They consist ____ a hydraulically driven ac/dc generator, a motor-generator control unit, and a control solenoid. The kVA rating of this emergency generator is much lower than the primary generator(s), so the emergency generator powers a limited number _____circuits.
As the rotor turns (hydraulic motor running), the permanent magnet induces power _____ the PMG. Regulated and rectified PMG output power goes _____ a stationary control field ____ the motor-generator. The motion _____ the rotor assembly induces PMG power ____ the windings ____ the exciter alternator. This power is rectified and, in turn, induced ____ the output ac winding and the dc winding. This unit adjusts the regulation ____maintain the ac output at 115 volts per phase ± 1.5% when operating ___+full hydraulic system pressure. The dc output ____ the stationary rectifier goes ___ the dc transfer relay contacts ___distribution ___ the essential dc buses. The hydraulic motor converts 3,000 pounds per square inch ___ hydraulic pressure___ constant-speed rotation, maintaining generator output frequency ___ 400 Hz. The motor-generator is cooled ___ hydraulic fluid __ the same source that drives the hydraulic motor. The motor-generator control provides voltage regulation ___, and fault detection ___, motor-generator output. When the motor-generator is operating, PMG power flows ___ the rectifier, where the three-phase ac is rectified __ a dc signal. The dc signal is __control panel and relay control power. The signal then flows __ the voltage regulator section __ the motor-generator control unit. The voltage regulator supplies field excitation ___the motor-generator and monitors the output voltage. Monitoring protective circuits __ the motor-generator control prevents __ - __tolerance power ___ being connected __ the essential bus system.The motor-generator solenoid control valve controls the operation __ the emergency electrical power system. The valve drives electrically ___the closed position when primary electrical power is available. The entire operation is completely automatic ___primary electrical power failure.
