MIL-HDBK-1004/2A
SECTION 2: OVERHEAD DISTRIBUTION SYSTEMS
2.1
Circuit Design. Apply proper design criteria (refer to Table 1) to
the specific project. Also refer to NFGS-16302, Overhead Electrical Work and
NFGS-16335, Transformers, Substations and Switchgear, Exterior and MIL-HDBK-
1190, Facility Planning and Design Guide.
Table 1
Information Required For Circuit Design
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ITEM
SPECIFIC INFORMATION REQUIRED
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Individual building
demand loads
Determine proposed demand loads utilizing calculation
methods similar to that used in Table 4 of MIL-HDBK-
1004/1 or based on field measurements.
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Coincident peak
demand
Determine facility peak demand utilizing calculation
methods similar to that use in Table 7 of MIL-HDBK-
1004/1 or based on field measurements.
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Number of circuits
and voltage level
Select number of circuits and voltage level. Number
of circuits will depend upon location and magnitude of
individual loads. Voltage level or type of distribution
should be in accordance with data in MIL-HDBK-1004/1.
Provide sufficient future capacity (+ or - 25 percent).
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Other considerations Balance single phase loads on multi-phase circuits.
Design large starting loads to have a minimal effect
on demands.
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2.1.1
Application. Use overhead distribution because it is generally less
costly than underground. Where underground distribution is more cost
effective, it should be used. When exceptions are considered, follow local
requirements and practices. For example, in Adak, Alaska, distribution is
placed underground in the unstable soil and manholes are placed above the
surface to keep mud from seeping into them. Also, family housing areas and
facilities in residential areas, such as Point Loma, California, require
underground systems to be compatible with the neighborhood. Additional
locations where overhead construction should be avoided are covered in MIL-
HDBK-1004/1.
2.1.2
Capacity.
Make provision for spare capacity in each portion of the
circuit.
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