upstairs light circuit tripping after laying loft floor

[raikky]

ill be completely honest and tell you everything. ive been laying loft flooring in the attic. its been going fine until this evening. after laying down another row i called it a night. the mrs came up and switched on our bedroom light and the upstairs light circuit tripped out. it only trips when we switch on our bedroom light. the other upstairs rooms are not effected.

now for the 'how not to lay loft panels' part. i was working right above our bedroom. i can see the cable entry point for our lights. this runs over 4 joists. when i was laying the panels the panel wouldnt fit in. i completely forgot about the cable and i was ramming the floor panel right into the other panel with the cable in between. after that i tucked the cable under the panels (it would just fit under) and put the other panels on.

so yes that is how not to install flooring. i will lift all the panels i layed down tmoz. i doubt ive drilled through a cable but i will check tmoz. i can only think of it being 2 things. either the cable is lose at the light (i didnt yank it and there was plenty of slack). or most likely i have damaged the cable. are these cables easily damaged inside.i suppose i thought if i did that everything would trip straight away? will prob have to get a spark out

any way to check if a cable is damaged on the inside?

 

[delmel]

Certainly bet you have either damaged the cable or pulled a cable out creating a short. You need to find the short, it should not be to difficult given you are sure you know the cable you had an issue with. Just remember it may actually be a cable you never noticed and nailed or screwed through creating a short when the live is switched.

 

[deadshort]

Hi, yes I would think you've damaged the cable

You will have to repair it with a maintainance free joint box.

Regards,

DS

 

[raikky]

ill check the bedroom lights tmoz see if owts lose/shorting. is it an easy repair ?

what size cable is used on light circuits. 1.5mm?

 

[deadshort]

Hi, yes you're just removing the damaged part of the cable by replacing the damaged section and joining it using a MF joint box. If you have to replace the cable 1.00mm t+e is fine.

Remember power off !

Regards,

DS

 

[ban-all-sheds]

If you really cannot replace the damaged cable, which would be by far and away the best option, you will have to repair it with a maintainance free joint box.

 

[raikky]

Ok I fixed it. I drilled through a cable. Bought some cable, terminal blocks and my junction box and 45 minutes later all sorted.

 

[sparkwright]

What are the terminal blocks for?

 

[raikky]

The junction is any empty white box so had to buy terminals seperately

 

[sparkwright]

The junction is any empty white box so had to buy terminals seperately

Ah, ok.

Of course you shouldn't have screw terninals anywhere inaccessible like under a floor.

(Though this was always the way years ago...)

 

[raikky]

hmmm ok thanks for that. ive marked on the flooring of the junction location. its easy access