| 摘要 |
PURPOSE:To reduce the rated value of a heater of an overcurrent relay by connecting the relay with a contact to be closed after the prescribed time from the start. CONSTITUTION:3-phase AC power source terminals R, S, T are connected through electromagnetic contactors 1a-1c with winch 3-phase induction motor 2. A resistor and reactors 4, 5 as the primary voltage controller are connected in series between the stator windings of the phases and a midpoint with respect to the stator winding of the motor 2. Contacts 6a, 6b shortcircuit between connecting points of the reactor 5 and the stator windings, and contacts 7a, 7b shortcircuit between the connecting points of resistors 4 and the reactor 5. Thus, the rated value of a heater of an overcurrent relay 3 can be set to a small value. |
