Replace outside light - breakers tripping

Mr.Stu · 12 Mar 2014 at 12:15

Not to be deterred by my previous failure I thought I would replace the outside lights with some up/down lighters to refresh the outside of the house.

Unfortunately I've hit another issue, and before I lose man points and phone the electrician, I'd like to check with your folks that I'm not missing anything obvious.

Before:

Everything working 100%

After

Replaced one light. This involved screwing new mounting holes for the up/down lighter and screwing the wires in to the new choc-block.

It worked for a few minutes, then the RCB tripped, taking out all of the sockets downstairs as well.

Now

To try and trace back my steps, I have removed the light, fitting, screws, just the bare wires are sticking out. If I turn on the smaller breaker for the downstairs lighting loop, it still trips the RCB?!

Any ideas?

Mr.Stu · 12 Mar 2014 at 12:32

Not drill, but yeah, new screws in different place (only wood) - if I've hit a cable it's not the one supplying the light as that can be easily seen from behind (inside the porch).

Mr.Stu · 12 Mar 2014 at 12:44

Power off to where?

Mr.Stu · 12 Mar 2014 at 13:04

I've not tried powering off the entire house/board. Is it just a case of power off the large switch, try the light-loop-B6 breaker again, and see if it trips the RCB? What will this show/prove?

Is it common for the actual breaker themselves to become faulty?

Cheers

Mr.Stu · 12 Mar 2014 at 13:05

I cut the wires fresh and stripped them back, did not help.

Mr.Stu · 12 Mar 2014 at 14:47

Ok

I removed the entire wiring to the outside lights, so whatever I touched today is completely disconnected.

Still tripping.

Could I have killed the breaker in the fusebox by tripping it so many times?

Mr.Stu · 12 Mar 2014 at 14:49

For reference this is the mess inside the junction (That is still connected, but was not touched)

Mr.Stu · 12 Mar 2014 at 17:45

It is tripping regardless of switch positions on downstairs loop.

Called the leccy, he came out and fitted a new breaker for the lighting loop - it fixed the problem, but as he was walking out the door it tripped again.

He isolated the circuit further removing the junction box entirely - problem persists.

Seems the fault is indeed unrelated to the work I did, but elsewhere on the downstairs neutral loop that spans four rooms.

He is coming back in the morning to isolate and test each light.

What a nightmare - all I wanted to do was replace my porch lights!

Mr.Stu · 12 Mar 2014 at 17:52

Yup, currently disconnected and still tripping immediately when I enable the MCB for downstairs lighting.

Electrician said it could be a weakness exposed elsewhere in the circuit when fitting the new light. I find it hard to swallow, as you say, its a massive coincidence - but still - we have completely removed that section of the wiring I worked on - so not sure what else to try now.

Mr.Stu · 12 Mar 2014 at 18:43

Not sure, but it looks like this at the moment....

Mr.Stu · 13 Mar 2014 at 15:57

Thanks for the pointers folks.

This somehow turned out to be related to a fault on the wiring to wall lights in the dining room. We've isolated them and will box them off when re-plastering the room which is happening soon anyway.

Took the leccy ages to find the fault, but lights are now up.