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Reply To: Switchgear Riddle No.4 – Anti Pumping Relay

#3040
Hamid

    Excuse me for late reply! I was very busy,sorry If the close circuit is energized continuously, the anti-pump relay will be latched in the energized position (after spring charge switch S3 closing). When the anti-pump relay is energized, its normally closed contacts, in series with the closing coil, ensure that the closing coil cannot be energized even if close circuit is completed by CB auxiliary contact S1 after an opening command. The closing coil activates only when the closing circuit is de-energized (de-energizing the anti-pump relay), then closed again.