Simple motor control latching circuit. The three relays on the right represent three phases in a three-phase system. Bottom relay serves as the auxiliary contact, which 'holds' the control circuit energized. This is a common method to control three-phase motor operation in industrial settings.
'Run mode': Once the NO start pushbutton is pressed and released, the motor will run and remain running. Pushing the NC stop pushbutton will 'unlatch' the circuit, causing the motor to stop.
'Jog mode': The control circuit will only remain energized only if the NO start pushbutton is held down. This is used for inching conveyor belts or other applications in small increments.
Use the single pole double throw switch to switch between run and jog modes.
Enjoy!
