New switch-disconnectors with protective function
With the 3KF product series, Siemens has developed new switch-disconnectors with fuses for currents up to 800 amperes. They reliably protect users from electrical accidents during maintenance and installation work in control cabinets. Together with the switch-disconnectors from the 3KD series, which can switch currents up to 1600 amps, Siemens now covers almost the entire product range for low-voltage power distribution with the Sentron portfolio.
The modular and compact units are suitable for AC applications such as industrial manufacturing, buildings and wind power as well as DC environments. If required, locks can be hooked into the front or side drives. These prevent unauthorized switching and provide additional protection. Siemens offers the switches in five sizes, all of which are available in three- and four-pole versions. They comply with the IEC 60947-3 standard for low-voltage switchgear and the device-specific EC directives for product safety.
Diverse protection
The combination of load-break switches and disconnectors is referred to as switch-disconnectors. They fulfil the function of both technologies and enable electrical equipment to be switched on and off, even under load. They are also suitable as repair switches when voltage-free maintenance work is required on systems. As emergency stop switches in production lines, they ensure protection of the operator from electric shocks in the event of faults. In addition, they can be used as main switches in floor distributions for mains disconnection.
The switch-disconnector 3KF offers a wide range of protective devices: Terminal covers for each application prevent live parts from being touched. The status of the fuses is clearly visible through transparent contact covers. Clip-on phase separators protect against flashovers. An optional fuse monitoring system reports tripped fuses so that immediate action can be taken.
The mounting of the switch-disconnectors is very simple: All variants can be mounted on mounting plates. The models up to 80 A also offer the option of being mounted on top-hat rails. The connection can be made using frame terminals (up to 80 A) or flat terminals (from 80 A). The integrated test function checks the wiring of the control circuits during installation.
The service and support offer rounds off the portfolio. Various CAx files are available for download for mechanical and electrical planning. These include device circuit diagrams, connection diagrams, dimensional drawings and 3D models. The CAx download manager enables flexible compilation for all common project planning tools.
