DC contactors for freight traffic in the 'smart cities' of tomorrow

The C310 contactor in use in electric trucks

In the cities, the call for a healthier and more liveable climate for inhabitants is becoming ever louder. In order to align the inner-city transport of goods and freight with these requirements, electrified trucks will increasingly be used in the future. Owing to their low noise levels, these vehicles can perform numerous tasks at off-peak hours in the early morning or late evening. They therefore contribute to a reduction in the high volume of traffic and run without emissions, thus ensuring an improvement in the quality of air and life.

In the discussion with a manufacturer of electric trucks for urban freight traffic, Schaltbau was able to demonstrate a new solution for the battery disconnect unit of the vehicle. The contactors previously used with an encapsulated switching chamber and filled with gas repeatedly led to problems, to the point where the customer sought an alternative.

Together with the customer, Schaltbau product specialists developed a solution which met all the requirements of the system (700 V / 500 A). After a successful trial phase, the user-specific design of the C310 series of contactors occurred in 2 versions.

What does the Schaltbau C310 contactor do?

For the battery disconnect unit (BDU) of these vehicles, Schaltbau supplies the C310/500, operating as a main contactor on the positive and minus pole of the drive battery. In the event of a fault, the high-voltage contactors disconnect the drive battery from the entire electrical drive train of the vehicle. In addition, the C310/300 version is used in order to be able to disconnect individual battery packs from the system separately, too.

Why was the C310 chosen?

By using the C310 DC contactor, the customer was able to significantly reduce its vehicle performance in terms of safety and reliability. An encapsulated switching chamber filled with gas can be omitted, because the C310 contactor works with an air system.
Excess pressure developing due to intensive electric arc formation in extreme switching conditions can therefore escape. This therefore eliminates the risk of cracks with the destruction of the component or surrounding components. Furthermore, the C310 family of contactors is characterised by very high current-carrying capacities, simplifying system design markedly with respect to other safety components (fuses).