Tag Archives: how to wire a light switch

4 way switch (or crossover switch)

Four-way switches have four terminals. This type of switch works in combination with two three-way switches to control electricity to lights from three (or more) locations. They support hot conductors (traveller wires), which receive and transfer electricity from each of the three-way switches.

Animated circuit diagram showing the operation of a 4 way switch

Browse lighting diagrams that use a 4 way switch
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3 way switch (single pole, double throw or SPDT)

3-way-switch-operation

Browse lighting diagrams that use a 3 way switch
You may also be interested to see how a two way switch works
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A 3-way switch will usually have 4 screws. Most older 3 way switches only have 3 screws. The difference between the older and the newer switch is, the ground screw. Code changes over the years have required the addition of the ground screw for safety reasons. However, it is not needed for the correct operation of the 3 way switch. It is needed for the safe operation of this switch or any other type of switching device. On some switches the colors of the screw terminals are different to differentiate between the common and traveler screws. Some switches are made differently from others so the colors used may differ between manufacturers. The common screw will nearly always be a different color from the traveler screws.


2 way switch (Single pole, single throw or SPST)

A simple on-off switch: The two terminals are either connected together (allowing current to flow) or disconnected from each other, breaking the circuit, as you throw the switch.

Sometimes referred to as a Single pole, single throw switch (abbreviated to SPST). May also be referred to as a toggle switch.

Animated circuit diagram showing the operation of a 2 way switch

Browse lighting diagrams that use a 2 way switch
You may also be interested to see how a three way switch works
You may also be interested to see how a four way switch works

Light switch wiring diagrams

If you need to know how to fix or remodel a lighting circuit, you’re in the right place…

We have and extensive collection of common light switch arrangements with detailed lighting circuit diagrams, light wiring diagrams and a breakdown of all the components used in lighting circuits. Don’t forget to take a quick look at the ‘key to wiring diagrams‘ to familiarize yourself with the conventions used on the site.

What kind of circuit are you looking for?

2 way circuitsTwo way light switch circuits - control single or multiple lights from a single location
3 way circuitsThree way light switch circuits - control single or multiple lights from two locations
4 way circuitsFour way light switch circuits - control single or multiple lights from 3 or more locations

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Key to wiring diagrams

Black wires are HOTBlack wires (HOT)
White wires are neutralWhite wires (NEUTRAL)
Red wire are travellers or switchRed wires (TRAVELLER or SWITCH)
Green wires are groundGreen wires (GROUND)
White wires marked as being HOTFor ease of illustration, white wires marked with a black circle are HOT not NEUTRAL. In real life these wires would normally be marked with black tape
two wire cable with ground2 wire cable with ground - the ground is shown as green for illustration but is actually a bare copper wire
3 wire cable with ground3 wire cable with ground - the ground is shown as green for illustration but is actually a bare copper wire

Switch box - metal type with ground terminalSwitch box - used to mount 2, 3 and 4 way switches
Octagon box - used for light fixturesOctagon box - used to mount light fixtures
Light fixture - showing lamp with hot and neutral terminalsLight fixture - showing lamp, hot and neutral terminals
2 way switchTwo way switch >>MORE INFO
3 way switchThree way switch - used to control a light from two locations >>MORE INFO
4 way switchFour way or crossover switch - used, in conjunction with three way switches, to control a light from three or more locations>> MORE INFO