It's to protect you from a surge after a blackout when the device turns on again. If you have something on and your house is struck by lightning, with or without a surge protector, you are fucked.

This post was edited by ROM on Oct 30 2015 10:17am

Ya mine goes out maybe 3 or 4 times a year

This post was edited by rc3mil on Oct 30 2015 12:52pm

Obviously, when everything repowers at once, current demand is maximum. So voltage is lowest. During power restoration, voltage slow climbs as everything powers on. This is hard on motorized appliances. And ideal for electronics.

But feelings justify myths such as "a surge during power restoration". Anyone can read numbers. Read the let-through voltage number on every box. For 120 volt protectors, a let-through voltage is 330 volts. That means voltage must well exceed 330 volts when power is restored - when everything is drawing maximum current and power. Even common sense says when power demand is greatest, then voltage drops ... does not increase from 120 volts to well over 330 volts. And yet that is what hearsay and wild speculation says. The myth is widely promoted by subjective and vague wording in sales brochures. Valid recommendations always include numbers.

Lightning far down a street is a direct strike incoming to every household appliance. Effective protectors are for destructive surges - lightning is one example. But plug-in protectors are so grossly undersized as to not protect from typically destructive surges ... such as lightning. So what does speculation say? "Nothing can protect from lightning." Speculation cannot say, "Those plug-in protector manufacturers lied".

Well, they did not lie. They only claim to protect from 'near zero' surges typically made irrelevant by protection already inside each appliances. Anyone can read numbers. Most who recommend 'near zero' protectors ignore 'near zero' numbers. Then *assume* nothing can protect from lightning.

Long before transistors existed, a telco CO (switching center) suffered about 100 surges with each storm (due to wires connected to all other buildings all over town). How often is your town without phone service for four days while they replace that $multi-million computer? Never? Because protection from direct lightning strikes has been routine for longer than any of us have existed. Telcos do not waste money on plug-in 'magic box' solutions. Instead, telcos always earth 'whole house' protectors. So that direct lightning strikes do not cause damage. Because that is what protectors (properly designed and earthed) are for. Protection from all destructive surges including lightning and some others that have even greater energy.

Again, how this stuff has been done is mostly unknown to consumers. Too many, instead, are educated by advertising, hearsay, and wild speculation. Protection from surges means a protector that connects low impedance (ie less than 10 feet) to single point earth ground. A concept, originally demonstrated by Franklin in 1752, is the basis of protection for today's household appliances.

A blackout (zero volts) is not a surge (thousands of amps and hundreds of thousands of joules). A 'whole house' protector (properly earthed) means nobody even knew a surge existed. Because all appliances and that protector do not fail. An effective solution, that costs tens of times less money, means protection even from multiple direct lightning strikes.

This post was edited by westom on Oct 30 2015 02:29pm

Yes. Ive said multiple times the same thing that your house is effectively grounded already and that power surges protectors are to protect you from power surges not lightning. So I have no idea what you keep going on about.

No you are ignoring what is written. Which ground? Digital ground on a motherboard is completely different from a computer's chassis ground, is different from a floating ground, is different from earth ground, is different from a bus bar ground in the breaker box, is different from safety ground in a receptacle ... etc.

The phrase made this obvious: low impedance (ie less than 10 feet). A plug-in protector is not earth grounded. Major electrical difference.

Some numbers. Let's say a plug-in protector tries to earth a tiny 100 amp surge. That ground wire is maybe less than 0.2 ohms resistance. And something like 120 ohms impedance. 100 amps times 120 ohms means that receptacle and protector is at something less than 12,000 volts. Where is the protection?

Earth ground. Low impedance (ie hardwire without any sharp bends). That is earth ground. A plug-in protector has all but no earth ground. Earthing - not the safety ground in a receptacle - is essential to protection.

Again, do not confuse safety (equipment) ground with earth ground. Each is electrically different. Therefore a 'whole house' protector can provide effective protection even if the house has only two wire receptacles. A plug-in protector cannot provide that protection even if the house has only three wire receptacles.

This post was edited by westom on Oct 31 2015 06:08am

So where do you think your houses ground leads to out of curiousity?

This post was edited by ROM on Oct 31 2015 06:12am

china

Which ground are you calling a house ground? And please discuss all grounds in terms of impedance. If you do not know what impedance is, then insufficient electrical knowledge exists to make any conclusions or recommendations.

Impedance was defined in layman terms. Low imipedance (ie less than 10 feet, no sharp wire bends, no wire splices, wires not inside metallic conduit, etc). To discuss any grounds (especially earth ground) means one can define why each compromises a low impedance ground.

Meanwhile, a protector is only as effective as its earth ground. That is clearly not the safety (equipment) ground found in wall receptacles. Unfortunately many have no idea why even human safety codes define equipment ground and earth ground as different. These are even discussed in separate sections of the code - because each is electrically different.

Why do you not know that? What part causes confusion? Do you understand a fundamental and relevant concept called single point earth ground? All four words have electrical significance. A protector is only as effective as its *earth* ground.

All of them. Where do they all lead?

Electricity at both ends of a wire is same? Classic ignorance of how electricity works. Makes one a victim of propaganda. This victim then spends tens or 100 times more money on near zero products.

Code is clear. Wall receptacle ground is not earth ground. Stated multiple times with reasons why and numbers. Being in total denial, it escapes you.

Chassis ground is different from motherboard digital ground, is different from floating ground, is different from analog ground, is different from a lightning rod ground, is different from receptacle ground, is different from breaker box ground, is different from water pipe ground, is different from earth ground. Many can be interconnected. And are electrically different. Somehow that reality escapes you.

Assuming all grounds are same, then a lightning rod can be connected directly to a computer's chassis. That will protect the structure and protect a computer - using your reasoning. Reality. Obviously a lightning rod must connect to earth ground. But according to you, a lightning rod can be earthed to a computer chassis. Basic electrical concepts escape you.


OP asked about surge protectors. Many are so easily manipulated as to even recommend a plug-in protector with its near zero joules. A $3 power strip with some ten cent protector parts routinely sells to naive consumers for $25. An equivalent Monster sold for $85 or $100. Some refuse to learn what a protector or UPS does. In this case, one even assumed safety and earth ground are same. Profits are obscene when the electrically naive are manipulated by hearsay, speculation and advertising.

Informed consumers earth one 'whole house' protector. If anything needs protection, then everything (even plug-in protectors and UPS) need that protection. Informed consumers locate this solution (proven by over 100 years of science and experience) in a breaker box or behind an electric meter. A protector is only as effective as its earth ground. That means a low impedance (ie less than 10 foot) connection to earthing electrodes. This proven solution costs about $1 per protected appliance. Best protection is also least expensive. So that even direct lightning strikes cause no damage.

This post was edited by westom on Nov 1 2015 08:45am