UFGS 26 20 00 Interior Distribution System.pdf

USACE / NAVFAC / AFCEC UFGS-26 20 00 (May 2025)

Change 1 - 08/25

Preparing Activity: NAVFAC Superseding UFGS-26 20 00 (August 2023)

UNIFIED FACILITIES GUIDE SPECIFICATIONS

References are in agreement with UMRL dated July 2025

SECTION TABLE OF CONTENTS

DIVISION 26 - ELECTRICAL

SECTION 26 20 00

INTERIOR DISTRIBUTION SYSTEM

05/25, CHG 1: 08/25

PART 1 GENERAL

1.1 REFERENCES

1.2 DEFINITIONS

1.3 RELATED REQUIREMENTS

1.4 SUBMITTALS

1.5 QUALITY ASSURANCE

1.5.1 Electrician Qualifications

1.5.2 Fuses

1.5.3 Regulatory Requirements

1.5.4 Standard Products

1.5.4.1 Alternative Qualifications

1.5.4.2 Material and Equipment Manufacturing Date

1.6 MAINTENANCE

1.6.1 Electrical Systems

1.7 WARRANTY

1.8 SEISMIC REQUIREMENTS

PART 2 PRODUCTS

2.1 MATERIALS AND EQUIPMENT

2.2 CONDUIT AND FITTINGS

2.2.1 Rigid Metallic Conduit

2.2.1.1 Rigid, Threaded Zinc-Coated Steel Conduit

2.2.1.2 Rigid Aluminum Conduit

2.2.2 Rigid Nonmetallic Conduit

2.2.3 Intermediate Metal Conduit (IMC)

2.2.4 Electrical, Zinc-Coated Steel Metallic Tubing (EMT)

2.2.5 Plastic-Coated Rigid Steel and IMC Conduit

2.2.6 Flexible Metal Conduit

2.2.6.1 Liquid-Tight Flexible Metal Conduit, Steel

2.2.7 Liquid-Tight Flexible Nonmetallic Conduit

2.2.8 Surface Metal Raceway

2.2.9 Surface Nonmetallic Raceway

SECTION 26 20 00 Page 1

2.2.10 Fittings for Metal Conduit, EMT, and Flexible Metal Conduit

2.2.10.1 Fittings for Rigid Metal Conduit and IMC

2.2.10.2 Fittings for EMT

2.2.11 Fittings for Rigid Nonmetallic Conduit

2.3 BUSWAY

2.3.1 Feeder Busways

2.3.2 Plug-In Busways

2.4 CABLE TRAYS

2.4.1 Trough-Type Cable Trays

2.4.2 Ladder-Type Cable Trays

2.4.3 Channel-Type Cable Trays

2.4.4 Solid Bottom-Type Cable Trays

2.4.5 Cantilever

2.5 OUTLET BOXES AND COVERS

2.5.1 Floor Outlet Boxes

2.5.2 Clock Outlet for Use in Other Than Wired Clock System

2.6 CABINETS, JUNCTION BOXES, AND PULL BOXES

2.7 WIRES AND CABLES

2.7.1 Conductors

2.7.1.1 Equipment Manufacturer Requirements

2.7.1.2 Aluminum Conductors

2.7.1.3 Minimum Conductor Sizes

2.7.2 Color Coding

2.7.2.1 Ground and Neutral Conductors

2.7.2.2 Ungrounded Conductors

2.7.3 Insulation

2.7.4 Bonding Conductors

2.7.5 Service Entrance Cables

2.7.6 Nonmetallic Sheathed Cable

2.7.7 Wire and Cable for 400 Hertz (Hz) Circuits

2.7.8 Metal-Clad Cable

2.7.9 Armored Cable

2.7.10 Mineral-Insulated, Metal-Sheathed Cable

2.7.11 Flat Conductor Cable

2.7.12 Cable Tray Cable or Power Limited Tray Cable

2.7.13 Cord Sets and Power-Supply Cords

2.8 SPLICES AND TERMINATION COMPONENTS

2.9 DEVICE PLATES

2.10 SWITCHES

2.10.1 Toggle Switches

2.10.2 Switch with Red Pilot Handle

2.10.3 Breakers Used as Switches

2.10.4 Disconnect Switches

2.11 FUSES

2.11.1 Fuseholders

2.11.2 Cartridge Fuses, Current Limiting Type (Class R)

2.11.3 Cartridge Fuses, High-Interrupting Capacity, Current Limiting

Type (Classes J, L, and CC)

2.11.4 Cartridge Fuses, Current Limiting Type (Class T)

2.12 RECEPTACLES

2.12.1 Split Duplex Receptacles

2.12.2 Weather Resistant Receptacles

2.12.3 Ground-Fault Circuit Interrupter Receptacles

2.12.4 Special Purpose Receptacles

2.12.5 Plugs

2.12.6 Range Receptacles

2.12.7 Dryer Receptacles

2.12.8 Tamper-Resistant Receptacles

2.12.9 Arc-Fault Circuit Interrupter Receptacles

SECTION 26 20 00 Page 2

2.13 PANELBOARDS

2.13.1 Enclosure

2.13.2 Panelboard Buses

2.13.2.1 Panelboard Neutrals for Non-Linear Loads

2.13.3 Circuit Breakers

2.13.3.1 Multipole Breakers

2.13.3.2 Circuit Breaker With Ground-Fault Circuit Interrupter

2.13.3.3 Arc-Fault Circuit Interrupters

2.13.3.4 LSIG Type Circuit Breakers

2.13.3.4.1 Long-Time Protection (L)

2.13.3.4.2 Short-Time Protection (S)

2.13.3.4.3 Instantaneous Protection (I)

2.13.3.4.4 Ground Fault Protection (G)

2.13.4 Fusible Switches for Panelboards

2.13.5 400 Hz Panelboard and Breakers

2.13.6 Branch Circuit Monitoring Panelboards

2.13.7 Lighting Control Panelboards

2.14 RESIDENTIAL LOAD CENTERS

2.14.1 RLC Buses

2.14.2 Residential Load Center Circuit Breakers

2.14.2.1 Multipole Breakers

2.14.2.2 Circuit Breaker With Ground-Fault Circuit Interrupter

2.14.2.3 Arc-Fault Circuit-Interrupters

2.14.3 Load Centers For Housing Units

2.14.3.1 Panelboard Buses

2.14.3.2 Housing Unit Load Center Circuit Breakers

2.14.3.2.1 Multipole Breakers

2.14.3.2.2 Arc-Fault Circuit-Interrupters

2.15 ENCLOSED CIRCUIT BREAKERS

2.16 TRANSFORMERS

2.16.1 Specified Transformer Efficiency

2.16.2 K-Rated Transformers

2.16.3 Harmonic Mitigating Transformers

2.17 MOTORS

2.17.1 High Efficiency Single-Phase Motors

2.17.2 Premium Efficiency Polyphase and Single-Phase Motors

2.17.3 Electronically Commutated Motors

2.17.4 Motor Sizes

2.17.5 Wiring and Conduit

2.18 MOTOR CONTROLLERS

2.18.1 Control Wiring

2.18.2 Control Circuit Terminal Blocks

2.18.2.1 Types of Terminal Blocks

2.18.3 Control Circuits

2.18.4 Enclosures for Motor Controllers

2.18.5 Multiple-Speed Motor Controllers and Reversible Motor

Controllers

2.18.6 Pushbutton Stations

2.18.7 Pilot and Indicating Lights

2.18.8 Reduced-Voltage Controllers

2.19 MANUAL MOTOR STARTERS (MOTOR RATED SWITCHES)

2.19.1 Pilot Lights

2.20 MOTOR SHORT-CIRCUIT PROTECTOR (MSCP)

2.21 MOTOR CONTROL CENTERS

2.21.1 Bus Systems

2.21.1.1 Horizontal and Main Buses

2.21.1.2 Vertical Bus

2.21.1.3 Ground Bus

2.21.1.4 Neutral Bus

SECTION 26 20 00 Page 3

2.21.2 Combination Motor Controllers

2.21.3 Space Heaters

2.22 LOCKOUT REQUIREMENTS

2.23 TELECOMMUNICATIONS SYSTEM

2.23.1 Community Antenna Television (CATV) System

2.23.1.1 CATV Outlets

2.23.1.2 CATV Faceplates

2.23.1.3 Backboards

2.23.2 Secondary Bonding Busbar

2.24 GROUNDING AND BONDING EQUIPMENT

2.24.1 Ground Rods

2.24.2 Ground Bus

2.25 HAZARDOUS LOCATIONS

2.26 NAMEPLATES AND SIGNS

2.26.1 Manufacturer's Nameplate

2.26.2 Field Fabricated Nameplates

2.26.3 Warning Signs

2.27 FIRESTOPPING MATERIALS

2.28 WIREWAYS

2.29 METERING

2.30 METER BASE ONLY

2.31 SURGE PROTECTIVE DEVICES

2.31.1 Warranty

2.32 FACTORY APPLIED FINISH

2.33 SOURCE QUALITY CONTROL

2.33.1 Transformer Factory Tests

2.34 COORDINATED POWER SYSTEM PROTECTION

PART 3 EXECUTION

3.1 INSTALLATION

3.1.1 Underground Service

3.1.2 Overhead Service

3.1.3 Hazardous Locations

3.1.4 Service Entrance Identification

3.1.4.1 Labels

3.1.5 Wiring Methods

3.1.5.1 Pull Wire

3.1.5.2 Metal-Clad Cable

3.1.5.3 Armored Cable

3.1.5.4 Flat Conductor Cable

3.1.6 Conduit Installation

3.1.6.1 Restrictions Applicable to Aluminum Conduit

3.1.6.2 Restrictions Applicable to EMT

3.1.6.3 Restrictions Applicable to Nonmetallic Conduit

3.1.6.4 Restrictions Applicable to Flexible Conduit

3.1.6.5 Underground Conduit

3.1.6.6 Conduit Interior to Buildings for 400 Hz Circuits

3.1.6.7 Conduit for Circuits Rated Greater Than 600 Volts

3.1.6.8 Conduit Installed Under Floor Slabs

3.1.6.9 Conduit Through Floor Slabs

3.1.6.10 Conduit Installed in Concrete Floor Slabs or Concrete

Walls

3.1.6.11 Stub-Ups

3.1.6.12 Conduit Support

3.1.6.13 Directional Changes in Conduit Runs

3.1.6.14 Locknuts and Bushings

3.1.6.15 Flexible Connections

3.1.7 Busway Installation

SECTION 26 20 00 Page 4

3.1.8 Cable Tray Installation

3.1.9 Boxes, Outlets, and Supports

3.1.9.1 Boxes

3.1.9.2 Pull Boxes

3.1.9.3 Extension Rings

3.1.10 Mounting Heights

3.1.11 Nonmetallic Sheathed Cable Installation

3.1.12 Mineral Insulated, Metal Sheathed (Type MI) Cable Installation

3.1.13 Conductor Identification

3.1.13.1 Marking Strips

3.1.14 Splices

3.1.14.1 Splices of Aluminum Conductors

3.1.15 Terminating Aluminum Conductors

3.1.15.1 Termination to Copper Bus

3.1.15.2 Termination to Aluminum Bus

3.1.16 Covers and Device Plates

3.1.16.1 Circuit Identification

3.1.17 Electrical Penetrations

3.1.18 Grounding and Bonding

3.1.18.1 Ground Rods

3.1.18.2 Grounding Connections

3.1.18.3 Ground Bus

3.1.18.4 Resistance

3.1.19 Equipment Connections

3.1.20 Elevator

3.1.21 Government-Furnished Equipment

3.1.22 Repair of Existing Work

3.1.22.1 Workmanship

3.1.22.2 Existing Concealed Wiring to be Removed

3.1.22.3 Removal of Existing Electrical Distribution System

3.1.22.4 Continuation of Service

3.1.23 Watthour Meters

3.1.24 Surge Protective Devices

3.2 FIELD FABRICATED NAMEPLATE MOUNTING

3.3 WARNING SIGN MOUNTING

3.4 FIELD APPLIED PAINTING

3.5 FIELD QUALITY CONTROL

3.5.1 Devices Subject to Manual Operation

3.5.2 600-Volt Wiring Test

3.5.3 Transformer Tests

3.5.4 Ground-Fault Receptacle Test

3.5.5 Arc-Fault Receptacle Test

3.5.6 Grounding System Test

3.5.7 Watthour Meter

3.5.8 Phase Rotation Test

-- End of Section Table of Contents --

SECTION 26 20 00 Page 5

USACE / NAVFAC / AFCEC UFGS-26 20 00 (May 2025)

Change 1 - 08/25

Preparing Activity: NAVFAC Superseding UFGS-26 20 00 (August 2023)

UNIFIED FACILITIES GUIDE SPECIFICATIONS

References are in agreement with UMRL dated July 2025

SECTION 26 20 00

INTERIOR DISTRIBUTION SYSTEM

05/25, CHG 1: 08/25

NOTE: This guide specification covers the requirements for the procurement, installation, and testing of electrical wiring systems for construction projects.

Telecommunications cabling is covered in Section

27 10 00 BUILDING TELECOMMUNICATIONS CABLING

SYSTEM. These wiring systems primarily involve voltages of 1,000 volts and less and mainly involve interior systems. When voltages greater than 1,000 volts are brought into a facility, consult and use Section 26 11 16 SECONDARY UNIT SUBSTATIONS; Section 26 12 21 SINGLE-PHASE PAD-MOUNTED TRANSFORMERS; and Section 33 71 01 OVERHEAD TRANSMISSION AND DISTRIBUTION. Also consult Section 33 71 02 , UNDERGROUND ELECTRICAL DISTRIBUTION and Section

26 11 14.00 10 MAIN ELECTRIC SUPPLY STATION AND

SUBSTATION. Add requirements for materials and procedures for special or unusual design as necessary to fit specific projects.

Adhere to UFC 1-300-02 Unified Facilities Guide Specifications (UFGS) Format Standard when editing this guide specification or preparing new project specification sections. Edit this guide specification for project specific requirements by adding, deleting, or revising text. For bracketed items, choose applicable item(s) or insert appropriate information.

Remove information and requirements not required in respective project, whether or not brackets are present.

Comments, suggestions and recommended changes for this guide specification are welcome and should be submitted as a Criteria Change Request (CCR) .

SECTION 26 20 00 Page 6

NOTE: Ensure the following information is shown on the project drawings:

1. Location of equipment

2. Single-line diagrams elevations, limiting dimensions, and equipment ratings which are not covered in the specifications

3. Remote indicating or control requirements.

PART 1 GENERAL

1.1 REFERENCES

NOTE: This paragraph is used to list the publications cited in the text of the guide specification. The publications are referred to in the text by basic designation only and listed in this paragraph by organization, designation, date, and title.

Use the Reference Wizard's Check Reference feature when you add a Reference Identifier (RID) outside of the Section's Reference Article to automatically place the reference in the Reference Article. Also use the Reference Wizard's Check Reference feature to update the issue dates.

References not used in the text will automatically be deleted from this section of the project specification when you choose to reconcile references in the publish print process.

The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only.

AMERICAN NATIONAL STANDARDS INSTITUTE (ANSI)

ANSI C12.1 (2014; Errata 2016) Electric Meters - Code for Electricity Metering

ASTM INTERNATIONAL (ASTM)

ASTM B1 (2013) Standard Specification for Hard-Drawn Copper Wire

ASTM B8 (2023) Standard Specification for Concentric-Lay-Stranded Copper Conductors, Hard, Medium-Hard, or Soft

ASTM D709 (2017) Standard Specification for Laminated Thermosetting Materials

SECTION 26 20 00 Page 7

INSTITUTE OF ELECTRICAL AND ELECTRONICS ENGINEERS (IEEE)

IEEE 81 (2012) Guide for Measuring Earth Resistivity, Ground Impedance, and Earth Surface Potentials of a Ground System

IEEE C2 (2023) National Electrical Safety Code

IEEE Stds Dictionary (2009) IEEE Standards Dictionary: Glossary of Terms & Definitions

INTERNATIONAL ELECTRICAL TESTING ASSOCIATION (NETA)

NETA ATS (2025) Standard for Acceptance Testing Specifications for Electrical Power Equipment and Systems

NATIONAL ELECTRICAL CONTRACTORS ASSOCIATION (NECA)

NECA NEIS 1 (2015) Standard for Good Workmanship in Electrical Construction

NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)

ANSI C12.7 (2022) Requirements for Watthour Meter Sockets

ANSI C80.1 (2020) American National Standard for Electrical Rigid Steel Conduit (ERSC)

ANSI C80.3 (2020) American National Standard for Electrical Metallic Tubing (EMT)

ANSI C80.5 (2020) American National Standard for Electrical Rigid Aluminum Conduit

NEMA 250 (2020) Enclosures for Electrical Equipment (1000 Volts Maximum)

NEMA BU 1.1 (2010) General Instructions for Proper Handling, Installation, Operation and Maintenance of Busway Rated 600 V or Less

NEMA FU 1 (2012) Low Voltage Cartridge Fuses

NEMA ICS 1 (2022) Standard for Industrial Control and Systems: General Requirements

NEMA ICS 2 (2000; R 2020) Industrial Control and Systems Controllers, Contactors, and Overload Relays Rated 600 V

NEMA ICS 3 (2005; R 2010) Medium-Voltage Controllers Rated 2001 to 7200 V AC

NEMA ICS 4 (2015) Application Guideline for Terminal Blocks

NEMA ICS 6 (1993; R 2016) Industrial Control and

SECTION 26 20 00 Page 8

Systems: Enclosures

NEMA KS 1 (2013) Enclosed and Miscellaneous Distribution Equipment Switches (600 V Maximum)

NEMA MG 1 (2021) Motors and Generators

NEMA MG 10 (2017) Energy Management Guide for Selection and Use of Fixed Frequency Medium AC Squirrel-Cage Polyphase Induction Motors

NEMA MG 11 (1977; R 2012) Energy Management Guide for Selection and Use of Single Phase Motors

NEMA RN 1 (2018) Polyvinyl-Chloride (PVC) Externally Coated Galvanized Rigid Steel Conduit and Intermediate Metal Conduit

NEMA ST 20 (2014) Dry-Type Transformers for General Applications

NEMA TC 2 (2020) Standard for Electrical Polyvinyl Chloride (PVC) Conduit

NEMA TC 3 (2021) Polyvinyl Chloride (PVC) Fittings for Use With Rigid PVC Conduit and Tubing

NEMA TC 14 (2002) Standard for Reinforced Thermosetting Resin Conduit (RTRC) and Fittings

NEMA VE 1 (2017) Metal Cable Tray Systems

NEMA WD 1 (1999; R 2020) Standard for General Color Requirements for Wiring Devices

NEMA WD 6 (2021) Wiring Devices Dimensions Specifications

NEMA Z535.4 (2023) Product Safety Signs and Labels

NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)

NFPA 70 (2023; ERTA 1 2024; TIA 24-1; TIA 25-2)

National Electrical Code

NFPA 70E (2024) Standard for Electrical Safety in the Workplace

NFPA 780 (2026) Standard for the Installation of Lightning Protection Systems

U.S. NATIONAL ARCHIVES AND RECORDS ADMINISTRATION (NARA)

10 CFR 431 Energy Efficiency Program for Certain Commercial and Industrial Equipment

SECTION 26 20 00 Page 9

29 CFR 1910.147 The Control of Hazardous Energy (Lock Out/Tag Out)

29 CFR 1910.303 Electrical, General

UL SOLUTIONS (UL)

UL 1 (2005; Reprint Jan 2022) UL Standard for Safety Flexible Metal Conduit

UL 4 (2004; Reprint Mar 2021) UL Standard for Safety Armored Cable

UL 5 (2016; Reprint Jul 2022) UL Standard for Safety Surface Metal Raceways and Fittings

UL 5A (2015; Reprint Apr 2024) Nonmetallic Surface Raceways and Fittings

UL 6 (2022) UL Standard for Safety Electrical Rigid Metal Conduit-Steel

UL 6A (2008; Reprint Nov 2024) UL Standard for Safety Electrical Rigid Metal Conduit - Aluminum, Red Brass, and Stainless Steel

UL 20 (2025) UL Standard for Safety General-Use Snap Switches

UL 44 (2018; Reprint May 2021) UL Standard for Safety Thermoset-Insulated Wires and Cables

UL 50 (2024) UL Standard for Safety Enclosures for Electrical Equipment, Non-Environmental Considerations

UL 67 (2018; Reprint Aug 2023) UL Standard for Safety Panelboards

UL 83 (2017; Reprint Mar 2020) UL Standard for Safety Thermoplastic-Insulated Wires and Cables

UL 248-4 (2010; Reprint Apr 2019) Low-Voltage Fuses

- Part 4: Class CC Fuses

UL 248-8 (2011; Reprint Aug 2020) Low-Voltage Fuses

- Part 8: Class J Fuses

UL 248-10 (2011; Reprint Aug 2020) Low-Voltage Fuses

- Part 10: Class L Fuses

UL 248-12 (2011; Reprint Aug 2020) Low Voltage Fuses

- Part 12: Class R Fuses

UL 248-15 (2018) Low-Voltage Fuses - Part 15: Class T Fuses

UL 360 (2013; Reprint Jan 2024) UL Standard for

SECTION 26 20 00 Page 10

Safety Liquid-Tight Flexible Metal Conduit

UL 467 (2022) UL Standard for Safety Grounding and Bonding Equipment

UL 486A-486B (2025) UL Standard for Safety Wire Connectors

UL 486C (2023; Reprint Feb 2025) UL Standard for Safety Splicing Wire Connectors

UL 489 (2025) UL Standard for Safety Molded-Case Circuit Breakers, Molded-Case Switches and Circuit-Breaker Enclosures

UL 498 (2017; Reprint Jun 2024) UL Standard for Safety Attachment Plugs and Receptacles

UL 506 (2017; Reprint Jan 2022) UL Standard for Safety Specialty Transformers

UL 508 (2018; Reprint Jul 2021) UL Standard for Safety Industrial Control Equipment

UL 510 (2020; Dec 2022) UL Standard for Safety Polyvinyl Chloride, Polyethylene and Rubber Insulating Tape

UL 514A (2024) UL Standard for Safety Metallic Outlet Boxes

UL 514B (2012; Reprint Mar 2024) UL Standard for Safety Conduit, Tubing and Cable Fittings

UL 514C (2014; Reprint Apr 2024) UL Standard for Safety Nonmetallic Outlet Boxes, Flush-Device Boxes, and Covers

UL 651 (2011; Reprint May 2022) UL Standard for Safety Schedule 40, 80, Type EB and A Rigid PVC Conduit and Fittings

UL 674 (2022) UL Standard for Safety Electric Motors and Generators for Use in Hazardous (Classified) Locations

UL 719 (2015; Reprint Nov 2023) UL Standard for Safety Nonmetallic-Sheathed Cables

UL 797 (2007; Reprint Apr 2023) UL Standard for Safety Electrical Metallic Tubing -- Steel

UL 817 (2025) UL Standard for Safety Cord Sets and Power-Supply Cords

UL 845 (2021; Reprint Feb 2025) UL Standard for Safety Motor Control Centers

UL 854 (2020; Reprint Jul 2024) Standard for

SECTION 26 20 00 Page 11

Service-Entrance Cables

UL 857 (2009; Reprint Apr 2021) UL Standard for Safety Busways

UL 869A (2006; Reprint Jun 2020) Reference Standard for Service Equipment

UL 870 (2016; Reprint Nov 2023) UL Standard for Safety Wireways, Auxiliary Gutters, and Associated Fittings

UL 943 (2016; Reprint Sep 2023) UL Standard for Safety Ground-Fault Circuit-Interrupters

UL 984 (1996; Reprint Sep 2005) Hermetic Refrigerant Motor-Compressors

UL 1004-1 (2012; Reprint Nov 2020) UL Standard for Safety Rotating Electrical Machines - General Requirements

UL 1063 (2017; Reprint Jun 2022) UL Standard for Safety Machine-Tool Wires and Cables

UL 1203 (2023; Reprint May 2024) UL Standard for Safety Explosion-Proof and Dust-Ignition-Proof Electrical Equipment for Use in Hazardous (Classified) Locations

UL 1242 (2006; Reprint Apr 2022) UL Standard for Safety Electrical Intermediate Metal Conduit -- Steel

UL 1283 (2025) UL Standard for Safety Electromagnetic Interference Filters

UL 1449 (2021; Reprint Dec 2022) UL Standard for Safety Surge Protective Devices

UL 1561 (2011; Reprint Aug 2023) Dry-Type General Purpose and Power Transformers

UL 1569 (2018; Reprint Apr 2024) UL Standard for Safety Metal-Clad Cables

UL 1660 (2019; Reprint May 2024) Liquid-Tight Flexible Nonmetallic Conduit

UL 1699 (2017; Reprint Feb 2022) UL Standard for Safety Arc-Fault Circuit-Interrupters

UL 4248-1 (2022; Reprint Jun 2025) UL Standard for Safety Fuseholders - Part 1: General Requirements

UL 4248-12 (2018; Reprint Feb 2022) UL Standard for Safety Fuseholders - Part 12: Class R

SECTION 26 20 00 Page 12

1.2 DEFINITIONS

Unless otherwise specified or indicated, electrical and electronics terms used in these specifications, and on the drawings, are as defined in IEEE Stds Dictionary .

1.3 RELATED REQUIREMENTS

NOTE: Include Section 25 05 11 CYBERSECURITY FOR FACILITY-RELATED CONTROL SYSTEMS on all projects requiring Cybersecurity for 26 20 00: Interior Distribution System.

Section 25 05 11 CYBERSECURITY FOR FACILITY-RELATED CONTROL SYSTEMS applies to this section, with the additions and modifications specified herein.

1.4 SUBMITTALS

NOTE: Review Submittal Description (SD) definitions in Section 01 33 00 SUBMITTAL PROCEDURES and edit the following list, and corresponding submittal items in the text, to reflect only the submittals required for the project. The Guide Specification technical editors have classified those items that require Government approval, due to their complexity or criticality, with a "G." Generally, other submittal items can be reviewed by the Contractor's Quality Control System. Only add a "G" to an item if the submittal is sufficiently important or complex in context of the project.

For Army projects, fill in the empty brackets following the "G" classification, with a code of up to three characters to indicate the approving authority. Codes for Army projects using the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO" for District Office (Engineering Division or other organization in the District Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project Office. Codes following the "G" typically are not used for Navy and Air Force projects.

The "S" classification indicates submittals required as proof of compliance for sustainability Guiding Principles Validation or Third Party Certification and as described in Section 01 33 00 SUBMITTAL

PROCEDURES.

Government approval is required for submittals with a "G" or "S" classification. Submittals not having a "G" or "S" classification are for Contractor Quality Control approval. Submittals not having a "G" or "S" classification are for information only. When used, a code following the "G" classification identifies the office that will review the submittal

SECTION 26 20 00 Page 13 for the Government. Submit the following in accordance with Section

01 33 00 SUBMITTAL PROCEDURES:

SD-02 Shop Drawings

Panelboards ; G, [_____]

Transformers ; G, [_____]

[ Busway; G, [_____]

][ Cable Trays ; G, [_____]

][ Motor Control Centers ; G, [_____]

] Wireways ; G, [_____]

[ Load Centers for Housing Units ; G, [_____]

] Marking Strips Drawings; G, [_____]

SD-03 Product Data

Switches ; G, [_____]

Receptacles ; G, [_____]

Circuit Breakers ; G, [_____]

Fuses ; G, [_____]

[ Residential Load Center Circuit Breakers ; G, [_____]

][ Housing Unit Load Center Circuit Breakers ; G, [_____]

][ Enclosed Circuit Breakers ; G, [_____]

] Transformers ; G, [_____]

Motor Controllers ; G, [_____]

[ Combination Motor Controllers ; G, [_____]

][ Load Centers for Housing Units ; G, [_____]

] Manual Motor Starters ; G, [_____]

[ Residential Load Centers ; G, [_____]

][ Metering ; G, [_____]

][ Meter Base Only ; G, [_____]

][ CATV Outlets ; G, [_____]

] Secondary Bonding Busbar ; G, [_____]

Surge Protective Devices ; G, [_____]

SECTION 26 20 00 Page 14

[ Cable Trays ; G, [_____]

][ SD-05 Design Data

Cable Tray Design ; G, [_____]

] SD-06 Test Reports

600-volt Wiring Test ; G, [_____]

Grounding System Test ; G, [_____]

Transformer Tests ; G, [_____]

Ground-fault Receptacle Test ; G, [_____]

Arc-fault Receptacle Test ; G, [_____]

SD-07 Certificates

Fuses ; G, [_____]

SD-09 Manufacturer's Field Reports

Transformer Factory Tests

SD-10 Operation and Maintenance Data

NOTE: Coordinate with options under paragraphs MAINTENANCE and METERING.

[ Electrical Systems , Data Package 5; G, [_____]

][ Metering , Data Package 5; G, [_____]

] 1.5 QUALITY ASSURANCE

1.5.1 Electrician Qualifications

Electrical work must be performed by qualified persons with verifiable credentials who are familiar with applicable code requirements.

Verifiable credentials consist of State, National [and][or] Local Certifications or Licenses that a Master or Journeyman Electrician may hold, depending on work being performed.

1.5.2 Fuses

Submit coordination data as specified in paragraph, FUSES of this section.

1.5.3 Regulatory Requirements

In each of the publications referred to herein, consider the advisory provisions to be mandatory, as though the word, "must" had been substituted for "should" wherever it appears. Interpret references in these publications to the "authority having jurisdiction," or words of similar meaning, to mean the Contracting Officer. Provide equipment, materials, installation, and workmanship in accordance with NFPA 70 unless

SECTION 26 20 00 Page 15 more stringent requirements are specified or indicated. NECA NEIS 1 is the minimum standard for workmanship.

1.5.4 Standard Products

Provide materials and equipment that are products of manufacturers regularly engaged in the production of such products which are of equal material, design and workmanship and:

a. Have been in satisfactory commercial or industrial use for 2 years prior to bid opening including applications of equipment and materials under similar circumstances and of similar size.

b. Have been on sale on the commercial market through advertisements, manufacturers' catalogs, or brochures during the 2-year period.

c. Where two or more items of the same class of equipment are required, provide products of a single manufacturer; however, the component parts of the item need not be the products of the same manufacturer unless stated in this section.

1.5.4.1 Alternative Qualifications

Products having less than a 2-year field service record will be acceptable if a certified record of satisfactory field operation for not less than 6000 consecutive hours, exclusive of the manufacturers' factory or laboratory tests, is furnished.

1.5.4.2 Material and Equipment Manufacturing Date

Products manufactured more than 3 years prior to date of delivery to site are not acceptable.

1.6 MAINTENANCE

[ 1.6.1 Electrical Systems

NOTE: Select this subpart only if the system is considered complex and there is a need for detailed system information.

Submit operation and maintenance data in accordance with Section 01 78 23 , OPERATION AND MAINTENANCE DATA and as specified herein. Submit operation and maintenance manuals for electrical systems that provide basic data relating to the design, operation, and maintenance of the electrical distribution system for the building. Include the following:

a. Single line diagram of the "as-built" building electrical system.

b. Schematic diagram of electrical control system (other than HVAC, covered elsewhere).

c. Manufacturers' operating and maintenance manuals on active electrical equipment.

SECTION 26 20 00 Page 16

] 1.7 WARRANTY

Provide equipment items supported by service organizations that are located within 250 miles of the equipment installation in order to render service to the equipment on a regular and emergency basis during the warranty period of the contract.

[ 1.8 SEISMIC REQUIREMENTS

NOTE: Do not use this paragraph for Navy projects.

When directed to meet seismic requirements, edit Sections 13 48 73 SEISMIC CONTROL FOR NONSTRUCTURAL COMPONENTS and 26 05 48 SEISMIC PROTECTION FOR ELECTRICAL EQUIPMENT to suit the project and include in the contract documents. Edit the following paragraph and include it in the project specification. When a Government designer is the Engineer of Record, provide seismic requirements on the drawings.

Provide seismic work[ conforming to[ Section 13 48 73 SEISMIC CONTROL FOR NONSTRUCTURAL COMPONENTS][ and to][ Section 26 05 48 SEISMIC PROTECTION FOR ELECTRICAL EQUIPMENT]][ as indicated].

] PART 2 PRODUCTS

2.1 MATERIALS AND EQUIPMENT

As a minimum, meet requirements of UL, where UL standards are established for those items, and requirements of NFPA 70 for all materials, equipment, and devices.

2.2 CONDUIT AND FITTINGS

NOTE: The Uses Permitted are as modified by UFC 3-520-01 (See Table 3-1), "Interior Electrical Systems." The Uses Not Permitted are as specified in NFPA 70 and when restricted by other UFCs for specific types of buildings, such as medical facilities. Do not use flexible metal conduit in damp and wet locations and for pumps. Do not use Electrical Nonmetallic Tubing (ENT).

Use malleable iron seal electrical fittings in fuel valve pits and similar locations where fittings are exposed to potential freeze thaw environments.

Nonmetallic fittings have failed in these environments.

Conform to the following:

SECTION 26 20 00 Page 17

2.2.1 Rigid Metallic Conduit

2.2.1.1 Rigid, Threaded Zinc-Coated Steel Conduit

ANSI C80.1 , UL 6 .

2.2.1.2 Rigid Aluminum Conduit

ANSI C80.5 , UL 6A .

2.2.2 Rigid Nonmetallic Conduit

PVC Type EPC-40[, and EPC-80] in accordance with NEMA TC 2, UL 651 [, or fiberglass conduit, in accordance with NEMA TC 14].

2.2.3 Intermediate Metal Conduit (IMC)

UL 1242 , zinc-coated steel only.

2.2.4 Electrical, Zinc-Coated Steel Metallic Tubing (EMT)

UL 797 , ANSI C80.3 .

2.2.5 Plastic-Coated Rigid Steel and IMC Conduit

NEMA RN 1, Type 40( 1 mm 40 mils thick).

2.2.6 Flexible Metal Conduit

UL 1 , limited to 1829 mm 6 feet in areas where not accessible or below a raised floor installation.

2.2.6.1 Liquid-Tight Flexible Metal Conduit, Steel

UL 360 , limited to 1829 mm 6 feet in areas where not accessible or below a raised floor installation. The use of flexible metal conduit for bends or transitions in RMC, IMC, or EMT is prohibited.

2.2.7 Liquid-Tight Flexible Nonmetallic Conduit

NOTE: Do not use liquid-tight flexible nonmetallic conduits in Continental United States (CONUS). In overseas locations, only use when specifically allowed by the Authority Having Jurisdiction.

UL 1660 . The use of liquid-tight flexible metal conduit for bends or transitions in RMC, IMC, or EMT is prohibited.

2.2.8 Surface Metal Raceway

NOTE: UFC 3-520-01 authorizes the use of surface metal raceway only for building improvements, renovations or for applications where a variety of cord-and-plug connected equipment will be utilized in a limited space, such as in some areas of medical facilities, shops, and laboratories. Authorized for

SECTION 26 20 00 Page 18 use on acoustic-rated walls to limit the number of penetrations and maintain acoustical integrity.

Typical applications include spaces such as Sensitive Compartmented Information Facilities (SCIF) and Special Access Program Facilities (SAPF).

UL 5 , two-piece painted steel, totally enclosed, snap-cover type.[ Provide multiple outlet-type raceway with grounding-type receptacle where indicated. Provide receptacles as specified herein, spaced a minimum of one every [455][_____] mm [18][_____] inches .][ Wire alternate receptacles on different circuits.]

2.2.9 Surface Nonmetallic Raceway

NOTE: The UFC 3-520-01 definition of "subject to physical damage" prohibits the use of nonmetallic wireways for exterior applications installed less than 2.4 meters 8 feet above finished grade or 2.4 meters 8 feet above floor elevation for raceways on elevated platforms, loading docks, or stairwells.

Coordinate with the Authority Having Jurisdiction responsible for the construction contract regarding the use of this wiring method in the project.

UL 5A , nonmetallic totally enclosed, snap-cover type.[ Provide multiple outlet-type raceway with grounding-type receptacle where indicated.

Provide receptacles as specified herein, spaced a minimum of one every [455][_____] mm [18][_____] inches .][ Wire alternate receptacles on different circuits.]

2.2.10 Fittings for Metal Conduit, EMT, and Flexible Metal Conduit

UL 514B . Ferrous fittings: cadmium- or zinc-coated in accordance with

UL 514B .

2.2.10.1 Fittings for Rigid Metal Conduit and IMC

Threaded-type. Split couplings unacceptable.

2.2.10.2 Fittings for EMT

NOTE: Moisture absorbed within die-cast fittings may cause them to deteriorate more rapidly than steel fittings. Utilize steel fittings in damp or wet locations, or when requested by Activity on Installations and Bases that have high ambient humidity environments.

[Die Cast][Steel] compression type.

2.2.11 Fittings for Rigid Nonmetallic Conduit

NEMA TC 3 for PVC[ and NEMA TC 14 for fiberglass], and UL 514B .

SECTION 26 20 00 Page 19

[ 2.3 BUSWAY

NOTE: Ensure phase sequence of voltages and orientation are indicated on the drawings for existing transformers, switchboards, switchgear, and motor control centers.

NEMA BU 1.1 , UL 857 . Provide the following:

a. Buses: [ copper][ or][ aluminum].

b. Busways: rated [_____] volts, [_____] continuous current amperes, three-phase,[ three-][ four-]wire, and include integral or internal[ 50-percent] ground bus.

c. Short circuit rating: [ [_____] root mean square (rms) symmetrical amperes minimum][ as indicated].

d. Busway systems: suitable for use indoors. [Fixed][Spring] support system.[ Provide flexible bus systems in accordance with NFPA 70 .]

e. Enclosures: [ steel][ aluminum][ metallic].

f. Hardware: plated or otherwise protected to resist corrosion.

g. Joints: one-bolt type with through-bolts, which can be checked for tightness without de-energizing system.

h. Maximum hot spot temperature rise at any point in busway at continuous rated load: do not exceed 55 degrees C above maximum ambient temperature of 40 degrees C in any position.

i. Internal barriers to prevent movement of superheated gases.

j. Coordinate proper voltage phasing of entire bus duct system, for example where busway interfaces with transformers, switchgear, switchboards, motor control centers, and other system components.

2.3.1 Feeder Busways

Provide[ ventilated, except that vertical busways within 1830 mm 6 feet of floors must be unventilated,][ unventilated, totally enclosed] low-impedance busway. Provide bus bars fully covered with insulating material, except at stabs. Provide an entirely polarized busway system.

2.3.2 Plug-In Busways

Unventilated type. Provide the following:

a. Plug-in units: [ fusible, handle-operated, switch type, horsepower-rated][ circuit breaker-type][ handle-operated, switch type, equipped with high interrupting-capacity, current-limiting fuses].

b. Bus bars: covered with insulating material throughout, except at joints and other connection points.

SECTION 26 20 00 Page 20

[ c. A hook stick of suitable length for operating plug-in units from the floor.

] ][ 2.4 CABLE TRAYS

NOTE: Indicate cable tray layout on the drawings.

When multiple types and sizes are used, indicate size and type of cable trays on the drawings. When using "as indicated" option, ensure information required is shown on the drawings. Coordinate with structural engineer when designating the Span/Load Class category. This designation is found in NEMA VE 1. Provide designation on drawings [and][or] in this specification.

NEMA VE 1. Provide the following:

[ Submit cable tray design , including dimensional layout, load and seismic calculations, and fill calculations. Dimensional layout includes cable spacings, cable tray splices, and supports. Fill calculations include an index of cables for each section and identification of the lb/ft, cross sectional area, and insulation voltage class for each cable.

] a. Cable trays: form a wireway system, with a nominal[ [75][100][150] mm [3][4][6] inch ] depth[ as indicated]. Cable tray is to have a span/load class designation of [_____] per NEMA VE 1.

b. Cable trays: constructed of[ aluminum][ copper-free aluminum][ steel that has been hot-dipped galvanized after fabrication].

c. Cable trays: include splice and end plates, dropouts, and miscellaneous hardware.

d. Edges, fittings, and hardware: finished free from burrs and sharp edges.

e. Fittings: ensure not less than load-carrying ability of straight tray sections and have manufacturer's minimum standard radius.

f. Radius of bends: [ [305][610][915] mm [12][24][36] inches .][ as indicated.]

2.4.1 Trough-Type Cable Trays

NOTE: Trough or ventilated cable tray is a fabricated structure consisting of integral or separate longitudinal rails and a bottom having openings sufficient for the passage of air and utilizing 75 percent or less of the plan area of the surface to support cables.

Provide[ size as indicated][ of nominal [150][305][455][610][760][915] mm [6][12][18][24][30][36] inch width].[ Cable tray must be suitable for use as an equipment grounding conductor.]

SECTION 26 20 00 Page 21

2.4.2 Ladder-Type Cable Trays

NOTE: Ladder cable tray is a fabricated structure consisting of two longitudinal side rails connected by individual transverse members (rungs).

Provide[ size as indicated][ of nominal [150][305][455][610][760][915] mm [6][12][18][24][30][36] inch width] with maximum rung spacing of [150][225][305][455] mm [6][9][12][18] inches .[ Cable tray must be suitable for use as an equipment grounding conductor.]

2.4.3 Channel-Type Cable Trays

NOTE: Channel cable tray is a fabricated structure consisting of a one-piece ventilated-bottom or solid-bottom channel section, not exceeding 152 mm 6 inches in width.

Provide[ size as indicated][ of nominal [75][100][150] mm [3][4][6] inch width]. Provide trays with one-piece construction having slots spaced not more than 115 mm 4 1/2 inches on centers.[ Cable tray must be suitable for use as an equipment grounding conductor.]

2.4.4 Solid Bottom-Type Cable Trays

NOTE: Solid bottom or non-ventilated cable tray is a fabricated structure consisting of a bottom without ventilation openings within integral or separate longitudinal side rails.

Provide[ size as indicated][ of nominal [150][305][455][610][760][915] mm [6][12][18][24][30][36] inch width].[ Provide solid covers.][ Do not provide solid covers.]

[ 2.4.5 Cantilever

Cantilever-type, may be provided at the Contractor's option in lieu of other cable tray types specified.

] ] 2.5 OUTLET BOXES AND COVERS

UL 514A , cadmium- or zinc-coated, if ferrous metal. UL 514C , if nonmetallic.

2.5.1 Floor Outlet Boxes

Provide the following:

a. Boxes: [ adjustable][ nonadjustable] and concrete tight.

b. Each outlet: consisting of [nonmetallic][ or ][cast-metal] body with threaded openings,[ or sheet-steel body with knockouts] for conduits,[ adjustable][,][ brass flange] ring, and cover plate with

SECTION 26 20 00 Page 22

[19][25][31.75][53.92] mm [3/4][1][1 1/4][2 1/8] inch threaded plug.

c. Receptacle outlets: consisting of[ surface-mounted, horizontal][ flush] aluminum or stainless steel housing with duplex-type receptacle as specified herein.

d. Provide gaskets where necessary to ensure watertight installation.

[ e. Provide plugs with installation instructions to the Contracting Officer for [5][_____] percent of outlet boxes for the capping of outlets upon removal of service fittings.

] [ 2.5.2 Clock Outlet for Use in Other Than Wired Clock System

NOTE: Battery-operated clocks are Navy standard.

Retain this paragraph only under special conditions.

Provide the following:

a. Outlet box with plastic cover, where required, and single receptacle with clock outlet plate.

b. Receptacle: recessed sufficiently within box to allow complete insertion of standard cap, flush with plate.

c. Suitable clip or support for hanging clock: secured to top plate.

d. Material and finish of plate: as specified in paragraph DEVICE PLATES of this section.

] 2.6 CABINETS, JUNCTION BOXES, AND PULL BOXES

UL 50 ; volume greater than 1640 mL 100 cubic inches , NEMA Type 1 enclosure; sheet steel, hot-dip, zinc-coated. Where exposed to wet, damp, or corrosive environments, NEMA Type [3R][4X][_____][as indicated].

2.7 WIRES AND CABLES

Provide wires and cables in accordance with applicable requirements of NFPA 70 and UL for type of insulation, jacket, and conductor specified or indicated. Do not use wires and cables manufactured more than 24 months prior to date of delivery to site.

2.7.1 Conductors

NOTE: UFC 3-520-01 allows the use of aluminum conductors of equivalent ampacity instead of copper for #4 AWG (25 mm^2)and larger sizes. If only copper is desired for these applications, select the bracketed option below. The second bracketed option follows the UFC guidance.

NOTE: In overseas locations, for conductors No. 10 AWG (6 mm^2)and smaller diameter, give consideration

SECTION 26 20 00 Page 23 to the use of stranded wires, if suitable terminal devices can be applied which enable proper connection. Also, stranded wires in sizes No. 10 AWG (6 mm^2)and smaller diameter may be required for projects involving uninterrupted power supply (UPS) installations.

Provide the following:

a. Conductor sizes and capacities shown are based on copper, unless indicated otherwise.

b. Conductors No. 10 AWG [6 mm^2] and larger diameter: stranded.

c. Conductors No. 12 AWG [4 mm^2] and smaller diameter: solid.

d. Conductors for remote control, alarm, and signal circuits, classes 1, 2, and 3: stranded unless specifically indicated otherwise.

e. [All conductors: copper.][Conductors indicated to be No. 6 AWG [16 mm^2] or smaller diameter: copper. Conductors indicated to be No. 4 AWG [25 mm^2] and larger diameter: either copper or aluminum, unless type of conductor material is specifically indicated, or specified, or required by equipment manufacturer.]

[ 2.7.1.1 Equipment Manufacturer Requirements

NOTE: Use this paragraph only if aluminum conductors are allowed.

When manufacturer's equipment requires copper conductors at the terminations or requires copper conductors to be provided between components of equipment, provide copper conductors or splices, splice boxes, and other work required to satisfy manufacturer's requirements.

][ 2.7.1.2 Aluminum Conductors

NOTE: In certain instances it may be necessary to require compact stranding, i.e., when outside diameter of cable must be limited. When necessary, specify the following: "Provide conductors with compact stranded utilizing method of stranding specified in ASTM B400/B400M; however, provide conductor material as specified herein."

Provide aluminum conductors of AA-8000 series electrical grade aluminum alloy conductors. Type EC/1350 aluminum is not acceptable. If Contractor chooses to provide aluminum for conductors No. 4 AWG [25 mm^2] and larger diameter, Contractor is responsible for increasing conductor size to have same ampacity as copper size indicated; increasing conduit and pull box sizes to accommodate larger size aluminum conductors in accordance with NFPA 70 ; ensuring that pulling tension rating of aluminum conductor is sufficient; providing panelboards[ and motor control centers] that are UL listed for use with aluminum, and so labeled; relocating equipment, SECTION 26 20 00 Page 24 modifying equipment terminations, resizing equipment; and resolving problems that are direct results of providing aluminum conductors in lieu of copper.

] 2.7.1.3 Minimum Conductor Sizes

Provide minimum conductor size in accordance with the following:

a. Branch circuits: No. 12 AWG [4 mm^2].

b. Class 1 remote-control and signal circuits: No. 14 AWG [14 mm^2].

c. Class 2 low-energy, remote-control and signal circuits: No. 16 AWG [1.5 mm^2].

d. Class 3 low-energy, remote-control, alarm and signal circuits: No. 22 AWG [0.34 mm^2].

e. Digital low voltage lighting control (DLVLC) system at 24 Volts or less: Category [5 UTP][_____] cables[ in EMT conduit][ in accordance with DLVLC system manufacturer requirements].

2.7.2 Color Coding

Provide color coding for service, feeder, branch, control, and signaling circuit conductors.

2.7.2.1 Ground and Neutral Conductors

Provide color coding of ground and neutral conductors as follows:

a. Grounding conductors: Green.

b. Neutral conductors: White.

c. Exception, where neutrals of more than one system are installed in same raceway or box, other neutrals color coding: white with a different colored (not green) stripe for each.

2.7.2.2 Ungrounded Conductors

Provide color coding of ungrounded conductors in different voltage systems as follows:

a. 208/120 volt, three-phase

(1) Phase A - black

(2) Phase B - red

(3) Phase C - blue

b. 480/277 volt, three-phase

(1) Phase A - brown

(2) Phase B - orange

(3) Phase C - yellow

SECTION 26 20 00 Page 25

c. 120/240 volt, single phase: Black and red

[ d. On three-phase, four-wire delta system, high leg: orange, as required by NFPA 70 .

] 2.7.3 Insulation

NOTE: Be sure conduit fill calculations are based on largest diameter insulation type allowed.

Designer may select other insulation types which may be more suitable for a particular project. For rewiring project where existing conduit is to be utilized, specify types THHN and THWN.

Conductors must be sized for ampacity at 60 degrees C or 75 degrees C as required in accordance with Section 110.14 of NFPA 70 for the lowest termination value in the circuit; however, ambient temperature correction may be based on the actual conductor insulation temperature rating per NFPA 70 Section

110.14. This requirement also applies to feeders

protected by 100 percent rated circuit breakers.

Unless specified or indicated otherwise or required by NFPA 70 , provide power and lighting wires rated for 600-volts,[ Type THWN/THHN conforming to UL 83 ][ or][ Type[ XHHW][ or][ RHW] conforming to UL 44 ], except that grounding wire may be type TW conforming to UL 83 ; remote-control and signal circuits: Type TW or TF, conforming to UL 83 . Where equipment or devices require 90-degree Centigrade (C) conductors, provide only conductors with 90-degree C insulation or better.

2.7.4 Bonding Conductors

ASTM B1, solid bare copper wire for sizes No. 8 AWG [10 mm^2] and smaller diameter; ASTM B8, Class B, stranded bare copper wire for sizes No. 6 AWG [16 mm^2] and larger diameter.

[ 2.7.5 Service Entrance Cables

Service Entrance (SE) and Underground Service Entrance (USE) Cables, UL 854 .

][ 2.7.6 Nonmetallic Sheathed Cable

NOTE: UFC 3-520-01 authorizes Type NC and NMC cables only in one- and two-family dwellings including attached or detached garages and storage buildings.

UL 719 , Type NM or NMC.

][ 2.7.7 Wire and Cable for 400 Hertz (Hz) Circuits

Insulated copper conductors.

SECTION 26 20 00 Page 26

][ 2.7.8 Metal-Clad Cable

NOTE: Type MC cable is UL listed and NFPA 70 recognized for most common building applications.

Review NFPA 70. MC cable does not protect conductors as well as rigid conduit but is more flexible to install and relocate. For Navy projects, consult with NAVFAC cognizant FEC electrical design branch manager and obtain written approval before specifying this wiring method.

NOTE: UFC 3-520-01 prohibits using Type MC cable except for branch circuits in the following dry locations: new construction in exposed locations;

renovations in exposed locations; concealed in renovations in existing areas where walls and ceilings are not disturbed; and cable trays.

UL 1569 ; NFPA 70 , Type MC cable.

][ 2.7.9 Armored Cable

NOTE: UFC 3-520-01 prohibits using Type AC cable except for branch circuits in the following dry locations: new construction and renovations in exposed locations; concealed in renovations in existing areas where walls and ceilings are not disturbed; and cable trays.

UL 4 ; NFPA 70 , Type AC cable.

][ 2.7.10 Mineral-Insulated, Metal-Sheathed Cable

NOTE: Type MI cable is used for low temperature, high temperature, hazardous locations, life safety, and heating applications. Refer to NFPA 70.

Clearly show the MI cable on the drawings. If MI cable utilized in hazardous areas is likely to be subject to high voltage surges, consider the use of surge suppressors in electrical panels serving the load from outside of the hazardous area. Locate suppressors in appropriately rated enclosures within the hazardous area only if there is no other option. MI cable is not available in ratings above 600 volts.

UL listed; NFPA 70 , Type MI cable. Do not use sheathing containing asbestos fibers.

SECTION 26 20 00 Page 27

][ 2.7.11 Flat Conductor Cable

NOTE: Type FCC cable has been listed by UL and recognized by NFPA 70 for under carpet tile applications. Review NFPA 70. FCC cable is available off the shelf for power and telecommunications transmission applications.

UL listed; NFPA 70 , Type FCC.

][ 2.7.12 Cable Tray Cable or Power Limited Tray Cable

UL listed; type TC or PLTC.

][ 2.7.13 Cord Sets and Power-Supply Cords

NOTE: Include this paragraph when equipment utilizing cord sets is permanently connected to boxes in lieu of use of plug and receptacles.

UL 817 .

] 2.8 SPLICES AND TERMINATION COMPONENTS

UL 486A-486B for wire connectors and UL 510 for insulating tapes.

Connectors for No. 10 AWG [6 mm^2] and smaller diameter wires: insulated, pressure-type in accordance with UL 486A-486B or UL 486C (twist-on splicing connector). Provide solderless terminal lugs on stranded conductors.

2.9 DEVICE PLATES

NOTE: Use last item below for brig facilities only.

Provide the following:

a. UL listed, one-piece device plates for outlets to suit the devices installed.

b. For metal outlet boxes, plates on unfinished walls: zinc-coated sheet steel or cast metal having round or beveled edges.

c. For nonmetallic boxes and fittings, other suitable plates may be provided.

[ d. Plates on finished walls: nylon or lexan, minimum 0.792 mm 0.03 inch wall thickness and same color as receptacle or toggle switch with which they are mounted.

][ e. Plates on finished walls: satin finish stainless steel or brushed-finish aluminum, minimum 0.792 mm 0.03 inch thick.

] f. Screws: machine-type with countersunk heads in color to match finish

SECTION 26 20 00 Page 28 of plate.

g. Sectional type device plates are not be permitted.

h. Plates installed in wet locations: gasketed and UL listed for "wet locations."

[ i. Device plates in areas normally accessible to prisoners: brown or ivory finish nylon-device plates rated for high abuse. Test device plates for compliance with UL 514A and UL 514C for physical strength.

Attach device plates with spanner head bolts.

] 2.10 SWITCHES

2.10.1 Toggle Switches

NEMA WD 1, UL 20 ,[ single pole][, double pole][, three-way][, and four-way], totally enclosed with bodies of thermoplastic or thermoset plastic and mounting strap with grounding screw. Include the following:

a. Handles: [white][ivory][brown] thermoplastic.

b. Wiring terminals: screw-type, side-wired. Do not use back-stabbed conductor terminals.

c. Contacts: silver-cadmium and contact arm - one-piece copper alloy.

d. Switches: rated quiet-type ac only, 120/277 volts, with current rating and number of poles indicated.

2.10.2 Switch with Red Pilot Handle

NEMA WD 1. Provide the following:

a. Pilot lights that are integrally constructed as a part of the switch's handle.

b. Pilot light color: red and illuminate whenever the switch is closed or "on".

c. Pilot lighted switch: rated 20 amps and 120 volts or 277 volts as indicated.

d. The circuit's neutral conductor to each switch with a pilot light.

2.10.3 Breakers Used as Switches

For 120- and 277-Volt fluorescent fixtures, mark breakers "SWD" in accordance with UL 489 .

2.10.4 Disconnect Switches

NOTE: Select heavy duty-type for those switches requiring frequent operation and indicate as such on the drawings.