ABB Compact & Withdrawable SF6 Gas Circuit Breaker Type HD4

HD4 medium voltage circuit-breakers use sulphur hexafluoride gas (SF6) to extinguish the electric arc and as the insulating medium.

Breaking in SF6 gas takes place without any arc chopping and without generation of overvoltages. These characteristics ensure long electrical life of the circuit-breaker and limited dynamic, dielectric and thermal stresses on the installation.

The circuit-breaker poles, which make up the breaking part, are systems with lifelong sealed pressure (IEC 62271-100 and CEI 17-1 Standards) and are maintenance-free.

The ESH type mechanical operating mechanism, with stored energy has free release and allows opening and closing operations independently of the operator’s actions.

The operating mechanism and the poles are fixed to the metal structure which also acts as a support for the kinetics for operating the moving contacts. Circuit-breakers in the withdrawable version are fitted with a truck to allow racking in and racking out of the switchgear or enclosure. The light and compact structure of the circuit-breaker
ensures great sturdiness and excellent mechanical reliability.

Technical Specification: