Upstairs lighting not working - new switch

[crackerjak]

Good evening all,

I have attempted to replace a plastic light switch with a metal one on the upstairs lighting ring. There was one red cable in the upper hole and 2 in the lower. The earth is to the metal back box. 2 black cables are in a junction box and wrapped in insulation tape.

When I fitted the new metal light switch I'm thinking the earth wasn't connected to the switch properly. It tripped the breaker. I reset the breaker to on but still nothing.

I have refitted the old switch and put it back together as it was - still nothing.

Has anybody got any idea what can be wrong and how I can fix it?

Thanks

Crackerjak

 

[sparkwright]

Make sure no wires have been damaged by the two fixing screws. This would cause a fault.

Assuming this is a one way switch, for a bedroom perhaps, then the wire on it's own would go in, for instance, 'common'; and the two wires would then go in 'L1'.

What are the markings of the terminals on your new switch?

 

[EFLImpudence]

And the earth must now be connected to the metal switch.

 

[crackerjak]

I couldn't see any damage but going to double check. Yes this is a 1 way switch for a ceiling pendant in a bedroom.

The new switch markings have L at the top and L1 & L2 at the bottom.

Just for clarity the breaker is now set to on but no power.

Thank you!

 

[sparkwright]

Ok, use com and L1, don't mix up the wire on it's own and the other two.

And, as mentioned, bring the earth wires to the earth terminal on the metal switch.

 

[sparkwright]

Have you worked anywhere else on the lighting circuit? This could account for it not working.

 

[crackerjak]

Hi,

No not touched anywhere else on the circuit.

The earth then - shall I add a cable from the back box or just disregard the earth there and connect it straight to the new switch?



If I did get the red cables mixed up when connecting what could be the consequences? I'm just worried this may end up costing me a fair bit. :/

Thanks for the help so far.

 

[sparkwright]

The best way to earth the switch is run the earth wires to the switch plate, and add a new wire from here to the metal back box. But earth to the metal switch plate is the most important.

Mixing up just the reds shouldn't have any disastrous effect, other than things not working properly.

The wire to the bedroom light goes in one side of the switch. The other wire or wires are permanent feeds, which supply other lights in other rooms.

 

[sparkwright]

With the power off, check all the connections at the switch are sound, including the neutrals - you never know, they may have got disturbed.

 

[sparkwright]

I have attempted to replace a plastic light switch with a metal one on the upstairs lighting ring. There was one red cable in the upper hole and 2 in the lower. The earth is to the metal back box. 2 black cables are in a junction box and wrapped in insulation tape.

If three reds, would usually expect three blacks. Though may not necessarily be wrong I suppose.

 

[crackerjak]

It was a damaged cable in the end. Thanks for the help folks!

 

[ban-all-sheds]

How did it get damaged, and where?

What did you do about the damage?

 

[crackerjak]

Looks like somebody in the past had damaged the live cable and simply covered it with tape as a "fix". So when I moved the tape not knowing it was damaged beneath it broke the circuit, so to fix it I took the cable back beyond the damage and then connected the cable into the switch. Good as new.

 

[ban-all-sheds]