Direct-Online Starters are the simplest form of motor starter for starting an induction motor and these starters consist of an MCB / Circuit Breaker, Contractor, and an overload relay for protection, the thermal overload relay under fault conditions can open electromagnetic contractor. Typically the contractor will be controlled by separate start and stop buttons, and an auxiliary contact on the contractor is used, across the start button as a hold-in contact i.e. the contractor is electrically latched/closed while the motor is operating
Over Voltage
Under Voltage
Over Load
Short Circuit
Phase Failure
Contractor
Pump Protective Relay
CT Coil
Timer
On/Off Push Button
MCB
Most Economical and Cheapest Starter
simple to establish, operate, and maintain
Simple Control Circuitry
Easy to understand and troubleshoot.
It provides 100% torque at the time of starting
Only one set of cables is required from the starter to the motor.
Manual / Auto Operation
Optional Control Circuit Voltages