How to fit a dimmer switch which has an sw connection a l and an arrow with a wave line through it which do you connect these to if in your house you have a red wire black wire and earth?

Answer 1

For countries in Europe and other world areas running a 50 Hz supply service.

The answer to your question is rather straightforward. The "Sw" connection is used for a "two-way switch" configuration. If you don't have another switch controlling the same light (as is usual on a staircase) then don't use this connection on the dimmer switch.

The "arrow with a wave" is the "Switched Live" connection. This provides live power service to your light fitting.

Since the dimmer switch doesn't require a connection to the "neutral" wire - nowadays a wire covered in blue-coloured pvc insulation - or, in old wiring, with black insulation - you must ensure that the circuit is completed by connecting the neutral wire from the incoming service to the neutral wire from your light fitting - nowadays a wire covered in blue-coloured pvc insulation - or, in old wiring, with black insulation . Ensure this is done correctly and safely using an insulated connector block.

BEFORE YOU ATTEMPT TO DO THIS WORK, ALWAYS SWITCH OFF THE LIGHTING CIRCUIT AT THE CIRCUIT BREAKER BOX OR, ON OLDER WIRING SYSTEMS, THE MAIN FUSE BOX!

1. For a 1-way installation: connect the live service wire - nowadays a brown insulated wire - or, in old wiring, a red wire - to the "L" (common) connection on the dimmer switch and the brown (or red) wire from the light fitting to the dimmer's "arrow with a wave" connection.

2. Ensure that the neutral connection (as described above) is correctly made.

3. Always connect the earth wire - nowadays a green/yellow wire - or just plain green in old wiring - to the brass earth terminal in the wall box, if there is one (but there may not be one in an old wiring system) and always be sure to connect any green/yellow (or plain green in old wiring) earth wire coming from the light fitting either into that earth terminal in the wall box or use a separate insulated connector block. Often the dimmer switch itself does not have any connection for an earth wire but, if it does, an insulated green/yellow earth wire should go to that as well.

It's as simple as that! Happy DIY'ing........

Warning

Because you needed to ask this question here, you do not have quite enough knowledge to be safe. Be aware that you are working with voltages that could injure or kill you if you don't know how to do this job safely!

Trying to answer this question without personally seeing what you are trying to describe is a recipe for disaster. There are too many things that could be misinterpreted.

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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

Answer 2

Connect the red wire from your house to the "L" terminal on the dimmer switch, the black wire to the "arrow with a wave line through it" (likely the load terminal), and the earth wire to the earth terminal on the switch. The "sw" connection is likely for a switch loop, which may not be needed in your setup. It's always best to consult the dimmer switch manual or seek professional help if unsure.