Main contactor in electrically powered aircraft tractors

Bidirectional C310 DC contactor enables energy recovery

The battery pack in an electrically powered aircraft tractor feeds the inverter for the drive systems. The inverter is protected by a fuse and a main contactor. For this task, the manufacturer wanted a bidirectional DC contactor for energy recovery during braking.

Why was the C310 used?

As a conventional contactor using air as the insulating medium, it is not at risk of developing leaks, unlike encapsulated or gas-filled contactors. The high current carrying capacity was also a deciding factor. In the selected C310A/500 model, the contactor can carry a conventional thermal current of up to 500 amps; in a short-circuit up to 3,000 amps can flow for one second without the contacts welding.
These are the key features of the C310:

  • Bidirectional switching of high DC power
  • Low holding power
  • Rated short-time withstand current Icw up to 3,000 amps (1 s)