1、NOTE: MIL-STD-1857 has been redesignated as a handbook, and is to be used for guidance purposes only. This document is no longer to be cited as a requirement. For administrative expediency, the only physical change from MIL-STD-1857 is this cover page. However, this document is no longer to be cited
2、 as a requirement. If cited as a requirement, contractors may disregard the requirements of this document and interpret its contents only as guidance. 1 MCH- POUND I MIL-HDBK-1857 27 MARCH 1998 DEPARTMENT OF DEFENSE HANDBOOK FOR GROUNDING, BONDING AND SHIELDING DESIGN PRACTICES I AMSC NIA AREA EMCS
3、Copyright Communications - Electronics Command Provided by IHS under license with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,- JL MIL-HDBK-1857 m 9999970 0262895 421 m MIL-STD-1857( EL) , 30 June 1976 ! HEADQUARTERS DEPARTMENT OF.THE ARMY WASHINGTON, D .C.
4、2031 O Grounding, Bonding and Shielding Design Practices MIL-STD-1857( EL) 1. This Military Standard is approved for use by Electronics Command, Department of the Army, and is available for use by all Departments and Agencies of the Department of Defense. 2. Recommended corrections, additions or del
5、etions should be addressed to Commander, US Army Electronics Command, ATTN: DRSEL-RD-TS-S, Fort Monmouth, N. J. 07703. ii Copyright Communications - Electronics Command Provided by IHS under license with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-“ . MIL-H
6、DBK-L857 m 9997970 0262696 368 m MIL-STD-I857(EL3 30 June 1976 FOREWORD In the past the Department of the Army has required contractors to use a number of bonding and grounding specifications which were primarily intended for use in the development and construction of airborne and shipboard electron
7、ic equipment. In general these specifications were considered adequate but because many of the requirements included therein were unique to airborne and ship- board equipments they could not be effectively applied to ground Army equipments. In light of these shortcomings this standard was developed
8、to provide to the design engineer bonding, grounding and shielding design requirements which can be more effectively applied and are unique to electronic equipments, subsystems and systems deployed by the Department of The Army. iii Copyright Communications - Electronics Command Provided by IHS unde
9、r license with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-l857(EL) 30 June 1976 CONTENTS Paragraph 1 2. 3. 3.1 3.1 -1 3.1.2 3.1.2.1 3.1.2.2 3.1.2.3 3.1.3 3.1.4 3.1.5 3.1.5.1 3.1.5.2 3.1.5.3 3.1.6 3.1.7 3.2 3.2.1 3.2.1 .1 3.2.1.2 3.2.1.3 3.2.2 3.2.2
10、.1 3.2.2.2 3.2.2.3 3.2.3 3.2.4 3.2.4.1 3.2.4.2 3.2.4.3 3.2.4.4 3.2.4.5 3.2 -5 3.2.6 3.2.7 3.2.7.1 3.2.7.2 REFERENCED DOCUMENIS - - - - - - - 1 REQUIREMENTS - - - - - - - - - - - 2 Grounding - - - - - - - - - - - 2 Grounding plane requirements - - - - 2 Grounding techniques - - - - - - - - 3 Floating
11、 ground system - - - - - - - 3 Single-point grounding system - - - 3 Multipoint grounding system - - - - 3 Ground connections - - - - - - - - - 3 Distribution of chassis potential - 5 Grounding of shields - - - - - - - - 9 Cable grounding - - - - - - - - - - 9 Printed circuit boards - - - - - - - 11
12、 Circuit grounding - - - - - - - - - 11 Power supplies - - - - - - - - - - 16 Equipment - - - - - - - - - - - 9 Bonding - - - - - - - - - - - 16 Genera1 - 16 Bond effectiveness - - - - - - - - - 16 Design requirements - - - - - - - - 18 Bonding jumpers (straps) - - - - - - 18 Types of bonds - - - -
13、- - - - - - - 18 Indirect bonds - - - - - - - - - - - 19 Bonding metal selection and bond- strap finishes - - - - - - - - - - 22 Bonding applications - - - - - - - - 24 Shock mounts - - - - - - - - - - - - 24 Rotating joints - - - - - - - - - - 29 Tubing conduit - - - - - - - - - - - 29 Cable trays
14、- - - - - - - - - - - - 29 Bonding practices summarized - - - - 29 Grounding requirements - - - - - - - 33 Earth ground - - - - - - - - - - - - 33 Ground resistance - - - - - - - - - 33 Grounding in sub zero zones - - - - 37 Direct bonds - - - - - L - - - - 19 Bond-straps - - - - - - - - - 19 Hinges
15、 - - - - - - - - - - - - - 29 iv Copyright Communications - Electronics Command Provided by IHS under license with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-HDBK-LB57 H 9999970 0262698 L30 W MIL-STD-1857 (EL) 30 June 1976 CONTENTS - Continued Paragra
16、ph 3.2.8 3.2.9 3.3 3.3.1 3.3.2 3.3.3 3.3.4 3.3.5 3.3.6 3.3.6.1 3.3.6.2 3.3.7 3.3.8 3.3.9 3.3.9.1 3.3.9.2 3.3.10 3.3.11 3.3.11.1 3.3.11.2 3.3.11.3 3.3.11.4 3.3.11.5 3.3.11.6 3.3.11 -7 3.3.11.8 3.3.11.9 3.3.11 -10 3.3.12 3.3.13 3.3.13.? 3.3.13.2 3.3.14 3.3.14.1 3.3.14.2 3.3.14.3 3.3.14.4 3.3.14.5 Sepa
17、ration of ac neutral from frame Marine craft bonding and grounding ground“- methods - Shielding - - - - - - - - - - - - - General- Shielding effectiveness - - - - - - Cable shielding - - - - - - - - - - Case and front panel shielding - - Shielding design fundamentals - - - Multiple shielding- - - -
18、- - - -. - Multiple shielding applications - - Enclosure seam design - - - - - - - Shielding of apertures - - - - - - Waveguide attenuation characteristics Conductive, gaskets - - - - - - - - General -c- Screening - - - - - - - - - - - General- Fasteners - - - - - - - - - - - - - General - - - - - -
19、 - - - - Application - - - - - - - - - - - - Fastening material - - - - - - - - Equipment panels - - - - - - - - - Conductive Elastomer Materials - - Pressure and rain seals - - - - - - Connector seals - - - - - - - - - - Characteristics of conductive gasket Shielding enhancement by conductive Quali
20、fication of gasket material - Insertion loss - - - - - - - - - - Classification of joints - - - - - Conductive gasket selection - - - - Special shielding techniques - - - Gas discharge lamps - - - - - - - - Magnetic shielding techniques - - - Data output openings - - - - - - - Direct view storage tu
21、bes - - - - - Cathode-ray tubes - - - - - - - - - material - - - - - - - - - - gaskets - - - - - - - - - - - - General- Page 37 39 39 39 39 42 45 45 52 52 53 53 57 57 57 60 64 69 69 72 1 72 72 77 77 77 79 81 82 83 83 83 88 88 88 90 93 93 96 V Copyright Communications - Electronics Command Provided b
22、y IHS under license with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Paragraph 3.3.14.6 3.3.14.7 3.3.14.8 3.3.14.9 3.3.15 3.3.15.1 3.3.15.2 3.3.15.3 3.3.15.4 3.3.16 3.3.17 3.3.17.1 3.3.17.2 3.3.17.3 3.3.17.4 3.3.18 3.3.18.1 3.3.18.2 3.3.18.3 3.3.18.4 3.3.19
23、 3.3.20 3.3.20.1 3.3.20.2 3.3.20.3 3.3.20.4 3.3.20.5 3.3.20.6 3.3.21 3.3.21.1 3.3.21.2 3.3.21.3 Figure 1 2 3 4 5 P.-ll MIL-HDBK-L857 m 9999970 0262899 077 m MIL-STO-I857(EL) 30 June 1976 CONTENTS - Continued Page Indicating and elapsed time meters 96 Fuse holder and indicator lamp Switching devices
24、- - - - - - - - - 98 Conductive surface coatings - - - - 1 O0 openings - - - - - - - - - 96 Cabling - - - - - - - - - - - - 103 General- 103 Cable types - - - - - - - - - - - 1 04 Cable shielding - - - - - - - - - - 103 Required cable characteristics - - 105 Cable connectors - - - - - - - - - 1 o9 C
25、able application - - - - - - - - - 1 o9 Magnetic coupling - - - - - - - - - 112 Multiconductor shielding - - - - - 113 Design requirements - - - - - - - - 113 Cable shield grounding - - - - - - 114 Special design features - - - - - - 116 Termination of shields - - - - - - 116 Cab1 e-shield bonding -
26、 - - - - - - 122 Cable routing - - - - - - - - - - - 122 Circuit coupling effects - - - - - 124 Transient response - - - - - - - - 128 Common-impedance cab1 ing elements - 135 Power cabling - - - - - - - - - - - 136. Equipment mounting - - - - - - - - 139 Rack bonding - - - - - - - - - - - 139 Cabin
27、et shielding and equipment General - - - - - - - - - - - - 109 General - -. - - - - - - - - - - - 114 Isolation - - - - - - - - - - - 120 Crosstalk - - - - - - - 122 Waveguides - - - - - - - - - - 138 General- 139 location - - - - - - - - - - - - 142 FIGURES Ground Systems - - - - - - - - - - 4 Grou
28、nd Lug Connection and Equivalent Grounding methods - - - - - - - - - 7 Typical Ground Potential Graph at a Specific Frequency - - - - - - - - 8 Single-Point Ground Bus Arrangement 10 Circuit - - - - - - - - - - - 6 R Vi Copyright Communications - Electronics Command Provided by IHS under license wit
29、h CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Figure 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 MIL-HDBK-L85? m 9999970 0262900 bL9 m MIL-STD-1857( EL) 30 June 1976 FIGURES - Continued Page Direct Use of Chassis
30、 for Good Example of Intercircui t Coupl ing - Effect of Circulating Currents on a Typical Circuit - - - - - - - - - Isolation Transformer Technique for Minimizing Ground Potential - - - Equivalent Circuit of Ground Noise in El ectroni cal ly Coupl ed Circuits Electronically Coupled Circuit with Bon
31、ding Strap Impedance Character- Recommended Bond Strap Bolting In- Impedances of Bond-Straps and No. 12 Typical Shock Mount Bond - - - - - Bonded Engine Shock Mount-Front - - Bonded Engine Shock Mount-Rear - - Cable and Conduit Bonding - - - - - Bonding of Hinges - - - - - - - - - Cable Tray Section
32、 Bonding - - - - Equipment Cabinets Bonded to Cable Soil Classification Chart - - - - - Variation of Soil Resistance with Temperature - - - - - - - - - - - Effect of Moisture Content on Soil Metal Shielding Effectiveness - - - Shield-Constructional Details - - - Multiple Shielding Applications - - S
33、eam Design for Minimum Interference Vertical Expansion Joint, an Example of a Complex Seam - - - - - - - - Air Impedance of Perforated Metal and Honeycomb - - - - - - - - - - Air Impedance of Copper and Nickel Honeycomb Type Ventilation Panel - Attenuation-Rectangular Waveguide - Attenuation-Circula
34、r Waveguide - - Tube Acting as Waveguide Attenuator Shaft Feedthrough Techniques - - - Ground“-“- Ground Noise - - - - - - - - - - - istics“- stal lation - - - - - - - - - - - - AWGWire“- Tray-“- Resistance - - - - - - - - - - - Meah - - - - - - - - - - - - - 12 13 14 14 15 15 17 20 21 26 27 28 30 3
35、1 31 32 34 35 36 40 43 54 55 56 58 58 59 61 62 65 65 vi i Copyright Communications - Electronics Command Provided by IHS under license with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-L857 m 9999970 0262903 555 M MIL-STD-I857(EL) 30 June 1976 Figur
36、e 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 FIGURES - Continued Buckling between Fasteners with Thin Material - - - - - - - - - - Seam Treatment with Mesh Gaskets - Improper Gasket Application - - - - Flat-Flange Tupe Joint - - - - - - Flat-Flange Type Joint with Gro
37、ove Typical Groove Type Gasket Appl i- Typical Conductive Gasket Applica- Typical Gasket Mounting Methods - - Various Gasket Configurations - - - Typical Conductive Gasketing Problem Pressurized Conductive Gasket Appli- Raintight Conductive Gasket Sea: - Insertion Loss vs. Pressure for Resilient Met
38、al Gasket - - - - - - Technique for Measurement of Inser- tion Loss of Resilient Metal Gasket“- cations - - - - - - - - - - - - - tions - cation - Gasket-“- Interference Gasket of the Armour Research Type - - - - - - - - - - Metal-to-Metal Contact Techniques of Cover and Case for Interference Shield
39、s - Effect of Joint Orientation on Flux Shield Economics - - - - - - - - - Meter Shielding and Isolation - - - Treatment of Cathode Ray Tube Magnetic and Electrostatic Cable Typical Conductive Caul king Appl i- Connector with Shielding Shell En- closure for Connecting Points - - Power Frequencies Co
40、upled into Low- Level Circuit Usi.ng Multipoint Shield Grounds - - - - - - - - - - quency Coupling by Shielded, Twisted-Pair Cable - - - - - - - - Paths - - - - - - - - - - - Openings - - - - - - - - - - - - - Shielding - - - - - - - - - - - - cations - - - - - - - - - - - - - Reduction of Signal an
41、d Power Fre- 66 68 70 71 71 73 73 74 75 76 78 78 84 85 86 87 91 91 94 97 99 1 o1 115 117 117 viii Copyright Communications - Electronics Command Provided by IHS under license with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Figure MIL-STD-l857(EL) 30 June 1
42、976 62 63 64 65 66 67 68 69 70 71 72 73 74 75 B-1 B-2 B- 3 B-4 B- 5 B-6 B-7 0- 8 FIGURES - Continued Incorrect Method of Introducing Correct Method of Introducing Continuous Equipment Enclosure Cable Shield Bonding - - - - - - Triazial Cable Application - - - Typical Cabling Methods - - - - - Magnet
43、ic Coupling - - - - - - - - Capacitively Coupled Circuits - - Equivalent Circuit for Derivation of Coupled Signal - - - - - - - Coup1 ing Signal Resulting from Step Voltage - - - - - - - - - - Cable .Circuit Configurations - - Dimensions of Flat-Conductor Flexible Cable - - - - - - - - - Cabinet Bon
44、ding Modifications - - Typical Cabinet Bonding Arrange- Shielding Effectiveness in Shielded Cable - - - - - - - - - Shielded Cable - - - - - - - - - $hiead“- , ments - Electric, Magnetic and Plane Wave Fields of Sol id Copper and Iron Shields (For Signal Source 12 inches from Shield at 100 Hz to10GH
45、z - Total Reflection Loss at Both Total Reflection Loss at Both Absorption Loss for Steel and Surfaces of a Sol id Steel Shield Surfaces of a Sol id Copper Shield Copper Copper Shields at 30 Hz to 10,000 MHz - - - - - - - - - - Shielding for Transmission Cable Values of Equivalent Series RF Resistan
46、ce of Uncoated Aluminum Sections Before and After 64- hour Salt Spray Test. - - - - - - Values of Equivalent Series RF Resistance of Chromate-Treated Aluminum Sections Before and After 64-hour Salt Spray Test - Typical We1 ded Screen Instal lation Over a Ventilation Aperture - - 118 118 119 121 123
47、125 127 130 132 132 134 1 34 140 141 158 159 160 161 162 163 163 1 64 ix Copyright Communications - Electronics Command Provided by IHS under license with CRAINot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-HDBK-L85? m 9999970 02b2903 328 m MIL-STD-l857(EL) 30
48、June 1976 Figure B-9 B-1 O B-1 1 B-1 2 B-1 3 B-14 B-1 5 B-1 6 B-1 7 B-1 8 B-1 9 FIGURES - Continued Typical Clamped Screen Installa- tion Over a Ventilation Aperture - - - - - - - - - Shielding Effectiveness of Vari- Shielding Effectiveness of Vari- ous Copper Screens - - - - - - - ous Galvanized Steel Screens Comparison of the Shielding Effectiveness of Single and Dougle 18 Mesh Copper Screen Effectiveness of Single and Double 40 Mesh Copper Screen Effectiveness of Single and Dou
