247suitable materials compressed into resilient pads of uniform thickness. The number of plys shall be such as to produce the specified thickness after compression and vulcanizing. Finished pads shall withstand compression loads perpendicular to the plane of the laminations of at least 10,000 pounds per square inch without a detrimental reduction in thickness or extrusion. SECTION 238—ELECTRICAL AND SIGNAL COMPONENTS
238.01 Description
These specifications cover conduits, conductors, junction boxes, traffic signal components, and necessary fittings to complete a described electrical or traffic signal system.
238.02 Detail Requirements
a.Metal Conduit and Fittings: Conduit shall be galvanized and conform to of UL-6. Fittings for metal conduit shall be galvanized and conform to UL-514B. Conduit for use in underground installations, concrete encasements, or corrosive environments shall also be coated on the outside with an asphalt mastic conforming to AASHTO M243 or shall have a PVC coating of 40 mils or another Depart - ment approved coating.
b.PVC Conduit and Fittings: Conduit shall be heavy wall conduit conforming to UL-651. Fittings for PVC conduit shall conform to the requirements of UL-514B. Exposed PVC conduit shall be UL or ETL Testing Laboratories, Inc. listed for use in direct sunlight. Each section of conduit shall be marked with the letters UL or ETL. Solvent cement used for joining conduit or fittings shall conform to ASTM D2564. Protective shields shall be galvanized sheet steel of commercial quality with a coating designation conforming to ASTM A653, coating designation G115, and a thickness of 0.0625 inch. PVC used in a directional boring operation shall be Schedule 40 with integral male/female cou - plings, a gasket, locking rings, and grooves designed to secure the conduit sections for installation in the bored area. Joints shall have a pull rating of 7,000 pounds for 3-inch conduit, 8,700 pounds for 4-inch conduit, 11,300 pounds for 5-inch conduit, and 14,000 pounds for 6-inch conduit.
c.Fiberglass-reinforced Epoxy Resin Conduit and Fittings: Conduit shall conform to NEMA TC-14. Conduit used in exposed areas shall be heavy wall and sunlight resistant. Epoxy adhesive used for joining conduit shall conform to NEMA TC-14. Protective shields shall conform to the same requirements as those with PVC conduit.
d.PE Conduit: shall conform to NEMA TC-7 for high-density PE duct except that the wall thickness of conduit with a diameter of 1-1/4 inches and less shall conform to UL-651 for heavy-wall PVC conduit. Conduit shall have a carbon black loading of 2.5 ±0.5 percent by weight in accordance with ASTM D1603.
e.Splice Boxes or Pull Boxes (512 cubic inches or less): The Engineer will only allow boxes conforming to UL-514B in exposed areas. Boxes shall be compatible with the appropriate conduit.238.02 248(f) Electrical and Signal Junction Boxes: Boxes, frames, and covers shall be water resistant. Covers shall be secured with stainless steel bolts and fasteners. Covers shall be flush with surface of the junction box and not protrude above the top of the junction box flange. Junction box bolt attachment holes shall be drilled through to prevent debris from collecting in the threaded bolt holes. A Materials Division approved independent testing laboratory shall test and certify junction boxes as meeting the requirements herein prior to their use. The Contractor shall furnish the Engineer documentation of such test results. Testing reports shall provide complete test results for the type of design testing indicated for the respective type of junction box. Junction Boxes for deliberate traffic in the roadway applications: • Concrete shall conform to Section 217 and shall be designed to meet the provisions of AASHTO’ s Standard Specifications for Highway Bridges for HS20 loading. Concrete shall have a design minimum compressive strength of 4000 psi. • Gray Iron frame and covers shall conform to Section 224. Junction Boxes for off roadway applications: • Boxes shall conform to ANSI/SCTE 77 2007 and tier 15 loading. Boxes shall be open bottom. • Boxes shall be polymer concrete with straight sides or polymer concrete with flared or straight fiberglass sides. • The Engineer may approve other materials for the sidewalls provided they conform to the requirements of ANSI/SCTE 77 2007 and tier 15 loading. Junction Boxes frames and covers for bridge structures encasements shall be one of the follow- ing types:
1.Steel castings conforming to Section 224, galvanized inside and out.
2.Welded sheet steel having a thickness of at least 3/16 inch or 7 gage, galvanized inside and out.
3.Polymer concrete with fiberglass sides or all polymer concrete.
g.Conductor Cables:
1.Power conductor cables shall be copper conforming to ASTM B3 and B8. Conductor cable sizes shall be based on No. 8 AWG minimum. Conductor cables of No. 8 AWG and larger shall be stranded. Conductor insulation shall be UL listed for the use specified on the plans and rated for 600-volt operation.
a.Service entrance conductor cables shall be UL with Type SE insulation.238.02 249 b. Underground service entrance conductor cables shall be UL with Type USE insulation.
c.Direct burial conductor cables shall be UL with Type USE or UF insulation.
d.Conductor cables in conduit shall be UL with Type THWN insulation except as follows: When the conduit size specified on the plans is such that the allowable percentage of conduit fill in Table 1, Chapter 9, of NEC is not exceeded, then UL Type RHW , TW , THW , XHHW , or XLPE insulation may be used. Direct burial conductor cables may be spliced to THWN conductor cables only at accessible locations where direct burial conductor cables enter a conduit.
2.Communication and signal cables:
a.Signal cables from the controller cabinet to signal heads shall be minimum No. 14 AWG copper.
1.IMSA 19-1 or 20-1 cables shall be used for aerial and duct installations.
2.IMSA 19-5 or 20-5 cables shall be used for direct buried installations.
b.Interconnect cables between controllers shall be No. 14, 18, 19, or 22 AWG solid copper.
1.No. 14 AWG cables shall conform to IMSA 19-2 or 20-2 for aerial and duct installations; IMSA 19-4 or 20-4 for self-supporting aerial installations; or IMSA19- 6 or 20-6 for direct buried installations.
2.No. 18, 19, or 22 AWG cables shall be solid copper conforming to IMSA 39-2 or 40-2 for aerial and duct installations; IMSA 39-4 or 40-4 for self-supporting aerial installations; or IMSA 39-6 or 40-6 for direct buried installations.
c.Loop detector cables shall be No. 12 or 14 AWG stranded copper.
1.No. 12 AWG cables shall conform to IMSA 51-3 Type XHHW insulations.
2.No. 14 AWG cables shall conform to IMSA 51-5.
d.Loop and magnetic detector lead-in cables shall be stranded copper, twisted pair, No. 14 AWG conforming to IMSA 50-2.
e.Pedestrian detection cables shall be two conductor No. 14 AWG copper. IMSA 19-1 or 20-1 cables shall be used for aerial or duct installations. IMSA 19-5 or 20-5 cables shall be used for direct buried installations.
h.Electrical Components:
1.Safety switches shall be enclosed in a rain-tight metal box and cover conforming to NEMA 3R, with a lock-on/lock-off external switch handle. Safety switches shall be heavy duty, two- pole minimum with solid neutral and fused compatible with the equipment load. Safety switch - es shall be rated at 100 amp/240 volts for signal installations.238.02 250 2. Circuit breaker boxes used as a service disconnect for signal equipment shall be a rain-tight metal box and cover conforming to NEMA 3R. The circuit breaker box shall be rated at 100 amp/240 V AC with a solid neutral and shall contain two single-pole, 120- V AC breakers with an ampere rating compatible with the equipment load and shall have provisions for padlocking. The service load shall be wired to only one breaker.
3.Grounding electrodes (rods) shall be copper-clad rods conforming to UL-467. Grounding electrodes shall have a diameter of 3/4 inch and a length of 10 feet. Grounding electrodes couplers shall be UL approved and shall be bronze, stainless steel, or copper clad with a solid center providing 100 percent conductivity.
4.Grounding electrode conductors shall be no less than No. 6 AWG (bare solid wire) conforming to ASTM B2.
5.Ground clamps shall be heavy-duty bronze or brass or galvanized malleable iron conforming to ASTM A220, any grade.
6.Signal head sections:
a.V ehicle traffic signal head sections shall conform to the ITE Standard for Vehicle Traffic Control Signal Heads dated April 1985 without the optical unit. Vehicle traffic signal head section modules shall conform to:
1.ITE Vehicle Traffic Control Signal Heads-Light Emitting Diode Circular Signal Supplement dated June 27, 2005 for signal head sections containing circular signal indications; or
2.ITE Vehicle Traffic Control Signal Heads-Light Emitting Diode Vehicle Arrow Signal Supplement July 1, 2007 for signal head sections containing arrow signal indications The Light Emitting Diode (LED) signal module shall use the same mounting hardware used to secure an incandescent lens and gasket assembly and shall only require a screwdriver or standard installation tool to complete the mounting.
b.Pedestrian signal head sections shall consist of a housing (with visor and/or screen as specified in the Contract), a door, pedestrian traffic signal module, gaskets, and miscellaneous hardware. The housing, door, gaskets, and miscellaneous hardware shall conform to the following requirements of the ITE Standard for Vehicle Traffic Control Signal Heads dated April 1985:
1.The top and bottom opening and serration requirements in Section 3.01 – Physical and Mechanical Requirements: General
2.Section 3.02 – Physical and Mechanical Requirements: Strength Requirements
3.Section 4.01 – Housing, Door, and Visor: General
4.Section 4.04 – Housing, Door, and Visor: Materials and Fabrication, except the require- ments for lens openings, visor, and backplates.
5.Section 7.00 – Exterior Finish238.02 251 Pedestrian traffic signal modules shall conform to the ITE Specifications for Light Emitting Diode Pedestrian Traffic Signal Modules dated August 4, 2010. The displays shall include “Walking Person” and “Upraised Hand” symbol indications in a separate or overlay configuration, as specified in the Contract. Symbol indications shall be filled.
c.LED vehicle traffic control and pedestrian signal modules shall be tested in accordance with the applicable ITE Specifications. The Contractor shall provide the LED manufactur - er’ s certificate of ITE compliance for the applicable module(s) furnished and independent laboratory test reports. Independent laboratory tests shall include specific test and test results of each test as specified in the ITE Design Qualification Testing Sections of the ITE Standards for both vehicle control signal and pedestrian modules. Independent test reports shall be submitted at the same time as the catalog cut is submitted for the model and type of LED signal module furnished. The Independent laboratory used for LED testing shall be on OSHA’ s current list of Nationally Recognized Test Laboratories (NRTLs). The testing laboratory shall be located within the continental United States or Canada. LED traffic signal modules shall be warranted by the manufacturer for 5 years from the date of manufacture against manufacturing defects and workmanship. The Contractor shall be responsible for the replacement and installation costs if the module fails due to material and/or workmanship defects during this 5-year period.
7.Backplates for signal heads: may be either aluminum or aluminum composite, unless other- wise specified in the Plans. ABS plastic shall not be used. Aluminum shall be 0.06-0.08 inch thick, smooth, flat, and free of metal burrs and splinters. Aluminum alloy shall conform to Section 229. Aluminum Composite shall be a 0.07-0.09 inch thick aluminum plastic composite. The composite shall be manufactured by bonding two panels of aluminum to an extruded polyeth - ylene core using a thermoset adhesive under tension and pressure in a continuous process. The interior coating of the aluminum panels shall be coated with an epoxy chromate primer for added bonding strength with the polyethylene.
a.Black (non-reflective) Signal Backplates: Aluminum black signal backplates shall be entirely powder coated black in accordance with manufacturer’ s instructions. For aluminum Composite black backplates, both sides of the aluminum composite exteri - or shall be entirely coated with black fluoropolymer paint.
b.High-Visibility Signal Backplates (HVSBs) shall be preassembled by the manufacturer with a 3-inch retroreflective fluorescent yellow border on the outside of the front of the backplate. All retroreflective sheeting on the front surface of the backplate shall be ASTM D4956, Type XI fluorescent yellow from the Materials Division’ s Approved Products List 46, which shall be warrantied in accordance with Section 247.03. Retroreflective sheeting shall be applied to the backplate with a zero-degree orientation (downweb direction perpendicular to the road) and adhered to the backplate in accordance with the retroreflective sheeting manufacturer’ s instructions. Retroreflective sheeting shall 238.02 252238.02 be butt spliced when more than one piece of sheeting is adhered to the backplate. For each surface of the backplate, a maximum of five butt splices shall be used for three-sec - tion and four-section signal heads, and a maximum of nine butt splices shall be used for five-section signal heads. Aluminum HVSBs shall be manufactured by covering the entire front surface with the retroreflective sheeting specified above, then subsequently applying black color to the front surface, except for the outer 3 inches of the front of the backplate which shall remain fluorescent yellow. The black color on the front surface of the backplate shall be obtained by screen printing or applying acrylic film. Black color on the back surface of Aluminum HVSB backplates shall be obtained by applying acrylic film to the aluminum or by screen printing on sheeting applied to the aluminum. Aluminum preparation and application of sheeting and film shall be in accordance with the sheeting manufacturer’ s instructions. Aluminum Composite HVSBs surfaces shall be coated with black fluoropolymer paint suitable for proper retroreflective sheeting adhesion. Retroreflective sheeting shall be applied to the outer 3 inches of the front surface of the backplate as specified above.
8.Cable clamps shall conform to NEMA PH-23 except for dimension which shall be as required to accommodate cable as specified:
a.Two bolt clamps shall be 4 inches in length, made to accommodate 1/4 inch diameter tether wire.
b.Three bolt clamps shall be the heavy 6-inch length made to accommodate span wire ranging from 1/4 to 5/8 inch in diameter.
9.Cable rings and lashing wires shall be weather resistant and the industry standard.
10.Connectors and terminals shall conform to NEC 110. Breakaway connectors shall consist of line and load side sections designed to separate without breaking the conductor. Connectors shall be waterproof with an insulation rating of 600 volts. Current carrying components ex - posed when the connector is separated shall be in the load section of the connector. Connectors for the hot conductors shall be designed for 13/32 inch by 1 1/2 inch cartridge type fuses. A fuse of a suitable ampere rating (10 amps maximum) shall be provided for lighting fixture devices and conductors.
11.Angle thimbleyes shall be Rural Utilities Service (RUS) listed.
12.Span wire saddle clamps for span wire connection on a bridle span shall use U-bolts for securing the clamp to the span wire and shall be galvanized malleable iron with a tensile strength of at least 25,000 pounds.
13.Stainless steel straps shall be solid, 5/8 inch width minimum, with a tensile strength of at least 100,000 pounds per square inch.
14.Service entrance heads shall be galvanized malleable iron.
15.Tether wire shall conform to ASTM A475, Common Grade, Class A, seven strand, or Type I, General Purpose, Class I, 6 x 7, iron, galvanized, fiber core, conforming to FS RR-W- 00410C. The breaking strength of tether cable shall be not more than 3,000 pounds. 253238.02
16.Thimbleye bolts shall conform to ANSI C135.4 and the following:
a.The tensile strength shall be at least 18,350 pounds for 3/4-inch bolts.
b.Dimensions for 3/4-inch bolts shall comply with the following as related to Figures 1 and 2 in ANSI C135.4: Bolt Diameter A D E 3/4 in 13/16 in 9/32 in 11/32 in
17.Thimbleye nuts shall conform to ANSI C135.4.
18.Washers for use with thimbleye bolts shall conform to NEMA PH-10.
19.Electrical Tape:
a.Vinyl tape shall be for electrical use and shall conform to ASTM D2301, Type 1.
b.Rubber tape shall be for electrical use and shall conform to ASTM D4388.
20.Photoelectric controls shall be used at the electrical service control center for roadway lighting system or electrical service for overhead sign lighting structures to turn fixtures ON or OFF , typically in sync with dusk to dawn. Photoelectric controls shall conform to ANSI C136.10, and the following: • Locking-type/twist-lock photoelectric control with locking-type receptacles • Use a cadmium sulfide or filtered silicon type sensor • Fail-on type so that the lights stay ‘ON’ if the photoelectric control fails to operate • Factory preset and calibrated to turn on at 1.5 ± 0.5 footcandles (fc), not exceeding 3 fc • Ratio of the turn-off to turn-on light level shall not exceed 1.65:1 • Output control relay shall have a time delay of 2 to 15 seconds to prevent false turn-off due to headlights and other transient light source. • Normal operating voltage shall be in the range of 120V - 277V or 347V - 480V • Capable of controlling load of up to1000 Watts for tungsten and 1800 volt-amps for ballast • Have a built-in metal oxide varistor of minimum 160-Joules for surge/transient protection • Operating temperature shall be in the range of -40ºF to 158ºF (-40ºC to 70ºC) • Cover shall be an impact and ultraviolet-resistant material that complies with the flamma- bility and impact requirements of UL-773 • Warranted against defects in materials and manufacture for at least 4 years. All the receptacles at the electrical service control cabinets and LED fixtures (with the ex - ception of individual sign lighting fixtures), shall be prewired 7-pin twist lock ANSI C136.41 compliant and shall come with rain-tight shorting cap.
21.Miscellaneous signal line hardware and/or attachments shall be galvanized or stainless steel.
22.Span wires shall conform to ASTM A475, High-Strength Grade, Class A.
23.Splice kits shall be packaged containing materials from a single supplier and shall consist of a plastic molded body with a compound that provides a water-resistant seal and insulation for the conductor cables for at least 600 volts. 254238.02
24.Span wire clamps for signal head mounting shall use U-bolts for securing the clamp to the span wire and shall be galvanized malleable iron or aluminum with a tensile strength of 6,000 pounds.
25.Contactors shall be UL listed, open type. The contactor shall be rated to be compatible with the equipment load and type of load.
26.Dead-end strain vise clamps shall be designed for the size of the span wire or tether wire and their tensile strength shall be the same as or exceed the tensile strength of the cable. Clamps shall be fabricated from corrosion-resistant materials or shall be galvanized. Clamps shall have a release slot for holding the jaws back for retensioning and removal of the wire. Clamps shall be internally coated with inhibitor oils to prevent corrosion and to allow for the free movement of the jaws.
27.Heat-shrink tubing shall consist of an adhesive-lined, polyolefin flexible material conforming to the following requirements: —————————————————— Property Requirement —————————————————— Shrinkage ratio 2:1 Water absorption 0.3% max. Electrical rating ≥600 volts ——————————————————
28.Guy markers shall be white, unless otherwise specified, and shall be PVC or polyolefin ma- terial complete with all necessary manufacturer-approved installation/mounting hardware and shall conform to the following minimum requirements: Materials Property Test Method Unit PVC Polyolefin Mechanical Tensile strength ASTM D638 psi 6,500 4,500 (MPa) (45) (31) Tensile modulus ASTM D638 psi 380,000 141,000 (MPa) (2617) (971) Hardness, Shore D ASTM D2240/D2583 N/A 78 68 Notched impact ASTM D256 ft-lb/in 11.0 5.0 (J/m) (587) (267) Thermal Heat distortion temperature ASTM D648 degrees F 162 N/A at 264 psi (1.8 MPa) degrees C 72 N/A Flammability UL-94 V -O N/A Electrical Dielectric constant ASTM D150 V olts per mil 3.5 2.3 of thickness Dielectric strength ASTM D149 V olts per mil 480 500 of thickness
29.Stainless steel cables for traffic signal hanger assemblies and traffic sign hanger assemblies to be installed on mast arms shall be stainless steel, 7x19, Type 304 in accordance with Federal Specification RR-W-410E with a breaking load of 3700 pounds. Ends shall be swaged to with - stand a 4200 pounds pull. 255240.02 SECTION 239—SODIUM CHLORIDE AND CALCIUM CHLORIDE
239.01 Description
These specifications cover chloride used as a stabilizer or to control snow and ice.
239.02 Detail Requirements
a.Sodium chloride shall conform to AASHTO M143, Type I, with the following exceptions:
1.The sodium chloride content shall be at least 97 percent of the dry weight.
2.The moisture content shall be not more than 5 percent.
3.When shipped in bulk, sodium chloride shall contain an anticaking additive.
4.Sodium chloride will be tested in accordance with VTM-28. When practicable, the Engineer will take samples at the source from indoor storage or from adequately protected outdoor storage at the rate of approximately one sample per 4,000 tons. Samples will not be taken from uncovered storage. The Engineer will take samples at the destination at the time of delivery when inspection at the source is not practicable, or when material is shipped directly from uncovered storage. Inspection service will be provided when the frequency of shipments from approved stock at the source, makes it economically justified. The Inspector’ s stamp on the shipping or delivery report will indicate inspection of the shipments. When inspection service is not provided, the supplier may ship material but shall certify that the sodium chloride came from an approved source. An authorized representative of the supplier shall sign the certification if it is stamped on the shipping or delivery report.
b.Calcium chloride shall conform to AASHTO M144. SECTION 240—LIME
240.01 Description
These specifications cover lime to be used as a stabilizer or soil conditioner.
240.02 Detail Requirements
a.Hydrated lime shall conform to ASTM C207, Type N, except that the average percentage of calcium oxide shall be at least 93. Single test results shall not be below 90 percent.
b.Hydraulic lime shall conform to ASTM C141.
Source: Virginia Road and Bridge Specifications, 2020 Edition. Pages 275–282 of 1,065.