22.214.171.124 Grounding methods. Plugs for use with metal cased portable tools and equipment should have provisions for automatically grounding the metal frame or case of tools and equipment when the plug is mated with receptacle, and the grounding pin should make first, break last. Ground connections to shields, hinges, and other mechanical parts should not be used to complete electrical circuits. Any external or interconnecting cable, where a ground is part of the circuit, should carry a ground wire in the cable terminated at both ends in the same manner as the other conductors. In no case, except with coaxial cables, should the shield be depended upon for a current-carrying ground connection. Static and safety grounds should not be used to complete electrical circuits. A point on the electrically conductive chassis or equipment frame should serve as the common tie point for static and safety grounding. The path from the tie point to ground should:
a. Be continuous and permanent.
b. Have ample carrying capacity to conduct safely any fault currents that may be expected, to be imposed on it by internally generated faults.
c. Have impedance sufficiently low to limit the potential above ground and to facilitate the operation of the over current devices in the circuits, and;
d. Have sufficient mechanical strength of the material to minimize possibility of ground disconnection.
Replaced/Superseded by document(s)
|File||MIME type||Size (KB)||Language||Download|
|Military Handbook- General Guidelines for Electronic Equipment.pdf||application/pdf||14.78 MB||English||DOWNLOAD!|
1.1 Guidelines applicable to electronic equipment. This handbook provides guidance and lessons learned in the selection of documentation for the design of electronic equipment. This handbook is for guidance only. This handbook cannot be cited as a requirement. If it is, the contractor does not have to comply.
1.2 Revision of guidelines. Revisions of individual guidelines are indicated by a date below the guideline number located at the bottom of the page. When the basic document is revised, those guidelines not affected by change retain their existing date.
1.2.1 Redating. Although individual guidelines are reviewed and updated or validated at least once every eighteen months, guidelines are not redated unless technical changes are made.
1.3. Method of reference. Guidelines contained herein should be referenced by specifying this handbook and the guideline number for guidance only.