For special occasions, environmental requirements of double electrical automatic switching device (ATS) is necessary,
the ATS can unmanned realize the mains (namely utility) and emergency power (namely genset) between the switch.
When the mains power voltage or below the normal voltage, ATS will automatically at 0-10 seconds (adjustable) inside
startup emergency generator, then will load from the mains electricity switch to the emergency power supply (genset),
generator to load power supply.