- Reaction score
- 67,272
As far as I'm concerned mate, it couldn't be simpler. I do a live Zs on socket and cooker circuits simply because I can plug the test lead directly into the socket outlets without opening the enclosure. Lights and water heaters etc I do dead and by calculation simply because it is illegal to work on or near live conductors (EWR1989 regulation 14). I know on the NICEIC schedules it asks for a measured value but I would argue this point with anyone from the NIC. The law is the law and it is simply wrong to encourage anyone to break the law. Its black and white for me, they get calculated values and thats that!
so, by that reckoning, a scuba diver shouldn't work in water, he might drown, a pilot should fly his plane just on the runway in case it falls from the sky, a miner should only pick up coal if it's lying on top of the ground in case he gets buried, a gas fitter should calculate his pressure and leaks with the gas supply turned off, in case he gasses himself. .
lts take it further. why bother to use MFTs to measure R1+R2? might set it to 1000V IR by mistake and get zapped. let's measure the cable length with a tape measure, then use tables to calculate the resistance. OH NO, H&S have banned tape measures, sharp edges can cut your head off.