i swear there is some kind of scam going on in pricing of whole house
suppressors, or secondary suppressors. I see unit pricing varying up
to 300% yesterday the lights dimmed on and off, while I heard a small
explosion in basement. The was a storm but no lightning heard.
My main suppressor connected to the air conditioner line blew. Blew
the breaker and now I need a new one. Device is scm plus, sepco. My 2
arc fault breakers also tripped. Everything working I know of.
Upgraded model about $50 from drill spot. Last one was$30 . Funny
thing, things often come directly from granger, with the discounted
pricing at drill spot.
It had a lifetime warranty whatever that means. I did not send
warranty in, but I'll check anyway.
Another thing, some really expensive units do look good on the specs.
I realize some units have multiple elements besides MOV's.
The price of suppression has gone up a lot recently because of
increased demand. There is so much more active suppression in Syria,
Libya, Bahrain. and other countries.
Active suppression uses 10 or 20 times the resources as does
suppression by intimidation.
Your evidence that strikes of 50,000 amps can make it to the
panel where his surge protector is located would be?
I say it's virtually impossible, because with that much energy
the surge is going to arc across long before it reaches the
surge protector. Meaning a surge protector capable of
20K amps is perfectly fine. To say it has to be capable of
upwards of 50,000 amps just means it's going to cost a lot
more. I'll bet 95% of the whole house surge protectors
installed don't have a rating of 50,000+ amps.
It's hard to predict institainous peak amps. It's not that. It's how
fast the double breaker will trip and shut open the short. The one
that blew was rated 100k amps. It was warranted along with damaged
equipment. I would have to go through the distributor to get
replacement. Also, the specs on this unit is 320 volt trip point which
is lower than most. I take it Thats good.
No breaker works for surges for so many reasons. For example, a
surge is done in microseconds. Breakers take milliseconds to trip.
Also, surge voltages increase as necessary to blow through anything
that might stop it. The open breaker would still conduct that surge
No protector must be damaged by a surge. 20,000 amp is too small;
can fail. If you had a surge exceeding 100,000 amps, then even your
primary surge protection system is missing or compromised. Every
protection layer is only defined by the one item that must always
exist. A picture demonstrates what creates and what must be
inspected in your primary surge protection system:
If you had a 100,000 surge, then a primary protection system is
missing or compromised.
Circuit breakers do not provide surge protection.
Newer breakers DO provide surge protection AND arccing detection! Jeez! You
can NOT discuss these events using ONLY current! Time has an immense effect
on it, along with a time vs surge plot to begin with. Then you need to know
the trip points, etc., and you are not talking about varistors or simple
Your breakers will open in a few microseconds? Nonsense. Its
millimeters gap will stop what three miles of sky could not?
Nonsense. Absolute nonsense. Nothing and I mean nothing stops or
blocks a surge. Protection is always about diverting energy to be
harmlessly absorbed in earth outside a building.
A failed protector is not effective protection. Effective
protection means nobody even knew a surge existed. Even the protector
remains functional. Means a surge was harmlessly diverted so that no
A minimal standard for a 'whole house' protector is 50,000 amps so
that even direct lightning strikes are diverted harmlessly to earth.
So that a protector remains functional. Nothing stops or blocks
surges. Nothing makes that energy magically disappear.
Kindly provide us with a data sheet that shows newer breakers
provide surge protection. Maybe we've all been missing something.
According to that theory, a new panel that's installed would have
40 surge protectors already in it by virtue of the new breakers.
Funny, I haven't seen any such thing. I have seen special
breakers that are sold as surge protectors that combine a breaker
with a surge protector, at a premium price. But that sure isn't
the typical new breaker that 99% of the world is installing. Or
what the OP apparently has, or what Tom is clearly referring to.
Nah, it's easy enough for you to look that up on your own. Informatoin is
abundant; do your own work. Your trollish attitude makes helping you not a
worthwhile effort. Just go to your favorte search engine; there are hundreds
of sites ranging from com to edu to gov and codes & RFCs.
And quit using html for posting.
I "come back" when I "come back". Period. The truth is there; all you have
to do is expend a very tiny amount of energy to find it. Well, probably a
LOT of energy for lazy children such as you.
See ya "when I get back"!
The "truth" from Twayne in this thread:
"Newer breakers DO provide surge protection..."
Surge protectors are not "simple MOV devices".
Trader is posting in html.
Still no support from Twayne for any, maybe because all are wrong.
The "truth" from the IEEE:
"the vast majority (>90%) of both hard-wired and plug-in protectors use
MOVs to perform the voltage-limiting function. In most AC protectors,
they are the only significant voltage limiters."
Among the "truths" from previous Twaye posts:
Power factor capacitor banks are not on utility poles (pictures provided
Edison circuits are not allowed.
Connecting 2 different circuits to a 2 pole breaker will delay the trip
A neutral can never also be used as a ground at a stove (code reference
already provided and Twayne link showed a bonding jumper)
Everything sold must be listed (UL, CSA, equivalent).
To test if a circuit is dead use the "ol' screwdriver test" (short with
My favorite sources of information on surges and surge protection are:
which is from the IEEE and is a little technical
which is from the NIST and is aimed at the general public.
The author of the NIST guide looked at the maximum likely surge on power
wires. It was based on a 100kA strike to a utility pole (primary wire)
behind a house in typical urban distribution. This is very near a worst
case. The surge on each hot power wire was 10,000A, and this is taken as
a practical maximum surge to protect against.
Since MOVs are used on almost all protectors and they deteriorate with
hits a higher rating is used for long life. The IEEE surge guide
suggests 20-70kA per wire, or 40-120kA in high lightning areas.
The author of the NIST guide has suggested that equipment can typically
withstand more like 800V, and that low let through voltage values cause
the protector to operate on surges that are not damaging to equipment,
which unnecessarily shortens the life of the protector. Low let through
voltage values have more to do with marketing.
Unless you are in a real high lightning area I have questions whether a
100kA protector should have failed. I would buy one from a major company
(never heard of yours). And I wouldn't buy based primarily on price.
I wonder what the failure mode of these MOVs actually is
and how it presents itself.
For example, I can invision a failure mode where even though
the device is rated at say 100K amps, repeated hits of say only 1K
amps might cause it to fail after about as many hits as one rated
only 20K amps. The 100K amp one would presumably survive
taking a single 50K amp hit that would probably destroy one
rated at only 20K.
In any case, I think the one the OP had served him well.
Since the surge took out not only the surge protector but
also the breaker, it must have been a substantial one. For
the small cost involved, I'd say it served well.
If you have a MOV rated 500 joules, one hit of 500J would put it at the
defined end of life, still functional but with the leakage current up
slightly. The normal failure mode is that with further hits the MOV will
start to conduct significantly at lower voltages until it conducts at
the normal line voltage, and then it will go into thermal runaway and be
a low resistance.
Failure likely to occur after a surge, and in any case a breaker would
trip long after the surge for a service panel protector. Internal
thermal protection has been required bu UL for plug-in protectors since
1998. Far as I know it is also required for service panel protectors.
For the 500J MOV, one 500J surge puts the MOV at end of life. It can
withstand multiple hits totaling 500J. If the individual hits are small,
like 1J, the cumulative rating is far higher than 500J. That is another
reason to get a large joule rating.
As explained in the IEEE surge guide, there is no UL defined joule
rating. Some manufacturers have used basically dishonest ratings which
puts honest manufacturers at a disadvantage. As a result, some
manufacturers no longer provide joule ratings. The surge current rating
is equivalent and is defined by UL.
The author of the NIST surge guide has written "In fact, the major cause
of [surge protector] failures is a temporary overvoltage, rather than an
unusually large surge." (Overvoltage is a far longer duration, like
crossed power lines.)
IMHO it shouldn't have taken out the breaker. The protector should have
been a more or less short circuit which the breaker should have handled.
The breaker is not opening on the surge, which was gone long before. And
if the OP didn't hear lightning, it was not likely very near.
Continuing in the tradition of wrong Twayne information.
According to the IEEE surge guide, a link to which was provided, "the
vast majority (>90%) of both hard-wired and plug-in protectors use MOVs
to perform the voltage-limiting function. In most AC protectors, they
are the only significant voltage limiters."
That is particularly true for service panel protectors.
You may have heard of the IEEE. It is the major association of
electrical and electronic engineers in the US and probably largest in
the world. The IEEE surge guide comes from the IEEE committee that works
with surge protection devices.
If you did minimal research you would find out how simple these devices are.
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