Pedal Foot Switch Connection Diagram for Motor Control
Hi, in this article, we are going to see the connection diagram of a pedal switch for motor control. A pedal foot switch can be used to control a motor by acting as a remote on/off switch. In a motor control system, the foot switch makes it easy to control the motor without using our hands, which is especially useful in environments where we need both hands free such as in industrial applications or workshops. This is a very useful device we can step on to activate or deactivate the motor. It can either be normally open (NO) or normally closed (NC) depending on the wiring. In most of the cases, especially, in motor control system we generally use NO type pedal switch.
Connection Diagram
Here, you can see Pedal Foot Switch Connection Diagram for a Three Phase Motor Control.
Apparatus Used
In the above system, in fact, in most of these types of systems the below common apparatus are used,
- Four Pole MCCB: Acts as the main switch and provides overall protection for the three-phase motor circuit.
- Single Phase MCB: Protects the control circuit connected to the pedal foot switch.
- Three Phase Contactor: Switches the motor ON/OFF based on the signal from the foot switch.
- Overload Relay: Safeguards the motor by disconnecting it during overload conditions.
- NO Type Pedal Switch: Sends a control signal to the contactor when pressed by foot.
- Three Phase Motor: Operates as the load and is controlled through the contactor and foot switch.
Connection Procedure
- Connect the Four Pole MCCB at the input to act as the main power switch for the entire system.
- From the MCCB, connect the three-phase lines to the Three Phase Contactor and pass them through the Overload Relay to the Three Phase Motor.
- Install the Single Phase MCB for the control circuit and take a phase and neutral from it.
- Connect the NO Type Pedal Switch in series with the coil terminals of the Contactor and overload relay's NC terminal using the single-phase supply.
- The Pedal Switch output goes to one side of the Contactor coil, and the other coil terminal returns to neutral.
- Ensure the Overload Relay is correctly wired in series with the contactor to break the motor circuit in case of overload.
- Double check all connections to ensure proper earthing and then turn on the MCCB to test the operation.
Working Principle
When the system is powered ON through the Four Pole MCCB, the control circuit receives power from the Single Phase MCB.
Now, when the user presses the NO Type Pedal Foot Switch, it closes the circuit and energizes the coil of the Three Phase Contactor.
Once the contactor is energized, it closes its contacts and supplies three-phase power to the Motor and starting its operation.
If the Pedal Switch is released, the circuit opens which de-energizing the contactor coil and cutting off power to the motor, so the motor stop immediately.
The Overload Relay continuously monitors the motor’s current. If the motor draws excessive current beyond the set limit, the overload relay trips and disconnects the contactor to protect the motor from damage.
Read Also: