Surge Counter as TOV Detector

----- Email from a an Arrester User ------
Jonathan
My project has a 230 KV line which may develop a TOV of @350 KV in the event of multiple failure of protecting equipment and in that event, to prevent transformer of 230/6.9 KV to see this high TOV, it is being proposed to provide a scheme which has surge arrestor and counter contact to be used as input to protection relay with time delay to differentiate lightening surge and TOV ( i guess) to trip transformer breaker.

My question-
1) Have you come across such scheme ever?
2) To your opinion, is this scheme good enough to protect transformer against line TOV.
3) Your opinion other than above questions.

Regards
P.S., Systems Engineer

Greetings PS
I believe there is a fundamental misconception in this scheme.
Surge counters do not sense TOV conditions. A TOV is not considered a surge as far as I understand it. The Surge counters I have worked with are usually sensitive only down to a few hundred amps. TOV conditions may force 5-20 amps through an arrester but that’s all.

If they did sense this low current, this may be a nice scheme.

I believe the only real solution is to use a voltage sensor of some type to trigger the protection scheme.

Good Luck
Jon