Lightning Arrestor Rating

You can, if you don't care that lightning or other surges will damage or destroy your electrical equipment and system. But if you want protection from lightning, you need to have a properly rated arrester, so that it diverts the surge to ground at a voltage level below the limits of what your equipment can withstand. Hire a qualified engineer to evaluate your system and specify the correct arrester rating for your needs.

If no, why?

Would you protect a 10A circuit with a 100A fuse? Best to get the correctly-rated surge arrestor otherwise it won't provide the protection required.

Are you filthily wealthy? Why then would you use a costly 198kV arrestor for a 33kV system?

Dear All,

Let me put it this way. I have a 220KV/33KV transformer for the power distribution within my plant. However, the 33KV CICO panel which I've ordered shall take some more time and so I'd to plan for an alternative. So, we have decided to use one 220KV outdoor spare bay for my 33KV side protection. It includes a 220KV breaker, a 198KV LA and the CTs rated for my LV current suitably. Now pls tell me whether I can use my 198KV LA for my purpose or I need to arrange specifically for an LA of suitable rating?

Pls answer with the technical drawbacks of using my 198KV LA for the purpose.

Using a spare 220kV bay to temporarily feed a 33kV circuit is an inventive idea, and should work for you. However, as I said before, the 198kV LA will NOT protect your 33kV rated equipment. You should temporarily install properly rated arresters for the duration of your temporary feed. You could even leave the 198kV units in place too - they won't hurt anything, but they won't help. The "technical drawbacks" of not having the right rating LAs: If you get a lightning strike or other transient high-energy surge, your cables could fail, your downstream transformer could go "boom!" or damage to other 33kV rated equipment can and will take place. It's your risk!

<...Pls answer with the technical drawbacks of using my 198KV LA for the purpose....>

Simples: It won't 'king work properly.