MIL-HDBK-1011/1
Section 15: ELECTRICAL
Scope. This section covers electrical materials, equipment, and
15.1
installation techniques used in general construction in a tropical
environment.
15.2
General Design Considerations. Salt-laden air, high temperatures
and relative humidity, insect infestation, and heavy rainfall are the primary
causes of electrical maintenance problems and system failures in a tropical
environment.
In addition, during hurricanes and typhoons, driven rain and
winds in excess of 100 miles per hour cause extensive damage to overhead pole
lines and insufficiently protected switchgear, transformers and circuit
components. The interiors of air conditioned buildings are not subject to the
harsh elements of the tropical climate; design them in accordance with
NFGS-16402, Interior Wiring Systems.
15.3
Application Guidelines
15.3.1
Equipment.
Installing equipment under building eaves or canopies,
within enclosed equipment rooms, and on the prevailing downwind sides of
buildings contributes to a more durable system with less maintenance costs.
Locating switchboards, panelboards, starters, motor control centers and other
major electrical items indoors improves system reliability during hurricanes
and typhoons and reduces the need for exotic, expensive enclosures.
15.3.2
Distribution.
Underground distribution and 600 volt wiring are
highly recommended to ensure superior protection from hurricanes and typhoon
wind damage. However, direct buried cables are difficult to replace, subject
to termite damage, and are not recommended. Design in accordance with
MIL-HDBK-1004/2, Power Distribution Systems. In hurricane and typhoon areas,
prestressed concrete poles are recommended as an alternative to wood poles,
funds permitting.
15.4
Construction/Materials Consideration. Table 4 is a comparison of
stainless steel, aluminum, polyethylene, fiberglass-reinforced concrete (FRP),
and copper in various environments and their relative abilities to resist
corrosion.
15.4.1
Non-corrosive Materials. Generally, use corrosion-resistant
materials such as plastic, fiberglass, copper or aluminum coated steel, or
anodized or copper-free aluminum for installations exposed to the elements.
Where corrosion resistant materials lack sufficient physical strength, or are
subject to deterioration from the sun, or are not available, provide ferrous
materials with protective enclosures and coatings.
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