How to Connect Two Switches in Parallel to Control a Single Load?
In previous basic home electrical wiring installation tutorial, we learned how to wire single way switches in series. Today, we will learn how to wire and connect two switches in parallel to control and operate a single light point.
Mostly, this is a preferred method to wire single way switches in parallel as parallel or series-parallel connections are used in common electrical wiring installation these days due to advantages over series connection.
Before we go in details, we will see the basic construction and operating mechanism of single way switch which is shown in fig below:
Below is a simple step by step tutorial with schematic and wiring diagram which shows how to wire single way switches in parallel?
- Single Way Switches (SPST = Single Pole Single Through) x 2 No
- Lamp (Light Bulb) x 1 No
- Short pieces of cables x 5 No
Connect the two single way switches, light bulb in parallel to the power supply as shown in fig below. Keep in mind that one of the switches S1 or S2 must be closed to complete the circuit.
If there are more switches connected in parallel with electrical appliance i.e. light point, one of them must be at ON position to operate the load. However, light bulb won’t go off if you switch OFF one of the switch. In other words, all the switches must be closed (OFF position) to disconnect the load from power supply.
The circuit will complete if one of the switches out of two are at ON position. In other words, If one of the switch are close or at ON position, the light bulb will glow then. This is the same case for other loads as well to control by two (or more) single way switches connected in parallel.
Below are the different positions of single way switches and light point when connected in parallel.
To get the switching position in ON condition for light bulb, the above operation is same as the Digital Logic OR Gate truth table which is given below.
|Switch 1||Switch 2||Lamp Position|
|0 = OFF||0 = OFF||0 = OFF|
|0 = OFF||1 = ON||1 = ON|
|1 = ON||0 = OFF||1 = OFF|
|1 = ON||1 = ON||1 = ON|
In simple words, there are four switching positions and if both the switches are at OFF position, the light bulb will not glow. On the other hand, if one of the switch is at ON position, the current will flow in the circuit as the circuit behaves like completed circuit, hence bulb will glow. No matter all of other connected switches are at OFF or ON positions.
Good to know:
- Switches and fuses must be connected through line (Live) wire.
- Switches connection in parallel is a prefer way to wire home appliances. parallel or series-parallel wiring method is more reliable instead of series wiring.
- More wires and cables are required in parallel wiring connection.
- It is a reliable and comfortable method of wiring.
Related Electrical Wiring Installations tutorials:
- How To Wire Switches in Parallel?
- How To wire Lamps in Series?
- How To Wire Lamps in Parallel?
- How to Control a Lamp by a Single Way or One-way Switch?
- How to control each lamp by separately switch in parallel lighting circuit?
- Stair case wiring circuit diagram, OR How to control a lamp from two different places by two ,2-way switches?
- How to control One Lamp from three different places? (by using two, 2-Way switches and one intermediate switch)
- How to control one lamp from six different places by using two, 2-way switches and four intermediate switches?
- Basic Electrical Wiring Diagrams