w_tom wrote:
Joules are a measure of energy. But that is all irrelevant
to MOVs. For MOVs, joules defines life expectancy. More
specifically, how fast the MOV will degrade. The manufacturer
defines MOV failure mode: degradation - not vaporization.
Joules is the parameter that defines that life expectancy.

Tony Hwang wrote:

Hi,
Joule is not a measurement of power it is unit of energy.
Let me put it this way, if you get a direct hit nothing uch will
work.
Telling from real world experience.
And real protector for whole house costs a lot. And surge current
is much faster than breaker or fuse.
Tony

For the record, Power is energy over an amount of time. Its measured in
Watts which is the same as one Joule per second.

--
Respectfully,


CL Gilbert