Whole house surge protection?

[westom]

Surge protectors, as I pointed out, don't stop direct strikes. Surge protectors stop transients which are not direct strikes. A transient is an over voltage. Not direct current from lightning. We aren't talking about direct lightning strikes. We are talking about power surges due to transients that can come from but are not limited to the effects of atmospheric electrical activity, indirect strikes, and direct strikes to equipment near but not at the home. That's what surge protectors protect against!
Do you know what an MOV is?

OK. Your post says you have never designed this stuff nor read MOV datasheets. Let’s go back to basics. All of which apply to the OP's questions.

First, a surge is a current source; not a voltage. Voltage increases as necessary so that current will flow uninterrupted. Therefore anything that might stop a surge simply increases the voltage and still gets blown through. Protection means conducting current as short as possible to earth. No protector adjacent to any appliance can (or claims to) do that. Essential is a connection from every wire inside every incoming cable short (ie ‘less than 10 feet’) to single point earth ground.

Second, all appliances contain serious protection. Required in electronics even before an IBM PC existed. Today's electronics are even more robust. Surges too tiny to harm appliances will sometimes destroy a grossly undersized plug-in protector. That unacceptable failure gets the most naïve to recommend it.

Third, any protector that does not protect from a direct lightning strike is best called a profit center. Especially when effective protection from direct lightning strikes costs about $1 per protected appliance. Why do so many spend $25 or even $150 per for ineffective protectors? Much of what others have posted comes from advertising. Not from 100 years of well proven science. The Syscon is one examples of effective protection.

Fourth, where do hundreds of thousands of joules dissipate? A hundreds joule surge is so tiny as to not even damage the furnace, dimmer switches, clock radios, GFCIs, and other less robust devices. Effective ‘whole house’ solutions for tens or 100 times less money also make direct lightning strikes irrelevant. Numbers were posted earlier. Remain unchallenged by subjective attacks.

Does an MOV stop any surge? Of course not. The NIST (US government research agency that studies this stuff) says what the OP must know:
> A very important point to keep in mind is that your surge protector will work by
> diverting the surges to ground. The best surge protection in the world can be
> useless if grounding is not done properly.

I was kind to ineffective plug-in protectors. The NIST was blunter. An MOV protector located adjacent to an appliance is "useless". Is not earthed. Does not claim to protect from a typically destructive surge. Claims to protect from transients that typically cause no damage. A profit center defined by the NIST as “useless”.

Fifth, a caution to the OP. Those who recommend obscene profit and ineffective protector will not post manufacturer numeric specs. Will post profanity and subjective accusations without numbers (ie 50,000 amps, 'less than 10 feet'). Will not discuss wire impedance. Will avoid all discussion of earthing – the most critical component in every protection ‘system’. Plug-in manufacturers are not selling surge protection. It is a profit center to protect from transients that harm nothing.

MOVs located too far from earth ground do not protect from typically destructive surges. Telco switching center (CO) does not want those obscenely overpriced and "useless" protectors in their facilities. They need protection; not a scam. Telcos always – no exceptions - earth 'whole house' protectors. So that even direct lightning strikes (and other destructive surges) do not enter. So that no damage can occur.

Many techniques, long available for residential buildings, were pioneered in places such as munitions dumps. Where direct lightning strike must never cause damage. Only the least informed call these commercial devices. Any homeowner can purchase an effective protector in Lowes and Home Depot for less than $50. Numbers were also provided that define effective protection.

Protection is always – no exceptions - always about where energy dissipates. Then protection inside appliances is not overwhelmed. A protector is only as effective as the protection - single point earth ground. What is the most important component in every protection ‘system’? What is only discussed by those who actually know this stuff? Single point earth ground. Anyone recommending a protector without constantly discussing earth ground is promoting a scam. How blunt must the NIST be?

Responsible companies that provide protectors even for direct lightning strikes means one ‘whole house’ protector with the always required short (ie ‘less than 10 foot’) connection to single point earth ground. Protector that costs tens or 100 times less money per protected appliance. So that a connection to earth is lowest impedance (another concept not discussed by advertising myths). Numbers – the effective protector is at least 50,000 amps so that even direct lightning strikes cause no damage to any protector. OP's only useful answer costs about $1 per protected appliance. Comes from more responsible companies listed previously. And always makes that short (ie ‘lowest impedance) connection to single point earth ground.

A protector is only as effective as its earth ground. Which quickly identifies ineffective (ie plug-in) protectors as profit centers - not effective protection.

[95DRGT]

I had bought one of these for some power surge issues I had at another house- never had it installed and still NIB.

I paid several hundred for it if I remember- anyone interested?

TVS2HWA50X — SQUARE D — HWA TVSS, 208Y/120V, 3 ph, 4 wire, 50kA

TRANSIENT VOLTAGE SURGE SUPPRESSOR...

Peak Surge Current Rating 50 (ka)
Service Voltage 120/208 3Ø4W Wye +G

[BERNIE MOSFET]

I'm going to retract my profane dispensation and derogatory tone. That was immature. Let me thus try humility.

No, I do not work in lightning protection and I have not looked at MOV data sheets in detail. Currently seeking C62.41-1991 to supplement the reading I've done today. Regretting the IEEE membership lapse.

I've incorrectly characterized a 'swell' as a 'surge'; protecting against the latter protects against the former, but not vice versa. Energy dissipation is king here, and I know that.

[westom]

Currently seeking C62.41-1991 to supplement the reading I've done today. Regretting the IEEE membership lapse.

ANSI/IEEE C62.41 defines test waveforms. The 8/20 usec pulse is considered most similar to lightning. And therefore used to characterize MOVs in datasheets.

C62.41 is often hyped by manufacturers as if it proves surge protection. It does not. It is the waveforms used to test hardware. To test only one system component. And not the protection 'system'.

The other standard is UL1449. Again, many believe that measures surge protection. It also does not. UL is about human safety. In earlier versions, the protector could fail during testing and still be UL listed. Because its failure to provide effective surge protection did not threaten human life.

Critical to protection is the low impedance connection to earth. For example, a wire from utility, through the 'whole house' protector, to earth ground must not be inside metallic conduit. That conduit would only increase impedance. Not by much. But to surges, that little impedance increase drastically subverts protection.

Same applies to sharp wire bends. For example, a ground wire from breaker box to earth that goes up over the foundation and down to earth is too long and has too many sharp bends. Better protection means a ground wire through the foundation and down to earth. Separated from other non-grounding wires. Shorter. Eliminate those sharp bends. All to reduce wire impedance.

Wire impedance is also why telcos want their protectors up to 50 meter distant from electronics. That distance and increased impedance also increases protection.

All example of how to divert more energy harmlessly outside the building. And why some specs hyped in advertising actually say nothing useful.

The two important numbers are how much energy (current) a protector 'system' can earth during each surge. And how many surges the protector can earth before degrading. The first is mostly about better earthing and lower impedance connections. The second is mostly about protector spec numbers including its current rating.

[bud--]

The best information on surges and surge protection I have seen is at:
<http://www.mikeholt.com/files/PDF/LightningGuide_FINALpublishedversion_May051.pdf>
- "How to protect your house and its contents from lightning: IEEE guide for surge protection of equipment connected to AC power and communication circuits" published by the IEEE in 2005 (the IEEE is the major organization of electrical and electronic engineers in the US).
And also:
<http://www.nist.gov/public_affairs/practiceguides/surgesfnl.pdf>
- "NIST recommended practice guide: Surges Happen!: how to protect the appliances in your home" published by the US National Institute of Standards and Technology in 2001

The IEEE guide is aimed at those with some technical background (MOSFET should have no trouble with it - excellent source). The NIST guide is aimed at the unwashed masses.

OK. Your post says you have never designed this stuff nor read MOV datasheets. Let’s go back to basics. All of which apply to the OP's questions.

First, a surge is a current source; not a voltage. Voltage increases as necessary so that current will flow uninterrupted. Therefore anything that might stop a surge simply increases the voltage and still gets blown through. Protection means conducting current as short as possible to earth. No protector adjacent to any appliance can (or claims to) do that. Essential is a connection from every wire inside every incoming cable short (ie ‘less than 10 feet’) to single point earth ground.

As is explained in the IEEE surge guide, plug-in protectors do not work primarily by earthing. They limit the voltage on all wires going through the protector to the ground at the protector. The voltage between the wires going to the protected equipment is safe for the protected equipment. (Explanation starts pdf page 40.)

How can you possibly protect flying airplanes. Do they drag an earthing chain?

Second, all appliances contain serious protection. Required in electronics even before an IBM PC existed. Today's electronics are even more robust. Surges too tiny to harm appliances will sometimes destroy a grossly undersized plug-in protector. That unacceptable failure gets the most naïve to recommend it.

This is nonsense. Some equipment has surge protection included, some does not.

But without that "less than 10 feet" to earth how could "serious protection" be provided at equipment Westom?

Third, any protector that does not protect from a direct lightning strike is best called a profit center. Especially when effective protection from direct lightning strikes costs about $1 per protected appliance. Why do so many spend $25 or even $150 per for ineffective protectors? Much of what others have posted comes from advertising. Not from 100 years of well proven science. The Syscon is one examples of effective protection.

More nonsense.

Both the IEEE and NIST surge guides say plug-in protectors are effective. The IEEE surge guide has 2 examples of surge protection. Both use plug-in protectors.

Westom in on a crusade to save the universe from the scourge of plug-in protectors. He has been posting this nonsense for years

Fourth, where do hundreds of thousands of joules dissipate? A hundreds joule surge is so tiny as to not even damage the furnace, dimmer switches, clock radios, GFCIs, and other less robust devices.

The author of the NIST guide, an expert in the field, looked at the energy dissipated in a plug-in protector with surges as large as there is any reasonable probability of occurring coming in on power wires. The energy was surprisingly small. Plug-in protectors, wired correctly, are very likely to protect from very near lightning strikes. (I could explain further if anyone is interested.)

(Neither service panel or plug-in suppressors work by absorbing the surge.)

Effective ‘whole house’ solutions for tens or 100 times less money also make direct lightning strikes irrelevant. Numbers were posted earlier. Remain unchallenged by subjective attacks.

Service panel protectors are a good idea.
But from the NIST surge guide:
"Q - Will a surge protector installed at the service entrance be sufficient for the whole house?
A - There are two answers to than question: Yes for one-link appliances [electronic equipment], No for two-link appliances [equipment connected to power AND phone or cable or....]. Since most homes today have some kind of two-link appliances, the prudent answer to the question would be NO - but that does not mean that a surge protector installed at the service entrance is useless."

The NIST surge guide suggests that most equipment damage is from high voltage between power and phone or cable wires. A service panel protector, by itself, does not provide protection from this. (Example in the IEEE surge guide starting pdf page 40.)

Note that if you use a plug-in protector all interconnected equipment needs to be connected to the same protector External connections, like phone, also need to go through the protector. Connecting all wiring through the protector prevents damaging voltages between power and signal wires.

Does an MOV stop any surge? Of course not. The NIST (US government research agency that studies this stuff) says what the OP must know:
> A very important point to keep in mind is that your surge protector will work by
> diverting the surges to ground. The best surge protection in the world can be
> useless if grounding is not done properly.

What does the NIST guide actually say about plug-in suppressors?
They are "the easiest solution".
And "one effective solution is to have the consumer install" a multiport plug-in suppressor.

I was kind to ineffective plug-in protectors. The NIST was blunter. An MOV protector located adjacent to an appliance is "useless". Is not earthed. Does not claim to protect from a typically destructive surge. Claims to protect from transients that typically cause no damage. A profit center defined by the NIST as “useless”.

All complete nonsense.

Both the IEEE and NIST guides say plug-in protectors are effective.

Protection is always – no exceptions - always about where energy dissipates. Then protection inside appliances is not overwhelmed. A protector is only as effective as the protection - single point earth ground.

This is a religious belief for Westom. He is evangelical in spreading his belief, which is why he is here.

The IEEE surge guide explains that plug-in suppressors work primarily by limiting the voltage from wires to the ground at the suppressor. Plug-in protectors do not primarily work by earthing a surge.

Responsible companies that provide protectors even for direct lightning strikes means one ‘whole house’ protector with the always required short (ie ‘less than 10 foot’) connection to single point earth ground.

All Westom's "responsible companies" except SquareD make plug-in suppressors and say they are effective. SquareD says for their "best" service panel suppressor "electronic equipment may need additional protection by installing plug-in [protectors] at the point of use."

Protector that costs tens or 100 times less money per protected appliance. So that a connection to earth is lowest impedance (another concept not discussed by advertising myths). Numbers – the effective protector is at least 50,000 amps so that even direct lightning strikes cause no damage to any protector.

For most homes the IEEE surge guide suggests 20,000A to 70,000 A (per hot wire). The maximum that has any reasonable probability of occurring, even with a very strong, very near lighting strike is 10,000 A. Protectors are sized larger to give a long life. Service panel protectors can protect from very near strikes (but do not necessarily provide complete protection).

Neither service panel or plug-in protectors will protect from a direct lighting strike to the building. For that you need lightning rods.

For real science read the NIST and IEEE surge guides. Both say plug-in protectors are effective.

Then look at the sources that agree with Westom that plug-in protectors are not effective. There are none.

What I have written is consistent with both surge guides (and much comes directly from the guides).


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Service panel suppressors are of 2 kinds. One is like a circuit breaker and plugs onto the service bus. You need breaker space to install it. The other mounts outside the panel through a knockout. I think for most of them the wires can attach to existing breakers. The protectors contain 3 MOVs, connected from each H-N, and H-H. MOVs limit the voltage between its terminals.

UPSs of the type usually used provide no surge protection. The same surge protection as in a plug-in protectors is commonly added. Higher ratings are easier to find in a plug-in protector. Any surge protector (in the US) should be listed under UL1449 (some UPSs aren’t).

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Contrary to Westom's claims, UL tests hits a protector with a series of surges. The protector has to survive intact and functional. For later tests, which are intended to possibly cause failure, the protector can fail safely.


bud--