GB612682A - A control system for electric motors and other electrical apparatus comprising push button operated contactors - Google Patents

Abstract

612,682. Controllers; control of motors; protective cut-out systems. ALLMANNA SVENSKA ELEKTRISKA AKTIEBOLAGET. May 30, 1946, No. 16445. Convention date, June 29, 1945. [Classes 38 (iii) and 38 (v)] No-volt release; push-button control systems.- A control system comprises a push-buttonoperated main contactor 1, the operating coil 2 of which is adapted to be connected across two supply-lines, the contactor being provided with an auxiliary time-delay contact 5 which causes reclosure of the main contactor if the line voltage returns, after wholly or partly failing, within the time-delay period thereof, and, during this period, a circuit is maintained across the contact 5, the operating coil 2, and a contact 9 of an auxiliary relay, which latter contact is open in normal operation when the auxiliary relay is energized. When an " off " push-button is actuated, the time-delay in opening of the main contactor is not afforded. Actuation of a push-button 10 effects closure of the main contactor 1 together with its auxiliary contacts 3, 4 and 5, there being no time-delay in closure of the contact 5. On release of the push-button, the circuit through the coil 2 is maintained through the contact 3. The auxiliary relay coil 8 is energized through the contact 4, the contact 9 taking its righthand position. On failure of the supplyvoltage, the coils 2 and 8 are de-energized, but a circuit to the coil 2 is maintained through contacts 9 and 5, as long as the latter is in its closed position. If a push-button 11 is actuated, with the supply voltage at its normal value, the coil 8 is maintained energized through the contact 9, and the time-delay contact 5 is rendered ineffective. The contactor 1 may act as a pilot contactor and may be of the two-pole type.