MIL-HDBK-1005/7A
b)
Alternating Current Motors. Use a squirrel-cage
induction motor for 200 horsepower (hp) (149.2 kW) or less, at
constant speed. Use a wound rotor induction or multi speed
motor for 200 hp or less, when several different speeds are
required. Where the power factor is important, use a
synchronous motor for power above 200 hp.
c)
Direct Current Motors. Use direct current (dc)
motors only when speed adjustment is an important factor and
when economic factors permit.
d)
Enclosure. Use appropriate standards of the
National Electrical Manufacturers Association (NEMA). General
types and applications are as follows.
(1)
Dripproof.
Use in nonhazardous, clean
surroundings.
(2) Totally enclosed, fan-cooled. Use in
nonhazardous corrosive atmospheres containing dusts or high
concentrations of chemicals, or where hosing down or splashing
is encountered.
(3) Totally enclosed, explosion proof. Use in
atmospheres containing potentially explosive gases, chemicals,
or dust.
5.3.3.2
Selection of Other Drives . Apply the selection
factors in MIL-HDBK-1003 Series, for internal combustion
engines, gas turbines, steam turbines, and air compressors.
5.4
Pump Characteristics . Listed below are general
guidelines to follow to determine the correct type of pump to
use. Other sources to refer to for additional information
include the Pumping Manual, T.C. Dickenson, 9th edition and
Hydraulic Institute Standards.
5.4.1
Curves. Obtain characteristic curves from several
manufacturers prior to the selection of a pump, including the
following curves for centrifugal pumps: head capacity (H-Q),
efficiency capacity (E -Q), brake horsepower capacity (BHP-Q),
suction lift capacity, and net positive suction head (NPSH)
required.
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