New fridge freezer needed water supply. Well toilet was in room above and 10mm was big enough so needed to cut channel down the wall. So two hacks saw blades with some spaces between and cut two lines down the plaster so I could bury pipe in wall. Everything was going according to plan, straight down the wall until level with light switch god it hurt and I woke up lying on the floor. I had not checked for cables I had never expected to find horizontal cables coming from switch although I knew it was permitted and I had a cable tracing machine but never bothered to use it.
Seems when extension was built the guy wiring had not gone up and around with strapers for two way light switch but had taken shortest route. Also no capping used so not felt anything with saw. It is now in mini trunking but same route. Also was surprised as getting such a belt I know it takes 40ms for the RCD to trip but never realised what a belt it could give you in that 40ms.
Lucky I suppose it was RCD protected had fitted RCD’s to protect kids never thought I would be testing it that way. Did stick RCD tester on supply and it did pass tripping at less than 30ma and at 5x it was tripping within the 40ms.
Worst was the embarrassment at getting a shock. I should have known better I have worked with electricity all my working live and I knew what the regulations said and that there could have been a cable there and still did not check.
Submitted by John B.