Environmental Potentials whole house surge protection, can I get your opinions?

The only thing that would totally protect a home from a direct lightning strike would be to totally enclose it inside of an earth grounded Faraday Cage. Though that could prove to be quite expensive.....

Or maybe hang a really big sign on the outside of the house where the electrical service and earth connection earth grounding electrode is located. Wordage something like, "Lightning Strike Here Only" with a big arrow pointing at the electrical service. Even then I doubt the best grounding electrode to earth soil resistance of 1 ohm could save all the electronics inside the house.

Of course there is no guarantee lightning is intelligent and can read the sign or would even care what the sign says.
What if the lightning decided to hit that power roof vent unit on the roof instead of the electrical service?

Or maybe just the branch circuit wiring that is running all over the place in the attic space on top of the ceiling joists?

http://stormhighway.com/what_happens_when_lightning_strikes_a_house.php

If there is real world testing documentation, conducted by a recognized 3rd party testing laboratory, that proves a whole house SPD in conjunction with an average to good low resistance earth soil to grounding electrode of, say, 5 ohms or less, then please produce the documentation/white paper.

jea482,247 posts

The only thing that would totally protect a home from a direct lightning strike would be to totally enclose it inside of an earth grounded Faraday Cage. Though that could prove to be quite expensive ... If there is real world testing documentation, conducted by a recognized 3rd party testing laboratory, that proves a whole house SPD in conjunction with an average to good low resistance earth soil to grounding electrode of, say, 5 ohms or less, then please produce the documentation/white paper.

I’m not sure what your point is. No safety device provides 100 percent protection against all threats under every circumstance every time. Life doesn’t work that way, but that doesn’t stop people from using seatbelts, does it?

Regardless, your statement below is false:

You won’t find any SPD that will protect your home from a direct lightning strike.

As I explained to you, Type 1 devices such as this are quite effective. But if you want an absolute, iron-clad, no-fault guarantee, you’re not going to find that in this realm.

westom said:

Impedance is taught to engineers; but not to electricians. Electricians are taught code - for human safety. Transistor (appliance) safety means doing things that both meet and exceed code. Connection to (ie impedance) and quality of single point earth ground define protection even from direct lightning strikes. As we engineers did decades ago.

Really?
Where did you hear that about electricians? And I don’t mean residential wireman. Not meant to demean a residential wireman but they do not have the training or the on job experience that a journeyman (Class A Licensed) electrician has that works in the commercial and or industrial electrical industry.

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westom said:

Fuses do what they are designed to do. Something completely different and invented by wild speculation is a "fuse myth". Fuses protect human life AFTER hardware damage occurs. So that fire and electrocution does not happen. Only myths and wild speculation claim a fuse will protect hardware. That myth is invented by many who ignore manufacturer specification numbers.

A fuse does not directly protect human life. That is not its’ intended purpose.
As for NEC its’ purpose is to provide overcurrent protection, short circuit protection, as well as ground fault circuit protection for branch circuit wiring, feeders, ungrounded hot busing of panelboards, switch gear, as well as disconnect switches. There are others...They also are used in protecting power transformers from being overloaded while providing short circuit protection as well as short circuit ground fault protection. They also provide short circuit protection for larger than small fractional HP motors. See NEC Article 430 as well as Article 440.

A fuse will not protect a person from electrical shock or electrocution. I have known of electricians that were electrocuted and the power was still live when they found them dead. Some were still connected to the live power. Fuses could care less what the connected load is as long as it does not exceed it’s ampere rating for a duration that will melt the internal fuse link breaking the circuit.

Fuses found in electronic equipment, if sized properly, can protect the equipment from severe damage.
First hand example. A few years ago a 6550 power tube shorted in my ARC power amp. The shorted tube caused an overload in the HV, high voltage, DC power supply which caused the HV secondary winding of the power transformer to overload which caused the primary winding of the transformer to overload which exceeded the ampere rating of the AC line fuse, protecting the primary and secondary winding of the transformer, causing the fuse to blow open. Imagine what could have happened if the fuse was bypassed....
No other damage was caused to anything else inside the amp. The line fuse did what it was designed to do. It did indeed protect the equipment.
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Equipment fuses are not designed to protect you from electrocution, but the safety ground (that nuisance that audiophiles love to remove) and Ground Fault Current Interrupters are (like the outlets in your kitchen, I hope).

GFCI trip at around 5 mA. That’s MILLI-amperes, while a circuit breaker is around 15 A, and typical audio gear in the range of 1-10 Amps (typical, not exhaustive.

Let’s say a tube preamp has a 1 Amp fuse, that’s 20 x more current than would trip a GFCI. The figure I read most often is that it is estimated that that about 10 mA of current is lethal under ideally fatal conditions.

Preventing damage from lightning is a difficult thing, in no small part due to the speed caused by the sudden arcing. Parallel systems require time to activate, series do not. Parallel systems rely on the drain location being low impedance, series do not.

An EMI pulse from a lightning (or nuclear) strike can induce current in the cables in the walls themselves, it does not necessarily telegraph in from the transformers. Series devices present a very high, always on, impedance to these rapid pulses, so the majority of the voltage will be presented at the blocking coil, instead of your precious gear.

There are also other sources of induced surges. Cable TV, phone and network wiring. Then there is stupid stuff like wind gusts on an antenna. I’ve suffered several losses of Satellite TV receivers not from lightning but from wind, I assume caused by static electricity developing across the broad antenna surface... and zap! Solved eventually by using a professional, bullkhead mounted surge arrester! :)

Best,


Erik

cleeds,

From your Link,

Type 1 Surge Protective Devices are typically mounted on the line side of the main service entrance (between the utility pole and where your electricity enters your service panel). They protect against external surges caused by lightning or utility capacitor bank switching.

That is not proof that the SPD will protect the electronics used in equipment or appliances found inside the house from a direct lightning hit to the electrical service of the house, or, if it hits some other part of the house first.

A direct lightning strike/stroke to the electrical service of a house IS NOT considered an "electrical surge" is it?  What is the average voltage and current  a direct lightning strike/stoke could deliver to the electrical meter socket/meter/SPD mounted on the outside of a house? 

The power of lightning....
https://www.youtube.com/watch?v=sKNgqPQIwnU
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