1、 MIL-PRF-8572bB 9999906 2066538 7LT MIL-PRF-85726B(AS) 15 Julv 1998 SUPERSEDING 29 October 199 1 MIL-E-8 5 726A(AS) PERFORMANCE SPECIFICATION ENCLOSURE, STANDARD AVIONICS, FORCED AIR-COOLED, SPECIFICATION FOR This specification is approved for use by the Naval Air Systems Command, Department of the
2、Navy, and is available for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers forced air-cooled standard avionics enclosures, hereinafter referred to as enclosures. The enclosures accommodate Standard Electronic Modules (SEMS) Format B Spa
3、n 2, Format C, and Format E, and a standard backplane. 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this section are specified in sections 3 and 4 of this specification. This section does not include documents cited in other sections of this specification or recommended for additiona
4、l 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 documents cited in sections 3 and 4 of this specification, whether or not they are listed. Beneficial comments (recommen
5、dations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, Naval Air Warfare Center Aircraft Division, Code 414100B120-3, Highway 547, Lakehurst, NJ 08733-5100 by using the Standardization Document Improvement Proposal (DD
6、Form 1426) appearing at the end of this document or by letter. AMSC NIA FSC 5975 DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2.2 Government documents. 2.2.1 Soecifi
7、cations, standards. and handbooks. The following specifications, standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those listed in the issue of the Department of Defense Index of Specifications and Stan
8、dards (DoDISS) and supplement thereto, cited in the solicitation (see 6.2). SPECIFICATIONS DEPARTMENT OF DEFENSE MIL-M-7793 - Meter, Time Totalizing. MIL-M-16034 - Meters, Electrical-Indicating (Switchboard and MIL-M- 16 125 - Meters, Electrical, Frequency. MIL-C-28754 - Connectors, Electrical, Modu
9、lar, Component Parts, General Specification for. MIL-C-38999 - Connectors, Electrical, Circular, Miniature, High Density, Quick Disconnect (Bayonet, Threaded, and Breach Coupling), Environment Resistant, Removable Crimp and Hermetic Solder Contacts, General Specification for. MIL-C-83527 - Connector
10、s, Plug and Receptacle, Electrical, Rectangular Multiple Insert Type, Back to Panel, Environment Resisting, 150 OC Total Continuous Operating Temperature, General Specification for. Portable Types). STANDARDS DEPARTMENT OF DEFENSE MIL-STD-462 - Measurement of Electromagnetic Interference MTL-STD-810
11、 - Environmental Test Methods and Engineering Guidelines. MIL-STD-1377 - Effectiveness of Cable, Connector, and Weapon Characteristics. Enclosure Shielding and Filters in Precluding Hazards of Electiomagnetic Radiation to Ordnance, Measurement of. MIL-STD-1389 - Design Requirements for Standard Elec
12、tronic Modules. MIL-STD-1472 - Hmm Enguieering. 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-PRF-8572bB 99999Ob 2066540 378 D MIL-PRF-8 5726B(AS) MIL-STD-2218 - Thermal Design, Analysis, and Test Procedures for Airborne Electronic Equipment
13、. (Unless otherwise indicateL, copies of the above specifications, standards, and handbooks are available from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 191 1 1-5094.) 2.3 Non-Government publications. The following document forms a part of this docume
14、nt to the extent specified herein. Unless otherwise specified, the issues of the documents which are DoD adopted are those listed in the issue of the DoDISS cited in the solicitation. Unless otherwise specified, the issues of documents not listed in the DoDISS are the issues of the documents cited i
15、n the solicitation (see 6.2). AMERICAN SOCIETY FOR QUALITY CONTROL (ASQC) ASQC-Zl.4 - Sampling Procedures and Tables for Inspection by Attributes. OD adopted) (Application for copies should be addressed to the American Society for Quality Control, 61 1 East Wisconsin Avenue, Milwaukee, WI 53202.) 2.
16、4 Order of precedence. In the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENT
17、S 3.1 First article. When specified (see 6.2), a sample shall be subjected to first article inspection in accordance with 4.2. 3.2 Materials. The enclosure shall be constructed of materials which shall meet the requirements of this specification. 3.2.1 Corrosion prevention and control. The materials
18、 selected shall be corrosion resistant or shall be treated to resist corrosion during service life (see 6.3). 3 2.2 Dissimilar metals. Where dissimilar metals are used in contact with each other, protection against galvanic corrosion shall be provided (see 6.6). When dissimilar metals are used they
19、shall not be susceptible to galvanic conosion identified in MIL-C-28754, table WI. 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-PRF-8572bB = 9999706 20bb54L 204 MIL-PRY-8 5 726B (AS) 3.2.3 Recycled, recovered, or environmentally safe materi
20、als. Recycled, recovered, or environmentally safe materials shall be used, provided that the material meets the performance requirements specified herein. 3.3 Intefiace and dimensional reauirements. 3.3.1 be 2 # 5 L? 10 12 MIL-PRF-85726B(AS) TABLE I. Standard MCU dimensions (see fime 1). Width (W) H
21、eight (H) Length (L) - 1/ Inches mm Inches mm Inches mm +0.02 +OS +O.O, -0.04 +O.O, -1.0 2.29 58.3 7.64 194 Li 12.52 f 0.04 Li 318 f 1 L2 12.76 max 324 ma 4.88 124.0 7.64 194 LI 12.52 + 0.04 Li 318 f 1 L2 12.76 max L2 324 ma 7.50 190.5 7.64 194 Li 12.52 f 0.04 Li 318 k 1 L2 12.76 max 324 ma 10.09 25
22、6.3 7.64 194 Li 12.52 k 0.04 Li 318 f 1 L2 12.76 max 324 ma L2 12.76 max 324 ms 15.29 388.4 7.64 194 Li 12.52 k 0.04 Li 318 h 1 L2 12.76 rnax 1; 324 rns 12.69 322.3 7.64 194 Li 12.52 f 0.04 Li 318 f 1 Alternates (LI): Alternates (L2): 19.53 f0.04 in (496 +1 .O mm) 9.76 in (502 mm) max (Ref) 7.78 in
23、(1 98 mm) max (Ref) 7.56 f0.04 in (192 f1.0 mm) 3.3.3 Backplane interface. The mechanical interface of the backplanes used to interconnect the modules shall be in accordance with the dimensions on figure 2. This applies to both multilayer and wire wrap backplanes. 5 Provided by IHSNot for ResaleNo r
24、eproduction or networking permitted without license from IHS-,-,-TABLE II. Standard enclosure size and confimiration. 4 MCU I Enclosure I Module 2 levels of SEM Format B 12 MCU 1 level of SEM Format C 2 levels of SEM Format 2 levels of SEM Format I IC 1 level of SEM Format E 1 level of SEM Format E
25、I IE Backplane interconnect medium Multilayer board 3 level wire wrap or multilayer board 2 multilayer boards 2 backplanes Using 3 levels of wire wrap each or 2 multilayer boards 3 level wire wrap or multilaver boards 2 backplanes using 3 levels of wire wrap each or 2 multilayer boards 2 backplanes
26、using 3 levels of wire wrap each or 2 multilayer boards 2 backplanes using 3 levels of wire wrap each or 2 multilayer boards 2 backplanes using 3 levels of l wire wrap each or 2 mulilaver boards Max enclosure Weights, pounds (Kg) 14.3 (6.49) 25.3 (1 1.48) 25.3 (1 1.48) 35.2 (15.97) 35.2 (15.97) 47.3
27、 (2 1.46) 57.2 (25.95) 57.2 (25.95) 67.1 (30.44) 3.3.4 Enclosure hold-downs. 3.3.4.1 Front. The enclosure shall be attached with two (one on the 2-MCU enclosure size) hooks or functional equivalents, located on the front of the enclosure as shown on figure 3. These hooks or other means of attachment
28、 shall be used to apply the force required to insert the rear-mounted connector, establish preload, and secure the front of the enclosure. 3.3.4.2 m. The rear hold-downs shail mate with dagger pin receptacles in accordance with figure 4 or a rack and panel connector but not both. 3.3.5 Module mes. T
29、he six MCU enclosure types shall accept a random mix of SEM Format E modules mounted at pitches of 0.4,0.5, and 0.6 inch (10.2, 12.7, and 15.2 mm). The 4-MCU enclosure shall accept a random mix of SEM Format C modules mounted at pitches of 0.3,0.4, 0.5, and 0.6 inch (7.6, 10.2, 12.7, and 15.2 mm). T
30、he 2-MCU enclosure shall accept SEM Format B modules mounted on pitches that are multiples of 0.3 inch (7.6 mm). Card guides uniquely machined for a given system are permissible with all enclosures. 6 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-f
31、lIL-PRF-8572bB W 9999906 2066544 TL3 MIL-PRF-8 5726B(AS) 3.3.6 Escape of fluids. The enclosure shall contain a means of allowing for the escape of fluids, such as drain holes. The method used to allow fluids to escape, shall accommodate mounting of the rack in any orientation. Where moisture pockets
32、 are unavoidable in unsealed enclosures, provision shall be made for the drainage of such pockets. Desiccants or moisture- absorbent materials shall not be used within moisture pockets. 3.3.7 Cooling The cooling source shall dissipate the heat in the enclosure, and provide the pressure required for
33、air to flow through the unit. 3.3.8 Fluid entrapment. The enclosure shall not have any feature that may trap a fluid on the exterior of the enclosure, thereby increasing the possibility of fluid entering the module compartment. 3.3.9 Module retainer. The module retainer mechanism shall not be part o
34、f the enclosure. The enclosure card guide may be machined to provide interface to module extractors and injectors. If the enclosure guide is machined, this machining shall not interfere with a retaining device to clamp the module to the thermal card guide. Machining for module extractor or injector
35、shall not preclude the use of modules that have no such mechanisms. The mechanism shall also be accessible (see 3.3.1.2) and replaceable by maintenance personnel. 3.3.1 O Wiring harness. The enclosure shall be designed to facilitate the removal and installation as an assembly of the enclosure inpu/o
36、utput connectors, wiring, EMI filters, and the connectors tying these items to the backplane. 3.3.11 Meters. The enclosure shall be capable of mounting both a time elapsed meter and built-in test status indicators. The enclosure shall be capable of accommodating meters in accordance with MIL-M-7793,
37、 MIL-M-16034, and MIL-M-16125. 3.3.12 Inuutloutput connectors. 3.3.12.1 Front. The enclosure shall accommodate fiont mounted connectors as specified in MIL-C-38999, series III and IV. Connectors shall be removable from the inside of the enclosure. 3.3.12.2 however, bending and distortion are permitt
38、ed. The test item shall remain in place (see 3.4.10). Enclosure size (MCU) 2 4.5.3 Thermal testing. Power capability (w-1 250 4.5.3.1 Thermal effectiveness. The thermal effectiveness test shall be conducted in accordance with MIL-STD-2218 using the procedures given in 4.5.3.1.1 through 4.5.3.1.3 (se
39、e 3.4.1 i). 4 6 8 10 12 4.5.3.1.1 Test set-uu. The enclosure shall be constrained using only its front and rear hold- downs, with cooling air being supplied through the same hardware as in its final installation. Each enclosure will be fully populated with dummy modules dissipating an equal amount o
40、f power. The dummy module guide ribs shall have dimensions in accordance with MIL-STD-1389. 500 750 1000 1250 1500 4.5.3.1.2 Test conditions. The test shall be run in a 71 f 1 “C ambient temperature. Cooling air inlet temperature and pressure drop across the enclosure shall be 27 k 1 “C (80.6 f 3.6
41、“F) and 2.5 k .1 inches (63.5 2 2.5 mm) of water, respectively. Input power shall be in accordance with table VII. TABLE VII. Standard enclosure power capacity. 4.5.3.1.3 Instrumentation. The enclosure shall be instrumented to gather the following data: a. Inlet air temperature and relative humidity
42、. b. The guide rib temperatures of modules 1,4,7, 10, 13, 17,20,23, and 26 (numbered sequentially from the air inlet end of the enclosure). These temperatures shall be recorded on enclosures that house 0.3-inch pitch SEMS. Temperatures of modules 1,2, 5,7,9, 10, and 13 shall be recorded on 0.6-inch
43、pitch SEM enclosures (comparable locations for other pitches). c. The exhaust air temperature. 14 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-PRF-857266 W 9906 2066552 09T MIL-PRF-8 5 726B (AS) d. The air mass flow rate through the enclosure
44、. 4.5.3.2 Thermal leakage. The enclosure shall be pressurized to not less than 2 inches (50.8 mm) ofwater at a temperature of 21 OC (69.8 OF) (see 3.4.12). 4.5.4 Electromagnetic interference testing. 4.5.4.1 Shielding effectiveness. The enclosure shall meet the requirements of 3.14.13 when tested as
45、 specified in ME-STD-1377. 4.5.4.2 Outside-to-inside shielding effectiveness. The enclosure shall meet the requirements of 3.14.14 when tested as specified in MIL-STD-1377. 5. PACKAGING 5.1 Packaping For acquisition purposes, the packaging requirements shall be as specified in the contract or order
46、(see 6.2). When actual packaging of materiel is to be performed by DoD personnel, these personnel need to contact the responsible packaging activity to ascertain requisite packaging requirements. Packaging requirements are maintained by the Inventory Control Points packaging activity within the Mili
47、tary Department or Defense Agency, or within the Military Departments System Command. Packaging data retrieval is available from the managing Military Departments or Defense Agencys automated packaging files, CD-ROM products, or by contacting the responsible packaging activity. 6. NOTES (This sectio
48、n contains information of a general or explanatory nature that may be helpful, but is not mandatory.) 6.1 Intended use. The enclosures covered by this specification are used in the production and maintenance of military aircraft exposed for prolonged periods to extreme seagoing environments not enco
49、untered by civilian aircraft. These enclosures provide cooling for the enclosed devices, protection from the environment, and shielding from electromagnetic interference (EM) unique to the military environment. The enclosures covered by this specification are not used in commercial aircraft. 15 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- - MIL-PRF-8572bB
