Incorrect connections in lighting (Ed.)

[stephen Sharp]

Hey all

2 down lights above our bed stopped working. I removed what I thought was a faulty dimmer transformer(switch was a on and off switch anyway). 2 wires coming out of the sealing Red(live) went into coms, and black(netursl) went into a separate block. Wires from the light went into - red(into L1) black(natural) into separate block.

As soon as I switch on the light flash then the fuse board trips....any ideas? faulty switch maybe?? I did notice a scorch looking mark inside the switch plate......

Any help would be ace.

Thanks.

 

[Jurassicspark]

What trips in the fuseboard?

If the MCB is tripping then you almost certainly have a short circuit some where from the switched line of the lights to earth or to neutral. The fact you say you got a scorching mark on the switch suggests that its the MCB. Show a picture of the fuseboard and which breaker has tripped.

 

[stephen Sharp]

No earth is, or has been used within the switch. Attached is the wiring for the switch and the fuse box....upstairs lights is next left the the ground floor. That's the one that tripes. I have not checked where the wire coming from the ceiling comes from - maybe issue there. But all other lights work fine upstairs.

 

[Jurassicspark]

Okay, don't keep on switching the MCB as frequent tripping of the MCB is not a good idea.

Was the wiring like this or did you mess something up? The switch is not the problem if it was originally wired like that.

Have you got a multimeter? Test continuity from the red wire of the switch to the black wire.

Bear in mind, you don't have an earth wire, so you cannot use that switch.

 

[pete01]

You do have an earth wire but it's been cut off, whether its connected the other end is a different matter.

 

[JohnD]

Why are the two black wires connected together?

 

[stephen Sharp]

I haven't not touched the earth wire. I just removed the dimmer transformer that was wired into to all this. And was left with the wires from the ceiling and the light wires.

 

[stephen Sharp]

The 2 black wires are neutral. One from the actual light and one from the mains wires.

 

[Jurassicspark]

You need to find out which cable comes from where.

Remove the red wire (connected to common at the switch) and separate the 2 black wires test with a continuity meter and let us knw what reading you get.

You mention its a bedroom so that means you got access to above. Which type of downlights have you got? Send in a picture.

 

[JohnD]

The 2 black wires are neutral.

What test did you carry out to establish that?

 

[Sparky3]

Hey all

2 down lights above our bed stopped working. I removed what I thought was a faulty dimmer transformer(switch was a on and off switch anyway). 2 wires coming out of the sealing Red(live) went into coms, and black(netursl) went into a separate block. Wires from the light went into - red(into L1) black(natural) into separate block.

As soon as I switch on the light flash then the fuse board trips....any ideas? faulty switch maybe?? I did notice a scorch looking mark inside the switch plate......

Any help would be ace.

Thanks.

A photo of the item you removed and what you did with the wiring may help.

 

[stephen Sharp]

Okay, don't keep on switching the MCB as frequent tripping of the MCB is not a good idea.

Was the wiring like this or did you mess something up? The switch is not the problem if it was originally wired like that.

Have you got a multimeter? Test continuity from the red wire of the switch to the black wire.

Bear in mind, you don't have an earth wire, so you cannot use that switch.

I just removed the dimmer transformer. No wires added. Attached is the original set up....the wire from the ceiling(red) came in switch(com), black wire from ceiling went in to small connection block......the other side of the conection block went into the transformer. The brown wire from the transformer went into L1. The output wires went to the lights. I hope that makes sense. All im left with now are the red and black wires from ceiling and red and black from lights.

 

[JohnD]

(Reply)

Your assumption is probably wrong.

In lighting fittings in particular, you cannot assume colours mean anything.

 

[mikeyd]

So is there a transformer still in the circuit?
If not then you are supplying 240V to your 12V lamps.

 

[stephen Sharp]

So is there a transformer still in the circuit?
If not then you are supplying 240V to your 12V lamps.

No.....we don't have an actual dimmer switch. Just a on and off switch. I removed that thinking it was the issue(I think it failed) and not needed. Makes sense why it is tripping then. I'll order a new transformer and wire the same as before.

I appreciate all your help chaps.