I can read your query two ways !

1) is your colleague suggesting it would be a good idea if this were the case?

If so perhaps for some of the more crumbly infrastructure it would be a good idea.

2) If the suggestion is that it is already required, I'm pretty sure it isn't, at least for most substations in the UK.

I  also assume we are only talking about the non intrusive ultrasonic 'listening' for sizzling and so forth and not anything more time consuming like current clamps on earth leads and spike counting that get used when problems have been seen before or where a failure would be catastrophic ?

Mike

Hi Mike, point 2 and yes, none intrusive. 

I'm not aware of it being a national requirement, There may be local policies or procedures for specific higher risk situations or locations perhaps.

I''d give it a day or two in case I am wrong ;-) - Its not really my area, I  only get let into such places when accompanied.

Mike.