1、 AMSC N/A FSC 6115 INCH-POUND MIL-PRF-21480B 22 March 2010 SUPERSEDING MIL-G-21480A(AS) 30 September 1970 PERFORMANCE SPECIFICATION GENERATOR SYSTEM, ELECTRIC POWER, 400 HERTZ, ALTERNATING CURRENT, AIRCRAFT; GENERAL SPECIFICATION FOR Comments, suggestions, or questions on this document should be add
2、ressed to the Naval Air Systems Command (Commander, Naval Air Warfare Center Aircraft Division, Code 4L8000B120-3, Highway 547, Lakehurst, NJ 08733-5100) or emailed to michael.sikoranavy.mil. Since contact information can change, you may want to verify the currency of this address information using
3、the ASSIST Online database at https:/assist.daps.dla.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-21480B iiCONTENTS PARAGRAPH PAGE 1. SCOPE . 1 1.1 Scope. 1 1.2 Classification. 1 1.2.1 Generator class 1 1.2.2 Part or identifying numbe
4、r (PIN) 1 2. APPLICABLE DOCUMENTS 1 2.1 General 1 2.2 Government documents 1 2.2.1 Specifications and standards. 1 2.3 Non-Government publications 2 2.4 Order of precedence 3 3. REQUIREMENTS 3 3.1 Specification sheets. 3 3.2 Qualification . 3 3.3 Materials .3 3.3.1 Selection of materials, parts, and
5、 processes 3 3.3.2 Moisture resistance . 3 3.3.3 Corrosion resistance 3 3.3.4 Contamination by fluids 3 3.3.5 Toxicity and fire resistance. 3 3.4 Design and construction 4 3.4.1 Electrical insulation and dielectric 4 3.4.2 Environmental performance 4 3.4.2.1 Temperature altitude . 4 3.4.2.1.1 Blast
6、air cooled and integral fan cooled components . 4 3.4.2.1.2 Liquid-cooled and self-cooled components 4 3.4.2.2 Humidity . 4 3.4.2.3 Salt-spray 4 3.4.2.4 Fungus. 5 3.4.2.5 Sand and dust 5 3.4.2.6 Mechanical shock (functional and crash safety). 5 3.4.2.7 Vibration . 5 3.4.2.7.1 Engine vibration (categ
7、ory 1) . 5 3.4.2.7.2 Aircraft platform vibration 5 3.4.2.8 Acceleration forces . 5 3.4.2.9 Water intrusion and immersion. 6 3.4.2.10 Chemical, biological, and radiological (CBR) 6 3.4.2.11 Lightning, electromagnetic pulse, and directed energy weapons . 6 3.4.3 Operating position. 6 3.4.4 Explosive a
8、tmosphere . 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-21480B iiiCONTENTS PARAGRAPH PAGE 3.4.5 Configuration 6 3.4.6 Consolidation of generating system components . 6 3.4.7 System control 6 3.4.7.1 Manual system control 6 3.4.7.2 Autom
9、atic reset (engine shutdown/underspeed). 7 3.4.8 System capacity (power source rating). 7 3.4.8.1 Continuous capacity (AC power) 7 3.4.8.2 Overload capacity (AC power) . 7 3.4.8.2.1 Motor starting (AC power) . 7 3.4.8.2.2 Emergency overload (AC power) . 7 3.4.8.3 Short circuit capacity (AC power) 8
10、3.4.8.4 Integral control power capacity 8 3.4.8.4.1 Excitation and control of AC power . 8 3.4.8.4.2 Rating of DC power source. 8 3.4.9 System design (generator and control components) . 9 3.4.9.1 Shaft speed 9 3.4.9.1.1 Maximum speed for regulation. 9 3.4.9.1.2 Overspeed . 9 3.4.9.2 Mounting and dr
11、iving provisions 9 3.4.9.2.1 Shaft spline 9 3.4.9.2.2 Shear section . 10 3.4.9.2.3 Maximum torque. 10 3.4.9.2.4 Flexible drive 10 3.4.9.3 Electric connections 10 3.4.9.4 Direction of rotation 11 3.4.9.5 Efficiency (heat rejection). 11 3.4.9.6 Cooling 11 3.4.9.6.1 Air cooling (convection or forced ai
12、r) 11 3.4.9.6.2 Liquid cooling. 11 3.4.9.7 Generator service life 12 3.4.10 Control component service life. 12 3.4.11 Color . 13 3.4.12 Markings . 13 3.4.13 Adjustments 13 3.5 Electrical performance 13 3.5.1 Voltage limits for normal operation 13 3.5.1.1 Voltage limits for AC power source . 13 3.5.1
13、.2 Voltage limits for DC power source (see 3.4.8.4.2. 13 3.5.2 Voltage modulation (AC power source). 13 3.5.3 Voltage unbalance and phase displacement 14 3.5.4 Voltage waveform (AC power source). 14 3.5.5 Voltage ripple and distortion (DC power source). 14 Provided by IHSNot for ResaleNo reproductio
14、n or networking permitted without license from IHS-,-,-MIL-PRF-21480B ivCONTENTS PARAGRAPH PAGE 3.5.6 Simultaneous load and speed transients 15 3.5.7 Protective functions (abnormal power and fault conditions) 15 3.5.7.1 False trips 15 3.5.7.2 Overvoltage protection 15 3.5.7.3 Undervoltage protection
15、 15 3.5.7.4 Frequency protection 15 3.5.7.5 Overcurrent protection (short circuit AC current limit) 16 3.5.7.6 Feeder fault . 16 3.5.7.7 Anti-cycling 16 3.5.7.8 Bus fault isolation . 17 3.5.7.9 Waveform protection (extraneous AC distortion and DC content) 17 3.5.7.10 Arc fault power feeder protectio
16、n. 17 3.5.8 Electromagnetic compatibility 17 3.5.9 Paralleling . 17 3.5.10 Generator output characteristics . 17 3.6 Interchangeability . 17 3.7 Mechanical connections, fasteners, inserts, and retaining hardware 17 3.8 Seals, coatings and sealant compounds 17 3.9 Endurance (durability) 17 3.10 Relia
17、bility 18 3.11 Maintainability 18 3.12 Workmanship 18 4. VERIFICATION. 18 4.1 Classification of inspections . 18 4.2 Qualification inspection 18 4.2.1 Qualification sample submittal . 18 4.2.2 Qualification inspections and tests 18 4.2.3 Qualification retention 19 4.2.4 Rejection, resubmittal, and r
18、etest 19 4.3 Conformance inspection . 19 4.4 Standard conditions. 20 4.4.1 Tolerances for controlled test environment 20 4.4.2 Test sample . 20 4.4.3 Loading of the AC power source 20 4.4.4 Loading of the DC power source 20 4.4.5 Voltage and frequency measurements 21 4.4.6 Power factor 21 4.4.7 Comp
19、onent mounting 21 4.4.8 Thermal. 21 4.4.8.1 Thermal isolation 21 4.4.8.2 Warm-up and temperature stabilization 21 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-21480B vCONTENTS PARAGRAPH PAGE 4.4.9 Generator package input shaft speed 21 4.4
20、.10 Environmental test methods 21 4.4.11 Electrical performance verification. 21 4.5 Methods of inspection. 21 4.5.1 Examination of product. 21 4.5.2 Maximum speed for regulation. 22 4.5.3 Electrical performance 22 4.5.3.1 Electrical performance at standard temperature . 22 4.5.3.2 Electrical perfor
21、mance at minimum temperature . 23 4.5.3.3 Electrical performance at maximum temperature. 24 4.5.3.4 Electrical performance for conformance inspection. 25 4.5.4 Overspeed . 26 4.5.5 Dielectric strength. 26 4.5.5.1 Qualification and conformance inspection . 26 4.5.5.2 Production lot inspection (manufa
22、cturer only) . 26 4.5.6 Load and speed transients . 26 4.5.7 Voltage ripple and distortion (DC power source). 26 4.5.8 Phase balance 27 4.5.9 Efficiency (heat rejection). 27 4.5.10 Short circuit capacity (AC and DC) 27 4.5.11 Output AC voltage modulation. 27 4.5.12 Electromagnetic emissions and susc
23、eptibility 27 4.5.13 Voltage waveform distortion 28 4.5.14 Temperature altitude . 28 4.5.15 Operating position. 28 4.5.16 Switch operation (control and reset functions) . 29 4.5.17 Protective functions 29 4.5.18 Electrical disconnect (safety interlock). 30 4.5.19 Maximum generator torque. 30 4.5.20
24、Salt-fog environment and oil-salt water ingestion 30 4.5.20.1 Salt-fog 30 4.5.20.2 Oil-saltwater ingestion 30 4.5.21 Fungus. 31 4.5.22 Sand and dust 31 4.5.23 Vibration . 31 4.5.23.1 Test fixture inspection and preparation. 31 4.5.23.2 Vibration exposure level and duration 31 4.5.23.2.1 Test procedu
25、re for engine and gearbox mounted components . 32 4.5.23.2.2 Test procedure for non-engine mounted components. 32 4.5.24 Shock. 32 4.5.25 Humidity . 33 4.5.26 Rain intrusion 33 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-21480B viCONTENTS
26、 PARAGRAPH PAGE 4.5.27 Contamination by fluids 33 4.5.28 Endurance . 33 4.5.28.1 Air cooled components . 34 4.5.28.2 Liquid cooled components 34 4.5.29 Loss of cooling 35 4.5.30 Spline wear examination. 35 4.5.31 Input shaft shear 35 4.5.32 Explosive atmosphere . 35 4.5.33 Toxicity and fire resistan
27、ce. 35 4.5.34 Coolant contamination 35 4.5.35 Acceleration (inertia loads). 35 4.5.36 Reliability and maintainability 35 5. PACKAGING. 36 5.1 Packaging 36 6. NOTES. . 36 6.1 Intended use 36 6.2 Acquisition requirements 36 6.3 Qualification . 37 6.3.1 Provisions governing qualification . 37 6.3.2 Qua
28、lification sample submittal . 37 6.4 Cross reference 37 6.5 Standard design practices 37 6.5.1 Materials and structural design . 37 6.5.1.1 Recycled, recovered, or environmentally preferable materials 37 6.5.1.2 Corrosion. 38 6.5.1.3 Fasteners, inserts and retaining hardware . 38 6.5.1.4 Bearing ins
29、tallation and lubrication 38 6.5.2 Electrical and electronics design. 38 6.5.2.1 Wiring and distribution. 38 6.5.2.2 Electronics internal wiring and electric connections 38 6.5.2.3 Electronics (semiconductors, resistors, capacitors, transformers, and relays) 38 6.5.2.4 Microelectronic devices 38 6.5
30、.3 Parts de-rating . 38 6.5.4 Reliability 39 6.5.5 Identification markings . 39 6.5.6 Oil, fuel, and hydraulic fluids . 39 6.6 Environmental requirements tailoring 39 6.6.1 Temperature altitude . 39 6.6.2 Salt-fog (corrosion resistance) 39 6.6.3 Vibration . 39 Provided by IHSNot for ResaleNo reprodu
31、ction or networking permitted without license from IHS-,-,-MIL-PRF-21480B viiCONTENTS PARAGRAPH PAGE 6.6.3.1 Vibration test fixture. 39 6.6.3.2 Vibration spectrum exposure level and duration 39 6.6.4 Shock. 40 6.7 Packaging 40 6.8 Definitions. 40 6.8.1 Constant speed operation 40 6.8.2 Control switc
32、h. 40 6.8.3 Crest factor 41 6.8.4 Current transformer. 41 6.8.5 Efficiency 41 6.8.6 Faults. 41 6.8.7 Generator speed range. 42 6.8.8 Generator system (channel) 42 6.8.9 Generator system component 42 6.8.10 Generator voltage rating . 42 6.8.11 Integral control power. 42 6.8.12 Phase current. 42 6.8.1
33、3 Phase load unbalance 42 6.8.14 Phase voltage 42 6.8.15 Phase voltage unbalance . 42 6.8.16 Point of regulation (POR) . 42 6.8.17 Slash rating 43 6.8.18 Voltage modulation. 43 6.8.19 Waveform distortion . 43 6.9 Subject term (key word) listing. 43 6.10 Changes from previous issue 43 6.11 Specificat
34、ion sheet requirements 43 TABLE I. Inspection schedules (qualification and conformance). 44 II. Electrical performance test conditions (see 4.5.3.1b). 46 III. Phase unbalance test conditions (see 4.5.3.1. and 4.5.8) 47 IV. Test schedule for generator package attitude/duration (see 4.5.15.a). 48 V. J
35、et aircraft vibration exposure(see 4.5.23.2.2.a and 4.5.23.2.2.c). 49 VI. Helicopter vibration exposure (see 4.5.23.2.2.c) 50 VII. Endurance schedule for air cooled generator systems (see .4.5.14.a and 4.5.28.1) 52 VIII. Endurance schedule for liquid cooled generator systems (see 4.5.28.2) 53 IX Spe
36、cification sheet requirements (see 6.11) 54 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-21480B viiiCONTENTS FIGURE PAGE 1. Aircraft compartment temperature-altitude ambient environment (see 3.4.2.1 and table VII). 56 2. Air inlet temperat
37、ure-altitude environment for air cooled generators (see 3.4.2.11, 3.4.9.6.1b and 6.6.1). 57 3. Shock response spectra (see 3.4.2.6, 4.5.24, 4.5.24.a, and 4.5.24.b) 58 4. Turbine engine vibration exposure (see 3.4.2.7.1, 4.5.2.3.2.1, and 6.6.3.2.a) 59 5. Jet aircraft vibration exposure (see 3.4.2.7.2
38、.a, 4.5.23.2.2.a, and 6.6.3.2.b). 60 6. Propeller aircraft vibration exposure (see 3.4.2.7.b and 4.5.23.2.2.b) 61 7. Helicopter vibration (see 3.4.2.7.2.c, 4.5.23.2.2.c, and 6.6.3.1.d) 62 8. Generator package attitude (pitch and roll) (see 3.4.3). 63 9. Normal voltage limits for AC power source (cla
39、ss N) (see 3.5.1.1). 64 10. Normal voltage limits for AC power source (class W) (see 3.5.1.1) 65 11. Voltage limits for DC power source (see 3.5.1.2 and 4.5.2). 66 12. Voltage modulation characteristics for AC power source (see 3.5.2) 67 13. Abnormal voltage limits for AC power source (class N) (see
40、 3.5.3.b, 3.5.7.3, 4.5.17.a, and 4.5.17.b). 68 14. Abnormal voltage limits for AC power source (class W) (see 3.5.3.b, 3.5.7.2, 3.5.7.3, 4.5.17.a, and 4.5.17.b) 69 15. Distortion spectrum limits for AC power source (see 3.5.4.b) . 70 16. Distortion spectrum limits for DC power source (see 3.5.5) 71
41、17. Protection limits for AC power source frequency (class N) (see 3.5.7.4.a and 4.5.17.c) 72 18. Protection limits for AC power source frequency (class W) (see 3.5.7.4.b and 4.5.17.c) 73 19. Altitude rating chart for air cooled generators (see 6.2.c) 74 CONCLUDING MATERIAL.75 Provided by IHSNot for
42、 ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-PRF-21480B 1 This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification establishes the general requirements for three phase, four wire, wy
43、e-connected, 400 Hertz, alternating current (AC), constant input speed, electric power generator systems for use on aircraft. 1.2 Classification. 1.2.1 Generator class. Generator systems are classified as follows (see 6.1): Class N Generator systems designed to operate within a narrow speed range (3
44、93 to 407 Hertz). Typical drive mechanisms with narrow speed range include hydro- mechanical constant speed drives and Auxiliary Power Units (APUs) with precision speed control. Class W Generator systems designed to operate within a wide speed range (380 to 420 Hertz). Typical drive mechanisms with
45、wide speed range include propeller gearboxes, helicopter rotor transmissions, hydraulic motors, ram air turbines, and APUs with electromechanical speed control. 1.2.2 Part or identifying number (PIN). Each component PIN will consist of the letter “M”; the general specification number; a slash follow
46、ed by the specification sheet number; and an assigned dash number (example: M21480/3-01). 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3 or 4 of this specification. This section does not include documents cited in other sections of this specific
47、ation or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements of documents cited in sections 3 or 4 of this specification, whether or not they are l
48、isted. 2.2 Government documents. 2.2.1 Specifications and standards. The following specifications and standards form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract (see 6.2). FEDERAL STANDARD FED-STD-595/17875 Miscellaneous, Gloss Provided by IHSNot for ResaleNo reproduction or networking per
