Three Main Causes Of Jamming In High-voltage Disconnect Switch Transmission

According to statistics, among the defects in switchgear, the High Voltage Disconnect Switch problem of operational jamming accounts for the highest proportion. Each refusal to switch on or off not only delays switching operations but can also trigger power grid safety incidents. What is the root cause of this "immobility" in the transmission mechanism?

Three Main Causes of Transmission Jamming

A thorough analysis of field cases reveals that the factors leading to mechanical transmission jamming in high-voltage disconnect switches mainly fall into three categories:

Environmental Corrosion and Lubrication Failure

In outdoor operating mechanisms, poor sealing allows rainwater to seep in, causing rapid corrosion of shafts, connecting rods, and bearings. In rotating parts that remain stationary for extended periods, internal grease dries and deteriorates; combined with wind and moisture, the oxide layer thickens, directly increasing resistance to movement. Some older equipment using brass bushings experiences dezincification corrosion after exposure to moisture, resulting in oxide powder filling the mating gaps and ultimately causing the mechanism to seize.

Component Design Defects

Specific models of high-voltage disconnect switches have inherent design flaws. For example, in some manual operating mechanisms, the clearance between the main shaft and the copper bushing is too narrow, preventing the retention of lubricating oil. The bearing housing lacks an external lubrication channel, causing the lubricating oil to dry out after prolonged operation, leading to corrosion. An improperly designed dust cover may even trap rainwater and allow water to enter the lower part of the bearing housing, accelerating the corrosion process.

Improper Installation and Commissioning

Neglect during installation also creates potential problems for later jamming. If new equipment is not disassembled and inspected before installation, ordinary grease used during production can easily run off and harden, resulting in a lack of lubrication in the transmission mechanism. Furthermore, applying excessive conductive grease to the contacts, after hardening and combining with dust, can also cause jamming at the contact points.