On Jun 20, 3:54*pm, mike wrote:
I've been following this thread, and I got to wondering are there any
accepted methods to tell if asurgearrestor setup is still usable as
such?

Assuming they are MOV based, read MOV datasheets to learn how MOVs
work and obtain relevenant numbers for the test. Perform a 1
milliamp test to confirm these numbers on that protector. This test
is described in some manufacturer application notes.

The test only confirms the protector can conduct. Does not say
anything about what makes a protector effective - the earth ground and
how it connects to earth. The best surge protection in the world can
be useless if grounding is not done properly.