TM5-811-1/AFJMAN
32-1080
Center for Public Works, the Directorate of Army
incoming power lines that are metered by the use
Power Procurement.
of items of equipment provided and maintained by
d. Rights-of-way. The Government grants all
the utility. The design of new stations, or modifica-
rights-of-way needed within their property limits
tions to existing stations, must be coordinated
and the utility procures all others. Utility-owned
with the supplying utility and with any other
facilities will be located to avoid any interference
suppliers or users of power supplied through the
with installation activities and planned functions.
station. Such coordination should be accomplished
e. Coordination. Selection of utility rate sched-
by the responsible field operating agency, or a
designer employed to accomplish the coordination
ules and rights-of-way over Government property
will be coordinated with, and approved by autho-
and design of new electrical facilities. Complete
rized personnel.
coordination should be performed to ensure proper
protection for electrical equipment and systems, to
4-2. Ownership.
obtain the required degree of availability, reliabil-
When electricity is supplied by a utility, equip-
ity and maintainability, and to achieve the most
ment on the line side of the station transformers
cost effective billing, construction, operation and
maintenance costs during a station life of 25 years
and the station transformers are normally pro-
or less.
vided by the utility. Government ownership of line
a. Billing. Since electric utility rates and rate
equipment and power transformers should be con-
structures vary from state to state and with the
sidered when permitted by the utility and when
user's energy and demand requirements, the serv-
Government ownership would be more economical
ing utility will be contacted at an early point in
based on an estimated life of 25 years for the
the planning process to assist in determining
transformers and line equipment. In making that
probable electric rates and charges. In dealing
determination, the cost of Government ownership
with a large user, the serving utility often has
must be compared against the corresponding cost
flexibility to negotiate a special rate. Where the
for utility ownership, based on the same energy
new installation will be large, this aspect of utility
demands and usage and the different construction
costs and applicable rate schedules.
charges will be vigorously pursued. A typical
facility monthly electric bill will contain the fol-
4-3. Station Designation and Elements.
lowing types of charges:
(1) Energy charge based upon kilowatt-hours
Station elements consist of apparatus associated
(kWH) used. The energy charge may be based on
with incoming and outgoing electrical power trans-
time-of-day usage (the "on-peak" rate often being
mission and distribution circuits, and the equip-
higher during the 12 daytime hours of the normal
ment required for the instrumentation and control
five day work week than during the "off-peak"
of the apparatus and circuits. The station elements
remaining time). Additionally, many utilities
may include power transformers with or without
charge more for energy used during the "peak-
automatic load tap changing provisions. Separate
season" summer months than for energy used
voltage regulators may be provided to regulate
during the "off-peak-season" fall, winter, and
station voltage when power transformers are not
spring months.
provided, or to regulate station voltage when
(2) Demand charge based upon the maximum
nonautomatic load tap changing transformers are
kilowatts (kW) used. This charge is based on the
provided. Separate regulators may be preferred to
maximum rate at which energy is used (kW
prevent outage of power transformers because of
demand) for a period of 15, 30, or 60 consecutive
outage of automatic load tap changing mecha-
minutes (depending on the utility) during "on-
nisms, or to circumvent the problems associated
peak" hours. Alternately, demand charges may be
with the parallel operation of transformers with
based partially on "on-peak" demand and partially
dissimilar features or characteristics.
on "off-peak" demand.
4-4. Main Electric Supply Station/Substation.
(3) Power factor charge. This charge may be
based upon the facility power factor recorded
The main electric supply station/substation is the
during the maximum demand period or upon total
installation/utility interface point where further
kWH and total kilovar-hours (kVARH). Often the
transmission, distribution and utilization of elec-
power factor adjustment is a multiplication factor
trical power, the monitoring and control of such
applied to the kWH and/or the kW demand. Some
power or equipment and the protection of electrical
utilities will charge a penalty for low power factor
equipment or systems becomes the sole responsibil-
(below the 0.85 to 0.90 range) and offer a credit for
ity of the Government. Electrical power will be
a high power factor.
supplied by the same utility over one or more
4-2
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