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MIL-HDBK-1012/1
continuous electrical path. Trays shall be bonded to equipment housings by
wide, flexible, solid bond straps. For a detailed discussion, refer to MIL-
HDBK-419, Section 1.7.4.1 of Volume II.
5.4.5.2
Long spans of conduit shall be bonded to the
Tubing and Conduit
structure at both ends and at several intermediate points.
a) Flexible conduit. A flared, split-sleeve clamp shall be used
to prevent deformation of flexible conduit.
b) Rigid conduit.
Ordinary clamps may be used on rigid conduit.
c) For a detailed discussion, refer to MIL-HDBK-419, Section
1.5.4.2 of Volume II.
5.4.6
General Shielding Requirements. Shielding requirements shall be as
set forth in the BESEP. For a detailed discussion, refer to MIL-HDBK-419,
Chapter 8 of Volume I, Section 1.6 of Volume II and MIL-HDBK-1012/2.
Specific Shielding Requirements
5.4.7
5.4.7.1
Shielded Enclosures/Screen Rooms. General requirements for
attenuation are normally 60 dB for existing facilities and 100 dB for new
facilities. Specific requirements shall be as set forth in the BESEP.
Penetration holes and discontinuities are discussed in MIL-HDBK-419, Chapter 8
of Volume I and MIL-HDBK-1012/2.
5.4.7.2
Tempest. In general, shielding to provide security will require
TEMPEST shielded enclosures. The normal attenuation is 100 dB. Specific
requirements shall be as set forth in the BESEP.
5.4.7.3
HEMP HEMP protection shall be provided as indicated in MIL-HDBK-
1012/2 and the BESEP.
5.5
HEMP Protection. The detonation of a nuclear device at high
altitudes produces extremely high electromagnetic transients over a large
geographical area. This phenomenon is referred to as HEMP. The primary
effect of HEMP is the production of large voltages and currents in conductors
such as power lines, telephone lines, metallic fences, buried cables, and
antennas. These induced voltages and current may cause secondary effects,
such as insulation flashover and equipment malfunction and/or damage. Solid-
state electronic devices are especially susceptible to transients such as
those produced by HEMP.
Consideration should be given to providing HEMP protection for all
critical electronic facilities through the use of voltage-limiting surge
arresters, low-pass filters, shielding, and other devices such as varistors
and carbon blocks. Bonding and grounding requirements for HEMP protection are
set forth in MIL-HDBK-1012/2. Shielding requirements for HEMP protection will
be specified in MIL-HDBK-1012/2 and the BESEP.
Energy Conservation. Every effort should be made during design to
5.6
minimize the use of energy over the life of a facility, insofar as the
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