R-400 28VDC GROUND POWER UNIT

The Rectodyne Model R-400 serves a broad range of aircraft ground power needs. It provides high currents for fast, reliable turbine spooling, as well as regulated DC power for avionics and lighting systems. Efficient and economical, the Model R-400 is the unit of choice for aircraft servicing functions in the hangar or on the ramp. The qualities and characteristics of the Rectodyne Model R-400 are summed up in one word: Reliability - and that means failure-free performance under all conditions. The R-400's NSN listing is # 6130-01-462-5927.

Key Features: • Adjustable Output Current Limiting • Worldwide, 3-Phase 50/60Hz AC Input • Adjustable Output Voltage • 400 Amps Continuous • 2,000 Amps Peak for Turbine Spooling

SYSTEM OPERATION

The Rectodyne Model R-400 has been specifically designed for electrical and mechanical simplicity, physical ruggedness and component accessibility, all of which contribute to its high reliability, convenience of use and ease of maintenance.

The Model R-400 accepts 3-phase, 50/60Hz, 208. 230, 380 or 460VAC input power, allowing the unit to be used virtually anywhere in the world. The power is applied through a manually adjustable input voltage selector and a power input control circuit to a 3-phase power transformer. The input control circuit contains heavy duty thermostats for thermal overload protection, as well as an airflow sensor which shuts the GPU down in the event of ventilating fan failure.

The power transformer steps the input voltage down appropriately, and applies it to a 3-phase, full-wave rectifier bank. Taps on the transformer secondaries allow the output voltage of the GPU to be adjusted, and a resistor network permits the output current to be limited. These functions are controlled by multiposition switches on the front panel of the R-400.

The 3-phase rectifier converts the AC power from the transformer into pulsating DC power. Ripple on the rectified AC is smoothed with an LC power filter circuit, and made available as a DC output through a resistor ballast regulator. The suppression of radio frequency energy generated by rectifier switching transients or other sources in the power supply is achieved by high-pass filter networks on the rectifier bank and output filter.

The resistor ballast regulator compensates for load variations. Both output voltage and current are metered by rugged analog meter on the front panel. Cables for connecting the R-400 to an aircraft can be stored on the GPU with convenient cable hooks.

FEATURES & BENEFITS

CONTROL & INDICATORS