| 摘要 |
PURPOSE:To prevent charge failure reliably by performing inching operation of an electromagnetic contactor when the electromagnetic contactor for an initial charging circuit is thrown in. CONSTITUTION:Power from an AC power source 1 is fed through a main electromagnetic contactor 3 and rectified through a rectifier 7 then it is smoothed through a capacitor 9 and inverted through an inverter 11 then the inverted power is fed to an inverter load 12. An initial charging circuit 4 is provided in parallel with the contact of the main electromagnetic contactor 3, then the capacitor 9 is charged gradually through the contact of an electromagnetic contactor 5 which is one component of the initial charging circuit 4 and a resistor 6 thereafter the main electromagnetic contactor 3 is thrown in order to prevent initial rush current. At this time, the electromagnetic contactor 5 is thrown in inching operation in order to prevent failure of initial charge due to adhesion of dust onto the contact of the electromagnetic contactor 5. |
