1、: 3-I%-EDocuMENTs 2.1 The following documents, of the issue in effect on date of invitation for bids or request for proposal, form a part of this specification to the extent specified herein: SPECIFICATIONS Federal QQ-P-416 Military MILSU6 MILM-3171 MIM-3965 MILE5272 MW-7742 MILA-8625 MILP-7936 MILE
2、-26l.44 MIIJl-70327 Plating, Cadmium (Electrodeposited) Preservation, Methods of Magnesium Alloy, Processes for Corrosion Capacitors, Fixed, Nonsolid Electrolytic (Tantalum, Foil, Environmental Testing, Aeronautical and Associated Screw Threads, Standard, Aeronautical Parts and Equipment, Aeronautic
3、al, Preparation for Delivery Anodic Coatings, for Aluminum and Aluminum Alloys Electric Power, Missile, Characteristics and Utilization, Drawings, Engineering and Associated Lists Protection of and Sintered-Slug) General Specification for Equipment, General Specification for Generd Specification for
4、 Militar2 MILSTLl30 MIL-STD-143 MIGSTD-701, Identification Marking of US Military Property Specifications and Standards, Order of Precedence for Characteristics and Utilization of Aircraft Electric Power the Selection of *. -?I/ THIS DOCUMENT CONTAINS PAGES. ! -. I. - Provided by IHSNot for ResaleNo
5、 reproduction or networking permitted without license from IHS-,-,-MIL-I-27273A bL 9979906 009LOLI2 3 MILI-27273A MILSTD- ms-831 Test Reports, Preparation of m33543 M33586 Metais, Definition of Dissimilar (Copies of specifications, standards, drams, and publications required by suppliers in connecti
6、on with specific procurement functions should be obtained from the procuring activity or as directed by the contracting officer.) 3. REQUIREMEWJ!S 3.1 fication.- The inverter furnished under this specifieatfonshall be a product that has been tested and passed the qualification tests herein and has b
7、een listed on or approved for listing on the applfcable qualified products %t. 3.2 we- Unless otherwise specified in the contract or order, no data (other than reports and drawings accompanying qualification samples) are required by thfs specfff- cation or any of the documents listed in section 2 (s
8、ee 6.2). 3.3 Selection of sriecifications and standards,- Specifications and standards for necessary comodities and services not specified herein shall be selected in accord- ance with MILSTLl43, except as provided in 3.3.1 and 3.3.2, 3.3.1 MiUtary standard parts,- Military standard parts (MS and AN
9、) shall be used wherever they are suitable for the purpose, and shall be identified on the draw by their part numbers. In the event there is no suitable corresponding standard part in effect on date of invitation for bids, commercial parts may be used, provided they con- form to all requirements of
10、this specification. 3.3.2 Comercial us-proof materials.- Materials that are nutrients for fngi shall not be used where it is practical to avoid them. they shaU. be treated with a fungicidal agent acceptable to the procuring activity. However, if they will be used in a hermetically sealed enclosure,
11、fungicidal treat- ment will not be necessary. 3.4.2 Metals.- Metals shall be corrosion resistant or suitably treated to resist corrosion due to fuels, salt spray, or atmospheric conditions that may be encountered in storage or normsl service. 3.4.2.1 Dissimilar metals.- Unless suitably protected aga
12、inst electrolytic corro- sion, dissimilar metals as defined in E33586 shall not be used in intimate contact with each other. Where used and not hermetic- sealed, 2 , -=- - -. c - .- _- - F Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-I-27273A
13、 bL W 779770b 0073043 5 W - MIL-I-27273A 3.5 Desim and construction.- The inverter shall be designed ad constructed in accordance with this specification and the applicable MS. 3-5.1 SePrriceabil%tyo- The fiverter shall be designed and constructed in such a manner that no parts WiilP work loose In s
14、ervice and shall be built to withstand the strains, jare.- The inverter shal be designed and constructed as specified herein in a manner that will hure the highest degree of operational reliabilfty under a1 sapvice con%tiom. !Che invsrter shd2 have 5i y. require- ments without the specific apprsvii
15、of the procuring act%v5%y. 3.5.4 input.- The rated hput voltage shall be as specified on the applhable IBO The invertes shall be designed to operate with no evidence of fistabflity froma flight vehicle system deklver power confordng to MIL-STD-704 and MIL-E-U Mth- in the voltage Mts specWied on the
16、applicable MS, 3.5P spt shall not exceed the lfmfts speciffed in the paragraph tit%.ed ftnfluence on electric systemlt of MIL-STD-74, 3.5.6 Electrled connections.- The input and output connectfons shall be in accord- ance wlth the connections shown on the applicable BEo no internal eonnectfons wlla
17、be required to obtain 3-phase wye, 3-ph-e delta, an single-phase output. 3.5.7 Safety wh4n.g and stE.- The inverter shaU have a minimum numer of parts consis- tent with reliability. Its design, where practicable, shela permit easy assembly, disassembly, Loeation of trouble sources, and maintenance w
18、ith tools and equipment normally available conunerciaUy, by service maintenance personnel with a minimum of training. 3.6 Performance,- 3.6.1 Dielectric strengtho- such critical components as transistors and capacitors, shall withstand a potential of 1,SW mas comercial frequency applied for lminute
19、between the termhals and the enclosure. The electrical components of the hverter, except for 3.6.1.1 Capacitars.- Capadtors shall withstand twice the peak voltage to which they wiU. be subjected during semice, OP 1W, whichever is greater, for lminute. tantalum capacitors CLpe used, they shall confor
20、m to table I and MIM-3965. If TABLE I. Tantalum capacitor voltages Dc surge voltage Capacitor de woking . voltage rating 6v 3ov 1% loov i 2 times peak 3.6.2 Outmt voltage remilation.- The kverter shall mihtain steady-state voltage limits specified on the appkicaable PIS. 3.6.3 Output frequency regul
21、ation.- The inverter shall maintain steady-state frequency Umits spscified on the applicable MS, 3,6.4 0rrerloa.- When the input voltage is set at l8V, the Inverter shall be capable of delivering 150 percent of rated load for lminpte at the minirmUn output voltage and the lagghg power factor specifi
22、ed on the applicable MS. 3.6,5 Short circuit camcity.- When the input is set at lev, the inverter shall be capable of delivering a minirmUn of 300 percent of rated cuprent to a zero impedance Uneto-ground short circuit and to carry this current for 5 seconds without sustafi- ing damage therefrom. cu
23、rrent during the 5-second intemal to any practical desired values greater than 300 percent of rated currant. circuitry and shall not open the output circuit. After the short chcuit has been rammed, the inverter shall automatically return to normal operation without impairment of reliability OP subse
24、quent performance. PPovisfons may be incorporated to limit this short circuit The purrent Wts shall be comprised of solid-static 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MILI-27273A 3.6.6 Efficiency.- The inverter shall provide the efficienc
25、y specified on the applicable MS. 3.6.7 Phase rotation phase inverters 1.- For 3-phase inverters, phase rota- tion shall be in the order of A-B-C. 3.6.8 Phase unbalance .- Steel parts shall be cachnium plated in accordance with type II or In of QQ-P-41 required. 3.U for identification in accordance
26、with MIL-STD-UO, and of a class that is adequate to achieve the degree of protection Identification of product.- Equipment, assemblies, and parts shall be marked 3.a Workmanshie.- fabricated in a thoroughly workmanlike manner. Particular attention shall be g%ven to freedom from blemishes, defects, b
27、urrs, and sharp edges; accuracy of dhensfons, radii of fillets, and masking of parts and assemblies; thoroughness of soldex-ing, welding, brazing, paintingg wfrhg, and riveting; alignment of parts, and tightness of assembly screws and bolts, 3,U.i Dimensional tolerances.- close as is consistent with
28、 the best shop practices, may affect the interchangeabiiity, operation, OF performnee of the inverter, they shall be held or limited accordingly, 3.U.2 Screw assemblies.- Assembly screws and bolts shall be tight. The word tight means that the screw or bolt cannot be appreciably tightened further wit
29、hout dataage to the screw, bolt, or threads. 3.hich this specification covers shall pass the qualification tests specified herein. If the product is later modified in any way, the modified form shall be subjected to and shall pass the same qualification tests. 4.3.3 Inspections.- The qualification i
30、nspections shall consist of all the examin- ations and tests described under 4.6. inverters as follows and essentially in the order listed: The tests shall be conducted on the sample (a) Sample No. 1 (i) I?xambation of product (4.6.1) (2) Dielectric strength (4.6.2) (3) Phase rotation (4.6.7) (4) Vo
31、ltage and frequency regulation (4.6.3) 5) Efficiency (4.6.6) 6) Phase unbalance (3-phase inverters) (4.6.8) (7) Eodulation (8) Waveform (9) bio interference (io) Transient voltage recovery (11) Reduced input voltage (U) Motor start- u) Short circuit capacity is) Factors affecting voltage 8nd frequen
32、cy regulation (16) Humidity (17) Disassembly inspection (b) Sanmle No. 2 (1) Examination of product (2) Dielectric strength (3) miase rotation (room temperature only (4) Voltage and frequency re 8 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-(5 )
33、Efficiency (6) Modulation (7) Waveform (8) Phase displacement angle (3-phase inverters ) (9) Factors dfsctlng voltage and frequency regulation (10) Shock (li) Vibration (12) Fungus resistance (u) salt spray (u) tn 0.1 second upon application or remval of rated load. oscillations under any loading co
34、ndition. 4.6.2 Inmt transient voltwe motection.- Step function voltages shall be applied for appropriate periods, as shown in table II. Prior to starting the test the inverter sha31 have been operating at rated load and naximm ambient sea level temperature specified on the applicable MS for a period
35、 sufficient for the inverter to have attain- ed msxirmun working temperature. each test ishail consist of one application of: The unit shall. not develop sustained The inverter shall be subjected to four tests and (1) Nominal voltage for the duration of period trAtl. (2) Voltage fVtl for the duratio
36、n of period irBff. (3) Nominal voltage for the duration of the period trr. There shall be no flash over and no insulation break-down. At the conclusion of this test the voltage and frequency regulation shall be Within the limits specified on the applicable MS. TABm II. Step-function voltages Period
37、Vt Number Period trA“ Period ttBtt Value Vtt of 1 7.5 28 0.04 80 7.5 28 1 2 7.5 28 0.13 68 7.5 28 1 3 7.5 28 5.0 36 7.5 28 1 4 7.5 28 10-5 200 7.5 28 1 * Test I No. Minutes Volts Seconds volts Minutes Volts appications- 4.6.13 Reduced input voltage.- The inverter shall be tested to demonstrate its a
38、bility to carry full-rated load within the output voltage limits specified on the applicable MS with the input vqltage varied from 18 to 29V in* increments of IV. 4.6.U E.- applicable MS, the inverter shall be operated at sea level with unity power factor full load for 500 hours. The inverter shall
39、be subjected to a votage and frequency regulation test as specified fn 4.6.3(c) at the beginning and at the end of this test, The voltage and frequency regulation shall be within the limits specified on the appU- cable MS. This test shall be repeated for 2,000 hours at room temperature (25 ;UT0 C).
40、Any malfunction of the inverter during this test shall be cause for rejection, 4.6.U.1 Source of impedance.- One hundred twenty five hours of the 500 hour test shall. be conducted using an aircraft 28V de generator having a current rating of not more than twice the input current rating of the invert
41、er or 25 amps., whichever is greater, for suppying power to the inverter. Performance shall be satisfactory nd there shall be no failure of input capacitors or other components of the inverter as a result of this test. At rated input voltage and the high temperature specified on the Provided by IHSN
42、ot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-I-27273A b1 m 777770b 0091054 T m MIL-I-27273A 4.6.15 Motor starting.- The inverter shall demonstrate its capability to start an induction motor load varying from 200 percent,of inverter rated VA, 0.5 lagging power
43、 factor at initial inrush to 100 percent of inverter rated VA,O.t35 lagging power factor at normal steady-state operation, Single-phase inverters shall be tested with single- phase motors and 3-phase inverters with 3-phase motors. A dummy load, which simulates the motor characteristics may be utiliz
44、ed in lieu of the motor. 4.6.16 g,se displacement angle (3-phase inverters).- The displacement between adjacent phasesshall be determined at no load, half load, and full load. load shall be balanced for this test, be within the limits of I20 f1.5 degrees as specified in MIL-STD-704, 4.6.17 Endurance
45、.- The inverter shall be operated for 200 hours during which time full-rated load at minimum lagging power factor shall be switched on for 5 seconds and off for 5 seconds. Sufficient readings shall be taken to ensme compliance with this test, Following this test, the unit shall pass the tests specif
46、ied in 4.6.3(a)(2). During this test, readings shall be taken at least every 12 hours to demonstrate that the output voltage and frequency does not drift outside the limits specified on the applicable FS. 4.6.18 Environmental.- The 3-phase “he displacement between adjacent phases shall 4.6.18.1 Fact
47、ors affecting voltage and frequency regulation.- Prior to each of the following tests (a) through (c), the voltage and frequency shall. be at a value termed %tandard.“ For the purposes of this test, the voltage and freqaeneg “standard“ shaL be a value that lies between the limits specified.on the ap
48、plicable E5 and %hat which has been determined after voltage, frequency, and temperature stabilize. The mainrum deviation of voltage and frequency in both positive and negative directions from the standard shall be recorded for each test. The ambient temperature shall be decreased from 25“ fi.5“ to
49、-55“ C, increased to the maJ3rmun ambient temperature specified on the applicable MS, and then checked at 25O 55“ C. Zach temperature shall be held for at least L how- or until the regulated voltage an frequency stabilize as indicated by readings taken at 10-minute intervals. The ability of the inverter to continuously deliver rated output at ambients between -55“ C and the maximum ambient temperature specified on the a
