AFGS-87219 Electrical Power Systems, AircraftThis specification establishes the performance requirements and verifications for electric power subsystems EPS for aerospace vehicles, including aircraft, helicopters, and missiles.

Pages 1 - 2 - 3 - 4 - 5 - 6 - 7 - 8 - 9 - 10 - 11 - 12 - 13 - 14 - 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22 - 23 - 24 - 25 - 26 - 27 - 28 - 29 - 30 - 31 - 32 - 33 - 34 - 35 - 36 - 37 - 38 - 39 - 40 - 41 - 42 - 43 - 44 - 45 - 46 - 47 - 48 - 49 - 50 - 51 - 52 - 53 - 54 - 55 - 56 - 57 - 58 - 59 - 60 - 61 - 62 - 63 - 64 - 65 - 66 - 67 - 68 - 69 - 70

AFGS�87219B

b. In the event of an EPS failure that reduces the amount of available power below total aircraft requirements; non-flight critical and/or pre-selected loads shall be automatically disconnected as required.

c. Flight critical loads shall have first priority to primary power and shall be supplied from the emergency power source when primary power is not available.

d. The power quality requirements of 3.2.1 shall be maintained.

e. Convenient means shall be provided for disconnecting ground power from those equipments not requiring power during ground operation.

f. Other requirements for electric power distribution are as follows: ------------.

3.2.8 Control and protection.

The electric power subsystem shall include all control and protective functions necessary for safe and effective operation.

a. Routine operations of the EPS such as normal start-up, shut-down, paralleling, and voltage and frequency regulation which require no crew decisions shall be performed automatically.

b. The crew shall be provided with the instruments and manual controls necessary for effective control of the EPS for normal and abnormal operation. This shall include indications of all system faults and malfunctions which affect flight safety or mission effectiveness.

c. Automatic protective functions shall be provided for abnormal conditions of the electric power subsystem which require a prompt predetermined response and for which no crew decisions are needed. Faults and malfunctions shall be detected, isolated, and

de-energized in a manner which eliminates the hazardous condition with minimum

effect on the safety and performance of the aircraft.

d. All distribution circuits including generator feeders, bus ties, and load circuits shall be protected against short circuits and overloads throughout their total length. Each load circuit shall be individually protected to prevent a single fault from affecting more than one critical function.

e. Multiple-wire feeder circuits shall be used as necessary to meet reliability and vulnerability requirements.

f. Redundant power circuits and components shall be routed/located separately to minimize vulnerability. Means shall be provided for detecting the failure of each redundant component.