1、. ._ ir. -e3 . - - MIL-I-27273A (3) bL 9999906 0091036 9 - . / 7 - /A-,-/ 5- -. “L I MIL-I-27273A B _. . Amendment 3 12 March i970 -. SUPERSEDING Amendment 2 28 January i969 9- MILITARY SPECIFICATION INVERTER, POWER, STATIC, GENERAL SPECIFICATION FOZ This amendment forms a part of Specification MIL-
2、I-27273AY .3 June 1965, and is mandatory for use by all Departments and Agencies of the Department of Defense. Page 1 , paragraph 2.1: and “MIL-STD-826“. Add : Delete “1-7936 ,“ “MIL-E-26144 ,“ “MIL-D-70327 ,“ “PPP-B-636 Box , Fiberboard MILI-6181 MIL-STD-100 Engineering Drawing Practices MIL-STD-12
3、9 MIL-STD-781 Reliability Test: Exponential Distribution MIL-STD- Interference Control Requirements, Aircraft Equipment Marking for Shipment and Storage Cushioning, Anchoring, Bracing, Blocking and Waterproofing with Appropriate Test Methods“. Page 3, paragraph 3.5.3: Delete and substitute: “3.5.3 R
4、eliability. The inverter shall have a minimum acceptable mean- time-between failures (MTBF) of 1,175 hours demonstrated to a 90 percent confidence eve. It Page 3 , paragraph 3.5.4, line 3: Page 3, paragraph 3.5.7, line 2: “O. 032 inch“. Page 4, paragraph 3.6.1.1, table I: Delete “and MI-E-26144“. De
5、lete “0.32-inch“ and substitute Change heading of first column from DC surge voltage“ to “Peak DC voltage in service“. (1 Page 4, paragraph 3.6.5, line 6: “solid-state“. Delete “solid-static“ and substitute Page 5, paragraph 3.6.10: Delete and substitute: “3.6.10 Output frequency modulation. Variati
6、ons of frequency resulting from frequency modulation during any 1-minute period shall be within a band of 22 cps about a mean frequency. -Rates of frequency change caused by frequency modulation shall not exceed i3 cps per second.“ . FSC 6130 Provided by IHSNot for ResaleNo reproduction or networkin
7、g permitted without license from IHS-,-,-MIL-I-27273A (3) bL m 9777906 0073037 T m .I hiI-L- I- 27 273A knenihent 3 Page 5, paragraph 3.6.11: harmonic content shall not exceed 4 percent and no individual harmonic shall exceed 3 percent of the fundamental.“ Delete the last sentence and substitute: “T
8、he total . Page 5, paragraph 3.6.12, lines 1 and 2: of MILSTD-704“ and substitute “shall remain within the limits of 54 and i73 Delete “shall not exceed the limits volts rms“. Page 5, paragraph 3.6.12.1: Delete and substitute: 3.6.12.1 Overvoltage spikes. Spikes of microsecond duration on the out- p
9、ut voltage shall not exceed a peak of 250 volts. stand imput voltage spikes in accordance with 4.6.12, table II. Moreover, during design, careful consideration shall be given to the protection of the inverter against any overvoltage spikes that-may be internally generated.“ Il The inverter shall wit
10、h- Page 6, paragraph 3.6.16, line 2: MILSTD-704“ and substitute “be 120 - +1.5 degrees .“ Delete “not exceed the limits specified in Page 6, paragraph 3.6.18( d) : Page 6, paragraph 3.6.21: Delete “landing“. Delete and substitute: 3.6.21 Source impedance. The inverter shall be capable of operating s
11、atisfactorily when connected to a 28V c aircraft generator having a current rating of not more than tvice the iqmt current rating of the inverter or 28 amps , whichever is greater.“ P8ge 6 , paragraph 3.7 , line 3: Delete “MIL-D-70327“ and substitute “MIL-STD-100“. Poge 6, paragraph 3.8, line 5: Del
12、ete “MIL-STD-826“ and substitute f1-61811t. Page 8 and 9 , paragraph 4.3.3: “(b) Sample no. 2, items (15) and (9) respectively, delete paragraph reference “4.6.3“ and substitute “4.6.18.1. It Under “(a) Sample no. 1 ,“item (15) and under Page 9, paragraph 4.6.3.1: Delete paragraph number and substit
13、ute “4.3.3.1“. Page 10, paragraph 4.6.3: Under “(a), add: “(3) At maximum specified input voltage, the load shall be varied from n.o load to full load in steps of one-fourth of rating. The load shall be sud- denly removed and applied for each observation. ings shall be taken to accurately plot the v
14、oltage and frequency at the minimum lagging and leading power factor loads as specified on the appli- Voltage and frequency read- cable MS.“ - 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NIL-I-27273A (3) 61 W 777770b 0073038 L MIL-1-27273 Amend
15、ment 3 Page 12, paragraph 4.6.9.2: Delete knd substitute: “4.6.9.2 Output frequency modulation. The output frequency modulation shall be measured under conditions of no load, half load, and full load and shall not exceed 22 cps from a mean frequency for a 1-minute period. The rate of frequency chang
16、e shall not exceed 13 cps per second. ments of frequency modulation shall be made by a method approved by the prociiring activity. “ Measure- Page 12, paragraph 4.6.1O.i, fifth sentence: Delete and substitute: “The totalharmonic content shall not exceed 4 percent and no individual harmonic shall exc
17、eed 3 percent of the fundamental.“ Page 13, paragraph 4.6.11, line 3: of MIESTD-704“ and substitute “shall remain within the limits of 54 and i73 volts rms.“ Delete “shall not exceed limits 2 and 3 Page 13, paragraph 4.6.14.1: Add the following sentence to the end of the paragraph: be used in the po
18、wer supply for the inverter.“ Change the title to read “Source impedance.“ “No battery shall Page 14, paragraph 4.6.16, line 4: degrees as specified in MIL-STD-704“ and substitute “be 120 +1.5 degrees .I Page 16, paragraph 4.6.21, lines 3 and 4: Delete “be within the limits of 120 21.5 - Delete “MIL
19、-STD-826“ and Substitute MIL 1-6181“ . Page 16, add: “4.6.23 Reliability. The inverter shall pass the qualification test without incurring any relevant failures (see MIL-STD-781, paragraph titled Relevant Failures ) to demonstrate a minimum acceptable.-m.BF 8 of 1,175 hours to a 90 percent .- confid
20、ence level.“ Page 16, paragraphs 5.1 and 5.2: Delete and substitute: 5.1 Preservation and packaging. Preservation and packaging shall be I1 level A or C, as specified (see 6.2). “5.1.1 Level A. Inverters shall be preserved in accordance with MIL-P-116, method II, and packaged one each in unit contai
21、ners conforming to PPP-B-636. “5.1.2 Level C. Each inverter shall be packaged in a manner that will .- afford adequate protection against corrosion, deterioration, and physical damage during shipment from the-supply source to the first receiving activity for immediate use. practice if it meets the r
22、equirements of this level. The level may conform to the suppliers commercial 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I MIL-I-27273A (3) b3 7777706 0073037 3 W MIL-1-27273 Amenment 3 “5.2 Packing. “5.2.1 Level A. Inverters preserved and pack
23、aged as specified in 5.1 shall be packed in exterior-type shipping containers conforming to the applicable type and class of PPP-B-636. Insofar as practicable, containers shall con- tain identical quantities and be of minimum cube and tare consistent with the protection required. Container closure a
24、nd strapping shall be in ac- cordance with the appendix to PPP-B-636. Packing shall be level A, B, or Cy as specified (see 6.2). . “5.22 Level B. shipping containers shall be of the domestic type. Level B packing shall be the same as level A except the “5.2.3 Level C. afford adequate protection agai
25、nst damage during direct shipment from the supply source -to the first receiving activity for immediate use. level shall conform to applicable carrier rules and-regulations and may be the suppliers commercial practice if it meets the requirements of this level. Each inverter shall be packed in a man
26、ner that will This 5.3 Physical Protection. Inverters packed as specified in 5.2.1 and II 5.2.2 shall be anchored, clocked, braced, and cushioned in accordance with MIESTD-1186. “5.4 Marking. or order, interior containers and exterior shipping containers shall be marked in accordance with MIL-STD-12
27、9.“ In additiion to any special marking required by he contract , Page 16, paragraph 6.2, c: Delete and substitute; c. Levels of packaging and packing required (see section 5)“. .II Page 16, paragraph 6.3: Delete and substitute: “6.3 Qualification. With respect to products requiring qualification, a
28、wards will be made only for products which are, at the time set for open- ing of bids, qualified for inclusion in the applicable Qualified Products List whether or not such products have actually been so listed by that date. The attention of suppliers is called to this requirement, and manufacturers
29、 are urged to arrange to have the products that they propose to offer to the Federal Government tested for qualification in order that they may be eligible to be awarded contracts or orders for the products 4 . :.-. . . : ,x -.:;,; . . .i;. . -a- L ,. ., Provided by IHSNot for ResaleNo reproduction
30、or networking permitted without license from IHS-,-,- MIL-I-27273A (3) bL = 7777706 0071040 T W MIL-1-27273 Amendment 3 covered by this, specification. Qualified Products List is the Aeronautical Systems Division, Attn: information pertaining to qualification of products may be obtained from that ac
31、tivity.“ The activity responsible for the ASNJP-10, Wright-Patterson Air Force Base, Ohio 45433, and Custodians : Amur - AV Air Force - 11 Review activities: Army - AV, EL Air Force - 82, 85 Preparing activity: Air Force - 11 Project No. 6130-0087 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
