UFC 3-550-01 Exterior Electrical Power Distribution
UFC 3-550-011 September, 2016UNIFIED FACILITIES CRITERIA (UFC)EXTERIOR ELECTRICAL POWERDISTRIBUTIONAPPROVED FOR PUBLIC RELEASE; DISTRIBUTION UNLIMITED
UFC 3-550-011 September, 2016UNIFIED FACILITIES CRITERIA (UFC)EXTERIOR ELECTRICAL POWER DISTRIBUTIONAny 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 thecopyright holder.U.S. ARMY CORPS OF ENGINEERSNAVAL FACILITIES ENGINEERING COMMAND (Preparing Activity)AIR FORCE CIVIL ENGINEER CENTERRecord of Changes (changes are indicated by \1\ . /1/)Change No.DateLocation
UFC 3-550-011 September, 2016FOREWORDThe Unified Facilities Criteria (UFC) system is prescribed by MIL-STD 3007 and providesplanning, design, construction, sustainment, restoration, and modernization criteria, and appliesto the Military Departments, the Defense Agencies, and the DoD Field Activities in accordancewith USD (AT&L) Memorandum dated 29 May 2002. UFC will be used for all DoD projects andwork for other customers where appropriate. All construction outside of the United States isalso governed by Status of Forces Agreements (SOFA), Host Nation Funded ConstructionAgreements (HNFA), and in some instances, Bilateral Infrastructure Agreements (BIA.)Therefore, the acquisition team must ensure compliance with the most stringent of the UFC, theSOFA, the HNFA, and the BIA, as applicable.UFC are living documents and will be periodically reviewed, updated, and made available tousers as part of the Services’ responsibility for providing technical criteria for militaryconstruction. Headquarters, U.S. Army Corps of Engineers (HQUSACE), Naval FacilitiesEngineering Command (NAVFAC), and Air Force Civil Engineer Center (AFCEC) areresponsible for administration of the UFC system. Defense agencies should contact thepreparing service for document interpretation and improvements. Technical content of UFC isthe responsibility of the cognizant DoD working group. Recommended changes with supportingrationale should be sent to the respective service proponent office by the following electronicform: Criteria Change Request. 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 followingsource: Whole Building Design Guide web site http://dod.wbdg.org/.Refer to UFC 1-200-01, General Building Requirements, for implementation of new issuanceson projects.AUTHORIZED BY:JAMES C. DALTON, P.E.JOSEPH E. GOTT, P.E.Chief, Engineering and ConstructionU.S. Army Corps of EngineersChief EngineerNaval Facilities Engineering CommandEDWIN H. OSHIBA, SES, DAFMICHAEL McANDREWDeputy Director of Civil EngineersDASD (Facilities Investment and Management)DCS/Logistics, Engineering & Force ProtectionOffice of the Assistant Secretary of Defense(Energy, Installations and Environment)
UFC 3-550-011 September, 2016
UFC 3-550-011 September, 2016UNIFIED FACILITIES CRITERIA (UFC)REVISION SUMMARY SHEETDocument: 3-550-01, Exterior Electrical Power DistributionSuperseding: UFC 3-550-01, Exterior Electrical Power Distribution, dated Feb 3,2010, including Change 1, dated Jul 1, 2012.Description: This UFC 3-550-01 provides design guidance for the design of exteriordistribution systems.Reasons for Document: Provide technical requirements. Incorporate new and revised industry standards.Impact: There are negligible cost impacts associated with this UFC. However, thefollowing benefits should be realized. Standardized guidance has been prepared to assist engineers with uniqueinstallation requirements. Exterior electrical equipment design criteria are specified to ensure that a reliableinstallation is realized.Unification Issues:The Air Force has the following noted exceptions: Paragraph 3-11.5.1 Permits use of pad-mounted sectionalizing cabinets insteadof manholes. Paragraph 3-11.5.2 Prohibits T splices and Y splices on any MV system. Paragraph 3-11.5.5 Does not permit manholes in aircraft aprons.The Navy has the following noted exceptions: Paragraph 3-2.3 Requires 600V insulated neutral conductor in pole riser andductbanks. Paragraph 3-7 Requires switchgear to be SF-6 gas or high fire point liquidinsulated. Paragraph 3-11.8 Does not permit concentric neutral conductors in ductbanks. Paragraph 3-11.8 Requires EPR insulation for MV cables.
UFC 3-550-011 September, 2016
UFC 3-550-011 September, 2016TABLE OF CONTENTSCHAPTER 1 GENERAL . 11-1PURPOSE. . 11-2APPLICABILITY. . 11-2.1NFPA 70 and IEEE C2. . 11-2.2Additional References. . 11-2.3Exclusions. 21-3GENERAL BUILDING REQUIREMENTS. . 21-4CRITERIA AND EXEMPTION WAIVER PROCESS. . 21-5REFERENCES. . 21-6UTILITY-OWNED AND OPERATED DISTRIBUTION SYSTEMS ONFEDERAL PROPERTY. . 2CHAPTER 2 ELECTRICAL POWER REQUIREMENTS . 32-1ELECTRICAL POWER REQUIREMENTS: GENERAL. . 32-2SELECTION OF PRIMARY VOLTAGE. 32-3DESIGN FOR MAINTENANCE. . 3CHAPTER 3 DESIGN CRITERIA . 53-1MAIN AND UTILIZATION ELECTRIC SUPPLY STATIONS. . 53-1.1Main Electric Supply Stations. . 53-1.2Utilization Electric Supply Stations. 53-2GENERAL ELECTRICAL REQUIREMENTS. . 53-2.1Industry Standards. . 53-2.2Arc Flash Analysis Criteria. . 63-2.3System Design. 63-2.4Pad-Mounted Equipment. . 63-3PRIMARY UNIT SUBSTATIONS. . 63-4SECONDARY UNIT SUBSTATIONS. . 73-5PAD-MOUNTED DISTRIBUTION TRANSFORMERS. . 83-5.1Reference Criteria. . 83-5.2Configuration. . 83-5.3Size and Secondary Voltage. 83-5.4Winding Configuration. . 93-5.5Surge Protection. . 9i
UFC 3-550-011 September, 20163-5.63-6Drawing Details. . 9MEDIUM VOLTAGE SWITCHGEAR. 93-6.1Metal-Clad Switchgear. . 93-6.2Metal-Enclosed Switchgear. . 103-6.3Circuit Breaker Operation Design. . 103-7PAD-MOUNTED SWITCHGEAR (SWITCHES). . 103-8PAD-MOUNTED SECTIONALIZING TERMINATION CABINETS. . 113-9CAPACITORS. . 113-9.1Application. . 113-9.2Disconnect Design. . 113-10OVERHEAD POWER DISTRIBUTION. 113-10.1Drawing Details. . 123-10.2Pole Types. . 123-10.3Conductors. . 123-10.4Pole-Mounted Transformers. . 133-10.5Pole-Top Switches. . 133-10.6Surge Arresters. 143-10.7Fuse Protection. 143-10.8Automatic Circuit Reclosing. . 143-10.9Ground Connections. . 143-11UNDERGROUND ELECTRICAL SYSTEMS. . 153-11.1Underground Distribution General Criteria. . 153-11.2Ductbanks. . 163-11.3Direct Buried Wiring Methods. . 183-11.4Directional Boring. . 193-11.5Underground Structures (Manholes and Handholes). . 203-11.6Locating Underground Structures. . 213-11.7Pull Boxes. . 213-11.8Medium Voltage Cable. . 213-12CONCRETE FOR UNDERGROUND ELECTRICAL SYSTEMS. . 223-13HOUSING DISTRIBUTION. 223-14DISTRIBUTION SYSTEM GROUNDING. . 233-14.1Separation of Grounding Conductors. . 23ii
UFC 3-550-011 September, 20163-14.2Materials and Special Requirements. . 233-14.3Low Voltage Grounding Interface With Utilization Electric SupplyStations. . 243-14.4Grounding Requirements – Fences. . 243-15METERING. . 253-16EXTERIOR SITE LIGHTING. . 253-17CATHODIC PROTECTION SYSTEMS. . 253-18ENVIRONMENTAL CONSIDERATIONS. . 253-19FIRE PROTECTION CONSIDERATIONS. . 25APPENDIX A REFERENCES . 27APPENDIX B DIRECTIONAL BORING. 31B-1CONDUIT TYPE. . 31B-1.1Conduit Design – 1,000 Volts to 34,500 Volts. 31B-1.2Conduit Design – Less Than 1,000 Volts. . 31B-1.3Conduit Design – Branch Circuit Wiring Less Than 600 Volts. . 31B-2INSTALLATION METHODS. . 31B-2.1Ampacity. . 32B-2.2Installation. 32B-2.3Allowable Pulling Tension. . 32B-2.4Termination into Equipment Pads. . 32B-2.5Multiple Conduits and Wiring Methods. . 38B-2.6Joining Methods. 38B-2.7Transition from HDPE to PVC. 38B-3DOCUMENTATION. . 43APPENDIX C BEST PRACTICES – GENERAL ELECTRICAL POWERREQUIREMENTS . 45C-1EXTERIOR SYSTEM DESIGN. . 45C-2METERING. . 45C-3DEMARCATION. . 46C-4SUBSTATIONS AND SWITCHING STATIONS. . 46APPENDIX D GLOSSARY . 49D-1ACRONYMS . 49D-2DEFINITION OF TERMS . 52iii
UFC 3-550-011 September, 2016FIGURESFigure B-1 HDPE or Rigid Conduit Electrical Equipment Transition . 33Figure B-2 Pavement Covered Area to Electrical Equipment Transition – Rigid Conduit(45 –90 ) . 34Figure B-3 Pavement Covered Area to Electrical Equipment Transition – HDPE Conduit(20 –45 ) . 35Figure B-4 Non-Pavement Covered Area to Electrical Equipment Transition – RigidConduit (45 –90 ) . 36Figure B-5 Non-Pavement Covered Area to Electrical Equipment Transition – HDPEConduit (20 –45 ) . 37Figure B-6 HDPE-to-PVC Pavement Covered Area Concrete Ductbank Transition . 39Figure B-7 HDPE-to-PVC Non-Pavement Covered Area Concrete Ductbank Transition. 40Figure B-8 HDPE-to-Manhole Pavement Covered Area Transition . 41Figure B-9 HDPE-to-Manhole Pavement Covered Area Transition . 42TABLESNoneiv
UFC 3-550-011 September, 2016CHAPTER 1 GENERAL1-1PURPOSE.This UFC provides policy and guidance for design criteria and standards for electricalpower and distribution systems. The information provided here must be utilized byelectrical engineers in the development of the plans, specifications, calculations, andDesign/Build Request for Proposals (RFP) and must serve as the minimum electricaldesign requirements. It is applicable to the traditional electrical services customary forDesign-Bid-Build construction contracts and for Design-Build construction contracts.Project conditions may dictate the need for a design that exceeds these minimumrequirements.UFC 3-501-01 provides the governing criteria for electrical systems, explains thedelineation between the different electrical-related UFCs, and refers to UFC 3-550-01for exterior electrical system requirements. Refer to UFC 3-501-01 for design analysis,calculation, and drawing requirements.1-2APPLICABILITY.The design criteria and standards contained within are the minimum requirementsacceptable for military installations for efficiency, economy, durability, maintainability,and reliability of electrical power supply and distribution systems. The criteria andstandards herein are not intended to be retroactively mandatory.1-2.1NFPA 70 and IEEE C2.Comply with the requirements of NFPA 70 and IEEE C2. Generally, IEEE C2 is thebasis for UFC 3-550-01 and NFPA 70 is the basis for UFC 3-520-01. However, thereare exceptions to which standard applies to each UFC, including: Systems covered by other UFCs, such as airfield lighting and shore powersystems. Exterior circuits such as lighting and service entrance (overhead andunderground), which are covered by NFPA 70.For medium voltage applications, feeder conductor sizing is permitted to be determinedby qualified persons under engineering supervision as defined by NFPA 70 Article 215.2(B) (3), Supervised Installations.1-2.2Additional References.Comply with UFC 3-560-01 for electrical safety requirements applicable to theinstallation and operation of electrical systems.Comply with UFC 4-010-01 and UFC 4-020-01 for security requirements related toexterior electrical distribution systems.1
UFC 3-550-011 September, 20161-2.3Exclusions.Onsite generation is not addressed by this UFC.1-3GENERAL BUILDING REQUIREMENTS.Comply with UFC 1-200-01, DoD Building Code (General Building Requirements). UFC1-200-01 provides applicability of model building codes and government unique criteriafor 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 criteriareferenced therein.1-4CRITERIA WAIVER PROCESS.The criteria waiver process is provided in MIL-STD 3007.1-5REFERENCES.Codes and standards are referenced throughout this UFC. The publication date of thecode or standard is not routinely included with the document identification throughoutthe text of the document. In general, the latest issuance of a code or standard has beenassumed for use. Refer to Appendix A to determine the publication date of the codesand standards referenced in this UFC.1-6UTILITY-OWNED AND OPERATED DISTRIBUTION SYSTEMS ONFEDERAL PROPERTY.This UFC does not apply to: Utility-owned and operated distribution systems with right-of-way oreasements on Federal property. Military installations that have privatized their electrical distribution system.2
UFC 3-550-011 September, 2016CHAPTER 2 ELECTRICAL POWER REQUIREMENTS2-1ELECTRICAL POWER REQUIREMENTS: GENERAL.Virtually all military bases have an existing overhead and underground distributionsystem that has been in service for many years. As part of any new design project,review the existing design with base personnel to determine which existing featuresshould not be duplicated in future designs. Address design preferences withresponsible engineering and operations personnel as part of the system designanalysis.2-2SELECTION OF PRIMARY VOLTAGE.NEMA C84.1 establishes typical voltages and voltage ranges for 60 Hz systems.Facilities located outside of the United States must also comply with the applicable hostnation standards; refer to UFC 3-510-01 and UFC 1-202-01 for additional information.2-3DESIGN FOR MAINTENANCE.Design primary distribution system equipment installations with future periodicmaintenance as a principal consideration. Equipment must be capable
Design/Build Request for Proposals (RFP) and must serve as the minimum electrical design requirements. It is applicable to the traditional electrical services customary for Design-Bid-Build construction contracts and for Design-Build construction contracts. Project conditions may dictate the need for a design that exceeds these minimum .
UFC 3-550-01 1 September, 2016 Change 3, 01 November 2019 UNIFIED FACILITIES CRITERIA (UFC) REVISION SUMMARY SHEET Document: 3-550-01, Exterior Electrical Power Distribution Superseding: UFC 3-550-01, Exterior Electrical Power Distribution, dated
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UFC 3-530-01 22 August 2006 Unified Facilities Criteria (UFC) New Document Summary Sheet Subject: UFC-3-530-01, Design: Interior, Exterior Lighting and Controls Description of Change: UFC-3-530-01 is a new Unified Facilities Criteria document that describes the criteria necessary to create effective and
UFC 3-530-01 22 August 2006 Unified Facilities Criteria (UFC) New Document Summary Sheet Subject: UFC-3-530-01, Design: Interior, Exterior Lighting and Controls Description of Change: UFC-3-530-01 is a new Unified Facilities Criteria document that describes the criteria necessary to create effective and efficient lighting designs for the wide
UFC 3-301-02 3 March 2020 UNIFIED FACILITIES CRITERIA (UFC) REVISION SUMMARY SHEET Subject: UFC 3-301-02, Design of Risk Category V Structures, National Strategic Military Assets Cancels: UFC 3-310-04, Seismic Design, Change 1, 20 June 2016 Description of Changes: This new UFC contains the seismic design provisions for DoD Risk Category V
UFC 1-200-01 8 October 2019 Change 1, 1 Oct 2020 UNIFIED FACILITIES CRITERIA (UFC) REVISION SUMMARY SHEET Document: UFC 1-200-01, DoD BUILDING CODE Superseding: UFC 1-200-01, DoD BUILDING CODE (GENERAL BUILDING REQUIREMENTS), dated 20 June 2016, with Change 2, dated 01 Nov 2018 Description: This update to UFC 1-200-01 represents the Tri-Services effort to bring
UFC 3-501-01 October 6, 2015 Change 1, 01 November 2019 UNIFIED FACILITIES CRITERIA (UFC) NEW DOCUMENT SUMMARY SHEET Document: UFC 3-501-01, Electrical Engineering Superseding: UFC 3-501-01, Electrical Engineering, with Change 3, 1 July 2012. Description: This UFC 3-501-01 provides electrical engineering design and analysis criteria for design-build and design-bid-build projects.
NAVAL AIR STATION KEY WEST (NASKW) ITB 17-007 Project OM19001601 PART 5 - CHAPTER 2 - Page 2 2.4 Appropriate Design UFC 1-300-09N Design Procedures UFC 3-301-01 Structural Engineering UFC 3-400 Mechanical Engni eerni g UFC 3-420-01 Plumbing Systems UFC 3-501-01 Electrical Engineering UFC
