Structural Features Of Gas Switchgear

Gas switchgear offer many advantages, such as being immune to external environments such as condensation, pollution, small animals and chemicals. Another advantage is that the use of compressed gas insulation materials is conducive to the development of miniaturization, and gas charging has good oil-free switch performance, especially for maintenance-free or low-maintenance vacuum switches, which greatly reduces the workload of maintenance and overhaul.

1. Fixed structure technology

Good quality gas switchgear use maintenance-free vacuum circuit breaker technology and use fixed vacuum circuit breakers instead of medium-sized, limited quantities of installed trolley oil-less circuit breakers. The isolating switch and earthing switch are combined into one switch instead of a single switch, thus greatly reducing space and reducing interlocking work. The current transformer adopts the ring iron core current transformer to replace the ordinary cast insulation current transformer which bears high electrical load. With SF6 gas insulation, there is no need to maintain and repair each switching element.

2. The cable connection adopts a fully insulated and electric shock-proof plug-in structure instead of ordinary cable joints

The key process of inflation, the shell of the gas switchgear is welded into a completely air-tight structure, thereby eliminating the influence of environmental factors. Laser welding technology is used to prevent the escape of SF6 insulating gas and the intrusion of moisture. The gas tightness is usually checked by leak detection devices integrated in each housing. The required operating power is transferred from the outside of the inflatable cabinet to the inside and through the bellows. Electrical components in gas-filled cabinets are connected to cables or busbars by welding bushings.

All in all, the structural features of the gas switchgear are fixed structure technology, and the cable connection adopts a fully insulated and electric shock-proof plug-in structure instead of ordinary cable joints. The working readiness of the inflatable cabinet is displayed by magnetic coupling without contact via the measuring box installed in the cabinet.