Sulfur hexafluoride circuit breakerIt is an oil-free switchgear that uses SF6 gas as the insulation medium and arc extinguishing medium. Its insulation performance and arc extinguishing characteristics are much higher than those of oil circuit breakers. Due to its high price and high requirements for the application, management, and operation of SF6 gas, it is not widely used in medium voltage (35, 10kV) applications, mainly for voltage levels above 110kV.
Mechanical component maintenance:
Regular lubrication and operational testing:
Lubricate the rotating and transmission parts every six months and operate them three times to ensure the normal functioning of the mechanism.
Check the on/off position indicator, fasteners, and energy storage motor to ensure there is no looseness, abnormal noise, or burnt smell.
Contact and insulation inspection:
Regularly check the wear of the contacts, and the contact resistance should be less than 45 μ Ω. If the wear is severe, it needs to be replaced.
Check whether the surface of the porcelain sleeve is damaged or dirty, and conduct a hydrophobicity test (recommended every two years).
Pressure monitoring and leak handling:
Regularly check the pressure gauge and compare it with the temperature pressure curve to confirm if the gas pressure is normal.
If the annual decrease rate of gas density is greater than 0.01 MPa/year, a leak detector should be used to detect the leakage point. Common leakage locations include welds, sealing surfaces, pipeline joints, etc. The treatment methods include welding repair, replacing sealing components, or treating sealing surfaces.
After the leakage, the micro water content needs to be tested to ensure compliance with the standards.
Security protection:
During maintenance, it is necessary to disconnect the main circuit and ground it. If an energy storage spring operating mechanism is used, the opening and closing spring should be loosened.
Before entering the SF6 distribution equipment room, it is necessary to check whether the gas content exceeds the standard.