MIL-HDBK-1003/11
5.3.2 Load Shedding. Load shedding (electrical load segregation to allow
dropping of less critical loads) is preferable to loss of an entire plant.
5.3.3 Spinning Reserve. Where critical loads cannot be shed, spinning
reserve is required for backup in the event that a unit is lost from the
system. Spinning reserve must provide for shutdown of one unit when
operating at maximum demand and with generators running at their maximum
2-hour capacity.
5.3.4 Type of Load Served. Motor loads may affect unit sizes, either
because of other voltage-sensitive loads or because of the size of the motor
in relation to unit size.
5.3.4.1 Voltage-Sensitive Loads. Communication, data processing, and other
voltage-sensitive loads should be segregated from all motor and other types
of utility loads by providing a split-bus system.
5.3.4.2 Size of Motors. Starting large motors will have an effect on
generators because the starting kilovoltamperes (kVA) of a motor is about
three to eight times its running kVA. Design motor starting loads to
prevent voltage dips which are significant enough to cause the system to
shut down. Reduced-voltage starters and sequential starting of motors are
usually provided to prevent unacceptable voltage dips. A unit supplying a
single motor may have to be evaluated to determine the cost-effectiveness of
special generator starting modifications, use of shunt capacitors, or
oversizing of generators.
5.4
Fuel Selection.
5.4.1 Fuel Types. The fuel for diesel engines may be any of the following
types, depending on availability and economics:
a) Grade Navy Distillate DF-2 Diesel Fuel Oil of Federal
Specification VV-F-800, Fuel Oil, Diesel.
b) Marine Diesel of Military Specification MIL-F-16884, Fuel Oil,
Diesel Marine.
c) Jet Fuel Grades JP-4 and JP-5 of Military Specification
MIL-J-5624, Jet Fuel Grade JP-5. Diesel engines may require special
metallurgy to accommodate the use of JP-4 or JP-5 on a continuous basis.
accommodate the use of JP-4 or JP-5 on a continuous basis.
d)
Arctic Grade DBF-800 of Federal Specification VV-F-8001.
e)
Jet (commercial) fuel.
5.4.2 Nondiesel Fuels. The use of a nonstandard fuel such as natural gas,
liquid petroleum gas, residual oils and gasoline may be allowed if economic
advantages are proven through a detailed life-cycle cost economic analysis.
NAVFACENGCOM Headquarters approval is required for the following fuel
selections:
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