The difference between a single and double pole switch is that the latter controls two circuits at the same time. A double pole single throw dpst switch controls the connections to two wires at once where each wire only has one possible connection.
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How does a double pole switch work. Two for incoming hots and two for outgoing hots. For example you might want to turn on a bathroom light separately from the ceiling fan. A double pole double throw dpdt switch is a switch that has 2 inputs and 4 outputs. A double pole switch has two connectors poles that can control two circuits. A double switch allows you to operate two lights or appliances from the same location. A double pole switch is what you need to control a 240 volt device because 240 volt circuits have two hot wires.
A double pole switch controls two separate circuits. A double pole single throw switch dpst turns two circuits on or off. These screw terminals are mounted on the side of the switch. This makes the the double pole double throw switch a very versatile switch. It is easy to wire a double pole switch to work as a single pole switch because only one side is used instead of both. A double pole switch is like two separate single pole switches that are mechanically operated by the same lever knob or button.
Most manufacturers use the abbreviations dpst and dpdt to indicate switch types. With 2 inputs it can connect to 4 different outputs. When the switch is on it is as if the wire had not been opened to insert the switch. Each of the terminals of a double pole double switch can either be in 1 of 2 positions. When the switch is off the wire is open and no current can. A double pole switch can be used to control light and a fan or 2 lights on separate circuits.
Each input has 2 corresponding outputs that it can connect to. The dpst switch often appears in circuit breakers where it is used for 240 volt circuits with each pole carrying 120 volts separately. A double pole double throw switch dpdt manages two circuits and turns both on and off together. Single pole switch is referred as a single pole single throw switch. In other words its like two simple switches controlled by a single actuator. It has four terminals.
Double switches sometimes called double pole allow you to separately control the power being sent to multiple places from the same switch. A switch is inserted in series with a single wire. Double throw switches can divert the flow of electricity from one set of screw terminals to another. A double pole switch such as the one in fig1 is just slightly bigger than a regular switch but constructed as two single switches harnessed side by side and activated by one common toggle. A double pole single throw switch is used for turning electricity either on or off.