Clean and quiet drives for emission-free cities

DC contactors with high breaking capacities of up to 1,000 V DC / 800 A impress in drives for electric buses.

Growing populations, air pollution and climate change have increasingly changed traffic in cities. Electromobility in public transport is an important component for environmentally friendly mobility and for achieving climate protection objectives in relation to transport. In order to reduce air and noise pollution in urban areas, operators of fleets of vehicles have begun electrifying their fleets. The electric bus is only the first step towards an emission-free city.
In the drive concept for these vehicles, the compact C310 high-current contactors from Schaltbau are ideally suited for disconnecting the high-voltage network from the drive train in the event of a fault. In the project currently implemented, they are used as an emergency cut-out component in the DC circuit of a permanent magnet synchronous motor.

What does the Schaltbau C310 contactor do?

AC disconnection mechanisms are usually used for synchronous motors. In this project, the AC disconnection unit would have had to be placed on the roof of the bus, which would have meant considerable extra cost for the cabling. Following extensive tests and competitor comparisons, a disconnection mechanism in the DC circuit using the Schaltbau C310 contactors was chosen. The following factors were decisive for this:

  • Superior disconnection capacity in a direct product comparison – 1,000 V DC / 800 A (two-pole disconnection)
  • Customer-specific wide-range coils with high bandwidth (input from 9 V – 45 V)
  • Short-time current-carrying capacity Icw of up to 3,000 A (1 s)
  • No encapsulated switching chamber filled with gas: C310 contactors are based on an air system. No excess pressure or leaks occur when extinguishing electric arcs, meaning a significant reduction in risk.