Issue with dimmer switch

[Simon Ross]

Hi all,

I wonder if anyone can provide a bit of advice. I've recently been doing some decorating in the house and part of that is to change the light switches in the house.

I'm in the process of changing 7 circuits in total, this consists of:

• Downstairs hall - 2 gang one of which is 1 way to control downstairs hall light and the other is 2 way to control the upstairs hall light as well.
• Kitchen - 1 gang 1 way
• Living room - 1 gang 1 way dimmer switch
• Upstairs hall - 1 gang 2 way (linked to downstairs hall light as above)
• 3 bedrooms - all 1 gang 1 way.

All of the light switches are decorative so are 2 way switches.

The issue I'm having is that I've changed all of the downstairs lights and wired them exactly how they were previously. Now whenever I turn the dimmer switch on in the front room, it's knocking off all of the bedroom and bathroom lights upstairs. When I turn the dimmer off the upstairs works fine as normal.

The dimmer switch has 3 red wires coming out of the wall and in to it, this is wired as previously with a wire going in to L1, COM and L2.

What am I doing wrong here?

Any help would be appreciated, tearing my hair out (what's left of it)

Thanks,

Simon

 

[ipf]

31st post......this must be a pish take.

 

[Simon Ross]

One way you can find out what conductors go where is to dead test using a decent tester and a wander lead

Is there any cruder way of doing it?

31st post......this must be a pish take.

Nope

 

[Simon Ross]

I've just put the wire which was in L2 into the middle terminal and the light stayed on permanently, regardless of the switch.

So I'm assuming those 2 wires are the permanent live and the connection to the light.

Therefore the one that's in L2 now should be in L2? And the one that's in L1 should be in the middle terminal as well?

 

[123]

I think you are a bit out of your depth now and it's just becoming a guessing game. As it stands you have made a probably safe and working electrical circuit neither safe nor working.

 

[Simon Ross]

I think you are a bit out of your depth now and it's just becoming a guessing game. As it stands you have made a probably safe and working electrical circuit neither safe nor working.

Without proper equipment to find out which wire is which yes you're probably right.

 

[camerabloke]

The only dead testing that’s gonna happen is an autopsy. Get a sparks in. Fixed in a hour

 

[Pete999]

The only dead testing that’s gonna happen is an autopsy. Get a sparks in. Fixed in a hour

Wouldn't be dead testing if the poor sid weren't dead, get a bit of a shock I reckon

 

[camerabloke]

If he keeps ----ing around with it he’s gonna kill someone

 

[Richard Burns]

It does seem a slightly odd arrangement of wiring since you can trip out the supply from the switch.
If with the wiring as shown in your picture both "1" and "1111" are live this might indicate the switch is nominally off i.e. com and L2 are connected, when putting "1" and "1111" together the light is permanently on then one is live in and one is switch wire to light, therefore because of the proximity of "111" and "1111" one assumes "1" might be the switch wire and should be in L1 and the other two a loop in and loop out and should be in COM, as in the below diagram.
However this is all supposition and cannot be definitely accurate and may well be very hazardous to try since there is something odd going on, as if one of the cores is a neutral or shorted at the far end.

 

[shaun1]

Don't think anyone has mentioned yet but bin the neon screwdriver. If it is the type that has a metal pad on the end that you touch, you are connecting yourself to the mains with only a resistor to limit the current to a safe level. If that resister got bypassed, e.g. by water in the driver, or the handle became damaged, you may as well be touching the wires directly to test if they are live.

 

[telectrix]

neon drivers have their uses. ..... they fit some terminal screws; good for stirring tea and scratching your arse (but not necessarily in that order).

 

[CACJL]

Hi all,

I wonder if anyone can provide a bit of advice. I've recently been doing some decorating in the house and part of that is to change the light switches in the house.

I'm in the process of changing 7 circuits in total, this consists of:

• Downstairs hall - 2 gang one of which is 1 way to control downstairs hall light and the other is 2 way to control the upstairs hall light as well.
• Kitchen - 1 gang 1 way
• Living room - 1 gang 1 way dimmer switch
• Upstairs hall - 1 gang 2 way (linked to downstairs hall light as above)
• 3 bedrooms - all 1 gang 1 way.

All of the light switches are decorative so are 2 way switches.

The issue I'm having is that I've changed all of the downstairs lights and wired them exactly how they were previously. Now whenever I turn the dimmer switch on in the front room, it's knocking off all of the bedroom and bathroom lights upstairs. When I turn the dimmer off the upstairs works fine as normal.

The dimmer switch has 3 red wires coming out of the wall and in to it, this is wired as previously with a wire going in to L1, COM and L2.

What am I doing wrong here?

Any help would be appreciated, tearing my hair out (what's left of it)

Thanks,

Simon

A neighbour of mine did something similar and I had to sort it out for him. Get somebody technically competent to sort it out.

 

[EbolaSideRoom]

What they all said. Without wishing to be rude or unkind, what seemed really straightforward has gone beyond you. Call a local electrician. And please, please get rid of that neon screwdriver, at least for assessing live cables & safety.