While I agree that surge protectors are not very effective, its mostly
because they are poor quality devices. You can find a good quality
surge protector. You need to know what size surge you intend to
protect. A device can call itself surge protector if its only
protecting a surge the size of say, the vacuum cleaner motor. Or even less.


w_tom wrote:
You are assuming the MOV is the protection. How? What will
that MOV do? Absorb the surge? Block it? Since that MOV is
so far from earth ground, AND because it is so close to
transistors, then it provides the same ineffective protection
provided by power strips.

Furthermore, if those $0.10 parts were so effective, then
they are already inside the appliance. Anything that is
effective on an appliance power cord is already inside the
electronics.

How do effectively protected sites do it? Let's take a
telephone Central Office computer - connected to overhead
wires everywhere in town. They put the connector directly on
earth ground AND up to 50 meters distant from the computer.


What do you mean here? They use 2 ground lines? There must be a + and
-. One can not be grounded. Please explain what 'connector' is?


No earth ground means no effective protection. Those MOVs
inside a plug-in box or inside the wall receptacle are not
effective.

Don't get mesmerized thinking the MOVs are protection.
Protection can be installed with a copper wire or it can be
installed with an MOV. The MOV only acts like a wire during a
limited time - during the transient. But if wire or MOV does
not make that 'less than 10 foot' connection to earth, then no
effective protection. Protection is the earth ground. MOVs
is only to connect a surge to earth ground. No earth ground?
Then no effective protection no matter how many joules are
installed.


The MOV just needs as good or better path to ground than the device it
is protecting. The distance is irrelevant.


--
Respectfully,


CL Gilbert