N
northernsparky
Upon doing a consumer unit upgrade + installation test today I came accross an unusal fault. I did all the usual dead tests and everything was fine, but when doing a Zs on the boiler/lighting/ring main circuits they all came back as reverse polarity. The first thing that came to mind was having the tails in the wrong way but the L+N tails were connected correctly from the meter to the DB (i tripple checked this as i have come accross meters which aren't the usual L-N-N-L connections plus i had already carried out a succeddful Ze test). The earth cable to/from the rod gave a great reading of 26 ohms although i admit it had been raining at the time of test. I checked the voltage at the boards main switch with the switch in the Off position and N-E i got a reading of 240v and 0v L-E; I also checked this at the meter, same results.
The strange thing is the fault seemed to fix itself, I didn't do anything other than remove the main fuse and then pop it back in place. Afterwards everything was working/reading fine.
Any ideas why this is as me and a colleague were stumped, dodgy meter maybe? I know it sometimes gives false readings if the batteries run low but they are fine. Any input is appreciated as i literally cant get my head around what happened.
The strange thing is the fault seemed to fix itself, I didn't do anything other than remove the main fuse and then pop it back in place. Afterwards everything was working/reading fine.
Any ideas why this is as me and a colleague were stumped, dodgy meter maybe? I know it sometimes gives false readings if the batteries run low but they are fine. Any input is appreciated as i literally cant get my head around what happened.
