1、Comments, suggestions or questions on this document should be addressed to DLA Land and Maritime, ATTN: VAT, Post Office Box 3990, Columbus, OH 43218-3990, or emailed to switchdla.mil. Since contact information can change, you may want to verify the currency of this address information using the ASS
2、IST Online database at https:/assist.daps.dla.mil/. AMSC N/A FSC 5930 INCH-POUND MIL-DTL-28827C 26 January 2011 SUPERSEDING MIL-DTL-28827B 4 October 2004 DETAIL SPECIFICATION Inactive for new design after 8 March 1999. SWITCHES, THERMOSTATIC, (VOLATILE LIQUID), HERMETICALLY SEALED, GENERAL SPECIFICA
3、TION FOR This specification is approved for use by all Departments and Agencies of the Department of Defense. 1. SCOPE 1.1 Scope. This specification covers the general requirements for hermetically sealed volatile liquid thermostatic switches intended primarily for use in equipment requiring rapid t
4、emperature response. The operating temperatures and operating temperature ranges of switches covered by this specification are as specified (see 3.1 and 6.1.2). 1.2 Classification. 1.2.1 Military part number. The military part number (when applicable) is to consist of the letter “M”, the basic numbe
5、r of the specification sheet, and an assigned dash number (see 3.1), as shown in the following example M 28827/1- Military Designation Specification Sheet Number Coded dash letters, see individual Specification Sheet for formulation 2. APPLICABLE DOCUMENTS 2.1 General. The documents listed in this s
6、ection are specified in sections 3, 4, or 5 of this specification. This section does not include documents cited in other sections of this specification or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users
7、are cautioned that they must meet all specified requirements of documents in section 3, 4, or 5 of this specification, whether or not they are listed. 2.2 Government documents. 2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks form a part of this
8、document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-28827C 2 FEDERAL STANDARDS FED-STD-H28 - Screw
9、-Thread Standards for Federal Services. COMMERCIAL ITEM DESCRIPTIONS A-A-59877 - Insulating Compound, Electrical, Embedding. DEPARTMENT OF DEFENSE SPECIFICATIONS MIL-DTL-5541 - Chemical Conversion Coatings on Aluminum and Aluminum Alloys. MIL-A-8625 - Anodic Coatings, For Aluminum and Aluminum Alloy
10、s. MIL-PRF-15160/2 - Fuses, Instrument, Power, and Telephone STANDARDS MIL-STD-202 - Test Methods for Electronic and Electrical Component Parts. MIL-STD-1276 - Leads, Weldable, for Electronic Component Parts. MIL-STD-1285 - Marking of Electrical and Electronic Parts. (Copies of these documents are a
11、vailable online at https:/assist.daps.dla.mil/quicksearch or from the Standardization Document Order Desk, 700 Robbins Avenue, Building 4D, Philadelphia, PA 19111-5094.) 2.3 Non-Government publications. The following documents form a part of this document to the extent specified herein. Unless other
12、wise specified, the issues of these documents are those cited in the solicitation or contract. AMERICAN SOCIETY FOR TESTING AND MATERIAL (ASTM) ASTM-D635 - Plastics In a Horizontal Postition, Rate OF Burning and / or Extent and Time of Burning of ASTM-D4066 - Nylon Injection and Extrusion Materials
13、(PA) ASTM-D5948 - Compounds, Molding, Thermosetting ASTM-G21 - Materials to Fungi, Synthetic Polymeric, Determining Resistance of (Application for copies can be found online at http:/www.astm.org/ or should be addressed to the American Society for Testing and Materials, 100 Barr Harbor Drive, P.O.Bo
14、x C700, West Conshohocken, PA, 19428-2959). INTERNATIONAL ORGANIZATION FOR STANDARDS (ISO) ISO 10012-1 - Quality assurance requirements for measuring equipment - Part 1; Meteorological confirmation system for measuring equipment. (Application for copies can be found online at http:/www.ansi.org/ or
15、25 West 43rd Street, New York, NY 10036-8002, telephone 212-642-4900, fax 212-302-1286) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-28827C 3 IPC ASSOCIATION CONNECTING ELECTRONICS INDUSTRIES J-STD-004 - Soldering Fluxes Requirements For J
16、-STD-005 - Soldering Pastes Requirements For J-STD-006 - Electronic Grade Solder Alloys and Fluxed and Non-Fluxed Solid Solders For Electronic Soldering Applications Requirements For (Copies of these documents are available online at www.ipc.org or from Association Connecting Electronics Industries,
17、 2215 Sanders Road, Northbrook, Illinois, 60062-6135, United States.) NATIONAL CONFERENCE OF STANDARDS LABORATORIES NCSL Z540.3 - General Requirements for Calibration Laboratories and Measuring and Test Equipment. Copies of these documents can be obtained online at http:/www.ncsli.org or by contacti
18、ng National Conference of Standards Laboratories, 2995 Wilderness Place, Suite 107, Boulder, CO 80310-5404 SOCIETY OF AUTOMOTIVE ENGINEERS SAE AMS-I 10 - Insulation Compound, Electrical, Ceramic, Class L SAE-AS50861 - Wire, Electric, Hookup and Interconnecting, Polyvinyl Chloride-Insulated, Copper a
19、nd Copper Alloy Conductor. SAE-AS58091 - Circuit Breakers, Trip-Free, Aircraft, General Specification for. SAE AS7928 - Terminals, Lug: Splices, Conductor: Crimp Style, Copper, General Specification for (Application for copies can be found online at http:/www.sae.org or should be addressed to the So
20、ciety Of Automotive Engineers (SAE) World Headquarters, 400 commonwealth Drive, Warrendale, PA 15096-0001) 2.4 Order of precedence. In the event of a conflict between the text of this document and the references cited herein (except for related specification sheets), the text of this document takes
21、precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. REQUIREMENTS 3.1 Specification sheets. The individual item requirements shall be as specified herein and in accordance with the applicable specification sheets.
22、 In the event of any conflict between requirements of this specification and the specification sheet, the latter shall govern (see 6.1). 3.1.1 Switch categories. Switches furnished under this specification shall be category I or II as defined herein. 3.1.2.1 Category I. Switches completely defined b
23、y a military specification sheet. 3.1.2.2 Category II. Switches the same as category I, except for minor differences such as terminations, mounting means, or temperature settings, which do not change the basic design or construction of the qualified switch. Category II shall be procured from a sourc
24、e listed on the applicable qualified products list for the particular similar product in category I. Category II switches are nonstandard. 3.2 Qualification. Switches furnished under this specification shall be products that are authorized by the qualifying activity for listing on the applicable qua
25、lified products list before contract award (see 4.5 and 6.2). Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-28827C 4 3.3 Material. Material shall be as specified herein. However, when a definite material is not specified, a material shall b
26、e used which will enable the switches to meet the performance requirements of this specification. Acceptance or approval of any constituent material shall not be construed as guaranty of the acceptance of the finished product. 3.3.1 Fungus resistance. All material shall be inert or fungus resistant
27、in accordance with ASTM-G21. 3.3.2 Metals. All metals parts, other than current-carrying parts, shall be of corrosion-resistant material, or shall be suitably protected to resist corrosion. Paint is not acceptable for corrosion protection. 3.3.2.1 Dissimilar metals. When dissimilar metals are used i
28、n intimate contact with each other, protection against electrolysis and corrosion shall be provided. The use of dissimilar metals which, in contact, tent toward active electrolytic corrosion (particularly brass, copper, or steel used in contact with aluminum or aluminum alloy) is not acceptable. How
29、ever, metal plating or metal spraying of dissimilar base metals to provide similar or suitable butting surfaces is permitted. The use of dissimilar metals separated by a suitable insulating material is also permitted 3.3.2.2 Magnesium. Magnesium and magnesium alloys shall not be used. 3.3.2.3 Alumin
30、um. Aluminum and aluminum alloys shall be suitably protected against corrosion. When anodized, it shall be in accordance with MIL-A-8625. Internal parts not in contact with the media or subject to wear may be chemically treated in accordance with MIL-DTL-5541. 3.3.2.4 Solder. Solder shall have a min
31、imum melting point of 100F above the maximum temperature rating of the temperature switch and shall conform to J-STD-006. Where solder is employed, flux shall be in accordance with J-STD-004. When stainless steel is used, corrosive flux may be used providing the device is cleaned and the flux is neu
32、tralized prior to final assembly. 3.3.2.5 Pure tin. The use of pure tin, as an underplate or final finish, is prohibited both internally and externally. Tin content of switch components and solder shall not exceed 97 percent, by mass. Tin shall be alloyed with a minimum of 3 percent lead, by mass (s
33、ee 6.3) 3.3.3 Nonmetals. Switches shall not be adversely affected by weathering and aircraft, missile, and spacecraft fluids, at the temperature specified for the applicable switch. 3.3.3.1 Plastic. Unless otherwise specified (see 3.1), thermosetting plastics shall be in accordance with ASTM-D5948;
34、however, cotton or wood-cell-filled materials shall not be used. Thermoplastics shall not be used for the switch case or cover. When used for non-case material, thermoplastic material shall be in accordance with Type I of ASTM-D4066. The plastic material used shall be self-extinguishing when tested
35、in accordance with ASTM D635, as applicable, to the thinnest section of the material used. The self-extinguishing requirement applies to all materials for external parts and enclosures regardless of whether the material used is procured to a Military Specification or not. 3.3.3.2 Ceramic. Ceramic in
36、sulating material shall conform to SAE AMS-I-10, Grade L411 or better. 3.3.3.3 Potting compounds. Potting compounds used in contact with the atmosphere shall be in accordance with A-A-59877 and shall be compatible with the design requirements of the switch. 3.3.4 Weldability. Leads designed for weld
37、ability shall conform to requirements of MIL-STD-1276, type K. 3.3.5 Screw terminals. Screw terminals shall be provided with hardware as specified (see 3.1 and 6.1.2). Lock washers shall be captive to the screw. For direct Government orders, all terminal hardware shall be assembled in proper order.
38、Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-28827C 5 3.4 Design and construction. Switches covered by this specification shall be of the design, construction, and physical dimensions specified (see 3.1 and 6.1.2). Switches shall be so con
39、structed as to ensure proper operation when mounted in any position. 3.4.1 Tamperproof calibration. Unless otherwise specified (see 3.1 and 6.1.2), the switches shall be sealed in such a manner that any tempering with the calibration after final adjustment by the manufacturer shall require dismantli
40、ng of the switch or the breaking of a seal. The seal shall not be easily broken by manual force or without the use of any device considered a tool, for example, screwdriver, pliers, soldering iron, and so forth. 3.4.2 Solder terminals. Solder terminals shall be treated to facilitate soldering. The t
41、erminal design shall be such that a mechanical connection can be made prior to soldering. Acceptable solder terminal designs are turret, hook, pierced, or post type. 3.4.3 Mounting. Mounting shall be as specified (see 3.1 and 6.1.2). Stud mounting shall have threads in accordance with FED-STD-H28. 3
42、.4.4 Weight. Weight shall be as specified (see 3.1 and 6.1.2). 3.5 Electrical ratings. The electrical ratings shall be as specified (see 3.1 and 6.1.2). 3.6 Solderability (when applicable, see 3.1). When switches are tested as specified in 4.7.2, 95 percent of the total length of fillet, which is be
43、tween the standard wrap wire and the terminal, shall be tangent to the surface of the terminal being tested. There shall be no pinholes, voids, and so forth. A ragged or interrupted line at the point of tangency between the fillet and the terminal under test shall be considered a defect. After the t
44、est, there shall be no evidence of fracture, loosening of parts, or any other mechanical failure of the switches. 3.7 Calibration. When switches are tested as specified in 4.7.3, the operating points for the opening and closing temperature shall be within the tolerances specified (see 3.1 and 6.1.2)
45、. 3.8 Proof temperature. When switches are tested as specified in 4.7.4, there shall be no evidence of damage and the operating points shall be within the tolerance specified. 3.9 High temperature exposure. When switches are tested as specified in 4.7.5, the operating points shall be within the tole
46、rance specified in 4.7.5. 3.10 Low temperature exposure. When switches are tested as specified in 4.7.6, the operating points shall be within the tolerances specified in 4.7.6. 3.11 Time constant. When switches are tested as specified in 4.7.7, the time required for the switch to actuate shall be as
47、 specified (see 3.1). 3.12 Proof pressure (when specified, see 3.1). When switches are tested as specified in 4.7.8, there shall be no evidence of leakage or damage, and the operating points shall be within the tolerances specified (see 3.1). 3.13 Seal (hermetic). When switches are tested as specifi
48、ed in 4.7.9, the leakage rate shall not exceed 1 x 10-8standard atmosphere cubic centimeters per second (atm cc/sec). 3.14 Dielectric withstanding voltage. Unless otherwise specified (see 3.1 and 6.1.2), when switches are tested as specified in 4.7.10, there shall be no flashover, arcing, or current
49、 flow in excess of 1 milliampere. 3.15 Insulation resistance. When initially measured as specified in 4.7.11, the insulation resistance between all insulated terminals and enclosures shall be not less than 1000 megaohms. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-28827C 6 3.16 Contact resistance. Unless otherwise specified (see 3.1 and 6.1.2), when measured as specified in 4.7.
