Hi all,
In Feb I was asked to fit a new bathroom light and extractor fan in a bathroom. There was already a supply for bathroom light so all I had to do was take a feed for fan isolator. I fitted the light and fan did the nessercary tests and filled in certificate everyone happy. The installation is a TNS with all circuits protected by individual single pole rcbos. At the beginning of May I got a call saying that the upstairs lights Rcbo( which included the bathroom lights/fan) and the cooker rcbo had tripped on two occasions together, once a week apart and then 4 days. I went back to property stripped back and disconnected what I had done and cooker circuit, did Ir test at 230 then 500v. I also did a ramp test with all accessories disconnected and again with everything reconnected to see if any earth leakage. I also did IR test for rest of circuits as a whole. I could not find anything obvious so asked customer to keep a log of times of tripping to see if any pattern emerged. I asked him to contact me when it trips agin and I would come back over.
I didn't hear anything for almost three weeks, so I emailed the customer and he said nothing had tripped. Then two days later I got an email saying that the upstairs lights had tripped again and the downstairs sockets rcbo had also tripped during the night.
I am going back tues armed with clamp meter and was wondering if anyone has any advice or suggestions. There always seem to be two rcbos tripping together at same time. The upstairs light and another rcbo, not even the same ones. If there was a neutral to earth fault wouldn't the individual rcbo trip first as the fault would go through rcbo first before the link to the neutral bar? There also only one outside light which I have checked for damaged or water ingress
Thanks
In Feb I was asked to fit a new bathroom light and extractor fan in a bathroom. There was already a supply for bathroom light so all I had to do was take a feed for fan isolator. I fitted the light and fan did the nessercary tests and filled in certificate everyone happy. The installation is a TNS with all circuits protected by individual single pole rcbos. At the beginning of May I got a call saying that the upstairs lights Rcbo( which included the bathroom lights/fan) and the cooker rcbo had tripped on two occasions together, once a week apart and then 4 days. I went back to property stripped back and disconnected what I had done and cooker circuit, did Ir test at 230 then 500v. I also did a ramp test with all accessories disconnected and again with everything reconnected to see if any earth leakage. I also did IR test for rest of circuits as a whole. I could not find anything obvious so asked customer to keep a log of times of tripping to see if any pattern emerged. I asked him to contact me when it trips agin and I would come back over.
I didn't hear anything for almost three weeks, so I emailed the customer and he said nothing had tripped. Then two days later I got an email saying that the upstairs lights had tripped again and the downstairs sockets rcbo had also tripped during the night.
I am going back tues armed with clamp meter and was wondering if anyone has any advice or suggestions. There always seem to be two rcbos tripping together at same time. The upstairs light and another rcbo, not even the same ones. If there was a neutral to earth fault wouldn't the individual rcbo trip first as the fault would go through rcbo first before the link to the neutral bar? There also only one outside light which I have checked for damaged or water ingress
Thanks