The GW4 series double-column horizontal rotating single-break outdoor three-phase high-voltage AC isolating switch is designed for power supply systems with a rated frequency of 50Hz or 60Hz and a rated voltage of 12kV/24kV. It is used for switching high-voltage lines under no-load conditions and for electrically isolating high-voltage electrical equipment such as high-voltage busbars and circuit breakers under maintenance from live high-voltage lines. Additionally, it is used to change the system's operating mode, switching busbar conversion currents and small currents within the specified range, such as those for voltage transformers and lightning arresters.