| 摘要 |
PURPOSE:To protect an enclosed switchboard against malfunction in the vibration of high acceleration by connecting auxiliary contacts of a moulded-case circuit breaker and an overload relay in series, by connecting a delay circuit to a coil of the auxiliary relay in parallel and by connecting the contacts of the above auxiliary relay and an operating coil of a control circuit in series. CONSTITUTION:Even if a casing vibrates in high acceleration, a travelling contact of a (a) contact 12a1 is so constrained in its position with the electromagnetic force of a coil 12c of an auxiliary relay as the coil 12c is always excited that no chattering is caused. Consequently, in an electromagnetic contactor 7 no contact pressure is reduced and no chattering or contact parting is caused, so that the main contacts of the electromagnetic contactor 7 can be prevented from being welded and a motor from being stopped. Should the chattering be caused to a (b) contact 8b or a (b) contact 5b, the coil 12c can be prevented from being demagnetized with a delay circuit 13. |
