260521 LOW VOLT CONDUCTORS.doc

09-10

SECTION 26 05 21

LOW-VOLTAGE ELECTRICAL POWER CONDUCTORS AND CABLES (600 VOLTS AND BELOW)

PART 1 ‑ GENERAL

1.1 DESCRIPTION

This section specifies the furnishing, installation, and connection of the low voltage power and lighting wiring.

1.2 RELATED WORK

A.

Section 07 84 00, FIRESTOPPING: Sealing around penetrations to maintain the integrity of fire-rated construction.

B.

Section 26 05 11, REQUIREMENTS FOR ELECTRICAL INSTALLATIONS: General electrical requirements that are common to more than one section.

1.3 qualITY ASSURANCE

Refer to Paragraph, QUALIFICATIONS, in Section 26 05 11, REQUIREMENTS FOR ELECTRICAL INSTALLATIONS.

1.4 FACTORY TESTS

Low voltage cables shall be thoroughly tested at the factory per NEMA WC-70 to ensure that there are no electrical defects. Factory tests shall be certified.

1.5 SUBMITTALS

In accordance with Section 26 05 11, REQUIREMENTS FOR ELECTRICAL INSTALLATIONS, submit the following:

1.

Manufacturer's Literature and Data: Showing each cable type and rating.

2.

Certifications: Two weeks prior to the final inspection, submit four copies of the following certifications to the COR:

a.

Certification by the manufacturer that the materials conform to the requirements of the drawings and specifications.

b.

Certification by the contractor that the materials have been properly installed, connected, and tested.

1.6 APPLICABLE PUBLICATIONS

A.

Publications listed below (including amendments, addenda, revisions, supplements and errata) form a part of this specification to the extent referenced. Publications are reference in the text by designation only.

B.

American Society of Testing Material (ASTM):

D2301-04 Standard Specification for Vinyl Chloride Plastic Pressure-Sensitive Electrical Insulating Tape

C.

National Fire Protection Association (NFPA):

70-08 National Electrical Code (NEC)

D.

National Electrical Manufacturers Association (NEMA):

WC 70-09

Power Cables Rated 2000 Volts or Less for the Distribution of Electrical Energy E.

Underwriters Laboratories, Inc. (UL):

44-05 Thermoset-Insulated Wires and Cables

83-08 Thermoplastic-Insulated Wires and Cables

467-071 Electrical Grounding and Bonding Equipment

486A-486B-03 Wire Connectors

486C-04 Splicing Wire Connectors

486D-05 Sealed Wire Connector Systems

486E-94 Equipment Wiring Terminals for Use with Aluminum and/or Copper Conductors

493-07 Thermoplastic-Insulated Underground Feeder and Branch Circuit Cable

514B-04 Conduit, Tubing, and Cable Fittings

1479-03 Fire Tests of Through-Penetration Fire Stops

PART 2 ‑ PRODUCTS

2.1 conductors and CABLES A.

Conductors and cables shall be in accordance with NEMA WC-70 and as specified herein.

B.

Single Conductor:

1.

Shall be annealed copper.

2.

Shall be stranded for sizes No. 8 AWG and larger, solid for sizes No. 10 AWG and smaller.

3.

Shall be minimum size No. 12 AWG, except where smaller sizes are allowed herein.

C.

Insulation:

1.

XHHW-2 or THHN-THWN shall be in accordance with NEMA WC-70, UL 44, and UL 83.

2.

Isolated power system wiring: Type XHHW-2 with a dielectric constant of 3.5 or less.

D.

Color Code:

1.

Secondary service feeder and branch circuit conductors shall be color-coded as follows:

* or white with colored (other than green) tracer.

a.

Lighting circuit “switch legs” and 3-way switch “traveling wires” shall have color coding that is unique and distinct (e.g., pink and purple) from the color coding indicated above. The unique color codes shall be solid and in accordance with the NEC. Coordinate color coding in the field with the COTR.

2.

Use solid color insulation or solid color coating for No. 12 AWG and No. 10 AWG branch circuit phase, neutral, and ground conductors.

3.

Conductors No. 8 AWG and larger shall be color-coded using one of the following methods:

a.

Solid color insulation or solid color coating.

b.

Stripes, bands, or hash marks of color specified above.

c.

Color as specified using 0.75 in [19 mm] wide tape. Apply tape in half-overlapping turns for a minimum of 3 in [75 mm] for terminal points, and in junction boxes, pull-boxes, troughs, and manholes. Apply the last two laps of tape with no tension to prevent possible unwinding. Where cable markings are covered by tape, apply tags to cable, stating size and insulation type.

4.

For modifications and additions to existing wiring systems, color coding shall conform to the existing wiring system.

5.

Color code for isolated power system wiring shall be in accordance with the NEC.

2.2 SPLICES AND JOINTS

A.

In accordance with UL 486A, C, D, E, and NEC.

B.

Aboveground Circuits (No. 10 AWG and smaller):

1.

Connectors: Solderless, screw‑on, reusable pressure cable type, rated 600 V, 220˚ F [105˚ C], with integral insulation, approved for copper and aluminum conductors.

2.

The integral insulator shall have a skirt to completely cover the stripped wires.

3.

The number, size, and combination of conductors, as listed on the manufacturer's packaging, shall be strictly followed.

C.

Aboveground Circuits (No. 8 AWG and larger):

1.

Connectors shall be indent, hex screw, or bolt clamp‑type of high conductivity and corrosion‑resistant material, listed for use with copper and aluminum conductors.

2.

Field-installed compression connectors for cable sizes 250 kcmil and larger shall have not fewer than two clamping elements or compression indents per wire.

3.

Insulate splices and joints with materials approved for the particular use, location, voltage, and temperature. Splice and joint insulation level shall be not less than the insulation level of the conductors being joined.

4.

Plastic electrical insulating tape: Per ASTM D2304, flame-retardant, cold and weather resistant.

D.

Underground Branch Circuits and Feeders:

1.

Submersible connectors in accordance with UL 486D, rated 600 V, 190˚ F [90˚ C], with integral insulation.

2.3 CONTROL WIRING

A.

Unless otherwise specified elsewhere in these specifications, control wiring shall be as specified for power and lighting wiring, except that the minimum size shall be not less than No. 14 AWG.

B.

Control wiring shall be large enough such that the voltage drop under in-rush conditions does not adversely affect operation of the controls.

2.4 WIRE LUBRICATING COMPOUND

A.

Lubricating compound shall be suitable for the wire insulation and conduit, and shall not harden or become adhesive.

B.

Shall not be used on wire for isolated-type electrical power systems.

PART 3 ‑ EXECUTION

3.1 GENERAl

A.

Install in accordance with the NEC, and as specified.

B.

Install all wiring in raceway systems.

C.

Splice cables and wires only in outlet boxes, junction boxes, pull-boxes, manholes, or handholes.

D.

Wires of different systems (e.g., 120 V, 277 V) shall not be installed in the same conduit or junction box system.

E.

Install cable supports for all vertical feeders in accordance with the NEC. Provide split wedge type which firmly clamps each individual cable and tightens due to cable weight.

F.

For panel boards, cabinets, wireways, switches, and equipment assemblies, neatly form, train, and tie the cables in individual circuits.

G.

Seal cable and wire entering a building from underground between the wire and conduit where the cable exits the conduit, with a non-hardening approved compound.

H.

Wire Pulling:

1.

Provide installation equipment that will prevent the cutting or abrasion of insulation during pulling of cables. Use lubricants approved for the cable.

2.

Use nonmetallic ropes for pulling feeders.

3.

Attach pulling lines for feeders by means of either woven basket grips or pulling eyes attached directly to the conductors, as approved by the COR.

4.

All cables in a single conduit shall be pulled simultaneously.

5.

Do not exceed manufacturer’s recommended maximum pulling tensions and sidewall pressure values.

I.

No more than three single-phase branch circuits shall be installed in any one conduit.

3.2 INSTALLATION IN MANHOLES(N/A)

3.3 SPLICE INSTALLATION

A.

Splices are not permitted.

B.

Tighten electrical connectors and terminals according to manufacturer's published torque values.

3.4 FEEDER IDENTIFICATION

A.

In each interior pull-box and junction box, install metal tags on all circuit cables and wires to clearly designate their circuit identification and voltage. The tags shall be the embossed brass type, 1.5 in [40 mm] in diameter and 40 mils thick. Attach tags with plastic ties.

B.

In each manhole and handhole, provide tags of the embossed brass type, showing the circuit identification and voltage. The tags shall be the embossed brass type, 1.5 in [40 mm] in diameter and 40 mils thick. Attach tags with plastic ties.

3.5 existIng wiring

Unless specifically indicated on the plans, existing wiring shall not be reused for a new installation.

3.6 CONTROL AND SIGNAL WIRING INSTALLATION

A.

Unless otherwise specified in other sections, install wiring and connect to equipment/devices to perform the required functions as shown and specified.

B.

Except where otherwise required, install a separate power supply circuit for each system so that malfunctions in any system will not affect other systems.

C.

Where separate power supply circuits are not shown, connect the systems to the nearest panel boards of suitable voltages, which are intended to supply such systems and have suitable spare circuit breakers or space for installation.

3.7 CONTROL AND SIGNAL SYSTEM wiring IDENTIFICATION

A.

Install a permanent wire marker on each wire at each termination.

B.

Identifying numbers and letters on the wire markers shall correspond to those on the wiring diagrams used for installing the systems.

C.

Wire markers shall retain their markings after cleaning.

D.

In each manhole and handhole, install embossed brass tags to identify the system served and function.

3.8 Acceptance Checks and Tests

A.

Feeders and branch circuits shall have their insulation tested after installation and before connection to utilization devices, such as fixtures, motors, or appliances. Test each conductor with respect to adjacent conductors and to ground. Existing conductors to be reused shall also be tested.

B.

Applied voltage shall be 500VDC for 300-volt rated cable, and 1000VDC for 600-volt rated cable. Apply test for one minute or until reading is constant for 15 seconds, whichever is longer. Minimum insulation resistance values shall not be less than 25 megohms for 300-volt rated cable and 100 megohms for 600-volt rated cable.

C.

Perform phase rotation test on all three-phase circuits.

D.

The contractor shall furnish the instruments, materials, and labor for all tests.

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