| 摘要 |
PURPOSE:To provide a long life with no contact arc and reduce the cost as the whole by continuing one phase of three phases before the continuation of other circuits in which a semiconductor element is opened by a contact switching means. CONSTITUTION:When a switch 56 is ON at the time of inputting a load current, the contact of a leak current interrupting contact mechanism 52 having a minimum contact space makes contact, and the contact of an auxiliary contact mechanism 54 and, finally, an output contact means 50 make contact. In a three-phase motor 58, thus, the phase of a circuit Y is first connected to a power source, but the current is not sent thereto, a photo TRIAC 51 is operated by the connection of the mechanism 54 to electrify the circuits V, W by the operation of a TRIAC 60, and the mechanism 50 is thereafter connected, so that the arc generation in the contacts is prevented. At the time of interrupting a load, the contacts are separated in the reversed order, the circuits V, W are separated when the circuit Y to which the TRIAC 60 is continued is electrified, and the arc generation can be prevented. |
