1、 MIL-DTL-49285/21A 1 March 2010 SUPERSEDING MIL-C-49285/21 19 October 1989 DETAIL SPECIFICATION SHEET CABLE, SPECIAL PURPOSE, ELECTRICAL, THREE INDIVIDUALLY SHIELDED CONDUCTORS OF 22 (7 X 30) AWG This specification is approved for use by all Departments and Agencies of the Department of Defense. The
2、 requirements for acquiring the product described herein shall consist of this specification sheet and MIL-DTL-49285. FIGURE 1. Cable illustration. AMSC N/A FSC 6145 INCH-POUND Inactive for new design after 16 June 1997. Provided by IHSNot for ResaleNo reproduction or networking permitted without li
3、cense from IHS-,-,-MIL-DTL-49285/21A 2 Engineering information: See table I. Note: Not for aerospace use. TABLE I. Description, electrical. Electrical characteristics Requirements Nominal capacitance between conductor and shield Continuous working voltage Nominal capacitance between adjacent shields
4、 Continuous working voltage between adjacent shields Shield dc resistance Drain wire resistance 55 pF/ft (picofarads/foot) 350 V rms maximum between conductors 150 pF/ft 50 volts maximum 40 ohms/1,000 feet maximum 102.0 ohms/1,000 feet maximum TABLE II. Description, physical. Components Construction
5、 details Number of conductors Conductor type and wire size Conductor stranding Conductor insulation Conductor insulation thickness Drain wire type and size Drain wire thickness Drain wire width Jacket material Jacket thickness Finished cable diameter Cable style (UL) Tensile strength (jacket) Elonga
6、tion (jacket) Overall cabling lay lengths Three individually shielded Stranded tinned copper 22 AWG 7 X 30 AWG Polypropylene 0.014 inch nominal thickness Tinned cadmium bronze tinsel .003 inch minimum .004 inch maximum .025 inch minimum .031 inch maximum Polyvinyl chloride 0.030 inch 0.215 inch maxi
7、mum outside diameter Not applicable 2,000 pounds per square inch minimum 150 percent minimum 2.0 twists per foot 10 percent Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-49285/21A 3 REQUIREMENTS: Design and construction: (see table II): Shi
8、eld color code. The shield color shall be blue. Shield location and orientation. The polyester aluminum shield is to be located on the outer circumference of the pair, with the aluminum foil side outward. Insulation on the interior of the shield is to be complete with no aluminum available for conta
9、ct. Drain wire location. The drain wire is to be spirally located between the noise reducing tape and the aluminum foil shield, and is to be in continuous contact with the aluminum surface of the foil shield and the noise reducing tape throughout the cable. Cable temperature rating. The cable temper
10、ature rating shall be -20C to +80C. Conductor color code. 1stconductor: Black 2ndconductor: Red 3rdconductor: Clear Flammability. The cable shall pass UL 2556 flame test requirement. Shield integrity test.* Each shielded conductor is to be tested as if it were a pair. Frequency Response * 100 kHz 11
11、5 dB below reference 500 kHz 100 dB below reference 1 MHz 94 dB below reference 5 MHz 76 dB below reference 10 MHz 65 dB below reference 15 MHz 59 dB below reference 20 MHz 55 dB below reference 25 MHz 50 dB below reference 30 MHz 47 dB below reference * Any two readings may deviate to a value of 0.
12、9 times the stated limits. * All values are a minimum numerical value. Fixture resonance will occur between 40 and 70 MHz. At 100 MHz: At least 34 dB below reference. Crosstalk test limits. Crosstalk testing is not required for this configuration. Insulation resistance between shields: 100 megohms/1
13、,000 feet (minimum). Durometer hardness. The cable jacket shall have a “Shore A” hardness of 85 5. Part or Identifying Number (PIN): The PIN shall be M49285/21. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-DTL-49285/21A 4 Changes from previous
14、 issue. The margins of this specification are marked with vertical lines to indicate where changes from the previous issue were made. This was done as a convenience only and the Government assumes no liability whatsoever for any inaccuracies in these notations. Bidders and contractors are cautioned
15、to evaluate the requirements of this document based on the entire content irrespective of the marginal notations and relationship to the last previous issue. Referenced documents. In addition to MIL-DTL-49285, this document references the following: UL 2556. CONCLUDING MATERIAL Custodians: Preparing
16、 activity: Army CR DLA - CC Navy SH Air Force 85 DLA CC Review activities: Army MI (Project 6145-2009-006) Air Force 71 DLA - IS NOTE: The activities listed above were interested in this document as of the date of this document. Since organizations and responsibilities can change. You should verify the currency of the information above using the ASSIST Online database at http:/assist.daps.dla.mil. Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
