When AC voltage is directly applied to the stator windings of a 3 phase induction motor, the motor draws a high starting current which may disturb the system voltage. The starting current can be 6 to 7 times the full load current of the motor. To reduce this starting current, different types of motor starters are used in industrial applications. TYPES OF STARTERS: DIRECT ONLINE STARTER (DOL): AC voltage is directly applied to the stator windings. No effort is made to reduce the starting current. DOL starters are generally used for motors up to 10 HP. Control Circuit: The control circuit of a DOL starter includes a contactor, overload relay, and push button switches. STAR DELTA STARTER: Initially, the stator windings are connected in star configuration. Once the motor reaches 2/3rd of its normal speed, the stator windings are switched to delta connection. This reduces the starting current to 1/3rd compared to a DOL starter. Types of Star Delta Starters: Manual Semi automatic Fully autom...
Welcome to FM Techie! A blog for Facility Managers, Engineers, and teams, offering insights on maintaining Diesel Generators, Transformers, UPS, STPs and more. We cover facility management, property management, soft services, safety, and provide SOPs, checklists, and logs helping you manage facilities efficiently and safely.