I really tried to come up with a post that wasn't a line-by-line because I know they are not as readable... but there's so much in here that really rebuffs itself.
Since a surge is typically once every seven years,
This is a good example. Where is this statistic from? I suspect it's simply invented.
Recommend only because salesmen (and urban myth purveyors) claim protectors wear out.
Yes, everything wears out.
Or this immediate self-contradiction that wearing out is a myth followed by admitting that things wear out. The followup
Switches are typically rated for 100,000 cycles. Why is that number so important? Because it means power cycling 8 times every day for 34 years. So, do switches wear out? Yes. What does hearsay claim? No. Because a 34 year failure rate says switches do not fail.
There's no one advocating replacing switches. We are talking about MOVs, which have a definate life-time. Many (most) of us have had surge supressors with MOV indicators. I'd bet most all of us have seen those indicators fail.
Of course he's railing against a hypothetical person that doesn't exist. Since no one has advocated yearly replacement of surge supressors, it's a straw man.
Earthing one 'whole house' protector on both units means each protector only adds protection to other units. What happens if your tenant uses a plug-in protector? Scary pictures posted some ten posts ago demonstrate another reason why you want a 'whole house' protector installed. Plug-in protectors need protection only provided by an earthed 'whole house' protector.
The only valid point here is that a MOV makes heat. The more power moving through it, the more heat it makes. It is possible for a heating MOV to melt / set fire to the surrounding material.
I suspect that places like consumer reports (likely UL) and google will provide information as to which surge supressors are prone to catching fire to themselves or things around them.
Mind you, this is not a problem restricted to local MOVs. Whole-House units also produce heat and can heat to failure. However, these are more often in steel on concrete and so unlikely to start a fire.
Earthing (not a protector) provides protection. Better protection is achieved by redirecting money away from plug-in protectors and towards upgraded earthing. Earthing – must be single point. Everything earthed to the same electrode.
Of course this completly ignores that no amount of earth is useful without a path to that earth.
Shall we run the AC straight to the ground? In that case our meter will spin wildly, no power will reach our appliances, and likely the transformer on the poll will fail.
So no. What we need is a bridge between the AC and the ground that allows excess power (surges) to go to the ground line while not providing a path of least resistance to normal power.
The most common such bridge is a MOV, a type of vari-resistor. You can find these on whole-house and plug-in protectors.
Contrary to popular myth, plug-in protectors do not provide a second layer (despite what Rickerst71 has posted). Each protection layer is defined by the only item that creates protection - earth ground.
Either semantics or simply wrong.
Obviously a surge which occurs inside the wiring may not find the shortest path to be through an external ground.
As an example: I once plugged a floppy power cable in upside down. The house surge supressor didn't help and neither did the plug-in protector. Why? Because the short didn't cross either. The power-supply blew, and the motherboard was never quite right again.
Why is this not often known? Who will spend money to advertise what really provides protection? How do they profit by telling the truth? An overwhelming majority only hear myths and half truths about magic boxes rather than learn about what makes any protector effective - earth ground.
This poster used to cite the millitary and the like. I'm waiting for him to do it again (the millitary uses both types of supressors). Go find the old thread in the surge supression area. He's basically cut-n-paste.
