Attachment 5 - ufc_3_501_01_2024 - Electrical Engineering.pdf

UFC 3-501-01

27 November 2024

UNIFIED FACILITIES CRITERIA (UFC)

APPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED

ELECTRICAL ENGINEERING

This Page Intentionally Left Blank

UNIFIED FACILITIES CRITERIA (UFC)

ELECTRICAL ENGINEERING

Any copyrighted material included in this UFC is identified at its point of use.

Use of the copyrighted material apart from this UFC must have the permission of the copyright holder.

Indicate the Military Department Preparing Activity responsible for the document.

U.S. ARMY CORPS OF ENGINEERS

NAVAL FACILITIES ENGINEERING SYSTEMS COMMAND (Preparing Activity)

AIR FORCE CIVIL ENGINEER CENTER

Record of Changes (changes are indicated by \1\ ... /1/)

Change No. Date Location

This UFC supersedes UFC 3-501-01, Electrical Engineering, dated 06 October 2015.

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, its territories, and possessions 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 most 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 Military Department’s responsibility for providing technical criteria for military construction. Headquarters, U.S. Army Corps of Engineers (HQUSACE), Naval Facilities Engineering Systems Command (NAVFAC), and Air Force Civil Engineer Center (AFCEC) are responsible for administration of the UFC system. Technical content of UFC is the responsibility of the cognizant DoD working group. Defense Agencies should contact the respective DoD Working Group for document interpretation and improvements. Recommended changes with supporting rationale may be sent to the respective DoD working group by submitting a Criteria Change Request (CCR) via the Internet site listed below.

UFC are effective upon issuance and are distributed only in electronic media from the following source:

• Whole Building Design Guide website https://www.wbdg.org/dod.

Refer to UFC 1-200-01, DoD Building Code, for implementation of new issuances on projects.

AUTHORIZED BY:

PETE G. PEREZ, P.E., SES

Chief, Engineering and Construction U.S. Army Corps of Engineers

S. KEITH HAMILTON, P.E., SES

Chief Engineer and Assistant Commander Planning, Design and Construction Naval Facilities Engineering Systems Command

THOMAS P. BROWN, SES

Deputy Director of Civil Engineers DCS/Logistics, Engineering & Force Protection (HAF/A4C) HQ United States Air Force

MICHAEL McANDREW, SES Deputy Assistant Secretary of Defense (Infrastructure Modernization and Resilience) Office of the Secretary of Defense http://www.wbdg.org/pdfs/ufc_implementation.pdf https://www.wbdg.org/dod i

TABLE OF CONTENTS

CHAPTER 1 INTRODUCTION

1-1 PURPOSE AND SCOPE

1-1.1 UFC Hierarchy

1-1.2 Upgrades and Modifications to Existing Systems

1-2 REISSUES AND CANCELS

1-3 APPLICABILITY

1-4 GENERAL BUILDING REQUIREMENTS

1-5 WAIVER AND EXEMPTIONS PROCESS

1-6 CYBERSECURITY

1-7 PERMITS – CONSTRUCTION, ENVIRONMENTAL, AND OTHER

1-8 GLOSSARY

1-9 REFERENCES

CHAPTER 2 TECHNICAL REQUIREMENTS

2-1 GENERAL

2-1.1 Removal of Existing Cables and Conductors

2-1.2 Hot Caps and Removal of T-Splices Inside Manholes

2-1.3 Modification to Existing Electrical Equipment

2-1.4 Salvaged Materials and Equipment

2-1.5 Scheduling and Sequencing Outages

2-1.6 Energy Efficiency and Sustainable Design

2-1.7 Antiterrorism and Physical Security

2-1.8 Facility Systems Safety

2-1.9 Corrosive and High Humidity Areas

2-1.10 Arc Flash Warning Labels

2-1.11 NFPA 70 (NEC) / IEEE C2 (NESC) Design Interface Points

2-2 SITE EXTERIOR POWER DISTRIBUTION SYSTEMS

2-2.1 Exterior Power Distribution Systems, Including Housing

2-2.2 Dockside Utilities for Ship Service

2-2.3 Exterior Lighting Systems

2-2.4 Airfield Lighting

2-2.5 Cathodic Protection Systems ii

2-2.6 High-Altitude Electromagnetic Pulse (HEMP) Shielded Systems – Exterior

2-2.7 Generators

2-2.8 Renewable Energy Systems

2-2.9 Microgrids

2-3 INTERIOR DISTRIBUTION SYSTEMS

2-3.1 Interior Electrical Systems

2-3.2 Interior Lighting Systems

2-3.3 Emergency and Standby Systems

2-3.4 Sensitive Compartmented Information Facilities (SCIF)

2-3.5 Hazardous Locations

2-3.6 Stationary and Mission Batteries

2-3.7 HEMP Shielded Systems – Interior

2-3.8 Renewable Energy Systems

2-3.9 Mission Critical Power, Cooling, and Control Systems

2-4 COMMUNICATIONS AND SECURITY

2-4.1 Telecommunication Systems

2-4.2 Television Systems

2-4.3 Community Antenna Television (CATV) Systems

2-5 ELECTRONIC SECURITY SYSTEMS (ESS)

2-6 MASS NOTIFICATION SYSTEMS

CHAPTER 3 DESIGN ANALYSIS AND DOCUMENTATION

3-1 GENERAL

3-2 DESIGN ANALYSIS

3-2.1 Basis of Design

3-2.2 Electrical Calculations – Overview

3-2.3 Load Analysis

3-2.4 Short Circuit Analysis

3-2.5 Protective Device Time-Current Coordination Study

3-2.6 Arc Flash Analysis

3-2.7 Voltage Drop

3-2.8 Motor Starting

3-2.9 Lighting iii

3-2.10 Underground Structures Design

3-2.11 Cable Pulling Tension Calculations

3-2.12 Calculations for Directional Boring

3-2.13 Sag, Tension, and Guying Analysis

3-2.14 Cathodic Protection Calculations

3-2.15 Lightning Protection Calculations

3-2.16 ESS Calculations

3-2.17 Renewable Energy System Calculations

3-3 DRAWING REQUIREMENTS

3-3.1 Legends and Abbreviations

3-3.2 Site Plans

3-3.3 Demolition Plans

3-3.4 Lighting Plans and Details

3-3.5 Power Plans

3-3.6 Telecommunication Plans

3-3.7 Grounding Plan

3-3.8 Roof Plan

3-3.9 Lightning Protection Plan

3-3.10 Hazardous Location Plan

3-3.11 Power One-Line/Riser Diagrams

3-3.12 Telecommunications Riser Diagram

3-3.13 Intercommunication/Paging Riser Diagram

3-3.14 Fire Alarm Riser Diagram

3-3.15 Special Systems Riser Diagrams

3-3.16 Schedules and Elevations

3-3.17 Details/Diagrams

3-3.18 Grounding Diagrams

3-3.19 Cathodic Protection Plans and Details

APPENDIX A TRI-SERVICE ELECTRICAL WORKING GROUP TECHNICAL PAPERS

APPENDIX B DESIGN DATA TABLES

APPENDIX C ELECTRICAL ENGINEERING PRELIMINARY CONSIDERATIONS

C-1 PRELIMINARY DATA

iv

C-1.1 Load Data

C-1.2 Load Analysis

C-1.3 Terminology

C-2 ESTIMATION OF LOADS

C-2.1 Preparation of Load Data

C-2.2 Individual Loads

C-2.3 Area Loads

C-2.4 Activity Loads

APPENDIX D GLOSSARY

D-1 ACRONYMS

D-2 DEFINITION OF TERMS

APPENDIX E REFERENCES

v

FIGURES

Figure 2-1 Illustration of NFPA 70 Service Point and NFPA 70 / IEEE C2 Demarcation

Figure C-1 Theoretical Relationship between Load Factor and Coincidence Factor at U.S. Naval Shore Establishments

TABLES

Table B-1 Typical Loading for Personal Computer Systems

Table B-2 Load Data for Preliminary Demand Calculations

Table B-3 Dwelling Demand kVA per A/C Size

Table B-4 Typical A/C Size for Dwelling Units

Table B-5 Demand for Electric Strip Heat

Table C-1 Factors for Individual Facilities by Navy Category Code (See Note 1) .. 53

Table C-2 Demand Factors for Specific Loads (See Note 1)

Table C-3 Annual Hours of Demand Usage for Specific Loads

Table C-4 Academic Building (Code 171-10) Demand and Load Factor Calculations (See Note 1)

Table C-5 Guides for Selection of Demand Factors

Table C-6 Guides for Selection of Loads Factors

Table C-7 Method of Calculating Coincident Peak Demand

Table C-8 Relationship between Load Factor and Coincidence Factor vi

CHAPTER 1 INTRODUCTION

1-1 PURPOSE AND SCOPE.

The purpose of this UFC is to provide technical requirements for general aspects of the electrical design of projects. Apply the criteria provided in this UFC for the development of the plans, specifications, calculations, and Design/Build Request for Proposals (RFP). It serves 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.

1-1.1 UFC Hierarchy.

This UFC provides the top-tier baseline requirements for electrical UFCs and is intended as a reference for all electrical work on projects. All electrical UFCs listed in Appendix E rely on this UFC for overall requirements regarding design analysis and documentation.

1-1.2 Upgrades and Modifications to Existing Systems.

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.

For minor projects, determine if the project will affect existing electrical system calculations such as by modifying circuit breaker settings. If any electrical system calculations are affected by the modification, update the calculations, including the arc flash calculation, as part of the project.

Note: Arc flash calculation updates are necessary for electrical safety.

1-2 REISSUES AND CANCELS.

This UFC reissues and cancels UFC 3-501-01, Electrical Engineering, dated 06 October 2015.

1-3 APPLICABILITY.

This UFC applies to the planning, design, construction, sustainment, restoration, and modernization of DoD-owned facilities. It is applicable to all methods of project delivery and levels of construction as defined by UFC 1-200-01 section 1-3.

1-4 GENERAL BUILDING REQUIREMENTS.

Comply with UFC 1-200-01, DoD Building Code. UFC 1-200-01 provides applicability of model building codes and government unique criteria for typical design disciplines and building systems, as well as for accessibility, antiterrorism, security, high performance and sustainability requirements, and safety. Use this UFC in addition to UFC 1-200-01 and the UFCs and government criteria referenced therein.

1-5 WAIVER AND EXEMPTIONS PROCESS.

The waiver and exemption process is provided in MIL-STD 3007.

1-6 CYBERSECURITY.

All facility-related control systems (including systems separate from a utility monitoring and control system) must be planned, designed, acquired, executed, and maintained in accordance with UFC 4-010-06, and as required by individual Service Implementation Policy.

1-7 PERMITS – CONSTRUCTION, ENVIRONMENTAL, AND OTHER.

Identify the permits and fees necessary for environmental, construction, and operation of facilities.

1-8 GLOSSARY.

APPENDIX D contains acronyms, abbreviations, and terms.

1-9 REFERENCES.

APPENDIX E contains a list of references used in this document. The publication date of the code or standard is not included in this document. Unless otherwise specified, the most recent edition of the referenced publication applies. If dates are not indicated in the contract or in the absence or other direction, the issue/version of publication in effect at the time the design started is to be used. Designs that have been started and then delayed will need to evaluate which version is applicable and may have to update to the newer version if considerable time has gone by. This may require some redesign.

CHAPTER 2 TECHNICAL REQUIREMENTS

2-1 GENERAL.

Design electrical systems to meet the needs of the activity and supporting facilities in accordance with this document.

Provide electrical equipment that is the manufacturer’s standard catalog products, conforming to the latest published industry and technical society standards at the date of contract award. Underwriters Laboratories (UL) listing 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.

2-1.1 Removal of Existing Cables and Conductors.

When a project requires disconnection of existing cables and conductors enclosed in either duct or conduit, physically remove the existing cables and conductors. Associated ducts or conduits may be abandoned in place only for the following conditions:

• They are planned for re-use.

• Removal will cause substantial facility damage.

• Conduits are inaccessible.

On duct systems between underground structures (handholes, manholes, and vaults), provide a pull wire (string or rope) for future use, and seal both ends of duct. Apply label to each end of the pull rope noting the location of the other end of the conduit.

2-1.2 Hot Caps and Removal of T-Splices Inside Manholes.

Regardless of voltage, do not hot cap conductors in a manhole or handhole as part of demolition.

If the conductor is part of a T-splice or Y-splice that is being removed, remove the splice and install an in-line splice for the remaining conductors. For the Army and Navy, if the conductor is part of a T-splice or Y-splice that is being re-used, a hot cap is allowed during construction to maintain an energized circuit.

Note: Hot caps are only allowed as a temporary method during construction to maintain an energized circuit.

2-1.3 Modification to Existing Electrical Equipment.

Uniquely identify equipment to be “Modified” or “Added to” and include the manufacturer’s name and other pertinent manufacturer’s identification (e.g., serial number, model number, style), if such information exists.

2-1.4 Salvaged Materials and Equipment.

Demolition projects may require equipment or material to be salvaged for, or by the Government. Uniquely identify all salvageable equipment or material. Include the manufacturer’s name and other pertinent manufacturer’s identification including serial number, model number, style, physical dimensions, and weight if such information exists. Indicate who is responsible for removal, storage, and transportation.

2-1.5 Scheduling and Sequencing Outages.

Designer of Record must:

• Determine and address scheduling, sequencing, and outage requirements including anticipated outage durations as a part of contract design documents. Provide a specific and detailed suggested sequence of construction. Identify any temporary requirements, including the need for emergency generators for backup power during construction-related outages.

• Require the contractor to review all identified requirements and submit outage requests for approval by the Government prior to initiating the specific work task.

• Require that all work complies with the electrical safety requirements contained in UFC 3-560-01 for government workers and EM 385-1-1 for contractor work.

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, include the appropriate requirements during the design phase in the contract documents.

2-1.6 Energy Efficiency and Sustainable Design.

Comply with UFC 1-200-02.

2-1.7 Antiterrorism and Physical Security.

UFC 4-010-01 is a multidiscipline document which contains several standards that may impact electrical system design. Electrical designers must 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.

2-1.8 Facility Systems Safety.

Incorporating safety into the engineering and design process is an important part of designing, constructing and maintaining safe facilities for use by U.S. Military, U.S.

Government, and Contractor personnel. To the extent practicable and feasible, incorporate the safety engineering practices delineated under the Facilities Systems Safety (FASS) program as prescribed under OPNAV M-5100.23 Chapter 38 and DA

PAM 385-16.

Ensure systems safety engineering related to equipment access and proper equipment clearances are addressed during a FASS review at the earliest phases of project development when remedies and solutions are more easily addressed rather than during construction or after facility turnover.

2-1.9 Corrosive and High Humidity Areas.

The special design requirements listed below apply when electrical equipment is routinely subjected to salt spray (such as installations at piers and wharves) or is installed in locations exposed to condensing humidity that has historically caused premature rusting and degradation of equipment enclosures. Coordinate with local Activity to obtain historical information and documentation to validate requirements.

• Provide an entire corrosion resistant transformer assembly, fabricated of stainless steel.

• Use stainless steel cabinets and hardware for pad-mounted switchgear, switchboards, and sectionalizing termination cabinets.

Note: When feasible, sectionalizing termination cabinets can be designed to comply with NEMA 4X non-metallic enclosure requirements instead of stainless steel if the enclosures are not subject to physical or structural integrity damage.

• Use stainless steel enclosures and hardware for exterior safety switches and other electrical equipment.

• Do not use aluminum-conductor steel-reinforced (ACSR) overhead conductors.

• Use weatherproof stainless steel or aluminum enclosures for outdoor engine generator applications.

• Use corrosion-resistant materials for other electrical components, such as conduit, conduit supports, couplings, fittings, plugs, connectors, receptacles, equipment supports, and luminaires.

2-1.10 Arc Flash Warning Labels.

Refer to UFC 3-560-01 for arc flash label requirements.

2-1.11 NFPA 70 (NEC) / IEEE C2 (NESC) Design Interface Points.

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:

a. Services. Apply the following:

• The location for the “service point” (for clarification of the NFPA 70

Article 100 and IEEE C2 Section definitions): at the building/similar support structure service equipment which contains the main incoming overcurrent protective device.

• The demarcation between NFPA 70 and IEEE C2 for electrical power design purposes: is always the secondary terminal of the building/support structure utilization electric supply system.

• The demarcation between NFPA 70 and IEEE C2 for communication and security systems design purposes: is always the incoming service interface equipment including the five-foot raceway extension outside the building/support structure.

Figure 2-1 illustrates the above in graphic form.

b. Exterior branch circuits. Design the following in accordance with the general requirements of NFPA 70:

• Exterior lighting systems (parking lot, roadway, security, and sports).

• Exterior branch or feeder circuits originating from building/support structure service equipment.

• Wiring from and connections to non-utility equipment supplying power to the wiring system of the facility or the low-voltage terminals of the medium-voltage distribution system, including engine-generator sets, photovoltaic power systems, wind turbines, and fuel cells.

c. 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 utilize the NFPA 70 ampacity and conduit fill tables for all designs.

Figure 2-1 Illustration of NFPA 70 Service Point and NFPA 70 / IEEE C2 Demarcation

Figure 2-2

2-2 SITE EXTERIOR POWER DISTRIBUTION SYSTEMS..

Provide the site utility distribution system that is 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 of record must coordinate with the government authority and receive direction regarding point of connection and concurrence that existing circuit can support the new loads.

Coordinate remote monitoring and control requirements for exterior distribution system equipment with the Activity.

2-2.1 Exterior Power Distribution Systems, Including Housing.

Comply with UFC 3-550-01.

2-2.2 Dockside Utilities for Ship Service.

Comply with UFC 4-150-02.

2-2.3 Exterior Lighting Systems.

Comply with UFC 3-530-01.

2-2.4 Airfield Lighting.

Comply with UFC 3-535-01.

2-2.5 Cathodic Protection Systems.

Comply with UFC 3-570-01

2-2.6 High-Altitude Electromagnetic Pulse (HEMP) Shielded Systems – Exterior.

Comply with MIL-STD-188-125-1A and MIL-HDBK-423. In lieu of concrete encasement for medium voltage direct buried metal conduits (ductbank), utilize a sand bed (minimum thickness of 3” (75 mm)) and topped with a minimum of 3” (75 mm) of sand.

Provide a 2” (50 mm) thick concrete cap, the width of the trench atop the sand encasement. Place detectable warning tape above the concrete cap, 12” (300 mm) below finished grade to provide easy identification for future excavations.

2-2.7 Generators.

Comply with UFC 3-540-01.

2-2.8 Renewable Energy Systems.

Comply with UFC 3-540-08.

2-2.9 Microgrids.

Comply with UFC 3-550-04.

2-3 INTERIOR DISTRIBUTION SYSTEMS.

2-3.1 Interior Electrical Systems.

Comply with UFC 3-520-01.

For Army Civil Works funded projects, the requirements of NFPA 70 Article 240.2(A)(4) do not apply if all the following conditions are met.

a. The molded-case circuit breaker (MCCB) is considered mission critical.

b. A new replacement for the MCCB is not commercially available.

c. The replacement MCCB is refurbished in accordance with ANSI/PEARL

Electrical Equipment Reconditioning Standard for Electrical Apparatus and Equipment used in Commercial and Industrial Applications (EERS).

d. Any equipment requiring the use of a refurbished MCCB must be prioritized for replacement.

2-3.2 Interior Lighting Systems.

Comply with UFC 3-530-01.

2-3.3 Emergency and Standby Systems.

Exit and Emergency Lighting.

Comply with UFC 3-530-01.

Fire Alarm Systems.

Comply with UFC 3-600-01.

Generators.

Comply with UFC 3-540-01.

2-3.4 Sensitive Compartmented Information Facilities (SCIF).

Comply with UFC 4-010-05.

2-3.5 Hazardous Locations.

Show boundaries of hazardous locations on the plans and identify the type of hazard by class, division, and group.

2-3.6 Stationary and Mission Batteries.

Comply with UFC 3-520-05.

2-3.7 HEMP Shielded Systems – Interior.

Comply with MIL-STD-188-125-1A and MIL-HDBK-423.

2-3.8 Renewable Energy Systems.

Comply with UFC 3-440-01.

2-3.9 Mission Critical Power, Cooling, and Control Systems.

Comply with UFC 3-520-02.

2-4 COMMUNICATIONS AND SECURITY.

2-4.1 Telecommunication Systems.

General.

Comply with UFC 3-580-01 for interior and exterior information communications technology.

Outside Plant.

Provide underground telecommunications wiring in conduit to a depth of 24 in (610 mm). Specify concrete encased conduits for telecommunications systems in accordance with UFC 3-550-01. 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.

BEQ/BOQ Housing.

Completely wire the building interior conforming to UFC 3-580-01.

Family Housing.

Provide a complete structured telecommunications system in accordance with UFC 3- 580-01.

2-4.2 Television Systems.

Coordinate television system requirements with the activity.

2-4.3 Community Antenna Television (CATV) Systems.

Comply with 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.

2-5 ELECTRONIC SECURITY SYSTEMS (ESS).

Comply with UFC 4-021-02.

2-6 MASS NOTIFICATION SYSTEMS.

Comply with UFC 4-021-01.

CHAPTER 3 DESIGN ANALYSIS AND DOCUMENTATION

3-1 GENERAL.

This chapter defines the minimum information to be provided at the various design submittal levels. During the design submittal process, the Designer of Record must clarify 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.

3-2 DESIGN ANALYSIS.

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.

3-2.1 Basis of Design.

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.

Exterior Primary Power Distribution Systems.

• 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.

• Estimated Electrical Project Load – Provide an estimate of total connected load (kVA) and the resulting demand load (kVA), transformer size, and service size.

• Voltage Selection – Provide basis for selection of primary and secondary voltages.

• Conductors – Include conductor size, type, number of conductors, insulation voltage rating, and insulation level.

• Standards of Design – Describe pertinent standards of design, such as voltage drop, and equipment ratings.

• Materials – Provide manufacturer’s data sheets and product data for selected equipment.

Other Exterior Systems.

• Telecommunications (including voice, video and data) System – Identify point of connection into base system. Describe modifications, if required, to existing base system.

• Special Systems – Identify any special systems, such as Electronic Security Systems (ESS) or Cable Television (CATV). Describe how and where the facility will connect to the basewide Mass Notification System.

• Exterior Lighting Systems – Describe types of luminaires and illuminance values.

• Alternate Energy Sources – Describe alternate energy systems such as engine-generator sets, photovoltaic power systems, wind turbines, and fuel cells.

• Metering – Determine installation specific metering requirements as part of the electrical distribution system connection during design.

• Conductors – Include conductor type and number of conductors.

• Standards of Design – Describe pertinent standards of design, such as voltage drop and equipment ratings.

• Materials – Provide manufacturer’s data sheets and product data for selected equipment.

Interior Distribution Systems.

Describe the electrical systems including the following: lighting systems; power systems; alternate energy systems, emergency lighting; emergency/standby power;

grounding systems; telecommunications system; other systems such as television;

physical and electronic security features such as ESS or TEMPEST. Refer to NSTISSI 7000, TEMPEST Countermeasures for Facilities, for TEMPEST criteria.

a. Electrical Characteristics – Describe the electrical system to be provided and justify its selection. Indicate ANSI voltage designation, phase, and number of conductors.

b. Switchgear and Switchboards – Provide specific design information for the following:

• Nominal system voltage.

• Short circuit ratings.

• Maximum voltage ratings.

• Basic impulse level (BIL).

• Main bus ampacity.

c. Estimated Electrical Loads – Provide a breakdown, by category, of the estimated loads (kVA). Include lighting, convenience outlet, mechanical equipment, special operating equipment, user equipment, and miscellaneous load categories.

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.

e. Conductors – Indicate the type of conductors and insulation material such as CU, AL, THW, XHHW, and where proposed to use.

f. Standards of Design – Describe the proposed standards of design, such as voltage drop, illuminance values, type of light sources, and energy conserving features.

g. ASHRAE compliance – Describe the approach for compliance with UFC 1- 200-02 and its ASHRAE 90.1 requirements.

h. Special Systems – Describe the proposed type of systems. Indicate each system’s function and the interrelationships between systems, when applicable. Identify government-furnished equipment, if any. Special systems include such systems as CATV, Closed Circuit Television (CCTV), Intercom, Sound, Nurse Call, Security, or Uninterruptible Power Supplies (UPS). Identify special security requirements. Identify special physical security requirements.

i. Telecommunications Systems – Identify space required for telecommunication equipment, and size of incoming duct/conduit. Include documentation concerning telecommunications room sizes, to accommodate interface equipment provisions for multi-use systems (i.e.

special use systems, such as voice, video, and data).

j. Materials – Where appropriate, like for design build, provide manufacturer’s data sheets and product data for selected equipment.

System Maintainability.

Design the system in a manner that facilitates safe periodic maintenance of the equipment in accordance with Section 2-1.8.

Instrumentation and Controls.

Coordinate all interfaces with instrumentation and control systems provided by other disciplines, and provide required connections, either empty conduits or power wiring as required. Normally, the designer for the discipline that is responsible for the process (such as electrical, mechanical, or civil) is also responsible for the instrumentation and controls design of that system.

3-2.2 Electrical Calculations – Overview.

The Designer of Record (DOR) is responsible for providing 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.

Note: There can be differences in how the required electrical analyses are handled, depending on whether the project is design-build or design-bid-build. Army projects might also use UFGS 26 05 73, Power System Studies, as the method for specifying requirements associated with the coordination study during the construction phase.

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. The information needed for the electrical analysis depends on the point of connection to the primary distribution system and the scope of the project.

• Determining the different operational configurations. If the facility or system has various operational configurations (such as different transformer supplies, emergency generator operation, UPS bypass, or microgrid) or operational modes (such as normal parallel mode, transition-to-island mode, island mode, and reconnection mode), evaluate each possible operating configuration and each operational mode, and provide the results for each case.

• Providing analyses and calculations that are 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.

Electrical Analysis Software.

Most electrical-related calculations for significant projects will be completed with software tools; hand calculations are typically only acceptable for minor modifications to an existing system. For power systems analyses, coordinate with the base to determine if specific software tools are required for the analyses. Whenever software tools are used to perform analyses, provide the electronic software files with each submittal.

Electronic software files must be in a format compatible with the analysis software used at the Government's facility. Before using any software tools, identify any base or service-specific limitations regarding which software packages can be used.

Note: The Navy Network is only able to utilize ETAP, SKM software modules and EasyPower for electrical analysis. If project calculations are done using any other software, they must also be provided in either ETAP, SKM or EasyPower so that they are usable by Navy personnel on the Navy Network. The designer performing the calculations shall verify with the Navy which software package they are using at that facility and provide there database calculations to the Navy in that software database.

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. Other software products can be used on standard desktop systems connected to the Air Force Global Information Grid after they have been certified in accordance with AFI 33-210 and placed on the Air Force Evaluated/Approved Products List.

Electrical Calculation Summary.

Provide calculations that include a complete analysis with supporting data. Address 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. Provide the following calculations 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 analysis.

g. Lighting.

h. Underground structure design.

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.

p. Alternate energy system calculations.

q. Utility interactive systems and distributed resources island systems evaluation.

r. ASHRAE 90.1 calculations.

Detailed requirements for each calculation item in the list are contained in the following paragraphs.

3-2.3 Load Analysis.

Preliminary Basis of Design.

a. Load Analysis for Service Entrance Equipment, Including Feeders:

• Complete a preliminary load analysis (Basis of Design). Base calculations on NFPA 70 and use load information provided in Appendix B or ASHRAE 90.1 as applicable. Use Appendix C to apply demand and load factors when sizing the service entrance transformer only. Do not apply these factors to distribution equipment downstream of the service entrance transformer.

b. Load Analysis for Service Entrance Transformer:

• Select appropriately sized transformer based on:

i. The standard available ratings and

ii. The calculated demand load which is connection to each transformer.

• Apply the demand and diversity factors from Appendix C to the preliminary load analysis to determine the transformer size.

• For building designs, do not exceed a service transformer size greater than 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 must 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.

c. Load Analysis for Emergency/Standby Generator:

• Provide sizing calculations including starting kVA.

• Refer to UFC 3-540-01 for additional load analysis requirements, including the effect of UPS systems on generator sizing.

d. Load Analysis for Alternate Energy Systems:

• Provide maximum power calculations applicable to the type of alternate energy system. This includes:

i. DC systems, including 270 VDC charging systems.

ii. Frequency conversion equipment.

iii. Renewable energy systems.

e. Load Analysis for Uninterruptible Power Supply (UPS):

• Provide sizing calculations in accordance with UFC 3-520-01, section entitled “Stationary Batteries and Battery Chargers”.

f. Load Analysis for utility interactive systems and distributed resource island systems (microgrids). Provide a load analysis in accordance with IEEE Std

1547.4 Clause 5. Include a system one-line diagram with system interconnection points. Evaluate historical demand profiles (real and reactive) and identify any large motor loads. Include in the load analysis a calculation of real and reactive power requirements in normal and island mode of operation.

Note: Microgrids are not included with all projects. When required by the project scope of work to install a new system or to incorporate a microgrid into an existing system, provide a complete description of the microgrid including its connection points to the system and how the system will operate.

g. ASHRAE 90.1 calculations:

• Power allowance for lighting.

• If the design methodology requires additional receptacles to satisfy the ASHRAE 90.1 automatic receptacle control criteria, identify as a line item in the system load analysis.

Follow-On Submittals.

a. Load Analysis for Service Entrance Equipment, Including Feeders:

• Complete a load analysis (Basis of Design). Base calculations on

NFPA criteria.

b. Load Analysis for Service Entrance Transformer:

• Apply the demand and diversity factors from Appendix C to the final total connected load analysis to determine the transformer size.

For example, Diversity Factor - A distribution feeder serves 4 buildings, each has a peak demand of 25 KW. The feeder peak demand is equal to 80 KW. The diversity is equal to 80/100 or .8.

Demand Factor - a residence having 12,000W of total connected load has a maximum demand load of 9,000W. The demand factor is 9,000/12,000= 75%.

• For building designs:

• For all transformers, do not exceed a service transformer size greater than 12 VA/square foot (130 VA/square meter) of facility gross floor area.

• For a transformer rated 300 kVA and larger, do not exceed a service transformer size of 70% of the total connected load.

• Validate that transformer size has not been increased by the design approach taken to comply with ASHRAE 90.1.

Any design calculations exceeding these requirements must be specifically approved by the Technical Reviewing Authority.

c. Load Analysis for Emergency/Standby Generator:

• Provide sizing calculations including starting kVA.

• Refer to UFC 3-540-01 for additional load analysis requirements, including the effect of UPS systems on generator sizing.

d. Load Analysis for Alternate Energy Systems:

• Provide maximum power calculations applicable to the type of alternate energy system. Identify actual power delivered from source.

e. Load Analysis for Uninterruptible Power Supply (UPS):

• Provide sizing calculations in accordance with UFC 3-520-01, section entitled “Stationary Batteries and Battery Chargers”.

f. Load Analysis for utility interactive systems and distributed resource island systems (microgrids) in accordance with the criteria provided in Section 3- 2.3.1.f.

g. ASHRAE 90.1 calculations in accordance with the criteria provided in Section 3-2.3.1.g.

Load Analysis Criteria.

Use the following additional criteria for the load analysis:

• Assign a “0%” demand factor for fire pump loads in demand calculations.

• Design underground service entrance distribution using commercially-available thermal analysis software based on Neher-McGrath or finite element methods. Assume a load factor of 100%.

• Size the service entrance conductors for a continuous load current not less than the ampacity of the main bus in the service entrance equipment.

For example, provide conductors sized for 1200 amperes with 1200 ampere rated equipment which is protected with a 1000 ampere device.

Listed conductor size adapters are acceptable. Design main service equipment to provide a minimum of approximately 15% combination of spare devices/space to accommodate future work. Include this 15% spare capacity in the demand load calculations for future or anticipated load growth.

Note: Consideration for spare device/space above 15% should be addressed during the scoping of the project.

• Select size of service entrance transformers based on the standard available ratings.

Note: This criterion does not apply to secondary substation transformers, dedicated site lighting transformers, etc.

For small systems 225 amps or less, or for small modifications to large systems, the load analysis can be performed manually using the above criteria. For larger systems, a load analysis using computer software tools is necessary to evaluate properly all of the possible facility modes of operation.

3-2.4 Short Circuit Analysis.

Complete a short circuit analysis in accordance with IEEE 3002.3 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 or technical reviewing authority for the utility system data and available fault current on the primary side of medium voltage equipment. When accurate data does not exist, 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. Use 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.

Comply with IEEE C37.06, IEEE C37.13.1, or UL 489 criteria, as applicable, for equipment interrupting capability evaluations.

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

e. Coordinate the calculated short circuit current at the service entrance with the available fault current labeling required by NFPA 70 for the service entrance equipment (switchgear, switchboard, or panelboard).

3-2.5 Protective Device Time-Current Coordination Study.

Selective Coordination.

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. If required by the contract, 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. 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 is responsible for the selective coordination of overcurrent protective devices, including protective relays and medium voltage protective devices, high side transformer protection for distribution transformers, main secondary breakers, and secondary feeder protective devices. Ensure coordination between the new equipment design and the existing distribution system.

Selective coordination shall not be required between two overcurrent devices located in series if no loads are connected in parallel with the downstream device.

Any permanently installed backup power source required by published DoD or agency-specific criteria shall be considered a legally required standby system or emergency system.

Required Time-Current Data.

The Designer of Record is responsible for ensuring that construction contract documents require the Contractor to submit the transformers’ inrush current and damage curve and the 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, perform a coordination study in accordance with the following paragraphs to ensure that protective devices are properly coordinated.

Coordination Study.

If required by the contract, provide a complete coordination study that includes a system one-line diagram, short circuit and ground fault analysis, and protective coordination plots.

The Designer of Record is responsible for providing to the Contractor settings for relays, main secondary breakers, secondary feeder protective devices, and any other protective devices in the circuit. Base the final coordination study and the specified setting information on the as-built configuration.

One-Line Diagram(s).

Show on the one-line diagram all electrical equipment and wiring to be protected by the overcurrent devices including breakers and fuses. Multiple one-line diagrams may be used if required to clearly present all the required data. Also, show on the one-line diagram the following specific information:

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. Identify feeder cable sizes and conduit sizes. Identify configuration such as 4-#2 AWG, 1-#4 AWG ground in 1-1/2" conduit. (Use worst case fill based on allowed materials.) Where limitations on materials and insulation are specifically required due to special environments, clearly identify this when applicable.

Coordination Curves.

Prepare the coordination curves to determine the required settings of protective devices to assure selective coordination. Graphically illustrate on a log-log scale that adequate time separation exists between series 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.

Settings.

Develop a table to summarize the settings selected for each protective device. Low voltage protective devices less than 225 amperes, unless adjustable trip, are not required to be included. Address all relays and relay functions. Include in the table the following:

a. Device identification and breaker or load controlled.

b. Relay CT ratios and electronic set point equivalents for relay tap, time dial, and instantaneous pickup points.

c. Circuit breaker sensor rating.

d. Fuse rating and type.

e. Ground fault pickup and time delay.

f. Differential relay settings.

Coordination Study Report.

Include the following in each coordination study report:

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.

d. Fully coordinated composite time-current characteristic curves to ensure coordinated power system protection between protective devices or equipment. Include recommended ratings and settings of all protective devices in tabulated form.

e. Evaluation of the total feeder inrush current with respect to relay or circuit breaker overcurrent trip settings. Power restoration following an outage should not cause a feeder trip on overcurrent.

3-2.6 Arc Flash Analysis.

Complete an arc flash evaluation in accordance with NFPA 70E, IEEE C2 and IEEE Std 1584 (including Amendments 1 and 2), and IEEE Std 1584.1 as applicable.

Note: Nominal system voltages over 15 kV must follow IEEE C2 (NESC) instead of NFPA 70E and IEEE Std 1584.

Note: Provide PPE criteria in accordance with Chapter 4 of UFC 3-560-01.

Complete an arc flash…