Lights Tripping MCB

[sl1210]

Hi guys,

Got to go back to a job tomorrow where the downstairs lights in property trip the mcb after 30 minutes or so. I was there briefly for an hour or so on friday and done an insulation resistance test on the cables going out from the fuseboard. I was getting a dead short from the line cable to the main earth bar with the lighting earth cable disconnected.

Any ideas on why this is. The feeds are at the switches, and i disconnected a couple of them and was still getting a bad reading. All I can think is the downstairs earths are connected at the 2 way light switch with the upstairs lights earth and this is what is coming back to the fuseboard. Will need to do more investigation for sure.

Any thoughts??

Cheers

 

[i=p/u]

hanging over your ears and walking aroun d like a distressed elephant, going should i do a runner or stick thinking cap on

 

[p11jor]

What readings were you getting?? Have you tried switching to low ohms to see if there actually is continuity between L-N-E!?

 

[sl1210]

no i didn't mate, i only done a brief ir test. was getting 0.00 ohms between line and earth, but like someone pointed out to me earlier i didn't remove the neutral from the bar, so that could be whats causing the low reading. i will have more time to work on it tomorrow so will totally remove the suspect cable and all lamps and re-test it.

 

[plugsandsparks]

Just pop a bigger MCB in apparently club3000 sell them now