UK Help with wiring dimmer switch

[Jamesdavidg]

Hi. I am not an electrician. After some advice. I am changing a light switch in my house from a single on/off switch to a dimmer switch. When removing the old switch, there are 3 of each wire. 3 blue, 3 brown and 3 earth. The dimmer switch has 3 connections. L1, L2 and an arrow with a wavy line. Please could you let me know how I connect this as I've tried already and every time I turn the switch off, the fuse box trips. Thanks for your help.

 

[buzzlightyear]

did you take a pic before hand , post a pic up.

 

[snowhead]

Is there another switch involved with these lights, 2 way switching for hall, passage or stairs or is this the onlty switch for the light?

Were the 3 Blue wires all connected together and not into the switch.?

As above pictures of the Old switch, whether connected or not, the new switch, whether connected or not and a picture showing the cables in the box in the wall would be of great assistance.

 

[Jamesdavidg]

did you take a pic before hand , post a pic up.

Hi, yes, please see attached photo of the wires in the switch and also the back of the dimmer switch. This is a single light switch and the light can't be operated from anywhere else. Thanks

 

[Jamesdavidg]

Is there another switch involved with these lights, 2 way switching for hall, passage or stairs or is this the onlty switch for the light?

Were the 3 Blue wires all connected together and not into the switch.?

Hi, this is a single light switch, not controlled from anywhere else and yes the blue wires were all connected together away from the actual switch.

 

[Avo Mk8]

So did the original switch have the left-hand brown wire in one terminal, the adjacent pair of brown wires in the other terminal, and all three blue wires in a choc block separate from the switch?. And of course the earth connected.

 

[Jamesdavidg]

So did the original switch have the left-hand brown wire in one terminal, the adjacent pair of brown wires in the other terminal, and all three blue wires in a choc block separate from the switch?. And of course the earth connected.

Yes, that's correct.

 

[Avo Mk8]

So when you wired the dimmer, did you put the pair of brown wires in L1 and the single brown on the left in the terminal with the arrow/wavy line? And of course all the blues in a choc block.

 

[Jamesdavidg]

So when you wired the dimmer, did you put the pair of brown wires in L1 and the single brown on the left in the terminal with the arrow/wavy line? And of course all the blues in a choc block.

No. I put ALL the blue wires in L1, ALL the brown wires in the one with the arrow and wavy line and all the earth wires to earth.

 

[Jamesdavidg]

No. I put ALL the blue wires in L1, ALL the brown wires in the one with the arrow and wavy line and all the earth wires to earth.

I cant tell if any of the 3 brown wires are different to each other as the all come into the box together, same with the blue wires.

 

[Jamesdavidg]

I cant tell if any of the 3 brown wires are different to each other as the all come into the box together, same with the blue wires.

Actually, looking closer there are actually 3 main cables. Each with a brown, a blue and the earth.

 

[westward10]

You have created a line to neutral short across the dimmer and it will be sheer luck if it still functions. The blues must be kept separate in their own connector, not to the switch. The line in and out go to L1 (two of the browns) and the other brown, line to light goes to the squiggly terminal. Question is which brown is which now. I would use the old switch to sort the browns you only have three options for them to be correct. When correct all other lights from that circuit will function with the switch off, nothing should trip but some lights may not function if connected incorrectly. Then transfer wires to new switch.

 

[littlespark]

All your blues go together, but not to the switch. These are neutral and you may have fried the internals of your dimmer by connecting them.

2 of the browns are live, and will go into the L1
The other brown is the switches live and will go into the arrow with the wavy line terminal. L2 does not get used in this instance.

from here, we cannot say which browns are which. There are only 3 configurations, and none will trip the breakers.

the earths go together in a connector, with another earth coming from there and into the brass terminal on the metal switch plate.

 

[Avo Mk8]

If the blue wires were not in the original switch, they should not be in the new dimmer.
it is probable that all you need to make the switch work, is one brown in one terminal (L1), and the other two in the other terminal (eg wavy). But if you can't remember which one was on it's own you may not be able to sort it without test equipment.

 

[buzzlightyear]

I would get a spark in just in case, might be live in and switch out. But with 3 brown tails it's a flip of a coin.

 

[westward10]

Trial and error will solve it.

 

[Jamesdavidg]

You have created a line to neutral short across the dimmer and it will be sheer luck if it still functions. The blues must be kept separate in their own connector, not to the switch. The line in and out go to L1 (two of the browns) and the other brown, line to light goes to the squiggly terminal. Question is which brown is which now. I would use the old switch to sort the browns you only have three options for them to be correct. When correct all other lights from that circuit will function with the switch off, nothing should trip but some lights may not function if connected incorrectly. Then transfer wires to new switch.

Thanks so much for your help. I have tried the above and tried the different brown wires but no luck. The swith doesn't work and none of the lights in the upstairs of my house work either. Have I broken something? Fuse box is fine and has not tripped.

 

[westward10]

Use the old switch to sort the browns. It is highly likely the new switch is blown. Can you show a picture of your consumer unit.

 

[Jamesdavidg]

Use the old switch to sort the browns. It is highly likely the new switch is blown. Can you show a picture of your consumer unit.

Ok, so I have the old switch working again now and also the other lights upstairs. See attached photos.

 

[littlespark]

If everything is working fine now, then the two browns together are your lives.
The single brown is your switchwire up to the light. Tag this one with a bit of red tape or something.

Try the dimmer again, with the two lives inL1 and the single brown in the wavy line terminal.... Again, L2 isnt used in this instance.

If it doesnt work, then either, you HAVE fried the dimmer, or the load isnt suitable for a dimmer switch, (ie, is the bulb a CFL or LED.... )