On Jun 19, 8:20 pm, "David" wrote:
A MOV is somewhat like two back-to-back Zener diodes. It is
a voltage clamp. You do not pass energy to ground, you pass
current to ground just like you do with any load. The energy
is totally dissipated in the MOV.

Now do the numbers. How does that hundred joule MOV absorb energy
that is hundreds of thousands of joules? You are reciting the myths
promoted by plug-in protectors.

For example, how to get the protector to last longer? Increase its
joules rating. Then the entire protector absorbs "LESS" energy.
Protector that absorbs a surge is the urban myth promoted by those who
never learned this stuff. This 100 years old technology.

So that energy dissipates harmlessly in earth - not inside the
building - the protector must make a short ('less than 10 foot')
connection to single point earth ground. No protector is protection.
None. A protector is only a connecting device. Either it connects a
20,000 amp surge harmlessly to earth. Or it does nothing. A
protector is only as effective as its earth ground - which those
educated by advertising never learn.