Confused by garden light switch wiring

[Dande]

Hey all,

Well basically someone gave me some nice unused light switches so I decided to fit them in my living room.

The problem was that they were intermediate so I couldn't match up the wiring. I need to use them both as a single switch.

There is the living room switch and then a switch for the garden light by the back door.

What I did for the living room light is put the black cable with the red sheath to one of the 2 L1 terminals at the top and the red cable to the diagonal L2 at the bottom. I moved the earth cable from the back box to the switch and ran a fly lead from the switch to the back box. All seems ok. Is this correct?

The problem I had was with the garden light. When I looked inside there was 2 black cables joined with a chocolate block terminal and 2 red cables powering the light?

I wired it the same as the other one and it tripped. Is this because one is not switched live? Can anyone tell why it it might be wired like that please?

Thanks in advance for any help.

 

[EFLImpudence]

What I did for the living room light is put the black cable with the red sheath to one of the 2 L1 terminals at the top and the red cable to the diagonal L2 at the bottom. I moved the earth cable from the back box to the switch and ran a fly lead from the switch to the back box. All seems ok. Is this correct?

Yes.

Using the diagonal L2 will have made the switch work "upside down".

The problem I had was with the garden light. When I looked inside there was 2 black cables joined with a chocolate block terminal and 2 red cables powering the light?

I wired it the same as the other one and it tripped. Is this because one is not switched live? Can anyone tell why it it might be wired like that please?

The black wires are the supply Neutral.
Reds are live and switched live.

Wire it as it was before when it worked.

 

[Dande]

Yes.

Using the diagonal L2 will have made the switch work "upside down".


The black wires are the supply Neutral.
Reds are live and switched live.

Wire it as it was before when it worked.

Thank you. So I don't use the neutrals? There problem is that the new switch is intermediate so I don't know what to do as I wasn't expecting the wiring that way. I did wire the same way with the 2 red wires but it didn't like it.

 

[EFLImpudence]

Thank you. So I don't use the neutrals?

They must be connected together but to nothing else.

There problem is that the new switch is intermediate

That's not a problem. Intermediates can be used as one-way and two-way as well.

so I don't know what to do as I wasn't expecting the wiring that way. I did wire the same way with the 2 red wires but it didn't like it.

Not sure what you mean.

Put the blacks in the connector block, then and one red in L1 and one in L2.

Perhaps you have burnt the switch when you caused the circuit breaker to trip.

 

[Dande]

They must be connected together but to nothing else.


That's not a problem. Intermediates can be used as one-way and two-way as well.


Not sure what you mean.

Put the blacks in the connector block, then and one red in L1 and one in L2.

Perhaps you have burnt the switch when you caused the circuit breaker to trip.

Thanks. On the living room switch I put the black wire with red sheath in the first L1 and the other red in the second L2 at the bottom and it worked great. I did the same on the garden light and it tripped.

But on the garden light there was 2 red wires instead of one that was black with red sheath. (Not sure if it matters) Then the 2 black neutrals connected together in a chocolate block terminal.

The only other thing I did was move the earth from the back box to the switch and then a fly lead from the switch to the back box.

I can't understand why it tripped and yeah it did burn the terminal. It worked for half hour before I turned it on and off and it tripped.

 

[EFLImpudence]

I am getting confused. Perhaps a picture of the wiring would help - just copy and paste.

Thanks. On the living room switch I put the black wire with red sheath in the first L1 and the other red in the second L2 at the bottom and it worked great. I did the same on the garden light and it tripped.

Yes, I know but the circuits are different.

There are no neutral wires in the living room switch so you have only one cable with two wires.
At the garden light switch you have two cables and four wires.

Yet in your first post you said you wired both switches the same.

But on the garden light there was 2 red wires instead of one that was black with red sheath. (Not sure if it matters).

No of course it doesn't matter. The wires do not know or care what colour they are.

Then the 2 black neutrals connected together in a chocolate block terminal.

Ok.

The only other thing I did was move the earth from the back box to the switch and then a fly lead from the switch to the back box.

That makes no difference unless another wire is touching the metal plate.


What is the situation now?

Wired correctly but light doesn't work? Still tripping the circuit breaker?

 

[Dande]

Ok here is some pictures. The garden light has the original switch back on there with everything as it was. I just used the 2 red wires and it blew. I didn't rewire it because I thought it was already correct and I couldn't understand why it tripped.

 

[EFLImpudence]

All looks as it should be.

What is tripping? An MCB or an RCD?

An RCD will have a test button.


Do I take it now that it was tripping before and nothing to do with fitting the new switch?

 

[Dande]

All looks as it should be.

What is tripping? An MCB or an RCD?

An RCD will have a test button.


Do I take it now that it was tripping before and nothing to do with fitting the new switch?

No I have lived here for 17 months and it has never tripped the lighting once. When I installed the new switch it worked the first few times that I used the light but then I went to turn it on and it went bang and tripped the RCD downstairs lighting.

I have had problems with my plug sockets tripping but the consumer unit was tested by an electrician and he found no faults.

Could the switch have been faulty?

 

[EFLImpudence]

No I have lived here for 17 months and it has never tripped the lighting once. When I installed the new switch it worked the first few times that I used the light but then I went to turn it on and it went bang and tripped the RCD downstairs lighting.

Ok.

I have had problems with my plug sockets tripping but the consumer unit was tested by an electrician and he found no faults.

A fault that causes an RCD to trip does not necessarily have to be on the circuit that appears to cause the trip - just one of the circuits covered by the RCD.

Could the switch have been faulty?

Well, anything is possible but that is unlikely to cause an RCD to trip, but having said that sometimes it just happens.


Check the garden light for moisture.

 

[Johnmdc]

When you have screwed the switch back on the box you have trapped the wire see the yellow circles on you picture.

 

[Taylortwocities]

When you have screwed the switch back on the box you have trapped the wire see the yellow circles on you picture.

Spot on, John!!

 

[Dande]

Ok.


A fault that causes an RCD to trip does not necessarily have to be on the circuit that appears to cause the trip - just one of the circuits covered by the RCD.


Well, anything is possible but that is unlikely to cause an RCD to trip, but having said that sometimes it just happens.


Check the garden light for moisture.

Ok thanks a lot for your help. I wanted to change the light anyway as the current one is a bit worn so that could be it.

I think I might just buy some 1 way switches as well.

So a fault with my boiler could cause my downstairs sockets to trip even if it's on a different circuit?

 

[conny]

Johnmdc has enlarged your photo and circled what the problem is. When you screwed the switch back on you trapped one of the red leads against the screw lug at the top.
This caused a short circuit to earth which tripped your RCD. You need to put some heat shrink sleeving over the damaged part of the wire and make sure you don't trap it again when fitting the switch back in place. The switch will not have been damaged when the RCD tripped.