A Helicopter Starting/Servicing System typically consists of a Transformer Rectifier unit (TRU), a Static Frequency Converter (SFC), contactor boxes, control panels, socket boxes and cables.
The Transformer Rectifier Units used for shipboard helicopter starting applications have three basic modes of operation:
- Powering the starter motor of a helicopter – The TRUs are specifically designed to supply the high peak current requirement.
- Providing a 28VDC supply to aircraft on-board equipment
- Providing an 18.2V DV supply for turning the helicopter turbo shaft engine at reduced speed for compressor washing
The Static Frequency Converters supply the helicopter with 200V, 3ph, 400Hz with high overload capability.
Contactors are typically used to control the outputs of the power equipment to the helicopter. They can be incorporated into the power equipment or supplied in separate enclosures.