AUTOMATIC TRANSFER SWITCH ADOPTING N-PHASE CLOSED TRANSITION SWITCHING SYSTEM

摘要

PURPOSE: An automatic transfer switch adopting N-phase closed transition switching system is provided to appropriately operate earthing trouble prevention device, eliminate erroneous operation of the device, and obtain earthing effect of AC power source. CONSTITUTION: When a three-phase operation terminal(4) is interposed horizontally between a normal power source side voltage terminal(2) and an emergency power source side voltage terminal(1), the normal power source side voltage terminal, the emergency power source side voltage terminal and the three-phase operation terminal have the same height. When an N-phase operation terminal(4') of neutral line is interposed horizontally between an N-phase normal power source side neutral terminal(2') and an emergency power source side neutral terminal(1'), the N-phase normal power source side neutral terminal, the emergency power source side neutral terminal and the N-phase operation terminal have height lower than the height of the three-phase operation terminal. The N-phase operation terminal contacts the emergency power source side neutral terminal, while maintaining contact with the N-phase normal power source side neutral terminal, to thereby achieve closed transition of N-phase.