220.127.116.11.1 Balancing. Rotatable and rotating parts, except locking
adjustment controls, shall be statically and dynamically balanced and
supported to prevent damage or unintentional movement under any environment
condition specified herein. If weights are necessary for balancing, they shall
be securely mounted to prevent movement or loss during operational or
environmental conditions specified herein.
18.104.22.168 Enclosures. Standard Enclosure Systems (SES)
shall be used when possible. The equipment shall be in accordance with
MIL-STD-2200. Other equipment enclosures shall be in accordance with
MIL-STD-108 and MIL-E-2036. The degree of enclosure shall be watertight for
equipment exposed to weather; dripproof to 15 degrees for surface ship
internal installations; and dripproof to 45 degrees for submarine internal
22.214.171.124 Equipment mounting. The method of equipment
mounting shall be specified in Table VIII and herein.
Horizontal mounting. Equipment intended for horizontal mounting shall have
mounting features which permit through bolts to be installed perpendicular to
the mounting surface and additional features to provide for installing sway
braces to the upper rear of the equipment enclosure when necessary for stable
126.96.36.199.2 Overhead mounting. Equipment enclosures
intended for overhead mounting shall be limited to lightweight devices as
specified in the end item specification, and shall incorporate mounting
features located to suspend the enclosure and to transmit the load to the
188.8.131.52.3 Panel mounting. Equipment intended for
front panel mounting shall incorporate a flange for securing the panel in a
vertical position in the enclosure. The enclosure shall project not greater
than 40 millimeters from the face of the panel (not including operating
handles). Design of rack-mounted and console equipment shall maintain the
center of gravity as low as practical.
184.108.40.206.4 Sliding drawer
mounting. Equipment design shall include provisions to prevent accidental
derailing and detachment or pulling off slides of equipment mounted on drawer
220.127.116.11.5 Vertical mounting. Equipment intended for vertical
mounting (except switchboards) shall have mounting pads on the rear surfaces
of the enclosure. Not less than two pads shall be above the center of gravity
of the enclosed equipment. Additional pads shall be positioned to transmit
loads to the supporting structure.
18.104.22.168.6 Resilient mounts. The use of resilient mounts
shall be used in accordance with the guidance of MIL-S-901. Mechanical shock
mounts are preferred to resilient material because of degradation of the
resiliency characteristics of the material over the equipment lifetime, and
resilient material is effective in one plane of shock only. Resilient material
used in the equipment shall undergo accelerated aging prior to shock testing
to demonstrate that equipment meets specified shock performance at the end of
the design life.
22.214.171.124 Grounding, bonding, and shielding. Provisions
for cabinet grounding, bonding, and shielding shall be tailored from
MIL-STD-1310. Practices for internal equipment grounding, bonding, and
shielding shall be tailored from MIL-STD-454, requirement 74, and MIL-STD-454,
126.96.36.199.1 Digital computer grounding. When identified
in the end item equipment specification as equipment used for the processing,
recording, or storage of digital or classified information, the equipment
shall be compatible with the requirements of DOD-STD-1399, section 406.
188.8.131.52 Handling. The equipment shall incorporate the
design features for efficient handling in accordance with ASTM F 1166.
184.108.40.206 Hazardous atmosphere. When specified in the end item
specification, the equipment or portions thereof shall be protected against a
hazardous atmosphere by one of the following methods:
(a). Enclosed in
a heavy-duty, explosion-proof housing as defined by MIL-STD-108.
Hermetically sealed conforming to the hermetic enclosure requirement of
(c). Embedment (potted) and encapsulation
are in accordance with MIL-STD-454, requirement 47.