Unified Facilities Criteria (Ufc)
Unified Facilities Criteria (Ufc)
Unified Facilities Criteria (Ufc)
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
ELECTRICAL ENGINEERING
ELECTRICAL ENGINEERING
Any copyrighted material included in this UFC is identified at the point of use. Use of
the copyrighted material apart from this UFC must have the permission of the copyright
holder.
FOREWORD
The Unified Facilities Criteria (UFC) system is prescribed by MIL-STD 3007 and provides
planning, design, construction, sustainment, restoration, and modernization criteria, and applies
to the Military Departments, the Defense Agencies, and the DoD Field Activities in accordance
with USD(AT&L) Memorandum dated 29 May 2002. UFC will be used for all DoD projects
and work for other customers where appropriate. All construction outside of the United States is
also governed by Status of forces Agreements (SOFA), Host Nation Funded Construction
Agreements (HNFA), and in some instances, Bilateral Infrastructure Agreements (BIA.)
Therefore, the acquisition team must ensure compliance with the more stringent of the UFC, the
SOFA, the HNFA, and the BIA, as applicable.
UFC are living documents and will be periodically reviewed, updated, and made available to
users as part of the Services’ responsibility for providing technical criteria for military
construction. Headquarters, U.S. Army Corps of Engineers (HQUSACE), Naval Facilities
Engineering Command (NAVFAC), and Air Force Civil Engineer Support Agency (AFCESA) are
responsible for administration of the UFC system. Defense agencies should contact the
preparing service for document interpretation and improvements. Technical content of UFC is
the responsibility of the cognizant DoD working group. Recommended changes with supporting
rationale should be sent to the respective service proponent office by the following electronic
form: Criteria Change Request (CCR). The form is also accessible from the Internet sites
listed below.
UFC are effective upon issuance and are distributed only in electronic media from the following
source:
Hard copies of UFC printed from electronic media should be checked against the current
electronic version prior to use to ensure that they are current.
______________________________________ ______________________________________
JAMES C. DALTON, P.E. JOSEPH E. GOTT, P.E.
Chief, Engineering and Construction Chief Engineer
U.S. Army Corps of Engineers Naval Facilities Engineering Command
______________________________________ ______________________________________
DENNIS FIRMAN MICHAEL McANDREW
Director of the Air Force Center for Engineering Director, Facility Investment and
and the Environment Management
Department of the Air Force Office of the Deputy Under Secretary of Defense
(Installations and Environment)
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Superseding:
Description: This UFC 3-501-01 provides electrical engineering design and analysis
criteria for design-build and design-bid-build projects. It is organized to provide the top-
level \1\ minimum mandatory electrical requirements /1/ and refers to other UFCs as
appropriate.
Impact: There are negligible cost impacts associated with this UFC. However, the
following benefits should be realized.
• This UFC coordinates with all electrical-related UFCs and provides \1\
requirements consistent /1/ with the other electrical-related UFCs.
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
TABLE OF CONTENTS
Page
i
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
ii
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
FIGURES
TABLES
iii
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
CHAPTER 1 INTRODUCTION
The purpose of this UFC is to provide technical \1\ requirements /1/ for general aspects
of the electrical design of projects. The information provided in this \1\ UFC shall /1/ be
used in the development of the plans, specifications, calculations, and Design/Build
Request for Proposals (RFP) and \1\ shall /1/ serve as the minimum electrical design
requirements for design-build and design-bid-build projects. Project conditions may
dictate the need for a design that exceeds these minimum requirements.
This UFC provides the top-tier baseline \1\ requirements /1/ for electrical UFCs and is
intended as a reference for all electrical work on projects. Figure 1-1 shows the
relationship of this UFC to other related UFCs. They rely on this UFC for overall \1\
requirements /1/ regarding design analysis and documentation. There are existing
individual service UFCs and other UFCs under development; these documents are
identified in similar figures in Appendix B.
Modernization of electrical systems solely for the purpose of meeting design criteria in
UFCs is not required. Upgrades or modifications to electrical systems should consider
the design criteria in this UFC, but it is not intended that an entire facility or system
require modernization solely because of a minor modification.
1-2 APPLICABILITY.
Compliance with this UFC is mandatory for the design of electrical systems at all
facilities, bases, and at leased facilities. Leased facilities are defined in UFC 4-010-01.
Facilities located outside of the United States must also comply with the applicable host
nation standards; refer to UFC 3-510-01 for additional information. Different voltages,
frequencies, and grounding conventions often apply in other host nations; however,
follow the design principles provided in this UFC to the extent practical. U.S.
Department of Commerce International Trade Administration document, Electric Current
Abroad, provides additional information and can be obtained at
http://www.ita.doc.gov/media/publications/pdf/current2002final.pdf.
\2\
1-3 GENERAL BUILDING REQUIREMENTS.
1
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
UFC 3-501-01
Electrical Engineering
UFC 3-580-10
NMCI Standard
Construction Practices
2
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
\1\ /1/ The electrical Designer of Record \1\ shall /1/ satisfy each of the following for
each project:
\1\
a. Apply NFPA 70 and IEEE C2 to electrical designs..
b. Provide contract documents that fully indicate the scope of work.
/1/
c. Comply with \1\ /1/ applicable UFCs, codes, regulations, laws, and service-
specific requirements.
d. Provide a completed project within funding limits.
e. Provide a completed project within scope of work limits.
f. Provide a completed project of acceptable appearance within design
standards.
g. Provide a completed project with coordinated systems (structural,
mechanical, electrical, and other applicable disciplines).
h. Provide complete, accurate, and coordinated construction documentation for
the project.
i. Provide a completed project considerate of the ecological, physical, and
visual features of the site.
j. \1\ Comply /1/ with applicable environmental requirements.
k. Provide a completed project that incorporates sustainable design principles.
l. Provide a completed project, meeting the \1\ Installation Appearance Plan
(IAP) or Base Exterior Architectural Plan (BEAP), as applicable. /1/
\2\/2/
Identify the permits and fees necessary for environmental, construction, and operation
of facilities.
3
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Design electrical systems to meet the needs of the activity and supporting facilities in
accordance with this document.
\1\ /1/ Electrical equipment \1\ shall /1/ be manufacturer’s standard catalog products and
\1\ shall /1/ conform to the latest published industry and technical society standards at
the date of contract award. Underwriters Laboratories (UL) \1\ listing /1/ or third-party
certification is required for all basic equipment. Use of shop or field fabricated electrical
equipment assemblies that are not manufacturer’s standard catalog products or do not
conform to the industry and technical society standards are not acceptable.
When a project requires removal of existing cables and conductors enclosed in either
duct or conduit, they \1\ shall /1/ be physically removed. Associated ducts or conduits
may be abandoned in place only for the following conditions:
Existing equipment to be “Modified” or “Added to” \1\ shall /1/ be uniquely identified.
This identification shall include the manufacturer’s name and other pertinent
manufacturer’s identification (e.g., serial number, model number, style), if such
information exists.
\1\ Note: UFC 3-560-01 is usually more stringent than EM 385-1-1. However, it
may be invoked on contractor work when desired and agreed to by the Activity.
In that case, modify contract documents appropriately/1/.
2-1.6 CALCULATIONS.
5
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Comply with UFC 3-400-01 to meet the energy conservation mandates of ASHRAE
90.1; EPACT 2005; Executive Order 13423; and the Energy Independence and Security
Act of 2007.
UFC 4-010-01 is a multidiscipline document which contains several standards that may
impact electrical system design. Electrical designers \1\ shall /1/ be familiar with UFC
4-010-01 and how it may affect the design of utilities, service entrance equipment,
emergency backup systems, and bracing of electrical equipment. Incorporate the
minimum standards into the design of all new construction and major renovations of
inhabited DoD buildings.
UFC 4-020-01 supports the planning of DoD facilities that include requirements for
security and antiterrorism. Use in conjunction with UFC 4-010-01 to establish the
security and antiterrorism design criteria that will be the basis for DoD facility designs.
The special design \1\ requirements /1/ listed below apply when electrical equipment is
routinely subjected to salt spray \1\ (such as installations at piers and wharves) /1/ or is
installed in locations exposed to condensing humidity that has historically caused
premature rusting and degradation of equipment enclosures.
• Use stainless steel cabinets and hardware for pad-mounted switchgear, \1\
switchboards, /1/ and sectionalizing termination cabinets.
• Use stainless steel enclosures and hardware for exterior safety switches and
other electrical equipment.
\1\/1/
• When feasible, equipment enclosures can be designed to comply with NEMA
4X non-metallic enclosure requirements instead of stainless steel if the
6
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
\3\ Refer to UFC 3-560-01 for arc flash label requirements. /3/
! WARNING
\2\
Design buildings and similar support structures such as piers, wharfs, parking
structures, sewage pump stations, and fueling facilities in accordance with the general
requirements of NFPA 70:
• The demarcation for the “service point” (for clarification of the NFPA 70 Article
100 definition) shall be at the building/similar support structure service
equipment line side connection.
• The demarcation between NFPA 70 and IEEE C2 for electrical power design
purposes shall be the secondary terminal of the building/support structure
utilization electric supply system.
7
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Design all exterior underground and overhead, medium and low voltage systems not
specifically associated with a building/support structure in accordance with the general
requirements of IEEE C2 except that NFPA 70 ampacity and conduit fill tables shall be
utilized to the extent possible for all designs.
Design the following in accordance with the general requirements of NFPA 70:
8
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
/2/
9
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
The site utility distribution system \1\ shall /1/ be compatible with the existing system
and comply with UFC 3-550-01. Where the site service is derived from an existing
primary feeder, the designer \1\ of record shall coordinate with the government authority
and shall receive direction regarding point of connection and concurrence that /1/
existing circuit can support the new loads.
Comply with UFC 3-570-02N for the Navy and UFC 3-570-02A for the Army.
10
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
\1\ Comply with ICD 705, ICS 705-1, ICS 705-2, and with IC Tech Spec for ICD/ICS
705./1/
Show boundaries of hazardous locations on the plans and identify the type of hazard by
class, division, and group.
Unless directed otherwise by the BCO, size outside category 3 copper cable for a
minimum of one pair per 100 ft2 (9 m2) of building and provide a minimum of one 12
strand single-mode fiber optic cable for each facility. Coordinate cable selection and
point of connection with the BCO and specify using RUS specifications.
Provide solid-state type primary communication circuit protectors with sneak current
protection for all twisted pair media terminating inside a building from an overhead or
underground outside plant.
11
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
\1\ Comply with /1/ UFC 3-580-01. Coordinate exterior cable installation with the local
service provider and Base Communications Officer (BCO). Provide a conduit and pull
wire from a point of connection to the base system and the main distribution equipment.
\1\ Comply with UFC 4-021-02NF for Navy and Air Force. Comply with /1/ UFC 4-020-
04A for the Army.
12
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
3-1 GENERAL.
This chapter defines the minimum information that \1\ shall /1/ be provided at the
various design submittal levels. During the design submittal process, the Designer of
Record \1\ shall clarify /1/ comments with the appropriate Government reviewer rather
than wait until the next submittal to respond. Whenever possible, the Designer of
Record is encouraged to meet with the reviewer to discuss comments.
The Design Analysis is a presentation of facts to demonstrate the concept of the project
is fully understood and the design is based on sound engineering principles. As a
minimum, include the following information in the Design Analysis.
Document design decisions throughout the design process. List any special features
and alternatives that were considered. Provide a written narrative accurately
addressing the electrical and telecommunication design. Describe the design approach
to all electrical systems. Include the method used for sizing conductors, conduit,
protective devices, and other equipment. Show all calculations used in determining
capacities of electrical systems. When tables from industry standards are used in the
design, indicate the title, source, and date of the document. Include a complete list of
all design standards and references used for the design.
Update the Basis of Design for each submittal to accurately show the current state of
the design. Include the information in the following sub-paragraphs as a minimum.
\1\
• Existing Primary Power Source – Identify the location of the point of
connection into the existing primary system. Address the characteristics of
this primary system, including ANSI voltage designation, phase, number of
conductors, available fault current, and the circuit grounding classifications
(ungrounded, uni-grounded, resistance grounded, or multi-grounded).
Address the adequacy of the primary system; if inadequate, state measures
proposed to correct the inadequacy.
13
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
• Materials – Provide manufacturer’s data sheets and product data for selected
equipment.
• Materials – Provide manufacturer’s data sheets and product data for selected
equipment.
/1/
14
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
d. Wiring Methods – Indicate the type of wiring method, such as rigid conduit,
electrical metallic tubing, cable tray, nonmetallic sheathed cable, and where
proposed to use.
15
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
i. Materials – Provide manufacturer’s data sheets and product data for \1\
selected equipment./1/
/1/
The Designer of Record \2\ (DOR) /2/\1\ shall /1/ provide calculations (in accordance
with the associated follow-on paragraphs) to verify proper design and operation of the
facility to the point of connection to the existing electrical systems. \2\ The DOR is also
responsible for contacting and obtaining all utility data required to complete the relay
coordination study from the respective Base Electric Utility Department or Private Utility
Company including existing upstream protective device types and settings. /2/
Calculations \1\ shall /1/ be described fully, written clearly, and lead the reviewer
through the design by stating all assumptions and design inputs. Computer printouts
are acceptable only if accompanied by explanations to allow adequate independent
review of calculation methods and results.
Note: The Navy Network is only able to utilize SKM software modules and EasyPower
for electrical analysis. If project calculations are done using any other software, they
must also be provided in either SKM or EasyPower so that they are usable by Navy
personnel on the Navy Network.
16
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Note: For the Air Force, only EasyPower is certified in accordance with AFI 33-210 for
use on standard desktop systems connected to the Air Force Global Information Grid
and placed on the Air Force Evaluated/Approved Products List. /2/
Calculations \1\ shall /1/ provide complete analysis with supporting data. Analysis \1\
shall /1/ cover system arrangement; voltage selection; and major equipment selections
including load analysis and equipment sizing calculations. Whenever sizing electrical
equipment, such as transformers, breakers, or electric cables, provide calculations to
demonstrate proper facility design. The following calculations shall be provided unless
the Basis of Design clearly explains why a particular calculation type is not applicable:
a. Load analysis.
b. Short circuit analysis, including protective device interrupting rating.
c. Protective device time-current coordination study.
d. Arc flash analysis.
e. Voltage drop.
f. Motor starting/flicker analysis.
g. Lighting.
h. \1\ Underground structure design. /1/
i. Cable pulling tension.
j. Directional Boring
k. Sag, tension, and guying analysis.
l. Cathodic protection calculation.
m. Lightning protection analysis.
n. CATV network loss calculations.
o. ESS calculations.
\1\ Detailed requirements for each calculation item in the list are contained in the
following paragraphs. /1/
17
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
• Apply the demand and diversity factors from Appendix D to the preliminary
load analysis to determine the transformer size.
• For building designs, the service transformer shall not exceed 12 VA/square
foot (130 VA/square meter) of facility gross floor area or 70% of the total
connected load on installations served by transformer rated 300 kVA or
greater. Any design calculations exceeding these requirements shall be
specifically approved by the technical reviewing authority.
Note: The above check is intended to serve as a simple confirmation that the
facility transformer is not oversized.
\1\
• Apply the demand and diversity factors from Appendix D to the final load
analysis to determine the transformer size.
18
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
• For building designs, the service transformer shall not exceed 12 VA/square
foot (130 VA/square meter) of facility gross floor area or 70% of the total
connected load on installations served by transformer rated 300 kVA or
greater. Any design calculations exceeding these requirements \1\ shall /1/
be specifically approved by the technical reviewing authority.
\1\
• Assign \1\ a “0%” /1/ demand factor for \1\ /1/ fire pump loads \1\ in demand
calculations /1/.
\1\/1/
• Size the service conductors (continuous current rating) in accordance with Annex
B (Neher-McGrath method) of NFPA 70. Minimum design ampacity rating shall
be larger than the ampacity rating of the main overcurrent protective device.
• Design the incoming service, \1\ including spare conduit /1/ to fully unload the
maximum rating of the service equipment (i.e. 1200 amperes for 1200 ampere
rated equipment protected with 1000 ampere device).
19
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
For small systems \1\ 225 amps or less, /1/ or for small modifications to large systems,
the load analysis can be performed manually using the above criteria. For larger
systems, a \1\ load /1/ analysis using computer software tools is necessary to evaluate
properly all of the possible facility modes of operation.
Complete a short circuit analysis in accordance with IEEE Std 551 and include the
following in the analysis:
a. Include the utility system data as well as data for the distribution system.
Contact the Contracting Officer \1\ or technical reviewing authority /1/ for the
utility system data and available fault current on the primary side of medium
voltage equipment. When accurate data does not exist, the Designer of
Record \1\ shall /1/ assume that maximum available fault exists, up to a
possible infinite bus on the primary side of the upstream transformer, and
design the system assuming such conditions.
b. Calculate the available short circuit and ground fault currents at each bus.
Incorporate any motor contribution in determining the momentary and
interrupting ratings of the protective devices.
c. The study \1\ shall /1/ be calculated by means of a commercially-available
software program designed for the type of required analysis. Incorporate
pertinent data and the rationale employed in developing the calculations in
the introductory remarks of the study. Equipment interrupting capability
evaluations \1\ shall /1/ meet the requirements of IEEE C37.06, IEEE
C37.13.1, or UL 489 criteria, as applicable.
d. Where diagrams will not fit on standard letter size paper, present the data
determined by the short circuit study in a tabular format. Include the
following:
• Device identification
• Operating voltage
• Protective device
• Device rating
• Calculated short circuit current
Design the electrical system such that any fault in the system will be preferentially
isolated by the selective operation of only the overcurrent protective device closest to
the faulted condition. Perform a coordination study at the design stage to establish the
basis for the system design and to enable completion of an initial arc flash analysis.
20
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Provide a final coordination study based on the as-built configuration of the system.
Identify locations where selective coordination is not achievable, such as with
instantaneous trips on molded case circuit breakers.
The Designer of Record \1\ shall /1/ ensure that construction contract documents
require the Contractor to submit manufacturer’s published time-current curves for
primary fuses, relays, main secondary breakers, and secondary feeder protective
devices. This information is required during the submittal process. Using the time-
current curve data, the Designer of Record shall perform a coordination study in
accordance with the following paragraphs to ensure that protective devices are properly
coordinated.
3-2.5.1 Coordination Study. The completed study \1\ shall /1/ include a system
one-line diagram, short circuit and ground fault analysis, and protective coordination
plots.
The Designer of Record \1\ shall /1/ provide to the Contractor settings for relays, main
secondary breakers, secondary feeder protective devices, and any other protective
devices in the circuit. The final coordination study and the specified setting information
\1\ shall /1/ be based on the as-built configuration.
a. Calculated short circuit values and X/R ratios at the project utility point of
connection.
b. Breaker and fuse ratings.
c. Transformer kVA and voltage ratings, percent impedance, and wiring
connections.
d. Identification and voltage at each bus.
e. Conduit material; and feeder conductor sizes, type, insulation, length and
configuration.
devices, including the utility company upstream devices where applicable. Plot the
specific time-current characteristics of each protective device in such a manner that all
applicable upstream devices will be clearly shown on one sheet. Include the following
information on the coordination curves:
a. Device identification.
b. Voltage and current ratios for curves.
c. 3-phase and 1-phase ANSI damage points for transformers directly fed from
the switchgear.
d. Minimum melt and total clearing curves for fuses.
e. Cable damage curves.
f. Transformer inrush points.
g. Maximum short circuit current.
3-2.5.4 Settings. Develop a table to summarize the settings selected for each
protective device. \1\ Low voltage protective devices less than 225 amperes, unless
adjustable trip, are not required to be included. /1/ The table shall address all relays
and relay functions. Include in the table the following:
a. A narrative describing the analyses performed, the methods used, and the
desired method of coordinated protection of the power system.
b. Descriptive and technical data for existing devices and new protective
devices. Include the manufacturers’ published data, nameplate data, and
definition of the fixed or adjustable features of the existing or new protective
devices.
c. Documentation of the utility company data including system voltages, fault
MVA, system X/R ratio, time-current characteristic curves, current transformer
ratios, and protective device settings.
22
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Complete an arc flash evaluation in accordance with NFPA 70E and IEEE Std 1584 as
part of the short circuit study to determine personal protective clothing (PPE)
requirements. Note: PPE criteria shall be in accordance with Chapter 4 of UFC
3-560-01. \1\ Direct current (DC) systems analysis is not required since it is not
currently addressed in industry standards. /1/ Include the following:
23
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Size service and feeder conductors for a maximum voltage drop of 2 percent at the
circuit’s rated capacity. Size branch circuits for a maximum voltage drop of 3 percent at
the circuit’s rated capacity.
If the conductor size must be increased due to voltage drop, do not increase the size of
the overcurrent protection device for the circuit. The overcurrent protection device may
be protecting downstream equipment and increasing the size of the overcurrent setting
can reduce the level of equipment protection. If the phase conductor size is increased
for voltage drop, increase the size of the equipment grounding conductor proportional to
the circular mil increase of the phase conductor.
Motor calculations \1\ shall /1/ account for both starting and running current.
Provide a motor starting/flicker analysis for motors 40 hp and greater \1\ for 480-volt
systems; for 25 hp for system rated for 240 volts and below; /1/ and for distribution in
housing areas utilizing electrical HVAC systems. Verify that the voltage drop at the
service entrance does not exceed 5 percent during motor starting.
Refer to IEEE Std 241 for information regarding the calculation and effect of flicker.
3-2.9 LIGHTING.
Provide calculations for interior and exterior lighting systems in accordance with UFC
3-530-01.
\1\ Provide sizing and cable bending radius calculations for underground structures
(manholes and handholes) with cable sizing exceeding 500 kcmil. Verify design
requirements of UFC 3-550-01 are met. /1/
Provide cable pulling tension calculations for \1\/1/ medium voltage cable.
24
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Provide calculations for all designs. Include environmental resistivities and justify all
assumptions.
Provide a lightning risk assessment in accordance with NFPA 780 Annex L and
document the required level of protection.
Provide adequate plans, including demolition, existing conditions, and new work,
legends, details, and diagrams to clearly define the work to be accomplished.
Coordinate construction drawings and specifications; show information only once to
avoid conflicts.
Provide a General Note at the beginning of the Electrical Drawings clarifying the work to
be accomplished. The following note is recommended for most jobs:
25
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Drawings \1\ shall /1/ be clear and consistent in presentation and format.
Follow the NFPA 70 Metric Designations (mm) and Trade Sizes (in) for
conduit.
• Acceptable: Two 4-inch conduits, each containing four 500 kcmil and one
#2 Gnd
• Acceptable: Two 4-inch conduits, each with four 500 kcmil and one #2
Gnd
• Acceptable: Two 4-inch conduits, with four 500 kcmil and one #2 Gnd in
each conduit
• Unacceptable: Two sets of four 500 kcmil and one #2 Gnd in 4-inch
conduit
• Unacceptable: Parallel Service: Four 500 kcmil and one #2 Gnd in 4-inch
conduit
All symbols used in the drawings \1\ shall /1/ be defined in the legend. Locate legend
on the first electrical sheet using multiple legends where required and identifying the
specific use of each legend. Use different legends for new and existing work. Avoid
using composite legends that include all symbols but fail to indicate which symbols are
to be used on which drawings.
26
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Show utility point of connectivity to the base power and telecommunications systems on
the site plan. Provide explicit direction on method of entering existing manholes.
Provide all details including composition of duct banks and depth and configurations of
the duct banks.
Electrical Site Plans \1\ shall /1/ be separate and distinct from other utility site plans and
\1\ shall /1/ be included with the electrical drawings. Electrical and civil site plans may
be combined only when the project requires minor utility work. Coordinate with the
electrical engineering reviewer before combining the electrical and civil site plans.
The orientation of electrical drawings \1\ shall /1/ be consistent with the civil drawings.
In addition, the orientation of partial building or site plans \1\ shall /1/ be identical to the
orientation of the larger plan from which the partial was taken. Indicate the exact title of
each particular detail, partial plan or elevation as identified on the cross-referenced
sheet.
For overhead distribution use a separate symbol for each individual circuit; define each
circuit by voltage level as well as number, size and type of conductors. Coordinate
guying and conductor sag information shown on the drawings with that shown in the
specifications.
NAVFAC pole details are available in Adobe PDF format and in AutoCAD format at
http://www.wbdg.org/ccb/NAVGRAPH/graphtoc.pdf.
Provide details in situations where an applicable pole detail has not been developed.
Designer developed details \1\ shall /1/ contain the same level of detail equivalent to the
NAVFAC pole details and include material requirements.
Review the information contained on Details OH-1.1 through OH-1.5a for examples of
how to show overhead distribution work. Do not describe proposed work by referencing
sketch numbers instead of pole detail designation symbols. Do not use pole detail
designation symbols to describe existing facilities to be removed. To maintain the
integrity of the pole details, do not modify pole details; include any required exceptions
or modifications as supplemental information with the pole detail designation symbols.
When using pole details, place a note referencing the pole detail designation symbols
(similar to the following) on the drawings:
“XFB, 15FR3-N are pole detail designation symbols. Refer to Sketches OH-1.1
through OH-41 on Sheets _______ for an explanation of the use and description of
equipment provided by these symbols.”
27
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Indicate conductor initial sag values. Provide initial sag values at ambient temperatures
in 10 degree C (18 degree F) increments for a temperature range, which includes the
outside summer and winter design temperature values. Clearly indicate each different
calculated ruling span on the plans and provide initial sag for one span in the calculated
ruling span.
Provide appropriate symbol and detail indicating the use of backup current limiting fuses
with the device being protected. Indicate the fuse type and ampere rating as well as the
voltage rating and current designation of the backup current limiting fuse.
These details are also provided in a PDF format within the electrical technical paper \2\
TP-12 /2/ “Appendices” located at
http://www.wbdg.org/ccb/browse_cat.php?o=29&c=248.
Include the following information for surge arresters and fused cutouts:
Profiles may be required for ductbank runs. Discuss profile requirements with the
electrical reviewer. Indicate structure (manhole and handhole) tops, ductbank
elevations, slopes and diameters. Coordinate structure numbers with plan sheets.
Show and label all crossing utility lines, both existing and new. If depths of existing
28
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
utilities are unknown, indicate the horizontal location of the utility and indicate the
vertical location with a line representing the anticipated range of elevations where the
utility will be found in the field. Indicate the method of new utility installation routing
above or below conflicts.
Provide manhole foldout details or exploded views for all multiple-circuit primary
systems and all primary systems requiring splices. Indicate the entrance of all conduits
and the routing of all conductors in the manholes.
Provide “Demolition” plans separate and distinct from “New Work” plans, except where
only minor demolition work is required. Clearly show what is to be demolished, at an
appropriate scale. Indicate the beginning and ending points of circuit removals.
Indicate the quantity of lighting ballasts that contain PCBs and the quantity of lamps that
contain mercury.
Do not show lighting and power on the same floor plan, unless the scale of the plan is
1:50 (¼ in = 1 ft – 0 in) or larger.
Provide luminaires (lighting fixtures) details and a separate luminaires schedule. Use
the details and the luminaires schedule that is available in Adobe PDF format and in
AutoCAD format at http://www.wbdg.org/ccb/NAVGRAPH/graphtoc.pdf. In order to
maintain the integrity of the details, do not modify details; make any required exceptions
or modifications in the remarks column of the luminaires schedule and not on the details
themselves. Provide applicable luminaires type symbol(s) with each luminaire
sketch/detail. When using luminaire(s) not included in the database, detail the
luminaire(s) on the drawings providing the following minimum information:
29
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Show all power requirements and points of connections. Specifically identify each piece
of equipment including HVAC and mechanical equipment (e.g., unit heater No. 1, unit
heater No. 2).
Typical illustrations showing proper methods for displaying equipment on the contract
drawings are provided in a PDF format within the electrical technical paper \2\ TP-12 /2/
“Appendices” located at http://www.wbdg.org/ccb/browse_cat.php?o=29&c=248.
Show locations of voice and data outlets in each room, closets, and equipment spaces.
Detail all outlet, cable tray and backboard or distribution frames.
Note: Power and communication systems may be shown on the same floor plans
provided the design is small, the electrical designer and the telecommunications \1\
registered communications distribution designer (RCDD) /1/ are the same person, and
combining the drawings is approved by the Contracting Officer \1\ or technical reviewing
authority /1/. However, when there is extensive communication work to be shown, show
power and communication systems on separate plans. \1\ The communications plans
shall be signed by both a registered professional engineer and an RCDD. /1/
30
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Provide lightning protection plan and details at an appropriate scale. Plan \1\ shall /1/
indicate locations and number of system components required. Show air terminal
installation details, roof and wall penetration details, and details to show concealed
components of the system.
Coordinate roof and wall penetrations with other disciplines to ensure that the integrity
of the facility envelope is not compromised.
Provide on the drawings the boundaries and classifications of all hazardous locations in
accordance with NFPA 70.
The one-line diagram must show all components (including metering and protective
relaying), and \1\ shall /1/ indicate sizes of bus, feeders and conduits. Connections of
transformers, PTs, CTs, and capacitors \1\ shall /1/ be shown on the one-line diagram
by means of the proper symbol. Show potential and current transformer ratios. Indicate
relay quantity and function (overcurrent, voltage, differential) using ANSI designation
numbers.
Indicate kV ratings for surge arresters, and kV and ampere rating for cutouts. Indicate
fuse link type and ampere rating. For capacitors indicate kVAR per unit, number of
units per bank, voltage (voltage rating of units, not the system voltage), phase (e.g.,
three-phase or single-phase units), fuse size, and fuse type.
31
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
• Primary switches.
• Wye or delta connection.
• Loadbreak elbows.
• Lightning arresters.
• kVA rating.
• Rated voltage (primary & secondary).
• Transformer identification number.
• Industry standard impedance.
• Meter type.
• CT and PT sizes.
• Fuse sizes.
Show all pertinent information on the transformer and the service entrance on the one-
line diagram as opposed to the specifications. Items that are common to all
transformers can be indicated by notes on the one-line diagram if a typical detail
drawing is provided.
\1\/1/
Show the following on the one-line diagram when pad-mounted switchgear is indicated:
Show the following on the one-line diagram when a new primary is indicated:
32
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Insure that information shown on the one-line diagram is not duplicated elsewhere in the
construction package, as this will likely cause conflicts if changes are necessary.
Indicate on the electrical legend the exact nomenclature used to indicate conductor and
conduit sizing. Provide a schedule for feeder runs. Medium voltage one-line diagrams
for stations and distribution systems \1\ shall /1/ have a geographic affiliation to the
actual constructed distribution system.
Typical illustrations showing proper methods for displaying one-line and power riser
diagrams on the contract drawings are provided in a PDF format within the electrical
technical paper \2\ TP-12 /2/ “Appendices” located at
http://www.wbdg.org/ccb/browse_cat.php?o=29&c=248.
Clearly indicate service entrance cable and duct, entrance protector assemblies, and
connections to existing outside cable plant. Include the following:
Show power source, master station with associated equipment, speakers, and outlets.
Include room numbers, wiring/conduit between components.
If required, fire alarm riser diagrams will be provided by the fire protection engineer.
33
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Provide schedules for all panelboards. The panelboard schedule \1\ shall /1/ reflect the
actual circuit breaker and bus arrangement. Include the following:
All circuiting (identifying conduit and wiring back to specific panels but not identifying the
exact routing required during construction) \1\ shall /1/ be shown on the design drawings
exactly as they are to be installed.
Provide plan and elevation or isometric drawings for switchboards and switchgear,
showing compartments, their intended use, and instruments and controls. Clearly show
contents of all sections including whether or not breakers are individually or group
mounted and indicate that switchboards and switchgear \1\ shall /1/ be mounted on 4 in
(100 mm) elevated concrete pads. Coordinate design of pad with structural engineer.
Provide plan and elevation or isometric drawings for Motor Control Centers (MCCs)
identifying compartments. Provide schedule listing each compartment. Schedule \1\
shall /1/ include (for each compartment) description of load, load in amperes, load in
horsepower, NEMA size and type of starter, breaker size, conductor and conduit size,
control devices, and other special requirements.
34
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
3-3.17 DETAILS/DIAGRAMS.
Provide a junction box detail on the drawings showing the interface between the
Systems Furniture wiring harness and the branch circuit wiring.
Provide \1\ grounding diagrams /1/ with explicit grounding requirements beginning with
the medium-voltage system and continuing through the transformer up to and including
the Service entrance equipment, step down transformers, sub-panels and
telecommunications systems grounding.
\1\ The service entrance grounding electrode systems and interconnections with other
system grounding electrodes must be clearly shown and identified on the grounding
plan. The main bonding jumper connection must be indicated and system bonding
jumper connections for separately derived systems must be clearly indicated.
Automatic Transfer switches must be identified indicating 3-pole design for single-phase
systems and 4-pole design for three-phase systems. /1/ Typical illustrations showing
proper methods for displaying grounding diagrams on the contract drawings are
provided in a PDF format within the electrical technical paper \2\ TP-12 /2/ “Appendices”
located at http://www.wbdg.org/ccb/browse_cat.php?o=29&c=248.
\1\/1/
Provide cathodic protection plans and details at appropriate scales. Indicate on the
drawing the location of all rectifiers, anode beds, structures protected by cathodic
protection system(s) and all structures that may be affected by stray current corrosion
as a result of cathodic protection of the specific structure within the affected area of
cathodic protection. \1\ An NACE-certified Cathodic Protection Specialist shall /1/
prepare cathodic protection drawings.
\1\/1/
35
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
GLOSSARY
AC Alternating Current
ACSR Aluminum Conductor Steel-Reinforced
A/E Architect/Engineer
AFCEE Air Force Center for Environmental Excellence
AFCESA Air Force Civil Engineer Support Agency
AHJ Authority Having Jurisdiction
AL Aluminum
ANSI American National Standards Institute
ASHRAE American Society of Heating, Refrigerating, and Air-Conditioning
Engineers
BCO Base Communications Officer
BDF Building Distribution Frame
BEQ/BOQ Bachelor Enlisted Quarters/Bachelor Officer Quarters
BICSI Building Industry Consulting Services International
BIL Basic Impulse Level
C Centigrade
CAD Computer Aided Drafting
cal/cm2 Calories per Centimeter Squared
CATV Community Antenna Television
CCTV Closed Circuit Television
CT Current Transformer
CU Copper
DC Direct Current
DoD Department of Defense
Degrees C Degrees Centigrade
Degrees F Degrees Fahrenheit
EIA/TIA Electronics Industries Association/Telecommunications Industry
Association
ESS Electronic Security Systems
\2\ ESS Electric Supply Station /2/
ETL Engineering Technical Letter
F Fahrenheit
ft Feet (or Foot)
ft2 Foot Squared
GFI Ground Fault Interrupter
GND Ground
HID High Intensity Discharge
HQUSACE Headquarters, US Army Corps of Engineers
HVAC Heating Ventilation and Air Conditioning
hp Horsepower
\1\ ICS Intelligence Community Standard /1/
IEEE IEEE (Formerly, Institute of Electrical and Electronic Engineers)
36
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
in Inch
IT Information Technology
kcmil Thousand circular mils
kN Kilo-Newtons
kV Kilovolts
kVA Kilo-Volt-Ampere
kVAR Kilo-Volt-Ampere-Reactive
lb Pound
LEED Leadership in Energy and Environmental Design
m Meter
m2 Meter Squared
mm Millimeter
MCC Motor Control Center
MDF Main Distribution Frame
MDP Main Distribution Panel
MVA Mega-Volt-Ampere
NAVFAC Naval Facilities Engineering Command
NEC National Electrical Code
NEMA National Electrical Manufacturers Association
\1\ NESC National Electrical Safety Code /1/
NFPA National Fire Protection Association
NMCI Navy and Marine Corps Intranet
O&M Operation and Maintenance
PCBs Polychlorinated Biphenyls
PPE Personal Protective Equipment (Clothing)
PT Potential Transformer
RFP Request for Proposal
RUS Rural Utility Service
SCIF Sensitive Compartmented Information Facility
SP Service Provider
SWD Switch Duty
\2\ UESS Utilization Electric Supply Station /2/
UFC Unified Facilities Criteria
UFGS Unified Facilities Guide Specifications
UL Underwriters Laboratories
UPS Uninterruptible Power Supply
V Volt
VA Volt-Amp
X/R Ratio of Reactance to Resistance
Terms
37
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
\1\/1/
Designer of Record – The engineer responsible for the actual preparation of the
construction documents.
Non-Linear Loads – Loads that convert AC to DC and contain some kind of rectifier.
Service – The conductors and equipment for delivering electrical energy from the
serving utility or Government-owned system to the wiring system of the premises
served.
Site Electrical Utilities – Site Electrical Utilities are the primary electric power
distribution to the facilities and other electrical loads, \1\ /1/ exterior lighting not attached
38
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
to the building; and \1\ /1/ telecommunication services (\1\ such as /1/ fiber optic, copper
cable, CATV \1\/1/) required by the Facilities.
TEMPEST – TEMPEST is the unclassified name for the studies and investigation of
compromising emanations (communications security).
\2\
Utilization Electric Supply Station – Equipment such as pole or pad-mounted
transformers or secondary unit substations that transforms the energy level (voltage) to
a utilization voltage for consumer use.
/2/
39
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
APPENDIX A REFERENCES
Note: The most recent edition of referenced publications applies, unless otherwise
specified. 1
Military Publications
1
Addresses for standards:
1. American National Standards Institute, 25 W est 43rd Street, New York, NY 10036.
2. Electronic Industries Alliance/Telecommunications Industry Association, 2500 Wilson Blvd.,
Arlington, VA 22201-3834.
3. Institute of Electrical and Electronics Engineers, 3 Park Avenue, 17th Floor, New York, NY
10016.
4. National Fire Protection Association, One Batterymarch Park, P.O. Box 9101, Quincy, MA
02269.
5. Underwriter’s Laboratories, Inc., 333 Pfingston Road, Northbrook, IL 60062.
40
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
\2\ UFC 3-575-01, Lightning and Static Electricity Protection Systems. /2/
UFC 3-580-01, Telecommunications Building Cabling Systems Planning and Design.
UFC 3-580-10, Navy and Marine Corps Intranet (NMCI) Standard Construction
Practices.
UFC 3-600-01, Fire Protection Engineering for Facilities.
UFC 4-010-01, DoD Minimum Anti-Terrorism Standards for Buildings.
UFC 4-020-01, DoD Security Engineering Facilities Planning Manual.
UFC 4-021-01, Design and O&M: Mass Notification Systems.
UFC 4-021-02NF, Security Engineering Electronic Security Systems.
UFC 4-030-01, Sustainable Development.
UFC 4-150-02, Dockside Utilities for Ship Service.
UFC 4-721-10, Navy and Marine Corps Bachelor Housing.
ANSI C84.1, Electric Power Systems and Equip-Voltage Ratings (60 Hz).
41
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Underwriter’s Laboratories
\2\ /2/UL 489, Molded-Case Circuit Breakers, Molded-Case Switches, and Circuit-
Breaker Enclosures.
Miscellaneous Documents
42
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Figure 1-1 shows the key electrical-related UFCs that have been issued. Figure B-1
shows other UFCs that provide electrical-related criteria. Additional UFCs are planned
and some existing UFCs will be deleted; Figure B-2 shows these UFCs.
/2/ /2/
43
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
\2\
UFC 3-501-01
Electrical
Engineering
Additional Published Electrical UFCs
Air Specialty Cathodic Security and
Navigation Systems Protection Miscellaneous
Electrical
UFC 3-535-01 UFC 4-121-10N UFC 3-510-01
UFC 3-570-02A
Visual Air Design: Aircraft Fixed Foreign Voltages and
Cathodic Protection
Navigation Facilities Point Utility Systems Frequencies Guide
Notes:
UFC 3-570-06 UFC 4-021-02NF
1. UFC 3-535-02 (draft) will be converted to
graphics under UFGS and referenced by the O&M Cathodic Security Engineering
airfield lighting systems guide specifications. Protection Systems Electronic Security Systems
44
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
UFC 3-501-01
Electrical Engineering
UFC 3-540-04N, Diesel Electric Generating Plants UFC 3-540-01, Engine Generators UFC 3-540-07, Maintenance (O&M): Engine
Generators
UFC 3-570-01, Cathodic Protection Systems
UFC 3-550-07, Maintenance (O&M): Exterior
UFC 3-580-02, Exterior Telecommunications Electrical Power Distribution
Systems
/2/
45
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Use the above information to aid in estimating demand for transformer sizing for
preliminary calculations. As the design progresses, update demand calculations to
reflect actual load of the building.
46
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Note: These Tables are provided to aid the Designer of Record in estimating the total
demand for “ALL ELECTRIC” dwelling units (including diversity). Size all distribution
systems for dwellings for “ALL ELECTRIC”. Use the data below for sizing distribution
transformers, service lateral voltage drops and flicker calculations. These tables are not
to be used for sizing the service laterals or service entrance conductors.
KW Rating KVA
of Strip Demand
5 5.0
10 8.0
15 10.5
20 14.0
47
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
FE (Full Electric) is the demand value (with diversity pre-calculated) of the load without
a summer (air conditioning) or winter (heat strip) HVAC mechanical load included.
"Total" is the demand which includes a summer air conditioner load (Total = FE + air
conditioning load). "Total" does not include the demand associated with resistive heat
elements (which may drive the need for larger transformers). HVAC diversity = the
diversity factor to use for winter HVAC unit demand calculations. It is incumbent of the
electrical designer to address loads that are larger than those associated with the
summer load. Size the transformer for the summer load unless the winter load
calculation is more than 140% of the summer calculation.
48
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
1.1 Scope. This handbook provides the criteria necessary for the proper selection of
electric power sources and distribution systems. It covers preliminary load estimating
factors, electrical power sources, and distribution systems.
1.3 Load Data. Before specific electric power sources and distribution systems can
be considered, realistic preliminary load data must be compiled. The expected electric
power demand on intermediate substations, and on the main electric power supply,
shall be calculated from the connected load by applying appropriate factors. Determine
these factors by load analysis and by combining loads progressively. To combine the
loads, start at the ends of the smallest feeders and work back to the electric power
source. Because all loads must be on a common kilowatt (kW) or kilovolt-ampere (kVA)
basis, it is necessary to convert motor horsepower ratings to input kilowatts or kilovolt-
amperes before combining them with other loads already expressed in those terms.
Preliminary electric power load estimates can be made by using the approximate value
of one kilovolt-ampere of input per horsepower (hp) at full load. Preliminary estimates
of lighting loads may be made by assuming watts per ft2 (m2) of building area.
1.4 Load Analysis. To determine appropriate load estimating factors, using the
tables and factors in the manual as guides analyze the characteristics of each load.
Consider items such as environmental conditions of weather, geographical location, and
working hours, as the situation dictates. Notice that when the load densities in w/ft2 (m2
) are used only in preliminary estimates, the demand and load factors will be used in the
final designs.
1.5 Terminology. Five terms are essential to the analysis of load characteristics:
demand factor, coincidence factor, diversity factor, and maximum demand. These
terms are defined in paragraphs 1.5.1 through 1.5.4.
1.5.1 Demand Factor. The demand factor is the ratio of maximum demand of a
system to the total connected load of the system or
49
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Equation: Demand factor = Maximum demand load / Total load connected (1)
1.5.2 Coincidence Factor. The coincidence factor is the ratio of the maximum demand
of a system, or part under consideration, to the sum of the individual maximum
demands of the subdivisions or
1.5.3 Diversity Factor. The diversity factor is the reciprocal of the coincidence factor or
Equation: Diversity factor = Sum of individual maximum demands / Maximum system demand
(3)
1.5.3 Load factor. The load factor is the ratio of the average load over a designated
period of time, usually 1 year, to the maximum load occurring in that period or
1.5.5 Maximum Demand. The maximum demand is the integrated demand for a
specified time interval, i.e., 5 minutes, 15 minutes, 30 minutes, or other appropriate time
intervals, rather than the instantaneous or peak demand.
2.1 Preparation of Load Data. Load data are generally computed in steps such as:
a) individual loads,
c) activity loads.
A particular design problem may be limited to step a), to steps a) and b), or may
encompass steps a), b), and c). This section outlines each step as a separate entity,
dependent only on previous steps for data. Paragraphs 2.2 through 2.4.4 describe the
three loads.
2.2 Individual Loads. Individual loads are those with one incoming service supplying
utilization voltage to the premises. In general, these loads would comprise single
structures. Large structures could contain more than one function; for example, aircraft
operations, aircraft fire and rescue stations, and photographic buildings. Under this
condition, factors that have been developed and keyed to Navy category codes (refer to
Table 1) would be used. In this case, the factors listed under Navy category Code
141-40, 141-20, and 141-60, respectively, would be combined to obtain the total load.
50
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
2.2.1. Lighting. To eliminate lighting loads, divide a facility area into its significant
components by function (for example, office, storage, mechanical, and corridor).
Determine the average lighting level and type of light source for each area. Consider
requirements for supplementary lighting (for example, floodlighting, security lighting, and
special task lighting). Preliminary load estimates may be made based on the following
load allowances:
2.2.1.1 Small Appliance Loads. Small appliance loads shall include those served by
general purpose receptacles. In general, the dividing of areas by function for estimating
lighting loads will serve for estimating small appliance loads. The determination of
loads requires not only the knowledge of the function of an area, but to what extent its
occupants use small appliances. For example, an office area demand may average
about 1 W/ft2 (10.76) W/m2, but could vary from a low of 0.5 W/ft 2 (5.38 W/m2 to a high
of 1.5 W/ft2, (16 W/m2) depending on the specific tasks to be performed. A minimum of
0.1 W/ft2 (1 W/m2) for auditoriums to a maximum of 2.5 W/ft2 (27 W/m2) for machine
shops is possible, although the upper limit would occur very rarely. Mechanical spaces
in building storage areas and similar spaces in which outlets are provided but
infrequently used are usually neglected in computing loads, except for special cases.
51
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Table 1
Factors for Individual Facilities by Navy Category Code (See Note 1)
Demand Load
Navy
Description Factor Factor
Code
(%) (%)
100 Operational and Training Facilities:
121 Aircraft fueling/dispensing facility 40-60 16-20
122 Marine fuel dispensing 40-60 16-20
123 10 Filling station 40-60 13-17
125 16 Miscellaneous POL pipeline facilities 100 13-17
126 Liquid fueling and dispensing-other 40-60 3-7
131 Communications – buildings 60-65 70-75
131 40 Telephone exchange building 55-70 20-25
133 75 Air surveillance radar building 55-70 70-75
137 40 Port control office 55-70 20-25
141 11 Air passenger terminal building 65-80 28-32
141 20 Aircraft fire and rescue station 25-35 13-17
141 30 Aircraft line operations building 65-80 24-28
141 40 Aircraft operations building * EXC 141-70* 65-80 28-32
141 60 Photographic building 65-80 16-20
171 10 Academic instruction building 40-60 22-26
171 20 Applied instruction building 35-65 24-28
171 40 Drill Hall 75-85 3-7
200 Maintenance and Production Facilities:
211 05 Maintenance Hangar O/H space (high bay) 45-50 28-30
211 06 Maintenance Hangar – 01 space (crew equipment) 45-50 28-30
211 07 Maintenance Hangar – 02 space (administrative) 45-50 28-30
211 10 Aircraft overhaul and repair shop (NARF) 32-38 25-30
211 12 Paint/finishing hangar 65-75 25-27
211 20 Engine overhaul shop (NARF) 32-38 20-25
211 30 Aircraft/engine accessories overhaul shop (NAR) 32-38 25-30
211 75 Parachute/survival equipment 60-65 23-28
211 81 Engine test cell (Non-NARF) 42-48 25-30
211 96 Maintenance, aircraft spares storage (Miscellaneous) 58-63 23-28
212 20 Missile equipment maintenance shop 35-40 15-20
213-10 Drydock 5-10 0.5-1
214-10 Combat vehicle maintenance shop 55-65 20-25
214-20 Automobile vehicle maintenance – noncombat 55-65 20-25
215 Maintenance – weapons/spares 70-80 20-25
52
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Demand Load
Navy
Description Factor Factor
Code
(%) (%)
216 10 Ammunition rework and overhaul shop 35-40 18-22
216 20 Rocket rework and overhaul shop 35-40 18-22
216 30 Mines and depth charge rework shop 35-40 15-20
216 40 Torpedo shop 45-55 18-22
216 50 Special weapons shop 35-40 18-22
216 60 Quality evaluation laboratory 55-65 22-27
217 10 Electronics/communications maintenance shop 35-40 20-25
218 20 Construction/weight handling equipment shop 35-45 20-25
218 40 Railroad equipment shop 35-45 15-20
218 50 Battery shop 55-65 20-25
219 10 Public works shop 32-38 18-22
221 10 Aircraft engine assembly plant 32-38 20-25
222 10 Missile assembly buildings 35-40 15-20
222 20 Missile handling launch equipment 35-40 15-20
223 10 Fabrication/assembly building 22-27 24-29
225 10 Small arms plant 15-20 22-27
225 20 Light gun (20mm/51n) plant 15-20 22-27
225 30 Heavy gun (6/161n) plant 16-21 21-26
225 50 Launcher/projector plant 15-20 22-27
226 10 Bag charge filling plant 62-67 23-28
226 15 Case filling plant 35-40 23-28
226 20 Case overhaul tank repair facility 35-40 18-22
226 35 Major-caliber projectile loading plant 35-40 18-22
226 40 Medium-caliber projectile loading plant 35-40 18-22
226 55 Cast high explosives filling plant 35-40 18-22
226 65 Propellant and related chemical facility 30-40 32-38
227 10 Radio and radar equipment plant 50-55 23-28
227 10 Sonar equipment plant 50-55 23-28
228 10 Parachute/survival equipment plant 35-40 20-25
229 10 Asphalt plant 75-80 7-12
229 20 Concrete batching plant 75-80 15-20
229 30 Rock crusher plant 75-80 15-20
229 40 Sawmill 45-55 15-20
300 Research, Development, Test & Evaluation Facilities:
310 13 Chemistry and Toxicology Laboratory 70-80 22-28
310 15 Materials Laboratory 30-35 27-32
53
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Demand Load
Navy
Description Factor Factor
Code
(%) (%)
310 19 Physics Laboratory 70-80 22-28
316 10 Ammunition, explosives, and toxics laboratory 28-32 20-25
317 20 Electrical and electronics systems laboratory 20-30 3-7
400 Supply Facilities:
421 Ammunition storage installation 75-80 …..
423 Ammunition storage-liquid propellant 75-80 20-25
431 10 Cold storage warehouse 70-75 20-25
441 10 General warehouse Navy 75-80 23-28
441 20 Controlled humidity warehouse 60-65 33-38
441 30 Hazardous/ flammable storehouse 75-80 20-25
441 40 Underground storage 65-70 23-28
441 70 Disposal, salvage, scrap building 35-40 25-20
500 Hospital-Medical Facilities:
510 10 Hospital 38-42 45-50
530 20 Laboratory 32-37 20-25
540 10 Dental Clinic 35-40 18-23
550 10 Medical Clinic 45-50 20-23
600 Administrative Facilities:
610 10 Administrative Office 50-65 20-35
620 10 Administrative facility, underground 50-65 35-40
700 Housing and Community Facilities:
711 Family housing-dwellings 60-70 10-15
712 Substandard: Trailers - family housing 70-75 10-15
714 10 Detached garages 40-50 2-4
721 11 Bachelor enlisted quarters 35-40 38-42
721 12 Bachelor enlisted quarters E5/E6 35-40 38-42
721 13 Bachelor enlisted quarters E7/E9 35-40 38-42
721 30 Civilian barracks GS 01/6 35-40 38-42
721 40 Disciplinary barracks 35-40 38-42
722 10 Detached dining facilities, enlisted men 30-35 45-60
723 20 Latrine, detached 75-80 20-25
723 30 Laundry, detached 30-35 20-25
723 40 Garage, detached 40-50 2-4
724 11 UOPH, W-1/0-2 40-50 20-25
724 12 UOPH, 0-3 and above 40-50 20-25
724 22 Civilian quarters, GS-7/PLS 40-50 20-25
54
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Demand Load
Navy
Description Factor Factor
Code
(%) (%)
724 30 Dining facility (attached) commissioned personnel 35-40 30-40
730 10 Fire station 25-35 13-17
730 15 Confinement facility 60-65 33-38
730 20 Police station 48-53 20-25
730 25 Gate/sentry house 70-75 28-33
730 30 Bakery 30-35 45-60
730 35 Enlisted personnel locker room 75-80 18-23
730 40 Laundry/dry cleaning plant 30-35 20-25
730 45 Dependent school – nursery school 75-80 10-15
730 50 Dependent school – kindergarten 75-80 10-15
730 55 Dependent school – grade school 75-80 10-15
730 60 Dependent school – high school 65-70 12-17
730 65 Fallout shelter 80-85 30-35
730 67 Bus station 80-85 30-35
730 70 Decontamination facility 75-80 15-2
730 83 Chapel 65-70 5-25
730 85 Post Office 75-80 20-25
740 01 Exchange retail store 65-70 25-32
740-18 Bank 75-80 20-25
740 23 Commissary including backup storage 55-60 25-30
740 26 Installation restaurant 45-75 15-25
740 30 Exchange auto repair station 40-60 15-20
740 36 Hobby shop, art/crafts 30-40 25-30
740 40 Bowling Alley 70-75 10-15
740 43 Gymnasium 70-75 20-45
740 46 Skating rink 70-75 10-15
740 50 Field house 75-80 7-12
740 53 Indoor swimming pool 55-60 25-50
740 56 Theater 45-55 8-13
740 60 Commissioned officers’ mess, open 55-60 15-20
740 63 Enlisted personnel club 55-60 18-23
740 66 Petty officers’ mess, open 55-60 18-23
740 70 Mess open, E-7 through E-9 55-60 15-20
740 76 Library 75-80 30-35
740 80 Golf club house 75-80 15-20
740 86 Exchange installation warehouse 58-63 23-28
55
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Demand Load
Navy
Description Factor Factor
Code
(%) (%)
740 88 Educational services office 70-75 30-35
760 10 Museum/memorial building 75-80 30-35
800 Utilities and Ground Improvements:
811 10 Electric power plant-diesel 60-65 58-63
811 25 Electric power plant-steam 60-65 58-63
811 45 Electric power plant-gas turbine 60-65 58-63
811 60 Standby generator plant 75-80 5-10
812 20 Street lighting 95-… 46-…
812 40 Perimeter/security lighting 80-85 22-27
813 20 Substation, more than 499 kV 25-30 20-25
821 12 Fossil fuel heating plant – medium 55-60 30-60
821 22 Fossil fuel heating plant – large 55-60 30-60
821 50 Non-nuclear steam plant 50-55 30-40
826 20 Chilled water plant 25/100 tons 60-70 25-30
Air conditioning-chilled water transmission/distribution
827 20 60-70 25-30
system – medium (25/100 tons)
831 10 Combination sewage and industrial waste treatment plant 60-70 15-20
832 30 Sewage-industrial waste pumping station 55-60 30-35
833 22 Incinerator building and incinerator 55-60 15-20
841 10 Water treatment facilities 60-80 15-25
841 50 Wells-potable water 60-80 15-25
Do not include – operate
843 20 Fire protection pumping station
for test off peak.
890 20 Compressed air plant 45-50 25-30
890 42 Air-conditioning plant 60-70 25-30
Miscellaneous Operational and Training Facilities:
125 10 POL pipeline
132 10 Antenna – communications 95-… 46-…
Miscellaneous Facilities for Ship Repair and Shipbuilding:
Ship repair shops:
213 41 Central tool shop – (06) (E) 32-37 23-28
213 42 Shipfitting shop – (11) (A) 22-27 24-29
213 43 Sheet metal ship (17) (B) 10-15 15-20
213 44 Forge and heat treatment space (23) (F) 25-30 13-18
213 49 Inside machine shop – (31) (G) 16-21 21-26
213 53 Boiler making shop – (41) (D) 12-17 14-19
213 54 Electrical shop – (51) (M) 33-38 20-25
56
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Demand Load
Navy
Description Factor Factor
Code
(%) (%)
213 55 Pipefitting shop – (56) (J) 22-27 17-22
213 56 Woodworking shop – (64) (R) 25-30 21-26
213 59 Abrasive blast facility 30-35 10-15
213 60 Paint and blasting shop – (71) (S) 50-55 23-28
213 61 Riggers shop – (72) (T) 50-55 20-25
213 62 Sail loft 35-40 20-25
213 63 Foundry – (81) (K) 35-40 22-27
213 64 Patternmaking shop – (94) (X) 28-33 12-17
213 67 Pumphouse, drydocks 75-80 0.1-0.2
Miscellaneous Facilities for Naval Ordnance Manufacture:
226 Ammunition components building 15-20 20-25
226 Manufacturing 30-45 17-32
226 Explosive loading 65-70 25-30
226 Miscellaneous explosives storage and handling 65-70 5-10
226 Assembly building 40-50 20-25
226 Detonator building 65-70 20-25
226 Pelleting 40-50 20-25
226 Plastic beading 55-60 18-23
226 Sewing room 35-40 25-30
226 Projective assembly breakdown 55-60 18-23
226 Machine shop 16-21 21-26
226 Phosphorous plant 35-40 25-30
226 TNT detonator (military) 35-40 15-20
226 Ammunition tank box assembly 35-40 15-20
226 Box emptying 35-40 15-20
226 Plating maintenance 35-40 18-23
226 Mixing 40-45 18-23
226 Segregation fleet return 35-40 15-20
226 Plaster load 35-40 15-20
Fluoroscope building 45-50 18-23
Tank building rocket 40-45 15-20
Hydrostatic test 35-40 15-20
Phosphorous loading 35-40 15-20
226 Vacuum and hydraulic pump building 35-40 12-17
226 Cable drive 35-40 12-17
226 Dryer building 75-80 3-8
57
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Demand Load
Navy
Description Factor Factor
Code
(%) (%)
Miscellaneous Production Facilities:
229 50 Printing Plant 45-55 25-30
Miscellaneous Storage Facilities:
Community Facilities – morale, welfare, and recreation – Determine by load
750
exterior count and time.
750 30 Outdoor swimming pool installation 80-85 20-25
750 54 Band stand 75-80 15-25
Miscellaneous Facilities for Utilities and Ground Improvements:
821 09 Heating plant building (condensate) 55-60 25-40
821 09 Heating plant building (heating) 55-60 30-35
833 40 Garbage house 75-80 20-25
Determine by load
841 Potable water – supply/treatment/storage
count and time.
845 20 Pipeline nonpotable water 55-60 3-8
852 30 Pedestrian bridge 80-85 20-25
872 20 Guard and watch towers 80- 46-
890 20 Compressed air plant 60-65 20-25
2.2.1.2 Electric Power Loads. Electric power loads shall include all loads other than
lighting loads and those served by general purpose receptacles and comprise the
environmental system electric power requirements and the facility occupancy equipment
electric power requirements.
2.2.2 Demand and load factors. The demand and load factors for a specific facility will
vary with the division of load and hours of usage. Refer to Tables 2 and 3 for values
that can be applied to determine demand and load factors. Table 4 is included as a
guide and an aid in illustrating the method of determining loads, which are calculated for
a particular type of building, such as an academic and general instruction building (Navy
Code 171-10). The values given are empirical and will vary from activity to activity, and
may vary from one facility to another within an activity. Annual hours use of demand
must be determined for each case in accordance with methods of operation and
characteristics of the installation. Demand factors and load factors for individual
facilities by the Navy category code given in Table 1 are based on a survey of existing
Navy facilities and past experience. Such factors should be used for quick estimating
58
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
2.2.2.1 Guides for Demand Factors. For guides on selection of demand factors, refer
to Table 5.
2.2.2.2 Guides for Load Factors. Guides for the selection of load factors indicate the
need for special considerations (refer to Table 6). Factors in the middle of the range are
for the average facility at the peacetime shore establishment and should be used unless
the guides in Table 6 indicate otherwise.
2.2.3 Load Growth. Determine the requirements for load growth for anticipated usage
and life expectancy with particular attention to the possibility of adding heavy loads in
the form of air conditioning, electric heating, electric data processing and electronic
communication equipment. Before determining the size of service and method of
distribution to a facility, an economic analysis shall be made to determine the most
feasible way of serving this future load. This analysis shall include the effect on the
existing installation if future loads require reinforcing or rehabilitation of the service
system.
Table 2
Demand Factors for Specific Loads (See Note 1)
Table 3
Annual Hours of Demand Usage for Specific Loads
60
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Table 4
Academic Building (Code 171-10) Demand and Load Factor Calculations (See Note 1)
Motors
Miscellaneous
Fractional & Air
General Lighting Total
Small Conditioning
Appliances
1. Watts/square foot 1.0 1.0 2.7 4.5 9.2
(Watts/square meter) (10) (10) (26.5) (45) (91.5)
2. Connected load 100 kW 100 kW 265 kW 450 kW 915 kW
3. Specific load demand factor 30% 10% 75% 70%
4. Maximum demand load
30 kW 10 kW 200 kW 315 kW 555 kW
(line 2 x line 3)
5. Annual operating
1,200 hrs 1,500 hrs 2,200 hrs 1,600 hrs
(1-shift) usage
6. Annual usage in megawatt hours
36 15 440 504 995
(line 4 x line 5)
7. Demand factor
- - - - 60%
Formula = Line 4 / Line 2 (1)
8. Load factor
Formula = - - - - 20%
Line 6 / (Line 4 x 8760 hours) (4)
Note 1: Calculated for a 100,000 square-foot (10,000 square meter) building. See
Tables 2 and 3 for data used for lines 3 and 5 respectively. Load growth is included in
connected load. Maximum demand load includes allowance for system loss. For this
illustration, the coincidence factor occurring when individual demand loads are added is
considered to be 1.00 and has not been shown.
61
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Table 5
Guides for Selection of Demand Factors
Select factors in upper half of range for conditions Select factors in lower half of range for conditions
described below described below
GENERAL GUIDES
Facilities of intermittent use or not being fully
Facilities in active use and approaching maximum
utilized.
capacity.
Motor loads made up of a number of independently
Loads predominantly lighting.
operated small motors.
Loads predominantly heating.
Motor loads controlled automatically unless control
Loads dominated by one or two large motors.
depends upon weather conditions.
OPERATIONAL AND TRAINING FACILITIES
Instruction buildings with little or no electric Large instruction buildings with electrical
equipment. demonstration and training equipment.
Communications buildings with telephonic
equipment only.
MAINTENANCE AND PRODUCTION FACILITIES
Shops and facilities when engaged in mass No special guides.
production of similar parts.
RESEARCH, DEVELOPMENT, AND TEST FACILITIES
Facilities used for repetitive testing of material or No special guides.
equipment.
SUPPLY FACILITIES
Refrigerated warehouses in South. Warehouses with many items of electric materials
Dehumidified warehouses in Mississippi Valley and handling equipment, including cranes and
along seacoasts. elevators.
Warehouses for active storage.
HOSPITAL AND MEDICAL FACILITIES
No special guides. No special guides.
ADMINISTRATIVE FACILITIES
Large administrative buildings with mechanical Casual offices, offices used infrequently by
ventilation and air conditioning. foremen and supervisors, or offices in which
Note: Group large administrative buildings there is little prolonged desk work.
separately only when administration is a
significant part of total activity load.
HOUSING AND COMMUNITY FACILITIES
Enlisted barracks at training centers. Food service facilities where load is primarily
Public quarters where less than 25 family units are cooking and baking.
involved.
Restaurants, exchanges, cafeterias, and other food
service facilities when gas or steam is primary
fuel.
UTILITIES AND GROUND IMPROVEMENTS
Central heating plants serving extended areas and No special guides.
buildings.
Water pumping stations serving extended areas or
carrying most of load of water systems.
Central station compressed air plants.
62
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Table 6
Guides for Selection of Loads Factors
Select factors in upper half of range for Selection factors in lower half of range for conditions
conditions described below described below
GENERAL GUIDES
Facilities operated on two or more shifts. Facilities used intermittently.
Loads that are primarily fluorescent or high Inactive facilities.
intensity discharge lighting. Large motor loads when the load consists of relatively small
Many small independently operated motors. numbers of motors.
Electronic equipment continuously operated for Wholesale-type service facilities.
immediate use.
Cooling and dehumidification loads for year-
round climate control in southern climates.
Retail-type service loads and loads that are in
active use.
OPERATIONAL AND TRAINING FACILITIES
Large, permanent instruction buildings in active Special-purpose instruction and training facilities not
use. regularly used.
MAINTENANCE AND PRODUCTION FACILITIES
Shops with battery charging equipment Welding loads or loads made up primarily of welding
operated after hours. equipment.
Active shops at full employment. Job-order workshops.
Mass production shops. Shops with large, heavy special function machines.
Large induction or dielectric heating loads.
RESEARCH, DEVELOPMENT, AND TEST FACILITIES
No special guides. No special guides.
SUPPLY FACILITIES
Refrigerated and dehumidified warehouses in Refrigerated warehouses in North.
South or in humid climates. Warehouses with large materials handling equipment loads.
Warehouses for active storage and in
continuous use.
HOSPITAL AND MEDICAL FACILITIES
Clinics and wards with daily operating hours No special guides.
and in active use.
ADMINISTRATIVE FACILITIES
Large, active, well-lighted offices with No special guides.
ventilation and air-conditioning equipment.
HOUSING AND COMMUNITY FACILITIES
Navy exchanges with food service facilities. Restaurants and exchanges serving only one meal a day.
Gymnasiums used in connection or with Restaurants and exchanges with gas steam food
physical therapy. preparation equipment.
Barracks at schools and training centers. Chapels used primarily on Sundays.
Subsistence buildings serving less than four meals a day.
Laundries with dry cleaning plants.
Exchanges operated less than 8 hrs/day
Gatehouses operated less than 24 hrs/day
UTILITIES AND GROUND IMPROVEMENTS
Heating plants that supply both heating and Heating plants in South.
process steam.
Water plants with little power load.
Air-conditioning plants for year-round control of
environment in South.
Compressed air plants consisting of many
banked compressors operating
automatically.
63
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
When the three categories of emergency electric power requirements have been
ascertained, determine where local emergency facilities are required, where loads may
be grouped for centralized emergency facilities, and what loads are satisfied by the
reliability of the general system. Base the aforementioned determinations on safety,
reliability, and economy, in that order.
2.3 Area Loads. Area loads consist of groups of individual facility loads served by a
subdivision of the electric distribution system. The term “area” applies to the next larger
subdivision of an overall distribution system. Demand loads for an area must be known
for sizing the distribution wiring and switching, and in a large installation will be required
for the design of substations serving the area. Table 7 gives an example of how the
coincident peak demand is calculated.
2.3.1 General Loads. To obtain the general load, add roadway lighting, area lighting,
obstruction lighting, and other loads not included in individual facility loads.
2.3.2 Coincidence Factor. Determine the maximum expected demands, taking into
consideration whether loads within the area peak at the same or at different times.
2.3.2.1 Relationships. Figure 1 indicates the relationship that exists between the load
factor of individual facility loads and the coincidence of their peak demands with the
peak demand of the group. This relationship was developed by a study of the loads of
selected naval shore activities and by the application of factors developed to the
formulas published by IEEE. For collateral reading on this subject, refer to IEEE
Technical Paper 45-116 Coincidence-Factor Relationship of Electric Service Load
Characteristics. Table 8 is Figure 1 in tabular form with values shown to the nearest
whole dollar, except for low load factors.
2.3.2.2 Selection. Areas with relatively insignificant residential type loads, where the
load curve indicates that most of the electric power consumed in the area is used during
the 40 normal working hours of a week, have coincidence factors at the higher end of
the range.
2.3.2.3 Electric Power Consumption. In general, areas where large amounts of electric
power are consumed outside the usual 40 working hours a week have a coincidence
factor at the lower end of the range (examples are hospitals, areas operated on two or
64
UFC 3-501-01
February 3, 2010
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
more shifts, or large barracks type activities). The upper limit of the range is for the 40
hour per week operation; the lower limit is for a 60 hour per week operation.
65
UFC 3-501-01
Including Change 1, May 11, 2011
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Table 7
Method of Calculating Coincident Peak Demand
Parenthesized ( ) numbers refer to Notes
66
UFC 3-501-01
Including Change 1, May 11, 2011
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
(1) The coincidence factor has been increased to allow for low load factor and number of facilities in the area. Refer to
paragraph 2.3.2.4, Influencing Factors, of this handbook.
(2) The coincidence factor has been increased because of the relative magnitude of the load. Refer to paragraph 2.3.2.5,
Individual Loads, of this handbook.
67
UFC 3-501-01
Including Change 1, May 11, 2011
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Figure 1
Theoretical Relationship between Load Factor and Coincidence
Factor at U.S. Naval Shore Establishments
68
UFC 3-501-01
Including Change 1, May 11, 2011
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
Table 8
Relationship between Load Factor and Coincidence Factor
69
UFC 3-501-01
Including Change 1, May 11, 2011
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
2.3.2.4 Influencing Factors. The number of individual loads in a group and their load
factors influence the individual load coincidence factor. The coincidence factors in table
8 apply for groups of 100 or more individual loads. These coincidence factors can also
be used for groups of as few as 30 to 50 individual loads if their load factor is 0.30 of
greater. For areas of fewer individual loads, the mathematical relationship from IEEE
Technical Paper 45-116 provides a basis for estimating the connected coincidence
factor as shown by the following equation:
where:
2.3.2.5 Individual loads. The coincidence factors in Table 8 are based on the individual
loads in a group being substantially the same size. If a single load or small group of
loads in an area represent a substantial percentage of overall load, the coincidence
factors as given in Table 8 will no longer apply. With an individual load, increase the
coincidence factor to a value commensurate with its effect on the overall area load.
This is not in addition to, but in place of, the normal coincidence factor. Determine this
value by considering intergroup coincidence factors given in paragraph 2.3.2.
2.3.2.6 An example of facility Navy Code 211-70 is presented in Table 7. For a small
group, determine the coincidence peak load, and to this apply the appropriate
intergroup coincidence factor to obtain the coincidence peak load for the area.
2.3.2.7 Groups of Loads or Areas. Where groups of loads within an area, or areas
within a facility are combined, an additional intergroup coincidence factor will exist. For
loads of similar nature, the intergroup coincidence factor should be in the range 0.93 to
1.00. If loads of a varying nature (evening loads and daytime loads) are combined, the
intergroup coincidence factor should be in the range of 0.70 to 1.00. The lower values
will occur when magnitudes of the loads are nearly balanced, and the higher ones when
the combined load is predominantly one type.
70
UFC 3-501-01
Including Change 1, May 11, 2011
Replaces 3-500-10 (DRAFT) and 3-500-10N (DRAFT)
Including Change 3, April 14, 2015
2.3.4 System Losses. Add distribution system losses to estimated area demands. For
a good approximation, use 6 percent of the calculated maximum demand.
2.3.5 Emergency Loads. Review the overall emergency requirements for the area,
based on criteria for the facility or as furnished by the using agency, to determine the
following:
c) Area loads that must be added to individual emergency loads; for example,
security lighting and minimum roadway lighting.
2.3.6 Expansion. The planned development of the area, as shown on the activity
general development map, shall be considered for requirements of future expansion.
2.4 Activity Loads. Activity Loads are loads that consist of two or more area loads
served from a single electric power source and an integrated distribution system.
2.4.1 General Loads. Follow the approach used in paragraph 2.3 for area loads. Area
loads used for determining activity coincidence demand should be the area coincident
demand exclusive of allowance for load growth.
2.4.2 Coincidence Factor. Refer to paragraph 2.3.2 for the necessary approach.
Where dissimilar areas, whether residential, administrative, or industrial, are part of an
activity, make a careful analysis of the coincidence factor used.
2.4.3 Load Growth. As for an area, components should be sized after due
consideration has been given to load growth. Apply this increase to the coincident
demand of the activity.
2.4.4 Expansion. The planned development of the activity, as shown on its general
development map, shall be considered for requirements of future expansion.
71