Lighting Circuit Help

[Juniorscone]

All,

Really need some help understanding a problem that I am having with my lights. Here are the facts:

- The consumer unit has 1 circuit marked lights
- I was changing a light switch in the living room and all was going well
- Until I tightened up the switch to the wall, flicked the RCB back up and then pop...
- The RCB had tripped
- I flicked it back up and its stayed up
- Now only half of my lights are working
- The bedroom and half of the hall lights are working at the front of the house
- The other half of the hall, the living room, kitchen and bathroom aren't working
- As far as i remember the other lights were all switched off at their relevant switches so i cant imagine i have blown all the bulbs
- The RCB is MK 7932S (MK Sentry 6 Amp 30mA RCBO 1 Module)

What on earth could be causing this? Is it a faulty RCB? If it is how could half of the lights be working and the other half not?

Thanks in advance for you help...I'm completely lost what this could be!

 

[Juniorscone]

I forgot to add; i have changed the switch in the living room back to the one that was on before and still no luck!

 

[echoes]

Can you unscrew the switch you worked on and take a photo?

You have created a fault. The RCBO told you that.
But now the RCBO stays closed and some lights work - so you now have a break in the circuit: probably a blackened, burnt out break - probably behind your living room switch...

 

[rjm2k]

If it wad the rcb then none of the lights would work, sounds like a loose or burned out wire. Can you put up a photo of the wires in the switch? Also you may need to check and post a photo of the ceiling rose wiring it controls. Did you only alter the switch?

 

[Taylortwocities]

Sounds like you damaged a wire in teh back box when you screwed the switch back on.

Don't go trying to fix it with the power still on, or in the dark!

 

[Juniorscone]

When the new switch blew there was a bit of blackening on the back of it, im loading some pictures now (internet is slow).

If its is a burned wire what is my next course of action?

 

[Juniorscone]

Images can be seen here:

//www.diynot.com/network/Juniorscone/albums/13663

 

[Juniorscone]

Images can be seen here:

//www.diynot.com/network/Juniorscone/albums/13663

 

[LearningSpark]

Red wire on left in second picture had indent in it which looks like you nipped it with the face plate screw.

 

[vibrobullit407]

Looks like you've nicked the red (line) core with the box screw when fitting the face plate back. Happens quite a bit I've discovered by DIYers. You need to isolate the supply then cut the damaged core before the nick. If there is not enough length to terminate then you'll have to joint it using either a 5A connector or a crimp as I don't think you'll pull any slack through.

 

[Taylortwocities]

Images can be seen here:

The problem!

• Juniorscone
• 29 Sep 2012
• 1

Untitled

• Juniorscone
• 29 Sep 2012
• 1

Learn how to insert images in your posts by reading //www.diynot.com/forums/viewtopic.php?t=129539

 

[echoes]

If that switch is wired correctly, and that nick was the cause of the fault, then there's still something else wrong to cause other lights not to work when the RCBO is closed...

 

[Juniorscone]

So the plot thickens..

I have pulled some slack through and cut both wires to be sure i had not broken them both and still no luck! Wired the old switch up again which i know was working before this issue and still no lights to half of the house.

See images below showing the latest progress:

Untitled

• Juniorscone
• 29 Sep 2012
• 1

Untitled

• Juniorscone
• 29 Sep 2012
• 1

 

[Taylortwocities]

1. Are you absolutely 100% certain that changing the switch was the only electrical work that you have done today.?
2. Are you absolutely certain that you have wired the new switch the same as the old and there was not another bit of wire (connecting the two L1s for instance).?

PS. Don't get fooled by markings on switches. Some say L1, L2 L3. Some say Com L1 L2, some say A1 A2 A3
It's hell out there...

 

[Juniorscone]

100% sure thats the only work thats been done today and I'm almost certain that switch is how it was before...but starting to doubt myself now.

The wiring should be pretty simple:

- Room has 2 individual lights
- There is only one light switch so its a one way switch I'm trying to wire up
- Red is live and black is the switched live
- So i have hooked up the Red to L1 and the black to L2

I think thats right....