Surge surpressors

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.

Greg

Reply to
Gz
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What I meant, some really expensive units do NOT look all that great on specs.

Greg

Reply to
Gz

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.

Reply to
micky

Andy comments:

When I need surge surpression.... I just try to think of baseball scores......

Andy in Eureka, Texas

Reply to
Andy

The ERA for any sufficient 'whole house' protector starts at 50,000 amps. Then even Zeus will not hit it out of the park.

Reply to
westom

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.
Reply to
trader4

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.

Greg

Reply to
Gz

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 electricity.

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:

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If you had a 100,000 surge, then a primary protection system is missing or compromised.

Circuit breakers do not provide surge protection.

Reply to
westom

My favorite sources of information on surges and surge protection are:

which is from the IEEE and is a little technical and

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.
Reply to
bud--

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.

Reply to
trader4

You're forgetting at least one important spec: How long that suppression current can be withstood by the device and what its expected duration might be. There certainly are such surge supressors available but talking about only one spec out of many, all variable, is sayiing absolutely nothing, nada, zip. In addition to that, there is surge suppression in the xfmr out on the pole so unless a strike hits very close to the bldg connection, it's going to still benefit from that clamping action. You guys all need to do some research of at least 101 calibre information.

HTH,

Twayne`

Reply to
Twayne

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 inactive cktry.

HTH,

Twayne`

Reply to
Twayne

You are NOT talking simple MOV devices in the area this discussion has gone into. There is much more to it. Do some research and then research the more complex devices these might be.

Reply to
Twayne

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 breakers tripped.

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.

Reply to
westom

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.
Reply to
trader4

According to whom? Kindly provide a reference that the typical whole house surge protector is not in fact based on MOVs.

Reply to
trader4

The issue of how long that suppression current can be withstood is rarely specd directly in the major whole house surge suppressor data sheets that I have seen. It is spec'd indirectly as the amount of energy in joules that it can handle. Typically they spec amps, joules and clamping voltage. And as amps go up, so does the joule rating. Which is not to say you won't see variation, but I think it would be unusual to find a device rated at say 40K amps from any of the major manufacturers that is woefully inadequate with regard to the joule rating compared to other 40K devices from other major manufacturers.

In other words, you are right there is more to it than amps, but if you bought just on the amp spec from the major manufacturers you would not be left with a totally inadequate surge protector.

Which means what? That we don;t need a surge protector? That we need a smaller one?

Speak for yourself. Nothing you've brought up in this thread so far is new to Bud, Tom or I.

Reply to
trader4

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.

Reply to
bud--

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.

Reply to
Twayne

m,

In other words, as Bud and I expected, you have nothing to back up your nonsense. And it took you a week and a half to come back and make more of an ass of yourself.

Reply to
trader4

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