Helicopter Starting Rectifier 3RC15KB

The Helicopter Starting Rectifier 3RC15KB is for shipboard Helicopter Start applications. It has three modes of operation:

• Powering the starter motor of a helicopter
• Providing a 28VDC supply to aircraft on-board equipment
• Providing a 18.2VDC supply for turning the helicopter turbo shaft engine at reduced speed for compressor washing

The 3RC15KB also provides a high quality 28V regulated output along with a two stage current limit protection circuit.  As a result, a short time rating of 3000A and continuous rating of 540A is possible.

Rugged Enclosure

A custom steel enclosure (designed for deck mounting), houses the Transformer Rectifier Unit.  This unit is suitable for sock levels up to 30g and has an IP23 protection level.  Suitable shock mounts are required for shock levels above 30g.  Easy access for maintenance and repair is available through hinged door that opens to 1800 with a minimum maintenance-opening requirement of 900 . The door also contains indicating lamps for supply available, anti condensation heater on and output on.  It also has an ON/OFF switch. Louvres on the front and sides of the assembly along with a shielded vent on the top of the unit provide fan assisted cooling during normal operation. Natural convection cooling also cools the unit when Anti Condensation Heaters are operating.

A Soft Start System

A soft start system is employed such that the input inrush current is less than the full load current. The TRU has an input isolation transformer and a 12 pulse thyristor rectifier configured as two fully controlled bridges combined in parallel by an interphase transformer. This produces a very smooth DC output and eliminates all harmonics below the 11th from the input current waveform. The input current to the equipment is close to sinusoidal with a “traditional” lagging power factor dependent on loading and mains voltage.

Electrical Connections

Electrical connections to and from the Transformer Rectifier Unit for supply, heater, remote and sense connections are made on rail-mounted terminals.  M12 bolt connections provide for the output. Furthermore, the cable gland plate situated on the bottom of the enclosure provide access to the terminals inside the cubicle.  Finally, an M10 (x 1.5) external earth stud is also provided adjacent to the gland plate, on the bottom of the enclosure.

Features of the Helicopter Starting Rectifier 3RC15KB Include:

• Enclosure fabricated mild steel folded and welded for strength. Deck mounted, top steadies. Lifting eyes.
• Dimensions: 1385 x 640 x 715 mm
• Weight: 460kg
• IP23 Ingress Protection Level
• Natural cooling via louvers
• Low fire hazard
• M10 external earth stud
• Meets vibration requirements of DGS 350
• Withstands ship motion due to sea action, weather and accelerations and velocities from deliberate ship manoeuvres
• Input: 440 volts 3 phase 3 wire 60Hz in accordance with STANAG 1008 Edition 8

For more information, contact us.