non tripping trip

[markr1]

hi i have just tested a fuse board that i fitted. The property has a TT system with a ze of 176 mohms and a pfc of 1.10ka yet on doing a trip test on the 30ma rcd it will not trip out on x1 or x5 ! I have changed the rcd for new to see if i had a faulty bit of kit but the new one didnt trip either just wondered if anyone had any ideas ?

[markr1]

sorry people it was a typing error it is ohms not mohms

[Jimbo]

Hi, does the meter trip on a normal TNS/TNCS system? Regards Jim

[markr1]

hi jim cheers for replying ! I have sourced the problem now it was a fault on a lighting circuit that for some unknown reason stopped the rcd tripping out on a trip test it is now behaving as it should and i am a happier man many thanks again mark ! :D

[daveparry]

Mark, I know you have sorted it now but what was the actual problem? I can't think what fault on the lighting circuit would have stopped the rcd from tripping,
regards,
Dave.