Compared with the commonly used ring main unit, the HAS-12 type ring main unit is designed with two upper and lower isolation switches, a grounding switch, two upper and lower contact boxes and valves. It has intuitive status, simple operation (electric), convenient maintenance, and safe and reliable operation.
HAS-12 type direct air circuit breaker is not only connected with the whole cabinet freely, but also has the following characteristics:
1. The vacuum arc chamber is combined with the upper and lower disconnectors into a sealed pole. After the disconnector is opened, the contact arm shrinks in the pole, and the whole switch can be pulled out of the cabinet for replacement or maintenance
2. Because the upper and lower contact arms are vertically extended, a nearly straight conductive circuit is formed from the busbar to the cable connector, the circuit length is shortened, and the volume of the whole cabinet is minimized under the premise of using air as the main insulation;
△ The heating parts such as the isolation contact can be directly observed to ensure safety;
△ The parameters such as the opening distance, overtravel, and synchronization that need to be detected and adjusted the most can be easily detected and adjusted;
3. In areas above 1000m above sea level, the whole switch is sealed in the high-voltage switch room and maintained at no less than an absolute atmospheric pressure, and is no longer affected by the external environment;
4. The disconnector is electrically operated, making the operation safer and more labor-saving, especially suitable for unmanned substations and box-type substations.