| 摘要 |
PURPOSE:To eliminate a shock at the time of starting by suppling a current to a multipolar stator winding at the time of starting, and supplying a current of a reverse phase to that of the current supplied to the winding temporarily to a small polarity stator winding. CONSTITUTION:In the case of a hoisting, currents are supplied from power sources U, V, W to low speed multipolar stator windings through terminals U1, V1, W1 of a 2-stage speed brake motor M. Simultaneously, a normal open contact MC1-2 is closed, a timer T is operated to operate a reverse phase brake relay R in a short time until the normal close contact is opened, and the contact R-1 is closed. Thus, a current of reverse phase to that of the current supplied to the stator winding is supplied to a high speed small polarity stator winding from the terminals U1, V1, W1 of the motor M. Thus, a magnetic field for releasing a brake is increased. Since the motor M is reverse phase braked, the motor M is smoothly started without shock. |
