On Tue, 19 Mar 2019 17:54:00 +0000, Clive Arthur
wrote:

On 19/03/2019 17:30, Scott wrote:
Not my finest moment, but I was carrying out a minor electrical job.
As I was wiping up the dust with a damp cloth, I came into contact
with a live part of a different circuit that I did not know about.

My question is why the RCBO did not trip. I only received a slight
tingle but I thought RCDs and RCBOs were supposed to detect any
leakage to earth.

A slight tingle is very probably much less than 30mA, so a 30mA RCD
won't trip - 1mA is often taken to be the smallest you can feel.

30mA would be quite painful, though with an RCD not for long, and you're
far more likely to injure yourself when you fall off the ladder or drop
the circular saw on your foot than from the shock itself.

Thanks. That explains it.