help to wire a dimmer switch

[jb1468]

Hi, I have a simple 1 way dimmer which I would like to use to replace my 1 way light switch. My lights do not exceed the maximum wattage of the dimmer. I would like some clarification on wiring.

The switch plate on the wall has 3 red wires entering it

1) wired to a connection on the plate marked 'cov'
2) & 3) the other 2 red wires are in the terminal marked L1 (there is an L2 but that is empty

The earth wire is connected to the back box.

The dimmer I purchased has 2 terminals, one marked L2 and the other a symbol like an x with an arrow head. the diagram that came with the dimmer stated - wire the mains supply to L2 and the 'lamp' to the symbol I described above.

light fitting has 3 bulbs each 60 watts. dimmer max is 250w

Some direction would be reassuring
Many thanks

 

[ban-all-sheds]

Does the switch control two lights? Or did it once upon a time?


As it's 1-way, it doesn't matter which terminals you use, as long as you don't mix up the two wires currently together with the one on its own.

i.e. keep the two currently in L1 together, and put them in one of the dimmer terminals, and put the one currently in COM in the other.

If the dinner is metal, connect the earth wire to the dimmer earth terminal and run a separate short length of G/Y sleeved wire from that to the back box.

 

[securespark]

WOW! You've been to civility classes, Ban!

I was expecting, "what makes you think you can mess about with something you know nothing about without doing some research first?"

 

[electronicsuk]

WOW! You've been to civility classes, Ban!

I was expecting, "what makes you think you can mess about with something you know nothing about without doing some research first?"

I think he may actually have been replaced with a B-A-S robot...

If the dinner is metal, connect the earth wire to the dimmer earth terminal and run a separate short length of G/Y sleeved wire from that to the back box.

 

[Taylortwocities]

If the dinner is metal,......

Maybe related to Monsieur Mangetout (Michael Lotito) perhaps?

 

[ban-all-sheds]

WOW! You've been to civility classes, Ban!

I was expecting, "what makes you think you can mess about with something you know nothing about without doing some research first?"

He is doing the research first...

 

[ban-all-sheds]

If the dinner is metal,....

That'll teach me too rely to mulch on a spilling chequer.

Still - we all need iron in our diet.

 

[jb1468]

Does the switch control two lights? Or did it once upon a time?


As it's 1-way, it doesn't matter which terminals you use, as long as you don't mix up the two wires currently together with the one on its own.

i.e. keep the two currently in L1 together, and put them in one of the dimmer terminals, and put the one currently in COM in the other.

If the dinner is metal, connect the earth wire to the dimmer earth terminal and run a separate short length of G/Y sleeved wire from that to the back box.

Thanks for your help, and as for the debate - I am confirming my thoughts with experts before I attempt anything with electricity.

The dimmer is not metal. You are clear in your instructions and I understand fully. Just out of interest why does it not matter what terminals on the dimmer I use for the single red wire and/or the two combined? I assume it matters when its a two way

Just asking

 

[ban-all-sheds]

With AC, the voltage on the live with respect to neutral varies from +325V to -325V at a rate of 50Hz.

So for 0.01s the current flows one way, then for the next 0.01s it flows the opposite way and so on, so whichever way round you connect the dimmer switch it will pass through it in both directions, changing direction every 0.01s.

 

[Taylortwocities]

Aah, so we are being cheated by the electrical companies.

If the electricity goes back and forth 50 times a second it stands to logic that we are using the same bit of electricity all the time.

You know, it slides up and down through the light bulb, but doesn't go anywhere.

Or is there more to it than that?

 

[Steve]

http://www.youtube.com/watch?v=3GRm_35rHlo

 

[martinxxxxxx]

If the dimmer is metal, connect the earth wire to the dimmer earth terminal and run a separate short length of G/Y sleeved wire from that to the back box.

Why not just put the existing G/Y to the dimmer earth terminal in this case?

Martin

 

[Johnmelad502]

If the dimmer is metal, connect the earth wire to the dimmer earth terminal and run a separate short length of G/Y sleeved wire from that to the back box.

Why not just put the existing G/Y to the dimmer earth terminal in this case?

Martin

Braces and belts. Good practise.

 

[martinxxxxxx]

How does it add anything?

This is not extraneous metal,so surely does not need be bonded.

I would of supposed belt and braces are well catered for by virtue of the two retaining screws.

Have I missed some regulation at all?


Martin

 

[electronicsuk]

How does it add anything?

This is not extraneous metal,so surely does not need be bonded.

I would of supposed belt and braces are well catered for by virtue of the two retaining screws.

Have I missed some regulation at all?

I would call the metal backbox an exposed conductive part, which could become live due to failure of primary insulation. Although it would normally be linked to the switch via screws, this is not the case when an accessory is off the wall for servicing, so many people (myself included) also use a short strap to link backbox and accessory earth terminals. For the 30 seconds it takes, you might as well do it.