9-142 Section 918. Electrical and Lighting Materials
918.01 Conduit
Provide nationally recognized testing laboratory labeled conduits with UV protection and manufactured for use at temperatures of at least 194°F unless otherwise required. For conduits encased in concrete, use Grade 3500 concrete. If steel reinforcement is required, provide reinforcement meeting the requirements of section 905. Wall thickness and OD dimensions must conform to ASTM D1785 for smooth-wall Schedule 40 an d 80 PVC conduit material . Maximum deviation from the minimum wall thickness is 3 %. Wall thickness range must be within 12% in accordance with ASTM D3035 for smooth-wall coilable Schedule 40 and 80 PE conduit.
A.Galvanized Steel Conduit . Provide nationally r ecognized listed and labeled galvanized steel conduit meeting the requirements of ANSI C80.1. Provide hot -dip galvanized couplings and fittings that meet the requirements of ANSI/NEMA FB1 . Provide elbows and nipples meeting the requirements for conduit . Provide thread -type fittings and couplings for rigid conduit.
B.Smooth -Wall Schedule 40 PVC Conduit . Provide smooth- wall PVC conduit, fittings, and accessories manufactured from PVC meeting the requirements of ASTM D1784 and the applicable NEMA TC2 and UL 651 requirements.
C.Smooth -Wall Schedule 80 PVC Conduit . Provide smooth- wall PVC conduit, fittings, and accessories manufactured from PVC meeting the requirements of ASTM D1784 and the applicable NEMA TC2 and UL 651 requirements.
D.Smooth -Wall Coilable Schedule 40 PE Conduit . Provide HDPE Type III, Grade P 33, Category 5, Class C conduit meeting the requirements of ASTM D3485, ASTM D3350, and ASTM D1248. Mark conduit in accordance with ASTM D3485. Mark the conduit to indicate the producer code and designation, whether HDPE or Type III . Provide conduit produced from material with a color and UV stabilization code of C, D, or E in accordance with ASTM D3350. Provide black conduit for use above gr ound. For each project, supply a general certification that the PE conduit meets these requirements. MDOT Standard Specifications for Construction Section 918 9-143 E. Smooth -Wall Coilable Schedule 80 PE Conduit . Provide smooth-wall, coilable, PE conduit meeting the requirements of applicable sections of NEMA TC7, UL 651 and 651A, and ASTM D3485. Provide HDPE Type III, Grade P -33, C ategory 5, Class C conduit meeting the requirements of ASTM D3485, ASTM D3350, and ASTM D1248. For each project, supply a general certification that the PE conduit meets these requirements.
F.Rigid Fiberglass . Provide filament -wound conduit and fittings cons isting of E glass and corrosion-resistant epoxy resin, manufactured for use at temperatures from −40 to 230°F . Ensure that conduit is pigmented with carbon black for UV protection and fire resistant in accordance with UL
94.Provide heavy walled fiberglass conduit meeting the specifications, labeling, and testing requirements of ANSI/NEMA TC14.
918.02 Electrical Grounding System
Provide material for the electrical grounding system meeting the following requirements.
A.Flexible Grounding Connection . Provide flexible grounding connections made of flexible, flat, tinned copper braid with seamless tinned copper ferrules at each end. Provide flexible grounding connections with a minimum cross -sectional area equal to the cross -sectional area of the grounding cable. Provide ferrule capable of being formed to fit the curved surfaces of a clamp or pipe.
B.Grounding Condu ctors and Bonding Jumper s. Provide grounding conductors and bonding jumper s sized in accordance with the current National Electrical Code (NEC ).
C.Grounding Rod . Provide a copper -clad steel grounding rod with a diameter of at least ¾ inch and a length of at least 10 feet, with no more than 10 ohms of resistance to ground.
D.Connecting Hardware . Provide silicon- bronze-connecting hardware meeting the requirements of ASTM B124/D124M . Provide materials supplied by the same manufacturer to ensure compatibility.
918.03 Electrical Conductors and Cable
Provide conductors and cable meeting the requirements of the NEC, the serving utility , and ASTM specifications . Provide nationally recognized , approved cable. Provide coated, soft drawn copper conductors in standard American Wire Gauge (AWG) sizes. MDOT Standard Specifications for Construction Section 918 9-144 Provide conductors and cables with the size, voltage rating, insulation type, and manufacturer ’s name permanently marked on the outer covering at regular intervals . The manufacturer must provide splicing or terminating information for installation of the cable to the Engineer and Contractor.
A.Overhead and Underground Service Conductors and Cable . Provide cable consisting of three 1/C PE-insulated stranded conductors, assembled under a common PE jacket . Provide cables meeting the requirements of IMSA 20-1 for aerial and duct installation, except provide conductors of the required sizes and numbers . Single conductors rated for direct burial in a dedicated service conduit are permitted. Provide Periwinkle -type, or Department -approved equal, aluminum multiplex cable consisting of two sheathed conductors wrapped around a ground and messenger cable. Ensure that the phase conductor consists of sev en-strand, No. 4 AWG with an insulation thickness of 45 mils . Provide a bare neutral messenger consisting of a 6/1 strand, No. 4 AWG, with a rated strength of 1, 860 pounds.
B.Traffic Signal Wire and Cable. Provide stranded traffic signal wire and cable for aerial, underground duct or direct burial systems . Except for IMSA 51 -5 cable, provide PE-insulated and PE -jacketed cables with 2 to 20 conductors . Provide IMSA 51 -5 PVC insulated, nylon-jacketed cables loosely encased in a PE tube. Provide the sizes and number of conductors shown on the plans. Provide IMSA cable that meets the requirements of IMSA 20 -1, IMSA 20-3, IMSA 20-5, IMSA 40-2 (aerial and duct), IMSA 40-4 (aerial self-supporting), IMSA 50 -2 (loop lead-in), and IMSA 51-5 (loop) with the exceptions and additions specified in this subsection.
1.Conductors . Provide concentric st randed, Class B, soft copper conductors meeting the requirements of ASTM B8 except do not allow joints in the conductors after completing final drawing operations.
2.Circuit Identification . Provide color -coded insulation in accordance with the following:
a.Table 5.1 of IMSA 20 1;
b.IMSA 20 2;
c.IMSA 20 5;
d.Table 5.2 of IMSA 40 2; and
e.IMSA 40 4. Do not print numerals or words on the insulation for conductor identification. MDOT Standard Specifications for Construction Section 918 9-145 C. Messenger Cable. Provide stranded, ¼ inch, Class C, galvanized, extra -high-strength steel strand messenger cable of no more than seven- wire meeting the requirements of ASTM A475, as specified by 9.1-A of IMSA 20-3 and 11.1 of IMSA 40-4.
918.04 Direct Burial Cable and Conductors
Install direct burial cable and conductors in conduit unless otherwise shown on the plans. Direct burial cable and conductors in conduit for use in wet locations must be a type allowed in the current NEC for direct burial . Unless otherwise required, provide nationally recognized listed cables rated at 600 volts . Provide cables and conductors resistant to oils and chemicals, rated 194°F dry and 167°F wet, for installation in wet and dry locations exposed to the weather and meeting the requirements of UL 44. Provide cables for electric service entrance runs with a USE rating. For all individual conductors, provide type RHW/USE .
A.Conductors . Provide uncoated, copper, UL 44 approved conductors meeting the requirements of ASTM B3. Provide Class B conductors stranded in accordance with ASTM B8. Ensure that the manufacturer ’s insulation curing process does not damage uncoated conductors. Color code the insulation on conductors No. 2 AWG and larger . Field tape at least 12 inches of conductors ends with half -lapped color tape. Use colors as described in the next paragraph. Use conductors with colored insulation for sizes smaller than No. 2 AWG . Color code neutral conductors white for 240/120-volt systems and gray for 480/277-volt systems. Color code a single-phase 3-conductor with one black conductor , one red conductor , and one white conductor for a 120/240-volt system. Color code a single-phase 2-conductor with one brown conductor and one orange conductor for a 480-volt system. Color code a single-phase 2-conductor with one black conductor and one white conductor for a 120-volt system. Color code a single -phase 3-conductor with one brown conductor , one orange conductor , and one gray conductor for a 480/240-volt system. Color code a three -phase 4-conductor with one brown conductor , one orange conductor , one yellow conductor , and one gray conductor for a 480/277- volt system.
918.05 Equipment -Grounding Conductor
Provide insulated or bare copper conductors meeting the requirements of ASTM B3 for equi pment -grounding conductors . Provide equipment -grounding conductors that are stranded in accordance with ASTM B8 for Class B . For MDOT Standard Specifications for Construction Section 918 9-146 installing conductor in conduit, insulate and color code the conductor green . For installing in earth, keep the conductor bare.
918.06 Handholes
A.Concrete. Provide Grade 3500 concrete.
B.Steel Reinforcement . Provide bar or welded cage mesh steel reinforcement capable of supporting HS -20-44 loading. Provide reinforcement as shown on the plans or in accordance with the manufacturer ’s design. If reinforcement deviates from the plans, provide calculations showing that the new design supports HS -20-44 loading.
C.Frame and Covers. Provide frame and covers of steel and classified as light duty or heavy duty . Provide covers with the required logo in the location and of the size specified on the handhole detail sheet.
1.Light -Duty Cover . Provide East Jordan No. 2982A -18 or Neenah Foundry No. R -6012-D round cover or a Department -approved equal.
2.Heavy-Duty Cover . Provide East Jordan No. 2860A or Neenah Foundry No. R -6052-D round cover or a Department -approved equal.
D.Polymer Concrete Handhole Boxes and Covers. Construct handhole boxes of polymer concrete, reinforced with a heavy weave fiberglass. Provide heavy -duty enclosures and covers designed and tested to −50°F with a compressive strength of at least 11,000 psi . Provide covers with a friction coefficient of at least 0.5.
1.Boxes. Provide stackable, heavy -duty, nominal 17- by 30- by 12-inch handhole boxes, rated for 5 ,000 pounds over a 10- by 10-inch area.
2.Covers. Provide handhole covers with a service load of at least 15,000 pounds over a 10- by 10-inch area. Provide covers marked with a logo as required. Secure covers with stainless steel, 300 series, ⅜ inch, 16NC hex bolts and washers.
E.Handhole, Square, 4 foot . Construct handholes from concrete.
1.Handhole . Provide handholes with live loads meeting the requirements of AASHTO HS 20 -44 for heavy traffic . Increase the handhole design live load by 20% , given an eart h cover from 2 to 5 feet. Provide standard telecommunications Type S precast handholes with inside dimensions of at least 48 by 48 by 48 inches. Center the top opening in the roof of the handhole and provide at least a 39-inch-diameter clear opening. Provi de eight bell end inserts in the MDOT Standard Specifications for Construction Section 918 9-147 sides for a 4-inch PVC conduit . Provide a knockout for one 14-inch-diameter sump crock in the base of the handhole. Provide a handhole that is watertight to within 42 inches of grade. Ensure that the manufacturer provides master sealer for joints and holes including grade rings and pull -in irons. Provide one 12 -inch, interlocking, grade ring with a galvanized step cast into the ring. Provide a grade ring with an OD of at least 45 inches and an inside diameter of 39 inches ±1 inch. Cast metal bolt anchor inserts for ½ -inch bolts into each wal l. Ensure that spacing between inserts is no greater than 24 inches. Protect the inserts during casting to prevent filling wi th concrete.
2.Hardware. Provide metallic hardware that is hot -dip galvanized or stainless steel . Provide a complete hardware package with each handhole including the following:
a.One hook ladder for hooking on the step of the grade ring when positioned at the climbing angle;
b.Four pull -in irons with backing plates;
c.Eight 36- inch cable racks (Underground Devices No. CR36 or Department -approved equal); and
d.Sixteen 3- inch throat saddle (Underground Devices No. 3HDS or Department -approved equal).
3.Frame, Ring , and Cover . Provide a heavy -duty cast -iron frame, grade ring, and cover manufactured by East Jordan Iron Works or a Department -approved equal . Provide a Model 1220C ring and cover with “Signals & Lighting” cast into the cover . Do not use other ring and cover model numbers . Provide a frame weighing 410 pounds and a cover weighing 245 pounds.
F.Handhole, Round, 3 -foot diameter . Construct handhole boxes from concrete.
1.Handhole . Provide handholes with live loads meeting the requirements of AASHTO HS 20 for wheel loading. Ensure that concrete attains a 28-day compressive strength of at least 4,500 psi. Provide smooth or deformed welded wire fabric in accordance with ASTM A1064 /A106 4M. Provide reinforcing steel meeting the requirements of ASTM A615/A615M for Grade 60 rebar if required. Bend bars and place in MDOT Standard Specifications for Construction Section 918 9-148 accordance with the latest American Concrete Institute (ACI) standards. Provide precast handholes with the following characteri stics:
a.Inside diameter of 36 inches, capable of accommodating round covers;
b.Integral wall and base;
c.Height of 44 or 48 inches;
d.OD of 44 inches;
e.One 6-inch knockout in the base for a sump drain hole; and
f.Walls with four tapered knock -outs for conduit entering the handhole, 2 inches deep from the inside and 10 to 11 inches in diameter. Construct the handhole to accept a heavy -duty frame and cover centered atop the handhole.
2.Frame and Cover . Provide a heavy -duty cast -iron frame, grade ring, and cover manufactured by East Jordan Iron Works or a Department -approved equal . Provide a Model 1220 ring and cover with required logo cast into the cover . Do not use other ring and cover model numbers . Provide a total assembly weighing 675 pounds .
918.07 Light Standard Foundation
A.Concrete. Provide Grade 3500 concrete.
B.Steel Reinforcement . Provide steel reinforcement as shown on the plans and meeting the requirements of section 905. When reinforcement meets the requirements of the NEC , it must be used for groundi ng.
C.Anchor Bolts, Nuts, and Washers . Provide anchor bolts, nuts, and washers meeting the requirements of subsection 908.14. Provide anchor bolts with a diameter of at least 1 inch with series 8UN threads . Provide anchor bolts threaded 4 inches beyond the anchor bolt projection shown on the plans.
D.Ground Rods . Use a ground rod meeting the requirements of subsection
918.02 C.
1.Grounding Electrode Conductor . Provide No. 6 stranded , bare copper , grounding- electrode conductor for the street lighting unit meeting the requirements of subsection 918.02.B. MDOT Standard Specifications for Construction Section 918 9-149 2. Conduit . Provide conduit in the foundation to allow placement of conductors and grounding wires as shown on the plans and meeting the requ irements of subsection 918.01.
918.08 Light Standards
Provide steel, aluminum, or other light standard material . Provide light standards designed in accordance with AASHTO ’s Standard Specifications for Structural Supports for Highway Signs, Luminaires, and Traffi c Signals . Use a wind importance factor based on a recurrence interval of 50 years for the design wind speed. Do not use alternative methods of determining wind speed. Use a Category I fatigue importance factor . Submit calculations for the light standard design, sealed by a Professional Engineer who is licensed in the State of Michigan, to the Engineer for approval.
A.Steel Light Standards
1.Shafts . Provide light standard shafts of hot -rolled , low-carbon steel or high-strength, low-alloy steel . Provide shafts with a tensile yield strength of at least 50,000 psi when tested before or after fabrication.
2.Handhole . Provide light standards with reinforced handholes with a steel cover and a grounding nut or lug inside the shaft . Ensure that the grounding nut or lug is easily accessible from the handhole.
3.Anchor Bases . Provide one-piece anchor bases of cast steel or hot-rolled steel plate. Cast steel anchor bases must meet the requirements of ASTM A27 /A27M for Grade 65-35, and hot-rolled steel plate anchor bases must meet the requirements of ASTM A36/A36M .
4.Bracket Arm Assembly . Provide a bracket arm assembly of truss-type design and steel meeting the requirements of ASTM A53/A53M Grade B or ASTM A36 /A36M. Ensure that the installed bracket arm assembly provides a weather -resistant connection with a smooth wiring raceway.
5.Hardware. Provide American Iron and Steel Institute ( AISI) Series 300 stainless steel threaded fasteners and lock washers to secure parts to the shaft.
B.Aluminum Light Standards
1.Shafts . Provide round, octaflute, or octagonal aluminum shafts with a uniform taper. Provide a shaft fabricated from a single piece of seamless tubing of aluminum alloy 6063 meeting the requirements of ASTM B221. MDOT Standard Specifications for Construction Section 918 9-150 After fabrication, ensure that the shaft has physical strength properties meeting the requirements for T6 temper. Provide aluminum alloy 356-T6 castings except for the shaft top, provide aluminum alloy 43F. Provide sand castings meeting the requirements of ASTM B26/B26M . Provi de permanent mold castings meeting the requirements of ASTM B108/B108M.
2.Handhole . Provide light standards with a reinforced handhole, an aluminum cover, and a grounding nut or lug inside the shaft . Ensure that the grounding nut or lug is easily accessible from the handhole.
3.Bracket Arm Assembly . Provide a bracket arm assembly of truss-type design and aluminum alloy pipe or tapered tubes . Ensure that the installed bracket provides a weather -resistant connection with a smooth wiring raceway. Provide pipes meeting the requirements of ASTM B241/B241M for aluminum alloy 6063-T6 or 6061-T6. Provide tapered tubes meeting the requirements of ASTM B221 for aluminum alloy 6063-T6 or 6061-T6.
4.Hardware. Provide aluminum alloy 2024-T4 or AISI Series 300 stainless steel threaded fasteners, lock washers, and other pieces to secure parts to the shaft.
C.Frangible Transformer Bases. Provide frangible transformer bases selected from the Qualified Products List .
D.Anchor Bolts . Provide galvanized anchor bolts, studs, nuts, couplings, and washers in accordance with subsection 908.14.
918.09 Luminaires
Use luminaires per the contract .
918.10 Tower Lighting Unit
Provide tower lighting units designed in accordance with AASHTO ’s Standard Specifications for Structural Supports for Highway Signs, Luminaires , and Traffic Signals . Use a wind importance factor for the design wind speed based on a recurrence interval of 50 years . Do not use alternative methods o f determining the wind speed. Use a Category I fatigue importance factor . Base design calculations on a yield strength of no greater than 50,000 psi.
A.Shaft. Provide steel shaft material from a single thickness steel sheet with no laminations . Shaft material must meet the requirements of ASTM MDOT Standard Specifications for Construction Section 918 9-151 A1011/A1011M, Grade 50, with a silicon content no greater than 0.060 % or a silicon content from 0.150 to 0.250% . Provide shafts with an overall diameter of at least 23½ inches at the base with uniform taper to the top t o a diameter of at least 6 inches. Shafts must have a minimum wall thickness of 3/16 inch.
1.Handhole . Provide shafts with hinged doors fabricated from the same material as the shafts . Provide doors at least 24 by 14 inches. Provide doors with a hasp for a padlock . Place access holes so they do not intersect the longitudinal seam weld on the pole.
B.Anchor Base. Provide steel base material from a single thickness steel sheet with no laminations . Base material must meet the requirements of ASTM A572/A572M, Grade 50, with a silicon content of no greater than 0.060 % or a silicon content from 0.150 to 0.250 %.
C.Anchor Bolts, Nuts, and W ashers. Anchor bolts, nuts , and washers must meet the requirements of subsection 908.14.
D.Head Frame Assembly . Provide a head frame assembly with a pair of pulleys for each stainless steel cable located to support the luminaire ring. Provide a roller assembly or a single pulley for the power cord. Provide a hoisting system with two or three stainless steel cables at the head frame assembly.
1.Power Cord Roller Assembly . If using a roller assembly to support the power cord, provide six rollers mounted between two cold-rolled steel plates that are zinc -electroplated in accordance with ASTM B633 and yellow chromatic -dipped. Ensu re that the power cord rides on rollers of acetate resin mounted on AISI 304 stainless steel shafts . Locate the six rollers to support the power cord in a bending radius of at least 7 inches . Except for pulleys and rollers, fabricate parts of the assembly from ASTM A572/A57M Grade 345 steel. Design the assembly to protect parts from the weather.
2.Power Cord Pulley . If using a pulley to support the power cord, provide pulleys fabricated from a single piece of galvanized steel with a diameter of at least 16 inches.
3.Pulleys for Stainless Steel Support Cables. Provide pulleys with a minimum diameter of 6 inches fabricated from one piece of stainless steel or galvanized steel. Provide pulleys with permanently lubricated bronze bearings and stainless steel axle pins . Ensure that the depth of the vee on pulleys is equal to or greater than the diameter of the cable. Provide guards to prevent cables from riding off the pulleys. MDOT Standard Specifications for Construction Section 918 9-152 4. Latching . The Contractor may locate the latching mechanism for the luminaire mounti ng ring at the head frame assembly or at the base of the pole. If the latching mechanism is at the head frame assembly, provide three latches as an integral part of the head frame assembly . Latch the luminaire mounting ring by the alternately raising and l owering of the luminaire ring assembly using the winch and hoisting assembly . Attach moving parts of the latching mechanism to the luminaire ring assembly . Ensure that the moving parts are serviceable at ground level. Ensure that the luminaire ring does no t move horizontally or rotate around the pole during the latching or unlatching process . Use indicator flags, visible from the ground, to signal the latching and locking of each latching mechanism. If using a two-cable hoist system, provide for the latchin g of the luminaire mounting ring at the base of the pole. Provide a cable anchoring device to latch each supporting cable in place.
E.Luminaire Mounting Ring . Provide a luminaire mounting ring capable of supporting 2-inch -diameter mounting tenons, complete with ballasts, evenly distributed around the ring for mounting the required number of lumina ires. Ensure that the lum inaire mounting ring provides a raceway or enclosure for the required electrical connections to the luminaires. Provide the mounti ng ring with at least No. 12 AWG copper wire rated at 200°F. Provide a galvanized steel luminaire mounting ring and related components . Galvanize in accordance with ASTM A123/A123M after fabrication. Equip the luminaire mounting ring with a weatherproof male receptacle to energize the luminaires in the lowered position. Ensure that connections are weathertight and protected when the luminaires are in the operating position. Make provisions for centering and damping contacts that the luminaire mounting ring may encounter while ascending and descending the pole. Provide roller -contact with spring-loaded centering arms on the luminaire mounting ring. Ensure that the luminaire ri ng centering device maintains the ring concentric with the pole.
F.Luminaires for Tower Lighting . Provide luminaires capable of operating at mounting heights greater than 100 feet . Provide luminaires capable of withstanding wind velocities of 120 feet per second and resulting vibrations . Provide a luminaire that weighs no more than 94 pounds . MDOT Standard Specifications for Construction Section 918 9-153 When mounted in the operating position, ensure that an area no greater than 5.4 square feet is exposed to the wind. Provide luminaires meeting the requirements specified by the following :
1.Housing . Provide a structurally rigid luminaire housing of cast or formed aluminum with a copper content no greater than 0.2 %. Provide a housing containing an integral slip fitter mounted on a 2-inch pipe bracket or a 1½ -inch pipe bracket with inserts. Provide a mechanical means to limit insertion of the pipe arm . Provide a mechanical means for leveling the luminaire to within a range of ±3 degrees from the horizontal. Provide a leveling surface on the housing exterior to mount the luminaire in the operating position. For luminaires producing asymmetrical light distributions, orient to distribute the light as shown on the plans . For exposed exterior hardware and fasteners, provide stainless steel, Monel metal, or aluminum alloy hardw are and fasteners . For the luminaire-to -bracket arm -mounting fasteners and other internal fasteners, provide stainless steel or zinc -coated steel fasteners . Provide remaining internal hardware of stainless steel, aluminum alloy, or zinc -coated steel.
2.Reflector . Provide aluminum or glass reflectors affixed to the refractor or the cover glass with a gasket . Provide extruded silicone rubber or synthetic fiber felt gaskets.
3.Aluminum Reflector . Provide enclosed aluminum reflectors fabricated with ALGLAS reflector finish or a sealed anodic coating over an electrolytically or chemically brightened specular surface. Provide optical parts that are weathertight and bug tight . Provide a coating that is at least 4 milligrams per square inch in accordance with ASTM B137 . Provide a coating seal meeting the requirements of ASTM B136 . The fabricator must submit certification that the reflector coating meets requirements upon the Engineer ’s request.
4.Glass Reflector . Provide one-piece, clear borosilicate glass reflectors free of bubbles and ripples . Protect the reflector back surface from the effects of atmospheric oxidation and moisture.
5.Cover Glass. Provide clear tempered cover glass . Mount the cover glass to the holding ring but allow for easy replacement. Use an ethylene-pr opyleneteroplymer or synthetic fiber felt gasket for the cover. MDOT Standard Specifications for Construction Section 918 9-154 6. Ballast . Mount the ballast or ballast housing on the luminaire housing. Ensure that the ballast, ballast housing, and luminaire housing are entirely enclosed. Install a gasket between the ballast housing and luminaire housing. Provide ballasts designed to operate at the rated voltage shown on the plans. Identify the ballast lamp wattage and circuit voltage in accordance with ANSI C 82.4. Provide a regulating auto-transformer-type ballast . Ensure that an applied primary voltage change of ±10 % of line nominal at the ballast does not cause more than a ±13% change in lamp wattage. Ensure a power factor of at least 90% at the rated voltage. Provide a ballast that starts reliably at −20°F with ±10 % of line nominal voltage variations.
7.Lamp . Provide lamps of the type and size shown on the plans.
8.Socket . Provide a socket assembly of rigid construction to ensure that the lamp retains the required position during service. Do not use socket adapters for positioning lamps. Provide nickel -plated brass sockets with a porcelain covering. Provide a socket with lamp grips . Provide a socket with a spring-loaded center contact . Weld or attach sock leads with crimp-type, solderless, compression connectors. If the socket is capable of variable socket positions, provide information to establish the correct socket position.
9.Wiring. Complete internal wiring and connections so only incoming supply conductors require attachment to pressure-type connectors on a terminal block. Provide a terminal block rated at 600 volts and meeting the requirements of the NEMA ICS 4 -2015. Provide a terminal board that accommodates crimp -on, solderless, compression connectors for interior wiring. Mechanically and electronically fasten the incoming supply conductors with compression terminals to accommodate wire from No. 12 to No. 16 AWG.
10.Fusing . Provide and mount inline FNM -type fuses in the luminaire housing. Provide fuses with the current ratings in Table 918 -2. MDOT Standard Specifications for Construction Section 918 9-155 Table 918- 2: Curr ent Ratings per Circuit Voltage Circuit Voltage Current Rating 120 volts 30 amperes 240 volts 15 amperes 277 volts 15 amperes 480 volts 15 amperes
11.Painting . Paint the luminaire housing metallic gray.
12.Packaging . Pack luminaires individually for shipment.
13.Assembly Drawings . Provide assembly and installation drawings.
14.Sampling and Testing . Provide test data certification for tower lighting luminai res.
G.Lowering Device. Equip the inside of each tower lighting unit with an electric motor and a hoisting device capable of raising the required number of luminaires plus 300 pounds to the operating position and lowering the luminaires to 5 feet above the foundation . Ensure that raising and lowering operations can be controlled 15 feet from the pole base. The Contractor may use a transformer to obtain the desired voltage of the motor for remote operation. Provide a lowering device with a worm gear, a gear reducer hoist of at least 30:1 and supporting, hoisting, and electric cables to the luminaire mounting ring. Mount the device inside the pole base with stainless steel hardware. Provide the hoist drum with a stainless steel cable at least ¼ inch in diameter, attached to the hoist drum and long enough for at least one complete layer on the drum plus the length required to lower the luminaire mounting ring to the lowest position. If using a single hoisting cable, provide a cable junction plate to join the three supporting cables to the hoisting cable and to hold the lower end of the electric cable . Ensure that the junction plate is accessibl e through the handhole when the luminaire mounting ring is in the raised position. Provide three stainless steel supporting cables 3/16 inch in diameter . Provide means to adjust the length of each of the three supporting cables by 4 inches with the luminaire mounting frame at the top of the pole. As an alternative, the Contractor may provide for each of the three supporting cables to terminate through a coil spring under compression so when the lumin aire mounting ring is in the raised position, differences in tension of one or two cables will compensate for a difference of 3 inches in the length of those cables. MDOT Standard Specifications for Construction Section 918 9-156 H. Electric Cable . Provide portable power cable Type W -4, round, 600-volt, No. 8 AWG, copper electrical cables with 133 strands in each conductor, rated at 167°F . Provide cable that meets the requirements of ICEA S-19-81. Provide the same type of cable for the electric supply from the safety switch to the terminal block in the pole and from the terminal block to the twist-lock connector . Ensure that the cable reaches through the handhole in the pole to serve as a power source for the electric drill or motor to operate the lowering device. Where the electric cable attaches to the cable junction, provide a strain relief grip to hold the electric cable. Provide a strain relief grip that has an insulated compression-type connector capable of supporting the cable when the luminaire mounting ring is lowered. Where the electric cable connects to the luminaire mounting ring, provide a similar strain relief grip to hold the other end of the electric cable.
I.Lightning Arrestor . Mount a lightning arrestor with the necessary operating voltage and conditions inside the pole base. Ensure that the lightning arrestor is accessible through the handhole and connected between the load side of the fused safety switch and the pole grounding lug by the shortest practical connections.
J.Twist Loc Connector . Provide a 600-volt, nationally recognized listed 50 amper e, three-pole, 4-wire, twist -type connector . Provide a power cord from the luminaire mounting ring with a male plug and a supply cord with a female plug.
K.Electric Drill/Motor . Provide an electric drill or motor to operate the hoisting device . If using an electric drill, provide a 240-volt, heavy -duty, industrially rated, ½ -inch capacity, electrically reversible electric drill with special chuck to fit the lowering device hoist . Provide an electric drill with a special mounting bracket for attaching to the hoist through the handhole in the pole. If using an electric motor, use a reversible, standard frame motor with a magnetic brake. Mount the drill or motor frame so it is connected to the hoist without being held by other means . Provide a drill or motor that operates the hoist in either direction from the mounted position. Provide a flexible electric cord with heavy -duty 600-volt insulation for the drill or motor and an attachment plug that fits the 240-volt outlet in the metal pull box . Provide a m omentary push-button control in the electric cord for the drill or on a separate cord from the drill to allow operation of MDOT Standard Specifications for Construction Section 918 9-157 the drill in either direction or stopping when the operator is as far as 15 feet from the pole. Provide a test cable with the drill or motor to energize the luminaires when the mounting ring is in the lowered position. Provide the same type cable as the electric cable up the pole. Provide a cable that includes the required fittings and length to connect the electric supply to the weathertight outlet in the luminaire frame.
L.Foundation . Construct the foundation for the tower lighting unit as shown on the p lans. Ensure that the pole manufacturer provides the anchor bolts for installation in the foundation. Provide each anchor bolt with two nuts for plumbing the pole . Zinc coat the upper 15 inches of the bolts and the nuts in accordance with ASTM A153/A153M . Provide anchor bolts and associated nuts, washers, and hardware meeting the requirements of subsection 908.14. Install anchor bolts as s pecified in section 810.
M.Fused Safety Switch . Provide the fused safety switch as shown on the plans.
918.11 Wood Poles
Provide western red cedar, red pine, or southern pine poles meeting the requirements of AS C O5 and ANSI O5.1 . Incise the circumferential surfac e area of poles beginning from at least 24 inches below the ground line and extending to at least 12 inches above the ground line . Machine shave poles full length above the incised area. Treat poles full length with pentachlorophenol -petroleum preservative solution in accordance with AWPA T1-20 and AWPA P35-16 . Provide a solution containing at least 5% of pentachlorophenol by weight.
A.Guys and Guy Anchors . Provide extra -high-strength-grade seven-strand guy wire. Provide heavy, two-bladed, malleable iron expansion-type guy anchors . Provide galvanized ¾ -inch by 8-foot thimble eye type guy anchor rods. Provide anchor guys with metal or plastic guards.
B.Miscellaneous Hardware. Provide the hot-dip galvanized miscellaneous pole line hardware that is a standard product of electrical materials manufacturers.
Source: Michigan Standard Specifications for Construction, 2020 Edition. Pages 952–967 of 1,146.