating. All are simply a $3 (retail) power
strip with some $0.10 parts installed. Some are then grossly
overpriced at $50. Only other part that makes a quality
difference is the power strip's circuit breaker. A 15 amp
breaker that has nothing to due with surges and must be
provided on every power strip for human safety reasons. Some
grossly overpriced protectors do not even have the essential
15 amp breaker.
Surge damage is being promoted as if surges were daily
events slowly degrading the electronics. Nonsense. Look at
the numbers on that protector. Threshold or let-through
voltage of 330 volts. Protector rarely sees or responds to
anything. For a typical eight years, protector can remain
inert - do nothing. A surge is a rare event that occurs maybe
once every 8 years (varies based upon weather, underlying
geology, etc). Furthermore, all appliances have internal
protection that make daily noise transients on utility wires
irrelevant. The surge protector never even sees that noise.
Protector is sized so at to remain fully functional after that
rare event. Joules is the rating. How many joules on the
recommended ADP or Tripplite protector? Joules is the ball
park number for a protector's life expectancy.
Neon lamps also degrade - also do not vaporize. If voltage
on neon light is higher, then bulb's anodes breakdown faster -
contaminating the inert gas. This few volts increase has
nothing to do with the hundreds of volts difference required
before an MOV sees the transient. Flickering light of a neon
bulb only says the unreplaceable bulb needs replacement.
Dan Hartung wrote:
As mentioned, the cheap power strip surge protectors don't protect much.
When lightning hit the pole in front of my house. I saw a spark jump from
one prong to the other on an outlet. It also came in on the phone line. The
surge protector power strip was left in smoking ruins. However, I had a
battery backup power supply for the computer and the computer survived
because on the battery backups, the ac charges the battery and in turn a DC
to ac switching supply creates the ac for the load, thus isolating the load
from the incoming power. At the time I had an external modem and the
incoming high voltage smoked the modem. Because it was an external modem, it
provided enough isoation to protect the computer. Aside from having to
replace the modem, two phones, a power strip, and all the lightbulbs that
were on at the time, there was no other damage. I had turned all appliances
off and unplugged the stereo from the power strip when the storm approached.
I think that's the best protection in an electrical storm. I don't think the
surge protector in the power strip would have offered any protection.
Definitely wouldn't jhave made any difference. Since
we're telling stories, a few years back we had a close
by lightning hit; hair on the arms stood up, strong
ozone smell, and also a LOT of smoke coming from the
entertainment center, we quickl realized. Which was
strange, because we'd unplugged everything and the
plugs were laying right there on the floor in plain
sight. Only ... we -didn't- disconnect the dc wiring
going out to the satellite dish and it came in on that!
The strike actually it a tree, and from the burn marks
and blasted bark all over the place (tree wasn't
damaged structurally but was butt-naked!), it travelled
along a nearby farmer's barbed wire fence and jumped to
our dish, from the look of it. Between the buried
wires and the dish itself, a ten footer, we had a great
entrance for those jewels, I mean, joules to flash
along. Thank heavens for insurance!
Another time it hit the phone in the kitchen at a
neighbor's while we were there and a plasma ball jumped
from the phone, ran down the wall and across the floor,
finally dissipating into the wall on the opposite side
of the room! The phone was toast, but no other damage.
We never did finish supper; my sister didn't even do
the dishes that evening.
Then there was the time it hit a power transformer
on a pole which my brother in law had just minutes ago
parked his brand new Pontiac under. . Glass, metal,
fibre, shards of wood & oil all over his previously
This was supposed to be a bad year for lightning in
this area this year again, but so far hardly a flash in
the sky. Knock on formica! We're far northeast NY
state, on the St. Lawrence River. Storms here are low
to the grouind, coming up oujt of the valley and
sometimes spectacular. There's lots of places worse
than here though.
Long ago proven even by early ham radio operators. They
would disconnect antenna and place antenna lead inside a
mason jar. Still suffered damage. Then they earthed the
antenna lead. All damage stopped. A lesson that even Ben
Franklin demonstrated in 1752.
Earthing is what effective protectors do. Connect an
incoming wire (the direct strike) to protection. Protection
is not a protector. Protector and protection are two
separate components in a surge protection 'system'. Protector
(and that plug-in UPS) does not stop, block, or absorb surges
- except in myths. Will a protector or plug-in UPS stop or
block what miles of air could not? Of course not.
Shunt mode protectors are not effective dams or surge
absorbers. They are only temporary shunts - connection, short
circuit, diverter - that connects an incoming surge less than
10 feet to earth ground - the protection. Why do we need such
protectors? So that internal protection inside properly
designed appliances is not overwhelmed. A surge must be
connected to protection before it can enter the building. An
effective MOV protector connects that surge less than 10 feet
Anything that can work adjacent to that appliance is
already inside that appliance. This explains why both cheap
(actually grossly overpriced) power strip protectors and
plug-in UPSes don't provide effective protection. Without the
less than 10 foot connection to earth, then where is that
destructive surge to be shunted to?
In the meantime, computer power supplies must have some of
the most resilient internal protection, as even demanded by
Intel specifications. Protection that assumes a destructive
transient will be earthed before transient can enter the
Review detailed numerical specs for a plug-in UPS. It
provides same protection circuits found in power strip
protectors. Notice the joules. Joules mean both (power strip
and UPS) utilize the same protection circuit. Many big name,
plug-in UPSes are even grossly undersized - too few joules -
ineffective protection. But then a plug-in UPS manufacturer
does not even claim to protect from a destructive type of
surge. Read his detailed numerical specs - if manufacturer
even provides detailed specs.
To protect an adjacent appliance, the protector must stop,
block, or absorb the transient. But those are shunt mode
protectors. They don't even claim such 'blocking' abilities.
Shunt mode protectors are effective when connected 'less than
10 feet' to the same earth ground that all other incoming
utilities connect to. This is how ham radio operators even in
the early 1900s discovered effective protection. Earthing -
and not a plug-in protector - is the protection.
Cheap power strip surge protectors don't protect much; nor do
they claim to. Plug-in protectors cannot claim to provide
that protection because the short, direct, and independent
earth ground connection does not exist. Plug-in UPSes
typically use a same protector circuit. They also do not stop
or block destructive transients. Earthing is the technique
well proven effective for over 50 years, is found in high
reliability centers that must operate during every
thunderstorm (telephone Central Office and 911 emergency
response centers), was even demonstrated by Ben Franklin in
1752, and proven effective by early 1900 ham radio operators.
Protection is about earthing. MOVs are the devices that
earth each incoming utility. Protection that also keeps an
appliance's internal protector circuits from being
overwhelmed. Protection that does not stop or block
destructive surges - which is what a protector must do if
adjacent to the appliance.
A shunt mode protector (power strip or plug-in UPS) cannot
protect an adjacent appliance if it is too far from earth
ground and too close to the appliance.
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