Features [Changeover Switch] Double power automatic transfer switch is composed of two units of miniature circuit breakers and auxiliary, alarm contacts, mechanical interlock transmission, controller and other components. [Multiple Functions] Automatic transfer switch with mechanical, electrical interlock function, can be manually or automatically powered, universal and standby circuit breaker rated current can be different. [Anti Interference] The automatic transfer switch is manufactured by superb craftsmanship, isolation anti interference, stable performance, and use with confidence. [Simple Structure] The switch is small in size, simple in structure, driven by a single motor, smooth, noiseless and low impact. [Display Panel] The switch has a variety of indications on the display panel to reflect the breaker status and is widely used in homes and shopping malls. Specification: Item Type: Dual Power Automatic Transfer Switch Material: ABS, aluminum alloy Rated Current: 125A Handle Color: Red Rated Voltage: 400V AC Frequency: 50Hz Pole Speed: 2P Rated Impulse Withstand Voltage: 4 (KV) Insulation Voltage: 4000 (V) Working Principle:  This series of dual power supply controller and drive mechanism power supply signal depends on the A phase and N line of the common switch or standby switch inlet port. Dual power supply in the automatic state, when the incoming phase A and N common switch voltage is normal (AC190-240V), regardless of whether the common power supply B.C and standby switch a.b.c, N voltage is normal or not, the common switch will be closed in priority... Package List: 1 x Dual Power Automatic Transfer Switch 1 x Instruction Package List 1 x Dual Power Automatic Transfer Switch 1 x Instruction