PRESENTED BY:AMOD SHAKYA

Power Circuit –connectoin with motor using contactor Control Circuit-using switch make a holding circuit

 A contactor is a large relay, usually used to switch current to an electric motor or another high- power load. Large electric motors can be protected from over current damage through the use of overload heaters and overload contacts

 Relays are switches that open and close circuits electromechanically or electronically. Relays control one electrical circuit by opening and closing contacts in another circuit. As Relay diagrams show, when a Relay contact is normally open (NO), there is an open contact when the Relay is not energized

 NO (Normally Open ) Switch  NC (Normally Close) Switch  Fuse  Isolator  Overload unit  Contactor  Wires  Motor

 Full voltage is applied to the motor at the time of starting  The starting current is 5-6 times the full load current  The three winding are connected generally in star  Low cost, very easy operation and less space required for installation  Use for motor up to 5 HP  East to connect motor with DOL

 High starting current  High starting torque  Very high mechanical load