The 200 amp rated parrallel MOV (or solid state) surge units i use are much
larger however this type would better then nothing or the small MOVs built
into outlet strips.
be aware that MOV units deteriate over time (the number of "hits")
web search TVSS for loads of info... sites like this
I've had a few computer die from power 'flickering'. I think it was
on a power strip(protected) but the flickering was like several hits
in a very short time, and something got through. :(
Just figuring if I can stop the bad stuff at the panel less gets
through and effects my whole house.
Thanks for reminding me, guessing I'll have to frequently check the
'ready' light. I read this bad boy has a 3 year warrenty, so guessing
it's very good, and being a square-d, that sold me.
Thx, I like ecm's site for information.
Cheap switching power supplies are easily damaged by repeated pulsing
of the supply voltage. Better quality power supplies are designed to
cope with the problems caused by the high turn on current. Companies
that build PCs are some of the cheapest bastards in the world. They use
the cheapest power supplies they can find and don't care if they blow
up, as long as they last through the warranty.
Another thing that degrades power supplies is leaving the PC on all
the time. The heat causes the ESR in the electrolytics to rise and this
can cause all kinds of problems. I have seen a couple PC power supplies
recently that had one of the small electrolytics overheat and explode.
One shot out through the fan, hit the motherboard and shorted out the +5
volt bus. When the short cleared it destroyed the motherboard, CPU,
memory and the hard drive. It was in a cheap Gateway PC built without a
floppy drive and it was an 85 watt supply. Its the worst design I've
seen in a long time.
I installed one on my last home. Lowes is cheaper.... I paid about $55 at
a electrical wholesale house. They had to order it.
You still need point of use equipment to get the levels down to what your
electronics can handle. Do not forget about the cable and telephone if they
are connected to your computer.
Good point about senstive equipment like electronics.
I want a blanket solution for all my outlets and then have point of
use protectors for specificly more sensitive equipment like the
So, I'm guessing it wasn't good enough peace of mind to install one at
your current house?
You were discussing the Home line product. My new home has a GE panel and
yes I purchased a panel arrestor the first week I was in the home. Slightly
different specs for the GE product.
I have a lot of money invested in the big screen, computers and the washing
machine. Read the installation instruction on most garage door openers now.
They suggest a surge arrestor on the outlet that the door opener is plugged
I live in a area with a couple of months of lightning storms. If I lived in
the Los Angeles county for example I might not install one for lightning.
For me it is a small price to pay for some peace of mind.
Best check your grounding I try to maintain 5 ohms or less on my service.
Pretty hard to do in the desert.
If the protector was protection, then a 'point of use'
protector would have value. First, anything accomplished by
that 'point of use' protector is already inside the
appliance. Second, the 'point of use' protector is only as
good as the protection it connects to. Protection is not a
protector - no matter how it was spun. Protection is earth
ground. Since a 'whole house' protector already connects to
that single point earth ground, then what good does the 'point
of use' protector do? It has no effective earth ground. So
what does a plug-in protector really accomplish?
The protector is not protection. A protector or wire to
earth ground are equivalent. Earthing is the protection.
Some utilities can be wired directly to protection (ie CATV).
Others require a protector to connect to earth ground (AC
electric and phone). Distance to earth ground is
significant. The important 'less than 10 foot' connection
that plug-in protectors would rather we not discuss determines
protection effectiveness. Those 'point of use' protectors
have all but no earth ground for many reason - including earth
ground too far away. No earth ground means no effective
Where to spend money. Into overpriced and grossly
undersized plug-in (point of use) protectors? Or put same
money into something that would increase protection - the
quality of that earth ground.
A protector is only as effective as that earth ground. How
to increase the protection provided by a 'whole house'
protector? Enhance the earth ground. Does a point of use
protector enhance 'whole house' protection? Of course not -
if for no other reason because the plug-in protector does not
even discuss earthing let alone make an effective connection
to earthing. Anything accomplished by a plug-in protector is
already inside that adjacent appliance.
Numerous other reasons why plug-in protectors are not
worth their inflated costs, such as induced transients (on
other circuits) created by those plug-in protector. A plug-in
protector can even provide a destructive transient with more
paths through that appliance. Yes an adjacent plug-in
protector has even been demonstrated to cause damage to a
powered off computer. The adjacent protector connected the
transient to earth ground - via the appliance.
Remember what provides the protection. Not a protector.
Protection is provided by a single point earth ground. The
protector - or a dedicated wire - is only a connection to
protection. A protector or a dedicated earthing wire is not
the protection. The protector and that wire both do the same
thing. Connect an incoming and destructive transient to earth
ground. They both connect to protection. The protector is
only as effective as the quality of and short distance to
earth ground. To recommend a 'point of use' protector, one
must forget what the protector does.
Resistance of earth ground (<5 ohms) is not the only
important parameter. Other critical concepts that make or
break a protection 'system' include short wire length, no
sharp bends, no splices, single point earth ground, earthing
wire not bundled with other non-earthing wires, and wire not
inside metallic conduit. Just more concepts that a plug-in
protector will not discuss since plug-in protectors violate
some if not most all concepts. Wire impedance means the
plug-in protector has all but no earth ground connection.
Plug-in protector made ineffective by violating those above
Ineffective protectors (ie plug-in types) identify
themselves by having no dedicated connection to earth. Listed
above are at least eight reasons why a plug-in protector has
no effective earthing. And again, anything that is effective
at that appliance is already inside that appliance. Internal
appliance protection that can be overwhelmed if the earth
ground and 'whole house' protector connected to that earth
ground is not sufficient. Best place to enhance building
protection? Enhance the earthing system because a protector
is only as effective as its earth ground.
BTW, discussed above is the secondary protection - the
building's earth ground. Also inspect your primary protection
Again, a protector is not protection. The protector only
connects to protection. Money foolishly spent on plug-in
protectors is better spent on enhancing the protection - earth
ground and connections to that earth ground. Again, one
little fact that a plug-in protector must forget to mention to
make a sale. Earthing - not the protector - is the
The Real Tom wrote:
The protection is addative. The point of use protector will
respond to any surge it "sees" that is within its specs,
regardless of protection inside the appliance, resulting in
Second, the 'point of use' protector is only as
Protection is not a
Protection is earth
You ignore let through voltage. You assume the whole
house protector completely eliminates the surge. See:
A tiered approach is best - whole house protection at
the panel and point of use at the device.
It has no effective earth ground. So
It turns on, switching from a very high resistance to a very
low resistance, when a surge occurs. That clamps the voltage
difference between n-h, h-g, and n-g at the receptacle, to the
clamp voltage rating of the device. That clamping voltage spec
will not be exceeded (assuming the device is working) whther or
not there is a ground.
A protector or wire to
False. A wire from hot to earth ground would trip the
breaker under normal conditions. Obviously, you cannot
install such a wire. An MOV protector will not trip
the breaker under normal conditions. But when the MOV
"sees" a surge, it conducts. The power in the surge
is dissipated in the circuit to and from the MOV and
in the MOV itself (as long as the MOV is working), all
in accordance with Ohm's law.
Earthing is the protection.
False. With no protection, the receptacle the device plugged
into can be exposed to whatever the peak voltage of the surge
is. That means the device "sees" that peak voltage. With a
point of use protector and nothing else, the maximum voltage
the device can "see" at the recptacle it is plugged into
(which is the surge protector's receptacle) is the clamping
voltage of the MOV. The device that is being protected will
survive a ~300 volt surge, 8 uS long. It will not survive a
~6000 volt surge, 8 uS long. When a surge protector prevents
damage to the plugged in device, that's effective, by any
definition of the word.
Repeating the same false statment over and over doesn't
make it true.
Another repeat of incorrect information. It still doesn't
make it true.
Maybe *you* need to consider what a protector does.
Current passing through a path dissipates power.
Consider this path:
Power will be dissipated in all elemements above:
the internal resistance of the source, the resistance
of wire1, the resistance of the MOV, the resistance
of wire2 and the resistance of the return. In addition,
the MOV will hold the voltage across points a and b,
to whatever the clamping voltage rating of the MOV is.
The device being protected by the point of use protector
is connected to points a and b, so it "sees" no more than
the clamping voltage, as long as the MOV is working.
You get this wrong every time. Learn what an MOV does.
You repeat the same incorrect information. Is your theory
that if you say something often enough it begins to be
accepted as the truth? In any event, you do people a
disservice. Why not just promote the idea of a good,
properly installed ground system? Your incessant (and
incorrect) knocking of point of use protectors does nothing
to enhance your recommendation for a good ground system.
I put in a panel surge arrestor in every home I live in. My last house had
Homeline so that is what I put in. Warranty.... your kidding right? I
make sure that my service is grounded to 5 ohms or less by testing it. Some
times I have to drive a supplemental ground rod to achieve the level that I
want. Since I live in a arid part of the country, I can plant flowers and
water frequently, that works as well.
There is no practical way of doing the forensics after the damage is done.
I guess if you had a access to a lab that had really high priced equipment
you might be able to find out why something failed. I worked for an
electrical OEM, one that offers the $X thousand protection policy. In 5
years I do not remember anyone getting the money. A few got new units.
Another poster so kindly pointed out that electronics fail over time,
multiple hits. MOV's are UL tested once. If you read the fine print you
will see that they claim that the unit will reduce the amount of energy to a
let through of XXX. The CEBMA curve or the modified Curve gives a graphical
explanation of the issue.
IEEE says that you need 2 zones of protection. I use my service and then
another protective device at the point of use. I change the point of use
stuff every couple of years. Due to the monsoon season we have with lots of
My electronics are worth well over the $60.00 (Homeline price at Lowes or
was a few weeks ago, over a $100 at the deeepot if you can find someone who
can read and order one. I shopped both before I bought.)
I have no idea if the surge protector mentioned had anything to do with
the following incident:
My father has a summer cottage in New York. It has a 200A QO breaker box
with some sort of panel surge protector (probably QO). One winter, when
nobody was around, the top of the pole the power transformer was on broke
off, and the primary wiring (4800 or 7200 volts, I believe) contacted the
secondary wiring. Two cottages connected to that transformer burned to
the ground. My father's place wasn't one of them. However, he typically
throws the main switch when closing for the winter, and most likely _that_
is really what saved the place.
More pictures of protectors that should not be located in
the wrong spot:
UL1449 is suppose to disconnect the potential 'burning
component' when that component is too hot. But the
disconnecting device is not rated to disconnect at voltages
that high - thousands of volts. Therefore the connection is
not disconnected. Plug-in protector can start a fire in
locations where a flame will burn down the house. A protector
surrounded by incombustible material (ie. a 'whole house'
protector that is also sufficiently sized) would not burn down
Minimally sized 'whole house' protector for residential
service starts at about 1000 joules. Some early Square D and
GE 'whole house' protectors were not sufficiently sized.
Supplementing these with a properly sized 'whole house'
protector would only increase the life expectancy of all
earthed protectors in that breaker box.
Joules being a number for estimating life expectancy.
Location of protector determines its potential for burning
down the house. The example being a good reason for switching
off the mains breaker during the off season.
Michael Moroney wrote:
Duh. Abuse (by preventing air-flow) of almost any utilization
equipment is a bad idea and can result in equipment failure,
smoke, fire etc. (More on this below.)
The first, from Zerosurge, is against MOV style protectors
because they sell non-MOV style protectors. They don't
The second doesn't mention location, either. They state:
> power strips can overheat and create a potential fire hazard.
Their recommendation is that power strips should be inspected and
replaced with models that comply with UL 1449 if the inspection
reveals signs of overheating. Quoting from the url:
No product recall has been received but users are encouraged to
inspect their power strips. Any that show signs of overheating,
such as discoloration and/or distortion, should be replaced with
a newer model that complies with the latest edition of UL 1449.
That presumes that "voltages that high - thousands of volts"
will exist over a relatively long period. That's just a
fantasy. Except in the hypothetical case where a high tension
line somehow shorts to the service lateral - a situation that
a surge protector is NOT intended to alleviate - that does
not happen. Even a direct lightning strike on the service
lateral is relatively brief.
In a normal residence, if the high tension line (>4000 V)
shorts to the service lateral, you can kiss (some or all) of
your electrical devices goodbye, regardless of any whole house
surge protection, point of use surge protection, grounding, etc.
Your equipment, including whole house and point of use
surge protectors, simply isn't capable of surviving sustained
voltage that high.
What UL1449 recognizes is that normal branch circuit voltage
will cause heating in an MOV that has shorted. The thermal
disconnect *IS* designed to interrupt normal branch circuit
Therefore the connection is
As can most electrical devices we use. The biggest
offender is extension cords, which are misused and
abused all the time. Perhaps I should say, the biggest
offender is people. We plug in too many devices,
abrade and flex cords beyond reason, run them under rugs,
daisy chain power strips and extensions and on and on.
People drape clothing and curtains and even shoes! over
lamps. They stuff metal knives into toasters. We buy
flimsy wired xmas lights and cheap ($2.99 specials, made in
some foreign country) extension cords, power strips and surge
protectors. Is it any wonder the stuff fails?
But, lest it be missed, *any* cord and plug or hard-wired
electrical device can fail and burn and possibly cause
a house fire, with or without abuse.
Right. A properly installed whole house protector is
a good idea. I'm not sure what you mean by supplementing.
If two (or more) whole house surge protectors are installed,
the joule ratings add together - perhaps that's what you
have in mind. The higher the total joule rating, the better.
Bottom line in all of this: the subject of Surge protection
is a swamp, created by marketing and churned up by continual
misinformation propagated by neophytes and the holy grail of
People, who don't give a rat's ass for a safe for humans
electrical system will plunk down good money for "surge
protection" for their damn PC's. They buy into the marketing
hype that "you gotta have surge protection for your PC"
and run out to spend $2.99 to get it. *Bzzzt* Wrong.
Most people can't tell you what breaker controls which receptacle,
but will spend money, time and effort to "protect" their PC's
against surges. How many will spend $100 to have a professional,
licensed electrician inspect their electrical system for safety?
How many know they have a good grounding electrode system? How
many would pay for it to be upgraded to allow for better surge
protection? They will throw a cheap (or expensive)
point of use surge protector and/or a ups at the "problem".
Such measures may be effective for some conditions, but they do
not belong as the whole fix for the "problem".
The right approach, if you want surge protection is really
three fold. First, the electrical system must be safe for
humans. There is no point in "upgrading" a system for
surge protection if it has human safety problems, such as
corroded or loose connections, missing/innefective grounding
electrode system, improper bonding, cable TV, telephone,
satellite dish etc cables improperly installed, etc.
The above cannot be dismissed. (What is below can, in many
cases, with no ill effects. Some locales just don't get
many surges. Surge protection is NOT mandatory, marketing
After that, surge protection can be installed. The experts
recommend two layers of protection: whole house (which
requires a good earth ground) and point of use. The
let-through voltage with good whole house protection
can be spikes as high as 5 or 6 thousand volts, so the
point of use protector is used for the second line of defense.
Plug-in protectors are typically undersized and can create
a fire hazard. Create a fire hazard before any visual
indication is apparent. Whether an adjacent appliance is
either protected or damaged is completely irrelevant.
Previously posted examples demonstrate a potential fire
Where should that protector not be located? On a desk full
of papers or on the carpet? IOW the plug-in protector is a
fire hazard because it is located on or adjacent to
combustible materials - as well as being typically
undersized. Pictures of plug-in protectors demonstrate the
Zerosurge does recommend a series mode protectors. But
their pictures of plug-in protectors is accurate. MOV
protectors are safe and effective if properly located. For
example, the 'whole house' protector is located not adjacent
to combustible materials.
Meanwhile, an internal thermal fuse to disconnect the
grossly undersized and vaporizing MOV is only rated to
disconnect hundreds of volts. One condition that causes MOVs
to be fire hazards is thousands of volts. That thermal fuse
is not rated to disconnect thousands of volts. Should thousand
of volts enter a building, then damage to household appliances
may occur. But much worse, it can cause that plug-in
protector to spit flames. Another reason why a plug-in
protector would be a fire hazard.
A homeowner worries first about a plug-in protector that can
burn down the house before worrying about appliance damage.
Danger created by plug-in protectors accurately demonstrated
by pictures such as:
Demonstrated are plug-in protectors that can cause house
fires even with a UL1449 rating (which is also why original
UL1449 was long ago deemed insufficient).
The last place one wants a power strip protector is in dust
balls behind a desk or sitting on the combustible carpet.
Since plug-in protectors don't even claim to provide
protection from the typically destructive transient, well, why
then are they even purchased? For tens of times less money
per protected appliance, the 'whole house' protector does
provide real world protection - and is located away from
Experts recommend two layers of protection. Each layer is
defined by an earth ground. A primary protector is installed
by the utility typically at the transformer. This is primary
Secondary protection 'system' is a 'whole house' protector
and building earth ground. Each layer is defined by an earth
ground - not by protectors.
Unfortunately some have been deceived by plug-in protector
manufacturers into believing a 'point of use' protector is
another layer of protection. After all, it is called a surge
protector. Therefore it must be the surge protection. It
Protection is defined by the earth ground. Plug-in
protectors, if they had an effective earth ground, would only
share same earth ground used by a 'whole house' protector.
The earth ground - not a protector - defines each protection
layer. Experts that once recommended those point of use
protectors are now quietly no longer recommending them. Any
'point of use' protection effective at the appliance is
already inside the appliance. Worse, those power strip
protectors can even become a fire hazard.
Effective secondary protection that costs tens of times less
money per protected appliance even can be installed by the
homeowner. Therefore effective 'whole house' protectors are
sold to the homeowner in both Home Depot and Lowes. 'Whole
house' protector, that actually is effective, is located where
house fire is less likely.
See my answer to the other post you made. It addresses
some of the points you raise here, so I won't repeat.
Here's material quoted from the Polyphaser site:
"Polyphaser Applications Guide
ac power Protectors: Use at ac mains, subpanels and extension outlets
throughout the building. The PSP model can be mounted inside the device
to be protected."
That refers to whole house (ac mains) point of use
(extension outlets) and inside the device (PSP model).
They offer a point of use protector:
which contains either a single or a duplex receptacle:
" IS-PLDO models are duplex outlets
IS-PLSO models are single outlets "
Now, if you want to argue against point of use surge
protection, I suggest you argue with them.
Unlike the non UL 1449 standard compliant cheap crap
in the photos (reminds me of the cheap crap xmas tree
lights you can buy for a few bucks), polyphaser's point
of use protector looks to be of high quality and is in
a non combustible and non meltable aluminium case.
The remainder of your post either doesn't address
mine correctly or was addressed in my earlier response
today to your other post, so needs no reply here.
One little sentence taken out of context is engineering fact
to ehsjr. Use of extension cord protectors in special
conditions proves that Polyphaser recommends protectors at all
wall receptacles? Polyphaser never recommends protectors for
wall receptacles. But Polyphaser does discuss the need for
single point earthing - extensively. ehsjr denies this
essential earthing requirement. ehsjr simply takes one
sentence out of context, and that is proof that Polyphaser
recommends plug-in protectors. He quickly ignores everything
else that Polyphaser posts. How convenient.
A road band may require protection not provided by the
building. Should they waste money on the grossly undersized
protector recommended by ehsjr - the pathetic solution?
Instead Polyphaser offers a second best solution. Since the
building does not have 'whole house' protection, then all
power is obtained through properly sized power cord
protector. However ehsjr has twisted this into "Polyphaser
recommends plug-in protectors".
Now wonder he will not reply any further. ehsjr cannot
dispute that plug-in protectors may be a fire hazard. That the
worst place for a plug-in protector is among combustible
carpet and desktop papers. Now that he cannot dispute those
pictures, ehsjr is taking his baseball bat and going home in a
huff. He never did provide any numbers or technical citations
for his claims - because he cannot. He simply denies the
essential need for single point earth ground. But he knows
better only because he says so. Those pictures must be wrong
only because he says so. No wonder he cannot be bothered to
even post numbers for his claims.
ehsjr denies a need for earthing. Earthing (and not the
protector) is protection. His total proof is one word replies
such as "False". Meanwhile, and in direct contradiction to
what ehsjr posts, Polyphaser demands single point earthing of
protectors. For example, reasons for damage in a telephone
room are described in TD1026:
That is what plug-in protectors hope the naive (such as
ehsjr) will recommend: the AC safety ground somehow makes a
plug-in protector effective. Reality: no earth ground means
no effective protection which is why "only an ac "safety
ground"" creates problems.
Polyphaser also demands single point earth grounds to make
protectors effective. ehsjr cannot dispute this, so he takes a
sentence out of context as well as post other myths. He also
has another problem demonstrated by his description of how a
This is correct if all transients are normal mode. ehsjr
apparently does not have sufficient education to know of other
and more destructive transients. A mistake not possible if
he had first year EE training. He repeatedly ignored
transients that typically do damage; that seek earth ground.
But then if one's entire electrical knowledge is based on a
citation from Panamax, etal, then of course one would not
understand why single point earthing of protectors is
MOVs are connected in parallel - shunt mode devices.
Previously ehsjr insisted that MOVs absorb surges. Somehow a
shunt mode MOV would suck up the transient like a vacuum
cleaner so that adjacent electronics would not see the
voltage. He admitted MOVs connected in parallel. But somehow
it sucked up surges as if wired in series. At least ehsjr now
admits that MOVs operate more like a wire. A shunt that only
exists during the transient. But what does the MOV shunt to?
Where does it connect the energy of a transient? The MOV is
only effective when it shunts a transient a short distance to
earth ground. Earth ground is the protection. A protector is
nothing more than a temporary wire connection to earth
ground. No earth ground means no effective protection.
ehsjr also does not provide numbers for his speculations.
He claims from a Panamax citation that UL1449 *proves* a
surge protector is effective. He should have known that UL
only defines numbers for human safety. A protector can even
self destruct during a first transient - provide no effective
protection - and still receive UL1449 approval. Why? UL1449
only says the protector did not threaten human life even when
adjacent transistors are destroyed. UL is about human safety;
not transistor safety. More little facts and numbers that
ehsjr provided to recommends a protector that is undersized,
overpriced, and not earthed. According the ehsjr, the
protector need not earth a typically destructive transient -
that destroys transistors on a path to earth ground.
ehsjr has demonstrated how some recommend plug-in
protectors; to even quote sentence out of context. Even cite
a misleading panamax citation to imply a safety standard,
UL1449, proves a protector is effective. Even once claimed an
MOV works by absorbing (not shunting) transients.
Plug-in protector as recommended by ehsjr does not even
claim to protect from the typically destructive transient.
Well at least ehsjr now admits that MOVs "turns on, switching
from a very high resistance to a very low resistance". At
least he no longer claims MOVs absorb or suck up surges.
ehsjr even tries to claim that Polyphaser recommends plug-in
protectors. Polyphaser does not. Polyphaser is very
specific. The protector must be located distant from the
protection and as close to single point earth ground as is
possible. Plug-in protectors have all but no earth ground.
Therefore ehsjr denies the need for earthing.
Money wasted on plug-in protectors is better spend on
enhancing the earthing system. Protectors are only as
effective as their earth ground. Better earth grounds mean
more effective protectors. Plug-in protectors (and ehsjr)
simply pretend destructive surges don't seek earth ground.
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