Precharging and main contactor for DC networks

Two versions of the C310 bidirectional contactor are used in a DC laboratory network

A research institute constructed a DC laboratory network for a research project on the optimisation of production systems. The project sets out to investigate the advantages of a smart DC power supply for production systems. Schaltbau is providing two different models of the C310 DC contactor.

Project partners include the German Electrical & Electronic Industry (ZVEI) and an industry consortium. The goal of investigations is to build and operate an energy-efficient DC network. The network supplies all drive inverters and thus achieves an internal energy balance – between driving and regenerative braking. In addition, the DC network is fed by a solar power and battery storage system. The central connection to the conventional AC network only needs to provide the difference in energy.

What tasks do the two DC contactors perform?

While the C310/150 variant takes care of the precharging path, the C310/500 is used as the main contactor. Normally the main contactor is only switched without load, and serves to electrically isolate the individual branches. In an emergency, however, the contactor can disconnect the full load. This increases safety in the event of a fault. The individual branches can be connected and disconnected as needed.

Why was the C310 chosen?
  • Bidirectional switching of high DC power
  • Compact size: 146.2 × 81.0 × 89.7 mm
  • Making capacity Icm up to 2,500 A
  • Continuous thermal current up to 500 A
  • Rated short-time withstand current Icw up to 3,000 amps (1s)