varistor help needed

[michael nikolaou]

Hi to newsgroup

I have a problem that needs some assistance.
I have a 220V 50 HZ industrial relay at 20 amps.
The arming inductor is rated at 6 watts . I need to
use a varistor as surge arrester but i don't know to
calculate the energy that will be produced and the
varistor ratings . As i understand it must be rated for
275 VAC rms.But how is the current capability related
and the energy (joules) that it is rated .Is there a rule
of thumb for such calculations ?.
Any help would be apprecciated .

 

[[email protected]]

Hi to newsgroup

I have a problem that needs some assistance.
I have a 220V 50 HZ industrial relay at 20 amps.
The arming inductor  is rated at 6 watts . I need to
use a varistor as surge arrester but i don't know to
calculate the energy that will be produced and the
varistor ratings . As i understand it must be rated for
275 VAC rms.But how is the current capability related
and the energy (joules) that it is rated .Is there a rule
of thumb for such calculations ?.
Any help would be apprecciated .

It is not crystal clear that you understand the terms you are using.
Or maybe it's me....