Schaltbau – High-voltage contactors in electric vehicles (BDU)

Used as main contactors in the Battery Disconnect Unit (BDU) the high power contactors from Schaltbau ensure safety for passengers and the vehicle throughout driving, braking or in case of emergency.
Learn more about our solutions for safe electromobility in our new video and get first impressions about our new contactor innovations C800 and C320.


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Voice over in video:

The future of mobility is electric. Schaltbau specialises in switching and controlling direct currents in demanding conditions.
The high-voltage Battery Disconnect Unit is responsible for ensuring safe galvanic isolation. The unit is equipped with sensors, fuses, diagnosis technology, one pre-charge contactor and two main contactors.

Switching on
In its idle state, the electric-vehicle battery is disconnected from the high-voltage electrical system. When the vehicle is switched on, the lower main contactor closes, and then the pre-charge contactor. The capacitor is charged via the resistor. This limits the inrush current. Then the upper main contactor closes and the pre-charge contactor opens. The process of switching on is now complete.

The vehicle drives.

Under braking, the propulsion engine becomes a generator. The C310 works bi-directionally. The recovered energy is stored in the battery.
If a malfunction occurs – such as thermal overload, a short-circuit or an accident – both main contactors disconnect the battery from the vehicle’s high-voltage electrical system galvanically and electrically. Current can no longer flow. This ensures safety for passengers, emergency services and the vehicle itself.

Every Schaltbau contactor is packed with expertise:
· Arc control – without gas encapsulated arc chambers
· Continuous thermal currents of up to 1000 amperes
· Bi-directional DC contactors up to 1500 volts
· Optimal switching performance – Low energy consumption
We provide solutions for all safety-relevant applications in electromobility: Contactors for battery disconnect units, propulsion motors, charging systems for high-voltage batteries and test stations for vehicle batteries.

Schaltbau – Your specialist in switching and controlling direct currents.
Connect. Contact. Control.


Schaltbau, high-voltage contactors, contactors, safety switchgear, bidirectional contactors, handling direct current, electromobility, galvanic isolation, e-mobility, e-cars, battery disconnect unit, driving, braking.