Oil Immersed Stator Rotor Starters

Operating Mechanism Stator Rotor Starters

• Is interlocked with Rotor Controller and the OCB cannot be switched ON until and unless the full external resistances are inserted in the circuit
  
• The Rotor Controller and OCB are connected strictly as per the circuit diagram
  
• The OCB is closed by putting the handle to "ON" position
  
• The push button provided with the Rotor Controllers is kept pressed till the resistance cutting "wheel" of the Rotor Controller is rotated to full "ON" position.
  

• The Stator Controlling OCB's are provided with heavy type copper contacts to ensure a trouble free life
  
• The contacts are made from hard drawn electrolytic copper strips
  
• Each unit is provided with two sets of contacts : arcing contact and main contact
  
• The arcing contacts make before and break after the main contacts, thus confining burning to the arcing contacts
  
• The main contact scarcely calls for replacement where as the arcing contact can be replaced very easily
  

• Overload Protection - is of magnetic type with oil dash pot time lag arrangement in all three phases.
  
• Under Voltage Protection - is provided by a closing type solenoid coil.
  

• Are generally provided with incoming and outgoing cable entry plates
  
• Cable boxes for paper insulated cables, fully interlocked isolator and ammeter can also be provided, on request
  

• Is designed to comply with latest IS for use in Rotor Circuit of A.C. Slipring Motor
  
• Adequately rated resistance wires are selected as per the current at various steps and are robust in design
  
• The Rotor resistance is based on the Rotor Volts and Rotor Amps of the Motor
  
• The cutting off resistances are achieved by the rotation of CAM operated "wheel" and this provides smooth starting of the motor.
  

• The Motor can be started only when full Rotor resistance is in the Rotor Circuit. Otherwise the Stator controlling OCB will not close.
  
• The motor cannot be left running with rotor resistance in the circuit. If by any chance the rotor resistance is left in the circuit the starter will trip no sooner the push button on the rotor controller is released.