DIY NEWB - Dimmer wiring question (quick one I promise)

[shininghero]

Hi all, just joined the forum - a complete DIY newb here

I currently have a normal 1-way ON/OFF switch for my living room. It has 2 red wires going into the COM port, and a thick red wire going into L1 port. L2 port is free.

Now I want to install a plastic dimmer switch, which I got from fleaBay It has C, L1 and L2 ports and also a possible earthing point at the back but I can't get the +ve screw cover thing to lift up, but I've read here that plastic dimmers don't need earthing.

Just need a confirmation here, but this is my plan...

- Connect the wires like-for-like (2 red ones into COM and 1 thick one into L1)

Q - the dimmer switch and it's back 'wee box' thing is plastic so I do not need earthing right?
Q - is there any harm in earthing them anyway?

Much appreciate your help in this such basic question...

 

[Spark123]

Can you explain what you mean by a +ve screw cover? A photo would be good too.

 

[shininghero]

Can you explain what you mean by a +ve screw cover? A photo would be good too.

sorry, here's a pic - it's the orange screw bit



also, i've noticed that the existing wall screws, as well as the ones that came with the new dimmer is too short [/img]

 

[Spark123]

Don't know what the orange screw is for, not for setting a minimum brightness or something? I take it you don't have any instructions for it?

 

[shininghero]

good point Spark123! i just rotated it and it's defo not for earthing as it only spins around 360 degrees. so i guess that answers my own question as i don't think this can be earthed anyway...

 

[Steve]

good point Spark123! i just rotated it and it's defo not for earthing as it only spins around 360 degrees. so i guess that answers my own question as i don't think this can be earthed anyway...

It isnt a terminal. It looks like some sort of setting dial. Be careful its not for voltage. Search google for the brand name and model. You may have to restore it to its previous setting before reconnecting, or risk damaging it when its powered up.

 

[Leighloz]

Not that I am an expert, but the orange screw looks like a potentiometer for setting the minimum brightness/ dimming range.

That's why it won't unscrew.

Try it once you're fitted (with the power off) give it a spin clockwise, reconnect and power on and you might find the lights brighter when fully on. My money would be on anticlockwise to make them dimmer at fully on.

Not that I am an expert.....or in the trade. Just got some dimmers that do exactly that. They are useful for dimmable compact fluorescent lights. You need enough current to stike them so they start up, but not too much so that they are bright when the dimmer is turned down. Off topic, but see here:

http://www.gil-lec.co.uk/products/L...merable+Compact+Fluorescent+18w+BC/2818885201

Leighloz

 

[Pensdown]

Q - the dimmer switch and it's back 'wee box' thing is plastic so I do not need earthing right?

Correct.

Q - is there any harm in earthing them anyway?

As there is no earth terminal you can't connect an earth cable.