26 24 16.00 40 PANELBOARDS.doc

SECTION 26 24 16.00 40

PANELBOARDS

NOTE: This specification covers the requirements for power-distribution panelboards and lighting and appliance branch-circuit panelboards.

Drawings must indicate the ampere rating of panelboards, the number of bus bars, and the voltage characteristics of the system to which they are to be connected. Frame size, trip rating, number of poles, and class of molded-case branch-circuit breakers must be indicated. Interrupting rating must be shown for power distribution panelboards and for lighting and appliance branch-circuit panelboards if the latter have an interrupting rating of more than 10,000 amperes rms symmetrical.

Edit this guide specification for project specific requirements by adding, deleting, or revising text. For bracketed items, choose applicable items(s) or insert appropriate information.

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

Comments and suggestions on this guide specification are welcome and should be directed to the technical proponent of the specification. A listing of technical proponents, including their organization designation and telephone number, is on the Internet.

Recommended changes to a UFGS should be submitted as a Criteria Change Request (CCR).

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 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.

1.1.1 The publications listed below form a part of this specification to the extent referenced. The publications are referred to in the text by the basic designation only. Unless other wise noted, the latest published version and/or revision shall be used.

1.1.1.1 NATIONAL ELECTRICAL MANUFACTURERS ASSOCIATION (NEMA)

a. NEMA 250 Enclosures for Electrical Equipment (1000 Volts Maximum)

b. NEMA AB 1 Molded-Case Circuit Breakers, Molded Case Switches, and Circuit-Breaker Enclosures

c. NEMA PB 1 Standard for Panelboards

1.1.1.2 NATIONAL FIRE PROTECTION ASSOCIATION (NFPA)

a. NFPA 70 National Electrical Code

1.1.1.3 U.S. DEPARTMENT OF DEFENSE (DOD)

a. MIL-HDBK 232 Red/Black Engineering Installation Guidelines

1.1.1.4 U.S. GENERAL SERVICES ADMINISTRATION (GSA)

a. FED-STD-595 Colors Used in Government Procurement

1.1.1.5 UNDERWRITERS LABORATORIES (UL)

a. UL 67 Standard for Panelboards

1.2 GENERAL REQUIREMENTS

NOTE: If Section 26 00 00.00 20 BASIC ELECTRICAL MATERIALS AND METHODS is not included in the project specification, applicable requirements therefrom should be inserted and the following paragraph deleted.

1.2.1 Section 26 00 00.00 20 Basic Electrical Materials and Methods applies to work specified in this section.

1.2.2 Detail Drawings shall be submitted for the panelboards consisting of fabrication and assembly drawings for all parts of the work in sufficient detail to enable the Government to check conformity with the requirements of the contract documents. Drawings shall include details of bus layout.

1.2.3 Outline Drawings for panelboards shall indicate overall physical features, dimensions, ratings, service requirements, and weights of equipment.

1.2.4 Statements signed by responsible officials of a manufacturer of a product, system, or material attesting that the product, system or material meet specified requirements. Statements must be dated after the award of this contract, name the project, and list the specific requirements which it is intended to address.

1.3 SUBMITTALS

NOTE: Review Submittal Description (SD) definitions in Section 01 33 00 SUBMITTAL PROCEDURES and edit the following list to reflect only the submittals required for the project. Submittals should be kept to the minimum required for adequate quality control.

A “G” following a submittal item indicates that the submittal requires Government approval. Some submittals are already marked with a “G”. Only delete an existing “G” if the submittal item is not complex and can be reviewed through the Contractor’s Quality Control system. Only add a “G” if the submittal is sufficiently important or complex in context of the project.

For submittals requiring Government approval on Army projects, a code of up to three characters within the submittal tags may be used following the "G" designation 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, Air Force, and NASA projects.

Choose the first bracketed item for Navy, Air Force and NASA projects, or choose the second bracketed item for Army projects.

1.3.1 Government approval may be required on any of the following items. Items requiring submittals will be listed on the AF Form 66. Provide copies of all submittals per the requirements in Section 01 33 00, Submittal Procedures, or as listed on the AF Form 66.

1.3.1.1 SD-02 Shop Drawings

a. Detail Drawings and Outline Drawings shall be submitted for panelboards in accordance with paragraph entitled, "General Requirements," of this section.

1.3.1.2 SD-03 Product Data

a. Manufacturer's catalog data shall be submitted for the following items:

(1) Panelboards

(2) Directory Card and Holder

1.3.1.3 SD-04 Samples

a. Keys shall then be properly tagged and delivered to the Contracting Officer.

1.3.1.4 SD-06 Test Reports

a. Test reports shall be submitted for the following tests in accordance with the paragraph entitled, "Site Testing," of this section. Panelboards shall not be energized until the recorded test data have been submitted to and approved by the Contracting Officer.

(1) Continuity Tests

(2) Insulation Tests

1.3.1.5 SD-07 Certificates

a. Statements shall be submitted in accordance with paragraph entitled, "General Requirements," of this section.

1.3.1.6 SD-08 Manufacturer's Instructions

a. Manufacturer's instructions shall be submitted for Panelboards including special provisions required to install equipment components and system packages. Special notices shall detail impedances, hazards and safety precautions.

PART 2 PRODUCTS

2.1 PANELBOARDS

2.1.1 Power-distribution panelboards and lighting and appliance branch-circuit panelboards shall be totally enclosed in a steel cabinet, dead-front circuit breaker type with copper buses, surface- or flush-mounted as indicated. Panelboards shall conform to NEMA PB 1 and NEMA AB 1. Branch circuit panels shall have buses fabricated for bolt-on type circuit breakers.

2.1.2 An outer door or cover, hinged on one side, shall be provided on surface-mounted panelboards to provide gutter space access. A center door shall be provided for circuit breaker/switch access only.

2.1.3 Voltage and current rating, number of phases, and number of wires shall be as indicated. Four-wire distribution panelboards and lighting and appliance branch-circuit panelboards shall be provided with an isolated full-capacity neutral bus. Panelboards shall be rated for 240-volt (maximum), single-phase, 120/208-volt, three-phase, 277/480-volt, three-phase, 60-hertz, as indicated.

2.1.4 Three-phase, 4-wire and single-phase, 3-wire distribution lighting and branch circuit panelboards shall be provided with an isolated full-capacity bus providing spaces for single-pole circuit breakers/switches and spaces indicated as spare.

2.1.5 Panelboards shall be provided with a separate grounding bus bonded to the enclosure. Grounding bus shall be a solid bus bar of rectangular cross section equipped with binding screws for the connection of equipment grounding conductors.

2.1.6 Each panelboard, as a complete unit, shall have a short-circuit current rating equal to or greater than the integrated equipment rating shown on the panelboard schedule or as indicated.

2.1.7 Panelboards and main lugs or main breaker shall have current ratings as shown on the panelboard schedule.

2.1.8 Bus bar connections to the branch circuit breakers shall be the "distributed phase" or "phase sequence" type. Single-phase, three-wire panelboard busing shall be such that when any two adjacent single-pole breakers are connected to opposite phases, two-pole breakers can be installed in any location. Three-phase, four-wire busing shall be such that when any three adjacent single-pole breakers are individually connected to each of the three different phases, two- or three-pole breakers can be installed at any location. Current-carrying parts of the bus assembly shall be plated. Mains ratings shall be as shown.

2.1.9 Mechanical lugs furnished with panelboards shall be cast copper or copper alloys of sizes suitable for the conductors indicated to be connected thereto.

2.1.10 Panelboard box shall be galvanized code-gage sheet steel without knockouts. Entire panelboard front shall be hinged on one side with a piano hinge for the full height and shall also have captive screws opposite the hinged side. Where panelboards are installed flush with the walls, the installation details shall be such that the hinged front can be opened without damage to the adjacent wall surfaces. Color of the finished coat of trim and front shall match the adjacent walls except that when the box is installed in electrical closets or equipment rooms, the gray finish as specified will be acceptable.

2.1.11 Panelboard enclosures shall be NEMA 250, Type 1. Enclosures shall be provided with hinged fronts and corrosion-resistant steel pin-tumbler cylinder locks. Locks shall be keyed alike, and two keys shall be provided for each enclosure.

2.1.12 Panelboards shall be finished with baked enamel. Finish color shall be No. 61 gray conforming to FED-STD-595.

2.2 CIRCUIT BREAKERS

NOTE: Include Section 26 05 73.00 40 OVERCURRENT PROTECTIVE DEVICES in the project specification or include the requirements herein.

2.2.1 Circuit breakers shall be the molded-case type as specified in Section 26 05 73.00 40 Overcurrent Protection Devices. Frame and trip ratings shall be as indicated.

2.2.2 Interrupting rating of circuit breakers shall be as indicated. If not shown, the interrupting rating for circuit breakers in 120/208-volt panelboards shall be not less than 10,000 amperes rms symmetrical, and that for breakers in 277/480-volt panelboards shall be not less than 25,000 amperes rms symmetrical.

2.2.3 Circuit breakers shall be bolt-on type. Plug-in type shall not be acceptable.

2.2.4 Shunt trips shall be provided where indicated.

2.2.5 In branch circuit panelboards, branch circuit breakers feeding convenience outlets shall have sensitive instantaneous trip settings of not more than 10 times the trip rating of the breaker to prevent repeated arcing shorts resulting from frayed appliance cords. Single-pole 15- and 20-ampere circuit breakers shall be UL listed as "Switching Breakers". UL Class A (5-milliampere sensitivity) ground fault circuit protection shall be provided on 120-volt ac branch circuit as indicated. This protection shall be an integral part of the branch circuit breaker that also provides overload and short-circuit protection for branch circuit wiring. Tripping of a branch circuit breaker containing ground fault circuit interruption shall not disturb the feeder circuit to the panelboard. A single-pole circuit breaker with integral ground fault circuit interruption shall require no more panelboard branch circuit space than a conventional slide pole circuit breaker.

2.2.6 Connections to the bus shall be bolt-on type.

2.2.7 When multiple wires per phase are specified, the circuit breakers shall be furnished with connectors made to accommodate multiple wires.

2.2.8 Circuit breaker spaces called out on the drawings shall be complete with mounting hardware to permit ready installation of the circuit breakers.

2.3 DIRECTORY CARD AND HOLDER

2.3.1 A directory card shall be mounted on the inside of hinged fronts and doors (0.030-inch) thick minimum plastic in a metal frame, with spaces for circuit numbers, outlets controlled, and room numbers. Directory card shall identify each branch circuit with its respective and numbered circuit breaker.

2.4 FACTORY TESTING

2.4.1 Complete panelboards shall be tested in accordance with UL 67.

2.5 PRECAUTIONARY LABEL

2.5.1 To ensure persons are aware of immediate or potential hazard in the application, installation, use, or maintenance of panelboards, each panelboard shall be conspicuously marked on the trim or dead front shield with the text (or equivalent) DANGER symbol. If the panel is supplied with a door, the label shall be visible when the door is in the open position.

PART 3 EXECUTION

3.1 INSTALLATION

3.1.1 Panelboards shall be installed as indicated and in accordance with the manufacturer's instructions. Panels shall be fully aligned and mounted so that the height of the top operating handle will not exceed (72-inches) above the finished floor.

3.1.2 Directory-card information shall be typewritten in capital letters to indicate outlets controlled and final room numbers served by each circuit and shall be mounted in holders behind protective covering.

3.1.3 Provide panelboard circuit directory cards upon completion of installation work. Insure the date of the work is indicated on the circuit directory card. Insure circuit directory card matches the panel for which it is furnished. Circuit directory cards shall be arranged with even numbered circuits separated by group or card from odd numbered circuits. All circuits, including spares and spaces, shall be labeled. Hand lettering is not acceptable. Provide a description of the load and its location for every circuit. The location must provide a written description and room number if available. Example: A receptacle circuit in an office could be “Recept. Office 203”.

3.2 SITE TESTING

3.2.1 Each panelboard enclosure key shall be shown to operate the enclosure locks in the presence of the Contracting Officer.

3.2.2 Panelboards shall be given continuity and insulation tests after the installation has been completed and before the panelboard is energized.

3.2.3 Test equipment, labor, and personnel shall be provided by the Contractor as required to perform the tests as specified. Continuity tests shall be conducted using a dc device with buzzer.

3.2.4 Insulation tests on 480-volt panelboards shall be conducted using a 1,000-volt insulation-resistance test set. Readings shall be recorded every minute until three equal and consecutive readings have been obtained. Resistance between phase conductors and between phase conductors and ground shall be not less than 50 megohms.

3.2.5 Insulation tests on panelboards rated 300 volts or less shall be conducted using a 500-volt minimum insulation-resistance test set. Readings shall be recorded after 1 minute and until the reading is constant for 15 seconds. Resistance between phase conductors and between phase conductors and ground shall be not less than 25 megohms.

3.2.6 Test data shall be recorded and shall include the location and identification of panelboards and megohm readings versus time.

3.3 MISCELLANEOUS

3.3.1 Provide four ¾” empty conduits for future from each flush mounted panelboard to an accessible space above the ceiling. Provide four ¾” EMT conduit fittings with knock out closers in the top of the panel for each surface mounted panelboard.

3.3.2 All wiring within panelboards shall be arranged in a neat and organized manner.

3.3.3 Coordinate installation of panelboards and enclosures with cable and raceway installation work.

3.3.4 Tighten connectors and terminals, including screws and bolts, in accordance with equipment manufacturer’s published torque tightening values for equipment connectors. Where manufacturer’s torque requirements are not indicated, tighten connectors and terminals to comply with tightening torques specified in UL Standards 486A and B or Manufacturer’s torque requirements when more stringent.

3.3.5 Anchor enclosures firmly to walls and structural surfaces, ensuring that they are permanently and mechanically secure.

3.3.6 Provide properly wired electrical connections within enclosures.

END OF SECTION 26 24 16.00 40

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26 24 16.00 40-1 03/16/10