479 SECTION 895
895.01 Description
Furnish material that meets the requirements of the Institute of Electrical and Electronics Engineers, Underwriters Laboratories, and the Institute of Transportation Engineers.
895.02 Conduit
Submit a certificate of compliance for conduit.
A.Steel Conduit. Provide corrosive-resistant steel conduit meeting UL 6.
B.Nonmetallic Conduit.
1.PVC. Provide PVC conduit that meets the requirements of UL 651 suitable for direct burial applications and has a minimum wall thickness equivalent to Schedule 40 as defined by ASTM D 1785.
2.HDPE. Provide HDPE conduit that meets the requirements of UL 651 and ASTM D 3035 that is suitable for direct burial applications. Use HDPE conduit that has a minimum wall thickness equivalent to DR 15.5 as defined by ASTM D 3035.
895.03 Conductors
A.Feeders. If using conductors as feeders provide either a single conductor or multiple stranded conductors formed into a cable. Provide underground phase and neutral conductors that are insulated to meet the requirements for direct burial cable, rated at 600 volts, and that meet ASTM B 3 and B 8.
1.Single Conductor. Use single conductor marked with Style “RHW-USE” and the required AWG size on the sheath. Use stranded No. 6-AWG -Type THW or THHN/THWN for grounding conductor. Rubber insulation specifically listed for that purpose by UL does not require an outer cover.
2.Multiple Conductor. Provide Style USE for multiple conductor that meets NEMA Standards WC -70, rated at 0 through 600 volts, modified as follows:
a.Provide multiple conductors insulated with either cross -linked thermosetting polyethylene (XLP), or butyl.
b.Use multiple conductors that have circuit identification. Assemble conductors into a cable of circular cross section with filler, binder, armor, and an overall outer cover.
c.Use armor that is a bronze tape meeting ASTM B 130 with a minimum thickness of 10 mils and a spiral overlap of not less than 1/4 inch. Use an outer cover on the 480 polyethylene insulated type that is a polyvinyl chloride material, and an outer cover on the butyl insulated type that is a neoprene rubber material.
d.Provide circuit identification, conductors, cables, fillers, and binders that meet Part 5 of NEMA WC -70 except only obtain identification by colored tapes, colored compounds, or colored coatings, and use rubber or rubber -like material fillers.
B.Internal Conductor.
1.Light Standard and Sign Lighting. Provide copper No. 12 AWG, stranded, Type THWN/THHN that meets ASTM B 3 and B 8 for the conductor connecting: - The fuse kit in the base of the light standard to the luminaire ballast; - The sign lighting load center to the sign lighting ballast; and - Fuse kit in the pull boxes to lighting luminaire ballast. The Engineer will not require an outer covering on rubber insulation if UL has specifically listed the rubber for the purpose of insulating.
2.High Mast Lighting Assembly.
a.Luminaire Wiring. Provide an individual luminaire wiring conductor that is No. 14 AWG stranded, Style THW or RHW -USE, rated at 600 volts.
b.Power Cables. Provide a power cable that is a four -conductor No. 8 flexible power cord that provides a 240/480 volt service. Use the fourth conductor as an equipment ground.
c.Power Cable Protection. The free hanging static conditions of the cable shall not affect its satisfactory performance and flexibility for a temperature range of minus 40°F to 120°F. Use a bushing to protect the cable from abrasion where cable passes through any metal device.
895.04 Feed Point
Provide a cabinet that has a NEMA 3R rating and is pad or pole mounted. Install photoelectric cell near the top of the cabinet that controls the “on/off” switching of the light circuits. Place a 3 to 5 minute delay switch in the light circuits. Install a pilot relay between the photoelectric cell and the lighting circuit relays. Enclose the relays and ensure they are normally in the “open” position. Install circuit breakers in the cabinet in a load center type panel board. The panel board shall be a type that is approved for s ervice equipment. Install a test switch that bypasses the photoelectric cell. 481 895.05 LIGHTING STANDARDS
A.General. Design lighting poles to meet the requirements of AASHTO publication, Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals . When a breakaway base is required, provide a manufacturer certification that the light standard base meets the AASHTO requirements for both breakaway and structural adequacy. Use a wind velocity of 90 mph with the following height and exposure correction factor: − If the traffic signal is less than 33 feet use a K za of 1.00; or − If the traffic signal is greater than 33 feet use the K za found in Table 3.8.4-1 “Height and Exposure Factors, K za”. Apply different wind pressures to the structure at different heights rather than using an average wind pressure for the entire height of the structure. Design each structural component on light standards 55 ft or greater for fatigue using the requirements of Table 11.6-2, “Fatigue Importance Categories for HMLT’s”. Furnish all the necessary calculations and drawings used in the design of poles with the shop drawing submittal. A Professional Engineer duly registered in the State of North Dakota must sign, seal, and date the calculations and work drawings used in the design of lighting standards.
B.Material. Fabricate the light standard from steel of one or two piece construction. Provide welds that develop the full strength of the adjacent shaft section. Provide either galvanized or stainless steel light standards. Provide a shaft that has no more than one longitudinal weld.
1.Galvanized Material. Provide galvanized standards, including the mast arm, shaft, and base that are galvanized as sp ecified Section 854, “Galvanizing” . Fabricate round or multi -sided shafts for galvanized steel poles that to have minimum yield strength of 48,000 psi.
2.Stainless Steel Material. Provide a multi -sided shaft for stainless steel poles that has a minimum yield strength of 60,000 psi. Use stainless steel that meets the requirements of ASTM A 666, Type 201 for mast arm, shaft, and base.
C.Mast Arm. Provide either a davit-type or trus s design mast arm.
1.Davit -Type. Provide a davit-type mast arm that is made of the same material as the shaft and has a tenon adapter for receiving the luminaire. 482 2. Truss. Provide a truss mast arm assembly that consists of upper and lower members securely joined using one or more vertical struts. Use upper and lower members that are steel pipe with a minimum diameter of 2 inches. On the pole end of the upper and lower members, provide a welded steel fitting suitable for attachment to the pole using cap screws. Install an opening near the top of the shaft to provide a cable entrance from the shaft into the mast arm. Weld a steel adapter into this opening that will act as a smooth cable guide for wiring and as a support for the attachment plate that is welded to the mast arm.
D.Base.
1.General. Install either an anchor base or a transformer base. Install a grounding lug inside the base.
2.Anchor Base.
a.General. Provide an anchor base that is a one-piece steel casting or hot-rolled carbon steel plate. Use a steel casting that meets ASTM A 27, Grade 65-35 using hot-rolled carbon steel that meets AASHTO M 270, Grade 36. Secure the anchor base to the lower end of the shaft by two continuous welds. Place the welds inside the base at the bottom of the shaft and at the top of the anchor base. Provide welded connections that develop the full strength of the adjacent shaft section. Provide four bolt covers and cap screws for securing the covers to the base with the anchor base. Locate a minimum 4 × 6 inch hand hole opposite the road side of the pole on each shaft. If the shaft is in a median, locate a minimum 4 × 6 inch hand hole parallel to the roadway. Install reinforcing frames inside the hole and secure the hole with a removable cover. If breakaway base is required, install a slip base with the anchor base.
b.Slip Base. Provide plates constructed of steel that meets the requirements of AASH TO M 270 Grade 36, bolts that meet the requirements of ASTM F 3125 Grade A 325, and a keeper plate that meets the requirements of ASTM A 653, Grade 33. Galvanize all materials as specified in Section 854, “Galvanizing” .
3.Transformer Base. Provide a steel or aluminum transformer base. Install a grounding lug inside the base. 483 Install a door in the base that has a tamperproof lock. Construct the base so that leveling nuts and hold down nuts placed on the anchor bolts secure the transformer base to the foundation; or provide four loose steel plate anchor clips to fasten the base to the anchor bolts. Fasten the transformer base to the shaft anchor base using four galvanized hex head steel machine bolts and nuts that meet the requirements of ASTM F 3125 Grade A 325 and that are galvanized as specified in Section 854, “Galvanizing”.
a.Steel Transformer Base. Fabricate the steel transformer base from steel that is a minimum thickness of 7 gauge, with the top and bottom plate made of not less than 3/4-inch steel plate. Galvanize the assembled base as specified in Section 854, “Galvanizing” .
b.Aluminum Transformer Base. Provide a casting that meets ASTM B 26 or B 108, Alloy 356 T6 and is smooth with all details well defined and true to pattern.
E.Festoon Circuits. When a festoon circuit is specified, provide an electrical outlet 15 to 20 feet above gr ound level. Provide all the material and wiring required for these convenience circuit outlets. Wire the outlets for 120 volts, 60 Hz, A.C. Provide the festoon receptacle with a single gang while-in - use cover. Provide body and plates made of gray colored polycarbonate, with a gasket made of closed cell foam, neoprene blend regular density, UL rated HBF. Mount covers vertically using stainless steel screws. Provide a cover that complies with NEC requirements for installation in wet locations.
895.06 Street Light Luminaire
A.General. Provide a luminaire that consists of a die-cast aluminum housing, optical system door, and a door-mounted ballast. Finish the luminaire using baked-on gray enamel.
B.Slip Fitter. Provide a luminaire with an adjustable slip fitter containing two or four bolts, suitable for tightening both internally and externally. Use a slip fitter that is capable of adapting to 1-1/4 inch through 2 inch pipe and that is adjustable to within 5 degrees from horizontal.
C.Optical Assembly. Provide an optical assembly that consists of: - An anodized aluminum reflector; - An adjustable socket assembly; - Filtered optical system of polyester fiber; - A gasket for sealing between the reflector and refractor; and - A borosilicate or acrylic polycarbonate prismatic refractor.
D.Ballast. Provide ballast that operates one lamp at the specified voltage using a 60 hertz power source and that is capable of starting and operating the specified lamp. Provide either a door mounted or removable power pad ballast.
1.Door Mounted. Provide a door mounted integral ballast that is removable and replaceable through the use of quick disconnect plugs. Use a ballast that is prewired to the lamp socket and terminal board, requiring only connection of the power supply leads to the terminal board.
2.Removable Power Pad. Provide an easily removable power pad allowing complete ballast assembly replacement using a simple quick -disconnect.
895.07 Fusing
Fuse each light ballast in the base of each light standard. Make connections to power distribution circuits using field-applied waterproof kits. Use a fused connector kit that contains a pair of spring-loaded, 90 percent maximum conductivity contacts suitable for gripping a 15 ampere cartridge fuse. Provide fully annealed contacts constructed to be crimped to the cable and are retained securely in the proper position within the rubber or molded plastic housing. Size each fuse kit to protect the ballast. Provide fused connector kits that: − Are suitable for burial in the ground or installation in the sunlight; and − Contain both line side and load side housings. Provide housings that: − Are made of water resistant synthetic rubber or molded plastic; - Have a section to form a water seal around the cable; - Have an interior arrangement to suitably and complementarily receive and retain the copper fuse contacts; and - Have a section to provide a water seal between the two housings at the point of disconnecti on. Provide a load side housing that is constructed to retain the fuse when disconnected. Permanently mark each housing “load side” and “line side.” Supply each kit with sufficient silicone compound to lubricate the metal parts and the rubber or molded plastic housing for easy assembly.
895.08 Sign Lighting Load Center
Provide a load center cabinet that is weather -proof and constructed to receive a padlock. Provide a grounding lug inside the cabinet. 485 895.09 SIGN LIGHTING LUMINAIRES
A.General. Provide a sign lighting luminaire that consists of: - An aluminum main casting containing a clamp mechanism; - A terminal block; - A socket assembly; - A reflector; and - A refractor door assembly. Shield the luminaire to oncoming traffic so motorists see no direct light.
B.Clamping Mechanism. Design the clamping mechanism for a 1-1/4 inch nominal pipe bracket using two 3/8-16 hex - head bolts and serrated, positive gripping, cast aluminum clamps. Design the clamping devise with a vertical adjustment range of 5 degrees up and 5 degrees down. Provide leveling pads on the bottom and inside of the luminaire casting.
C.Lighting Lamps. In addition to the requirements of Section 106.01 C, “Certificate of Compliance” , provide verification through photometric data that the specified uniformity ratio will be obtained.
D.Terminal Block. Provide a terminal block under the reflector at the wire entry location. Use terminal screws that are captive to the terminal block. Ins tall terminal plates that provide a positive hold action.
E.Reflector. Hold the reflector in place using four screws. Provide keyhole slots in the reflector to permit removal without removing the mounting screws.
F.Refractor Door. Attach the refractor door assembly to the main casting using two hinges at the front of the luminaire and two stainless steel, spring-tempered tension latches at the rear. Use spring latches that provide sealing pressure for the gasketed assembly. Provide an assembly that cons ists of an anodized extruded aluminum channel form fitted to the prismatic refractor using a captive gasket. Use a single piece gasket of high thermal -resistant material, incorporating a sealing pad. Provide a refractor assembly that is readily removable and capable of being completely immersed for cleaning. Protect the glass refractor using a rubber bumper mounted on the pipe bracket.
G.Ballast. Enclose the ballast in a weather -proof enclosure constructed of cast aluminum. Mount the ballast enclosure dir ectly to the ballast support with four 3/8 inch bolts. Locate 3/4 inch conduit openings on each side of the ballast enclosure for the electrical conductor to enter the ballast. Attach the gasketed cover plate to the bottom casting with four hex head bolts. Provide a 1- 1/4 inch threaded pipe at the end of the ballast enclosure to support the luminaire. 486 895.10 HIGH -MAST SODIUM VAPOR LUMINAIRES
A.Ballast. Use an auto-regulator ballast with a 1,000 watt sodium vapor lamp. Provide a ballast that operates at 240 volts. Enclose the ballast in a weather -proof cast aluminum housing that is fully serviceable without removing the luminaire from its bracket.
B.Slip Fitter. Provide a cast aluminum slip fitter housing that accommodates a 2 inch horizontal pipe bracket and that is adjustable 3 degrees above and below the bracket axis for leveling. Provide means to prevent the twisting of the luminaire about the bracket. Include terminal boards in the housing.
C.Lamp Socket. Provide a lamp socket that is a heavy -duty, mogul multiple type, porcelain-enclosed, with an integral lamp grip to ensure electrical contact under conditions of normal vibration. Provide additional lamp clamps to help prevent vibrational damage to the lamp and socket. Use a lamp socket that is adjustable to provide for different light distributions and maximum candlepower angles.
D.Optical Assembly. Use an optical assembly that is either an open ventilated unit or an enclosed globe unit. Provide a symmetrical luminaire that has a maximum beam angle of between 55 degrees and 60 degrees. Provide asymmetrical luminaires that have an IES short, semi -cutoff, Type III distribution.
1.Open Ventilated Unit. Provide an open ventilated unit that permits the free flow of air upward by chimney action. Provide an open ventilated unit that is a fully -detachable optical assembly consisting of an annealed borosilicate glass reflector with a sealed metal cover and an open borosilicate glass refractor. Use lamps that have a light center of 8-3/4 inches below the top of the reflector. Provide an effective projected area of a ballasted luminaire that is approximately 2.7 square feet. Provide a ballast and luminaire with a combined maximum weight of 62 pounds.
2.Enclosed Globe Unit. Provide an enclosed globe unit reflector assembly that is spun aluminum finished with the anodize process. Provide an upper portion that redirects the reflected light away from the arc tube of the lamp. Enclose and gasket the assembly. Provide an assembly with an activated charcoal filter that allows “breathing.” Use a globe that is made of heat and shock -resistant tempered borosilicate glass. Attach the globe to the reflector housing using a hinged, gasketed door with stainless steel latches. Construct the unit to allow the attachment of external shields. For ballasted symmetrical luminaires, provide an effective projected area of approximately 3.2 square feet. Use a ballasted symmetrical luminaire that has a maximum weight of 65 pounds. 487 For ballasted asymmetrical luminaires, provide an effective projected area of approximately 3.4 square feet. Provide a ballasted asymmetrical luminaire that has a maximum weight of 80 pounds.
E.Symmetrical Luminaires. Provide symmetrical luminaires from the following list or an equivalent: − Holophane Symmetrical Luminaire, Catalog No. HMAO C10HP 24R9; − General Electric Symmetrical Luminaire HMAA -01-S-3 -A-1-C-SC5; or − Quality Symmetrical Luminaire, Catalog No. VA25V -1H.
F.Asymmetrical Luminaire. Provide asymmetrical luminaires from the following list or an equivalent: − Holophane Asymmetrical Luminaire, Catalog No. HMST C10HP 24 A1; or − General Electric Asymmetrical Luminaire HMAA -01-S-3 -A-1-C-MC3 .
895.11 Sodium Vapor Wall -Mounted Luminaire
A.General. Provide a luminaire that consists of a cast aluminum housing containing the ballast, terminal board, and anodized aluminum reflector and a cast aluminum door with a heat and impact resistant prismatic refractor sealed to it. Use a reflector that has anodized aluminum finish. Use a refractor that is a prismatic type constructed of thermal and shock -resistant material. Provide a ballast that is an integral part of the housing and completely prewired. Provide a socket that is a mogul base porcelain-grip type with two positions for beam control.
B.Housing. Provide a luminaire housing that is die-cast corrosion -resistant aluminum, completely gasketed to keep out dust, insects, and other contaminants. Provide a ballast area that has a neoprene gasket and a polyester fiber gasket in the optical assembly for maximum weather - resistant protection. Use a door assembly that is hinged to the housing at the bottom, protected by a safety chain, and secured by stainless steel latches. Construct the housing to allow installation on any flat surface and provide wiring holes including a threaded 3/4 inch side entry for exposed conduit.
895.12 Sodium Vapor Underpass Ceiling- Mounted Luminaire
Provide a mounting system that protects the enclosed lamp from shock or breakage. Provide a fixture that is indestructible and guaranteed to withstand vandalism. Provide a fixture that is for ceiling mounting complete with 100-watt high-pressure sodium lamp, 240 volt high power factor ballast, and neoprene gaskets for outdoor use. Provide an unbreakable opalescent lens diffuser, ultraviolet stabilized for outdoor application, and 14 gauge steel backplates, of baked enamel finish, with stainless steel tamperproof screws.
895.13 High -Mast Lighting Assembly
A.Design. Design high -mast lighting poles to meet Section 895.05 A, “General” .
B.Shaft. Provide a shaft that is circular or multi -sided and constructed of steel meeting either AASHTO M 270, Grade 50 or Grade 50W. Provide a shaft that has a minimum yield strength of 50,000 488 psi and a minimum thickness of 3/8 inch. Use reinforcing material, backup bars (if required) etc., that meets the same AASHTO steel requirements as the steel in the shaft. If using Grade 50 steel, galvanize the s haft as specified in Section 854, “Galvanizing” . If using Grade 50W steel, shot blast the shaft to obtain a uniform finish and to allow fast, even oxidation. Clean all exposed surfaces to remove welding slag, loose scale, paint, and grease. Furnish the shaft in a single unit or in telescoping sections. If furnishing a sectional shaft, do not exceed five sections. Fabricate each section so that each section is able to telescope over the next section without the use of welds. Provide sections that lap a minimum of 1- 1/2 times the outside diameter of the bottom shaft at the location of the lap joint. Mark the telescoping points and match mark the sections. If using Grade 50W steel provide telescoping sections of the shaft that are metallized in the overlap areas on both inner and outer tubes. Provide metallizing that meets Section 894.05 A.1.c, “Metallizing Process ” or Section 854, “Galvanizing” . Seal the outer joint with a sealant that prevents the intrusion of moisture. Use a sealant that is recommended by the pole manufacturer. Provide a shaft that is uniformly tapered from top to bottom. Ground each shaft. Locate a grounding nut within the base. Construct the internal portion of the shaft to accommodate the necessary lowering device equipment and that it is free of any obstructions, sharp projections, or protrusions that would interfere with or damage any part of the lowering device.
C.Base Plate. Provide base plate material that meets AASHTO M 270, Grade 50 or Grade 50W. Design the base plate to withstand the full bending moment of the shaft. Provide a minimum plate thickness of 3 inches. If using Grade 50 steel, galvanize the base plate as specified in Section 854, “Galvanizing” . If using Grade 50W steel, shot blast the base plate to obtain a uniform finish and to allow fast, even oxidation. Clean all exposed surfaces to remove welding slag, loose scale, paint, and grease. Do not enlarge anchor bolt holes to provide for the possible shifting of the anchor bolts.
D.Anchor Bolts. Use anchor bolts that meet the mechanical requirements of AASHTO M 31, Grade 75 or ASTM F 1554 Grade 105 or equal. Galvanize the exposed portion of the bolt above the foundation according to Section 854, “Galvanizing” . Take precaution against embrittlement, warpage, and distortion according to ASTM A 143. Provide each anchor bolt with two extra-heavy, high-strength hex nuts, one for leveling and one for hold down. Galvanize the hex nuts according to Section 854, “Galvanizing” . Use hex nuts that meet ASTM A 143 for prevention of embrittlement. Ensure the nuts make full contact with the base plate. Ship the anchor bolts before the rest of the equipment. Precluster the anchor bolts, or cluster using mechanical rings that can be field-assembled. Supply a removable template to ensure proper fit of the pole base on the anchor bolts. Provide a certificate of compliance stating that the anchor bolts are of adequate strength to resist the required loading. Provide anchor bolts that are of sufficient length to develop the required loading of the bolt. Do not weld anchor bolts to meet the required lengths.
E.Access Opening. Provide an access opening of a size that allows for service and maintenance of internal apparatus near the base of the shaft. Provide openings that do not interfere with the operation of the lowering device. Provide an opening that is: − Internally reinforced to return the shaft to its full strength; or − Externally reinforced to provi de 150 percent of the unaltered shaft section modulus beginning and ending at a distance of 1/4 shaft diameter above the top and 1/4 shaft diameter minimum below the bottom of the access openings. Furnish a cover with stainless steel cap screws and a hand grip to secure the opening. Furnish the cover with gaskets that will seal out dust, rain, and snow.
F.Welding. Provide welding that meets AASHTO, Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffic Signals and Section 616.04 D, “Shop Welding ” . Provide a bottom shaft section with a maximum of 3 longitudinal seams welds. Provide all other shaft sections with a maximum of 2 longitudinal seam welds. For sections with a single longitudinal seam weld, produce a weld with a minimum of 60 percent penetration. For sections with multiple longitudinal seam welds, produce welds with a minimum of 80 percent penetration. Weld longitudinal slip joints with 100 percent penetration. Do not provide circumferential welds. Make full penetration-type welds for the shaft to base plate welds. If backup bars are used, use bars that are continuous and fabricated of the same material as the shaft. Contour the backup bars for full contact with the shaft. Do not tack backup bars to the shaft. Fill all spaces between the backup bars and the shaft with molten lead. Perform attachment welds using full penetration fillet welds. Do not perform field welds. Visually inspect all welds to check that there are no cracks, undercutting, or surface blow holes. Ultrasonically or magnetic particle test all welds. Submit records of welding procedure and all test results. Make full penetration- type welds in the overlap area. Radiographically examine the penetration- type welds in an area consisting of the overlap plus an additional 6 inches of tube length. Repair and retest any deficient welds after making repairs. 490 G. Certification. Submit a manufacturer certification that all joints and welds of the assembled structure, when loaded, will develop the full strength of the shaft and that deviation of the shaft alignment or “canting” will not occur at any of the joints when erected.
H.Lowering Device.
1.General. Provide a lowering device that lowers the luminaire ring to within 4 feet of the base plate. Provide a luminaire ring assembly that is capable of being raised or lowered at a minimum rate of 10 feet per minute. Provide electrical and hoisting cables that can be inspected from ground level. Provide a complete lowering system that consists of a head frame assembly rigidly attached to the top of the pole shaft, a luminaire ring assembly on which the luminaires are mounted, and a winch and hoisting assembly that is located in the base of the pole shaft.
2.Head Frame Assembly. Provide a head frame assembly that includes a minimum of 4 hoist cable sheaves grooved to exact cable diameter for 180 degree cable bearing surface and one or two grooved power cable sheaves. Use sheaves that have oil impregnated, sintered bronze bushings over the stainless steel shaft. Ensure the sheave s are the only moving components of the assembly. Do not weld sheave pins. Use washers and cotter keys or pins to secure the sheave pins. Use sheaves that have a minimum diameter of 25 wire rope diameters for the positive locking load cable system. If two-point suspension and two winches are used, use sheaves that have minimum diameter of 24 wire rope diameters. For nylon-jacketed wire rope, use the wire rope diameter of the unjacketed wire rope diameter. Arrange the electrical and support cables and sheav es to minimize their exposure. Minimize the openings into the shaft by a cover plate or other suitable means that reduces water intake, and permits adequate shaft ventilation. Use an assembly that provides for a two or three point suspension of the luminaire ring. Use structural members that are stainless steel or that are galvanized steel according to Section 854, “Galvanizing” . Where the structural members have been welded together to form a weather -tight head frame assembly, only provide openings that are the holes through which the hoisting cables and the power cables pass. Securely fasten the head frame to the shaft. If the luminaire ring is to be held in place by latching devices, include two or three latching devices to support the raised luminaire ring in the head frame assembly. Attach all moving parts of the latch mechanism to the luminaire ring assembly so that they are serviceable from the ground. Provide a latching mechanism that will not be impaired by the formation of ice. Provide a head frame assembly designed to remove all tension from the hoisting cables when the luminaire ring is latched to the assembly. Provide means to indicate the luminaire ring is latched to the head frame. 491 3. Luminaire Ring Assembly.
a.Slip Fitters. Provide slip fitters for the mounting of the luminaires that are 2 inch steel pipe. Attach the slip fitters to the luminaire ring using threaded welded hubs or bolts. If using U - bolts to attach slip fitters, provide a smooth wire entrance into each slip fitter.
b.Ring. Provide a ring that serves as a fully -enclosed wire raceway for all electrical connections to the luminaires. Provide either a factory prewired or field wired ring.
c.Assembly. Galvanize the assembly according to Section 854, “Galvanizing” .
d.Power Receptacle. Provide a weather -tight, twist-type lock, power receptacle on the ring to allow for the testing of lamps and ballasts while the ring is in a lowered position. Provide two 10 foot sections of pole power cable for the testing. Provide each section with electrical connections to connect the power source to the ring.
e.Roller Arms. Provide a minimum of three steel spring-loaded centering roller arms that guide the luminaire ring when it is raised or lowered. Use arms that are stainless steel or aluminum. Use springs that are stainless steel. Use rollers that are made of a water - resistant non-marking material. The Engineer will allow the use of a PVC bumper ring instead of roller arms.
f.Luminaire Ring. Provide a luminaire ring that is of adequate size, strength, and shape to accommodate the number of luminaires required per pole. Design the luminaire ring so that it has no free movement when in the raised position. Design the luminaire ring to be held in place using a constant load cable system or a positive latching device that will not be impaired by accumulation of snow or ice. If using a constant loading cable system, provide a backup cable and grip system to prevent free fall of the luminaire ring if a winch cable failure occurs. Provide a minimum 1/4 inch diameter stainless steel aircraft cable. Equip the luminaire ring assembly with an approved lightning arrester. Install the luminaire ring assembly. Splice the line leads of the arrester to the hot power cable conductors within a junction box. Connect the ground lead of the arrester to the ground conductor of the power cable and make a positive ground connection to the luminaire ring. Construc t the positive ground using a grounding lug attached to the luminaire ring but not to the junction box. Ensure all splices and connections are internal to the system and not exposed to the elements. Securely attach the furnished arrester to the junction bo x or the ring. Provide facilities to energize the luminaires and ballasts while the luminaire ring is in a lowered position. 492 Provide a junction box that contains all splices required for connecting the power cable to the individual luminaire wiring.
4.Winch and Hoisting Assembly.
a.Lowering Device. Provide either a two-cable or three-cable lowering device. If using a three-cable lowering device, provide a device that is self-locking, worm -gear type, with a permanently lubricated gear box. If using a two-cable lowering device, provide a winch assembly that consists of a worm -gear speed reducer with a double output shaft and with stainless steel drums with calibrated spring-loaded clutches that compensate for possible hoist cable overrun. Provi de a winch with a minimum drum diameter equal to 16 times the wire rope diameter for the positive locking system and 20 times the wire rope diameter for the cable system. If using two winches, provide a minimum drum diameter of 14 times the wire rope diameter. When designing the lowering device, use a maximum allowable yield stress for the sheaves, pins, drums, brackets, and other structural members equal to half of the nominal yield stress of the material. Provide at least three full wraps of wire rope on the winch drum when the luminaire assembly is in the fully -lowered position. Securely attach the starting end of the wire rope to the wind drum through use of either a clamp or a “keyhole and stop” arrangement. Provide a drum with flanges designed so the winch cable does not build up on the end of the drum and run off. When using a “positive locking system”, provide a system that prevents the winch cable from loosening on the drum and causing the cables to cross each other when the load is removed from the cable after the luminaire is locked in place. Secure fasteners so that they cannot be loosed by vibration. The Engineer will allow the use of star washers, jam nuts, self-locking nuts, or locking compound to secure nuts and machine screws.
b.Winch. Internally mount the permanent winch assembly in the pole base. Provide a winch that is operated by an electric drill and adaptable to manual operation. Provide a winch that is removable from the pole without having to make electrical disconnects or mechanical manipulations.
c.Circuit Breaker. Install a circuit breaking switch and a twistlock disconnect in the pole base. Provide a switch that is capable of switching the power on and off to the main power cable for the lowering device and the portable power cable. Provide single throw 30 amp circuit breakers that are double pole mounted in a 100 amp frame.
d.Torque Limiter. Provide a current or torque limiter that shuts down the drill when the luminaire ring becomes seated in the head frame assembly.
5.Cable.
a.General. Equally spread the two or three cables attached to the luminaire ring. When using a positive locking system, use nylon jacketed hoisting cables.
1.Three Cable System. When using a three cable system, provide hoisting cables that are a minimum 3/16 inch diameter, 7 × 19 stainless steel cable. Provide a winch cable that is a minimum 1/4 inch diameter, 7 × 19 stainless steel cable. Wind the winch cable on the winch drum when the luminaire ring is in a raised position.
2.Two Cable System. When using a two cable system, provide hoisting cables that are 1/4 inch diameter 7 × 19 stainless steel cable.
b.Materials.
1.Stainless Steel. Use material for stainless steel cables that meets the following composition: Carbon 0.15% maximum Sulfur 0.030% maximum Manganese 2.00% maximum Chromium 17.0% - 20.0% Silicon 1.00% maximum Nickel 8.0% - 12.0% Phosphorous 0.045% maximum
2.Nylon-Jacketed Cables. Extrude nylon jacketing material over the rope. Use only virgin nylon material to coat wire ropes. Provide nylon for wire rope that meets the following requirements of Federal Specification MIL-2 -83420: Property Test Value Ultimate Tensile Strength 5000 psi minimum Elongation 250 percent minimum Specific Gravity 1.02 to 1.14 psi minimum Stiffness 35,000 psi minimum Water Absorption 1.5 percent maximum Brittleness -65°F ( -54°C) maximum Heat Deflection 110/45°C at 66/264 psi minimum 494 Property Test Value Melting Range 320°F to 374°F Burn Resistance 4 inch minimum
3.Lubricant. Use wire that is impregnated with a non-corrosive friction preventing compound.
4.Wire. Use wire in the steel cable that is cylindrical and smooth and uniformly high quality. Use wire that is free from splits, cold shuts, and other defects. Shape the individual wires and strands composing the wire rope into the exact helical position that they will have in the finished wire rope. Provide rope that if the wire rope is cut or severed, the measured diameter of the wire rope at the unseized cut ends does not increase by more than the amount specified in Table 895-01. Weld or braze all wire splices or joints. Ensure joints in individual wires in any layer of a strand are not closer than 20 feet. Use Table 895-01 to determine the type of construction for the respective diameters, the dimensional tolerances, and the physical properties. Table 895 -01 Construction, Physical Properties of Galvanized Carbon Steel and Stainless Steel Wire Rope Nominal Dia. Of wire rope (In.) Const. Tolerance on Dia. (Plus only) (In.) Allowable Inc. of Dia. (In.) Nominal Break Strength Galv. Carbon Steel (Lbs.) Nominal Break Strength Stainless Steel (Lbs.) Approx. Wt. per 100 ft (Lbs.) 5/32 7 × 19 0.016 0.017 2,800 2,400 4.50 3/16 7 × 19 0.018 0.019 4,200 3,700 6.50 7/32 7 × 19 0.018 0.020 5,600 5,000 8.60 1/4 7 × 19 0.018 0.021 7,000 6,400 11.00 5/16 7 × 19 0.022 0.024 9,800 9,000 17.30 3/8 7 × 19 0.026 0.027 14,000 12,000 24.30
5.7 by 19 Construction. Provide wire ropes of this construction that consist of 6 outer strands of 19 wires each laid around a core strand of 19 wires. Provide six outer strands that each consist of a layer of six wires laid around a center wire in a left-hand direction and a lay er of 12 wires laid over the 7 wire strand in a left-hand direction. Provide a core strand that consists of a layer of 6 wires laid around a center wire in a right- hand direction and a layer of 12 wires laid around the 7 wire strand in the right- hand direc tion. Provide 6 outer strands that are laid around the core in a right-hand direction. Provide a length of lay of the inside layer of 6 wires in each of the 6 outer strands and the one core strand that does not exceed 60 percent of the lay of the outside l ayer of 12 wires in each strand. Provide a length of the lay of the outside 495 layer of 12 wires in each of the six outside strands and the core strand that does not exceed 50 percent of the lay of the finished wire rope. Provide a length of the lay of the fi nished wire rope that is not more than eight times and not less than six times the nominal wire rope diameter. The Engineer will allow other wire rope construction to improve the operation of the high mast lighting unit if the conditions of the design fac tor, stretch limits, sheave and drum ratios are met. In such cases, provide a manufacturer certification that the wire rope meets the specific design application.
6.Wire Quality Testing. Perform quality conformance testing that consists of all the inspections such as workmanship and physical appearance specified.
a.Sampling. Take one sample after any discard has been removed from the head or starting end of the first manufacturing reel for each lot of wire rope. A lot consists of not more than 20,000 feet of wire rope of the same construction and diameter produced continuously by one machine or by one series of progressive processing machines.
b.Workmanship. Provide finished cable that is: - Uniform in construction; - Securely laid; - Free of kinks; - Free of loose wires; - Free of loose strands; and - Free of other defects.
c.Nylon-Jacketed Cables. Provide a nylon coating that is: - A uniform thickness as specified in Table 895-02; - Uniform in appearance; - Transparent; - Homogeneous; and - Uniform in consistency. Provide jacketed wire rope that: - Has no cracks or seams; - Is not separated from wire rope; and - Has no extrusion die marks on the surface that affect wire rope performance. 496 Table 895 -02 Construction and Dimensional Properties of Nylon Jacketed Wire/Rope Jacket Tolerances Nominal Dia. Of wire rope (In.) Const. Tolerance on Jacket
O.D. (Plus only) (In.) Outside Dia. Of Jacket (In.) Jacket Wall Thickness (Reference) (Lbs.) Approx Wt. per 100 ft. (Lbs.) 3/16 7 × 19 0.022 5/16 0.063 9.20 7/32 7 × 19 0.020 9/32 0.031 9.76
d.Breaking Strength. Use a 24 inch wire rope specimen from the same sample from each lot. Where necessary use swaged terminals meeting Federal Specification MIL-T -781 and accompanying hardware to facilitate installation of the specimen in the jaws of the testing machine. Do not use ball -end fittings. Use a distance between the jaws of the testing machine with the sample that is no less than 10 inches. Determine the breaking strength according to ASTM E 8.
e.Stretch Test. Select and test one specimen from each sample of wire rope to determine the percent stretch. Provide a specimen that is no less than 24 inches. Where necessary, use swaged terminals and accompanying hardware to facilitate installation of the specimen in the jaws of the test machine. Determine the amount of st retch on a tension-testing machine according to ASTM E 8. Load the specimen to within 1 percent of the nominal breaking strength shown in Table 895-01 to straighten the wire rope. While the specimen is under tension, mark off the wire rope an adequate gauge length s between the jaws of the testing machine. Load the specimen to 60 percent of minimum breaking strength and measure to elongation under load. The specimen must not elongate more than 1.5 percent.
f.Responsibility for Inspection. The supplier shall perform all inspection requirements. The supplier may use its own or any other suitable facilities for the performance of the inspection requirements, if approved by the Engineer.
g.Certification. In addition to submitting a certificate of compliance as specified in Section
106.01 C, “Certificate of Compliance”, submit a test report from the wire rope
manufacturer. If the rope is nylon coated, also submit a test report from the nylon coating manufacturer.
6.Cable Attachments. Permanently swage the wire rope attachments that are not readily accessible for inspections onto the cables in accordance with the recommended practice of the fitting manufacturer. Assemble the attachments and cable in a manner that ensures that the attachments generate the full breaking strength of the cable. 497 Attach adjustable or semi -permanent end attachments, such as wire rope clips, in the manner and number recommended by the fitting manufacturer. Use a minimum of two clips of correct size on each termination, and inspect and retighten clips as necessary. Provide a “saddle” portion of the clips that bears on the live or long end of the cable and a U-bolt that bears on the dead or short end of the cable. Thimble all eyes to protect the wire rope from abrasions. Do not apply wire rope attachments over nylon jackets of cables.
7.Portable Power Unit. Provide a portable power unit that supplies all necessary driving power to the winch. Provide two identical 240 volt, 1/2 inch heavy duty reversible electric drills with torque limiters. Provide a means of checking the restraint offered by the torque limiters. Provide drills with UL approved overload protection. Arrange the drills for remote control operation. Attach a drill mounting assembly to the base of the pole with a quick -connect securing mechanism that can accommodate any size or shape pole. Provide a pendant control switch with a 20 foot cord to allow the operator to stand clear of the service area while the luminaire ring is raised or lowered. Section 896 498 SECTION 896 HIGHWAY TRAFFIC SIGNALS
896.01 Rigid Conduit
A.Steel Conduit. Use steel conduit of corrosive-resistant material meeting the requirements in UL 6. Do not use aluminum conduit.
B.Nonmetallic Conduit. Use either polyvinyl chloride (PVC) or high-density polyethylene (HDPE) conduit for nonmetallic conduit.
1.PVC. Provide PVC conduit that meets the requirements of UL 651 suitable for direct burial applications and has a minimum wall thickness equivalent to Schedule 40 as defined by ASTM D 1785.
2.HDPE . Provide HDPE conduit that meets the requirements of UL 651 and ASTM D 3035 that is suitable for direct burial applications. Use HDPE conduit that has a minimum wall thickness equivalent to DR 15.5 as defined by ASTM D 3035. Install HDPE conduit when the conduit temperature and the ambient temperature is greater than minus 10°F.
896.02 Conductors
A.Feeders. If using conductors as feeders provide either a single conductor or multiple stranded conductors formed into a cable. Provide underground phase and neutral conductors that are insulated to meet the requirements for direct burial cable, rated at 600 volts, and that meet ASTM B 3 and B 8. Use single conductor marked with Style “RHW-USE” and the required AWG size on the sheath. Use stranded No. 6-AWG -Type THW or THHN/THWN for grounding conductor. Rubber insulation specifically listed for that purpose by UL does not require an outer cover.
B.Loop and Loop Lead-In Conductor. Provide a loop and loop lead-in conductor that meets one of the following:
1.Copper Loop Conductor. Use No. 14 AWG, Type XHHW or THWN or THHN single-stranded 600 volt conductor or as recommended by the detector manufacturer.
2.Polyethylene Conduit Pre-Wired. Provide a certificate of compliance stating that the 1/4 inch polyethylene conduit meets ASTM D 1248, Type III, E10, Category 5, Class C and Tables 896-01 and 896-02.
Source: North Dakota Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 514–532 of 550.