On the basis of more than 40 years experience in production of high voltage circuit-breaks that are in operation all over the world in all climatic zones, has developed a new generation of compact single-pole operated SF6 circuit-breaks with electrohydraulic or spring operating mechanism.

New metal-enclosed gas SF6 insulated switchgear type K8D9 and K9D7 for 72.5 kV to 300 kV is characterized with high-tech quality, contemporary technical solutions and high reliability as a result of many years of experience of production of metal-enclosed switchgears and using contemporary methods and tools in development of those switchgears.

During designing of switchgear, computer workstations and adequate software were used for electrical

and mechanical

calculations and that approach resulted with excellent characteristics including high safety standards.

The basic characteristics of K8D9 and K9D7 switchgear are:

- Small dimensions and weight
- System adaptability which allows different  installations layouts
- Accessibility to all standard modules, low noise level thanks to fully   enclosed switching and mechanism
- Possibility to set up all the standard circuit arrangements fast and   easy to transport and easy to assembly due to construction simplicity   because of modular structure
- Small costs of maintenance because of long necessary service   periods due to high tech standard and high quality materials in   construction
- Minimal gas losses because of reliable sealing system
- Safety for operating personnel because for full enclosure of   switchgear
- Acceptable for environment because of minimal space taking, low   noise level, minimal gas losses and high reliability wich is sutable for   urban centers