Wireway and Conduit System Art. 1088.01 SECTION 1087. GROUNDING
1087.01 Grounding Materials.
a.Grounding Electrode Conductors. Grounding electrode conductors shall be solid, soft drawn 1/C No. 6 copper and shall be installed according to NEC requirements.
b.Grounding Electrodes. Grounding electrodes shall be copper-clad steel with a minimum copper thickness of 10 mils (0.3 mm) and shall be according to UL 467. Grounding electrodes shall be one piece, sectional (threaded) steel rods not less than 5/8 in. (16 mm) in diameter and 10 ft (3 m) long.
c.Access Wells. Grounding electrode access wells shall be constructed of PVC or composite polyester resin/fiberglass material with a diameter of 8 to 12 in. (200 to 300 mm), a length of 36 in. (900 mm) and a cast iron or composite polyester resin/fiberglass lid, secured via stainless steel hardware. A concrete handhole may be used for the access well according to Article 1088.05. SECTION 1088. WIREWAY AND CONDUIT SYSTEM
1088.01 Electrical Raceway Materials. Electrical raceway materials shall be
as follows.
a.Rigid Metal Conduit. The conduit, after fabrication, shall be thoroughly cleaned and the inside and outside surfaces shall be galvanized. Couplings and conduit bodies shall meet ANSI C80.1 and shall be hot-dip galvanized. Elbows and nipples shall be according to the specifications for conduit. All conduit bodies and couplings for rigid conduit shall be of the threaded type.
1.Rigid Steel Conduit. Rigid steel conduit shall be galvanized and manufactured according to UL 6 and ANSI C80.1.
2.Intermediate Metal Conduit. Intermediate metal conduit shall be manufactured according to UL 1242 and ANSI C80.6. After fabrication, the conduit shall be thoroughly cleaned and the inside and outside surfaces galvanized. Couplings and conduit bodies shall meet ANSI C80.6 and shall be hot- dip galvanized. All conduit bodies and couplings for conduit shall be the threaded type.
3.Coated Galvanized Steel Conduit. The conduit prior to coating shall meet the requirements for rigid metal conduit and be manufactured according to NEMA RN 1. Art. 1088.01 Wireway and Conduit System The coating shall have the following characteristics. Property Value Hardness 85+ Shore A Durometer Dielectric Strength 400 V/mil @ 60 Hz Aging 1,000 Hours Atlas Weatherometer Brittleness Temperature 0 °F (-18 °C) when tested according to ASTM D 746 Elongation 200 percent The exterior galvanized surfaces shall be coated with a primer before coating to ensure a bond between the zinc substrate and the coating. The bond strength created shall be greater than the tensile strength of the plastic coating. The nominal thickness of the coating shall be 40 mils (1 mm). The coating shall pass the following bonding test. Two parallel cuts 1/2 in. (13 mm) apart and 1 1/2 in. (38 mm) in length shall be made with a sharp knife along the longitudinal axis. A third cut shall be made perpendicular to and crossing the longitudinal cuts at one end. The knife shall then be worked under the coating for 1/2 in. (13 mm) to free the coating from the metal. Using pliers, the freed tab shall be pulled with a force applied vertically and away from the conduit. The tab shall tear rather than cause any additional coating to separate from the substrate. A two-part urethane coating shall be applied to the interior of the conduit. The internal coating shall have a nominal thickness of 2 mils (50 µm). The interior coating shall be applied in a manner so there are no runs, drips, or pinholes at any point. The coating shall not peel, flake, or chip off after a cut is made in the conduit or a scratch is made in the coating. The urethane interior coating applied shall afford sufficient flexibility to permit field bending without cracking or flaking of the interior coating. All conduit fittings and couplings shall be as specified and recommended by the conduit manufacturer. All conduit fitting covers shall be furnished with stainless steel screws which have been encapsulated with a polyester material on the head to ensure maximum corrosion protection.
4.Liquidtight Flexible Nonmetallic Conduit (LFNC). LFNC shall be manufactured according to UL 1660 Type B. The conduit shall have a temperature range of -20 to 176 °F (-29 to 80 °C). The thermoplastic covering shall be resistant to oil, water, chemical and UV and shall be suitable for outdoor, direct bury, and extreme cold use. Conduit grounding shall be by a separate grounding conductor.
5.Aluminum Conduit. Aluminum conduit shall be manufactured of 6063 aluminum alloy, T-1 temper, according to UL 6A and ANSI C80.5. Wireway and Conduit System Art. 1088.02
6.Stainless Steel Conduit. The conduit shall be Type 304 or Type 316 stainless steel, shall be manufactured according to UL 6A, and shall meet ANSI C80.1. Conduit fittings shall be Type 304 or Type 316 stainless steel and shall be manufactured according to UL 514B. All conduit supports, straps, clamps, and other attachments shall be Type 304 or Type 316 stainless steel. Attachment hardware shall be Type 304 stainless steel.
b.Rigid Nonmetallic Conduit. The conduit, fittings, and accessories shall be manufactured from polyvinyl chloride complying with ASTM D 1784 and with all the applicable requirements of NEMA TC 2 and UL 651 for Schedule 40 conduit, except Schedule 80 conduit shall be used under pavement, stabilized shoulder, paved median, paved driveway, curb and/or gutter, and sidewalk. Fittings and accessories for the electrical plastic conduit shall comply with all applicable requirements of NEMA TC 3. The solvent cement used to join the conduit and fittings shall be according to ASTM D 2564.
c.Coilable Nonmetallic Conduit. The conduit shall be a high density polyethylene duct which is intended for underground use and can be manufactured and coiled or reeled in continuous transportable lengths and uncoiled for further processing and/or installation without adversely affecting its properties or performance. The conduit and its manufacture shall be according to UL 651A for Schedule 40 conduit, except Schedule 80 shall be used under pavement, stabilized shoulder, paved median, paved driveway, curb and/or gutter, and sidewalk. Performance Tests. Testing procedures and test results shall meet the requirements of UL 651A. Certified copies of the test report shall be submitted to the Engineer prior to the installation of the conduit.
1088.02 Expansion Fittings for Raceways.
a.Metallic Couplings. Expansion couplings for metallic raceways shall consist of an appropriately sized expansion fitting plus a deflection fitting which allows for a 3/4 in. (19 mm) deflection. All couplings, except those used indoors, shall have a bonding jumper. Couplings used indoors shall be listed for use without a bonding jumper. Bonding jumpers for exposed metallic raceways shall be external. The coupling may be a combination of the two fittings or a single fitting assembly. All metallic parts shall be stainless steel or hot-dip galvanized.
b.Nonmetallic Couplings. Expansion couplings for nonmetallic raceways shall be made of PVC and consist of an appropriately sized expansion fitting plus a deflection fitting which allows for a 3/4 in. (19 mm) deflection. The coupling may be a combination of the two fittings or a single fitting assembly. Art. 1088.03 Wireway and Conduit System
1088.03 Fasteners and Hardware. Fasteners used to mount conduit supports,
boxes, and other items attached to the structure shall be suitable for the weight supported and shall be compatible with the structure material. Wood screws shall be used for wood, toggle bolts shall be used for hollow masonry, expansion bolts or power-set studs shall be used for solid masonry or concrete, and clamps shall be used for structural steel. Expansion anchors and power set anchors shall not be less than 1/4 in. (6 mm) diameter and shall extend at least 2 in. (50 mm) into the masonry or concrete. All steel hardware shall be hot-dip galvanized. Hardware for stainless steel boxes and other stainless steel items shall be Type 304 stainless steel. Screws for the attachment of pole handhole covers, covers on cast metal boxes, doors on transformer bases, and other such applications shall be Type 304 stainless steel unless otherwise specified. All stainless steel hardware shall be coated with anti-seize compound.
1088.04 Junction Box. Junction boxes shall be mounted on the surface of a
structure or embedded in a structure as shown on the plans. The junction box shall be furnished with a cover, gasket, and hardware. Hardware furnished for the cover shall be stainless steel. A grounding lug shall be provided in every junction box. A stainless steel conduit fitting shall be used to connect conduit to a stainless steel junction box. Box covers shall have a continuous formed, seamless, urethane, oil-resistant gasket. The gasket shall be placed directly onto the junction box cover. The gasket shall adhere to the cover without the use of adhesives. Junction box covers shall be attached to the box with un-slotted hex head screws unless otherwise specified. For boxes mounted on bridge structures, the cover shall be furnished with a retaining chain and captive screws. Specific requirements for different materials used for junction boxes shall be as follows.
a.Stainless Steel Junction Box. The box shall be made of Type 304 stainless steel, not less than 14 gauge (2.03 mm), with all seams continuously welded with stainless steel weld wire and ground smooth. Exterior surfaces shall have a smooth polished finish. The box shall be according to NEMA Type 4X and be UL 50 "Junction and Pull Box", "Junction Box", or "Pull Box". When specified for attachment to a structure, the box shall be suitable for surface mounting, complete with external stainless steel mounting lugs or brackets welded to the box. The box shall have an overlapping stainless steel cover that is secured to the box with a continuous stainless steel hinge and a minimum of four captive stainless steel clamps utilizing captive stainless steel hex-head bolts or deep slotted stainless steel screws. Wireway and Conduit System Art. 1088.05 When specified for embedment in structure, the box shall be constructed with the cover arranged to fit flush with the structure surface. The cover shall be attached with stainless steel unslotted hex-head screws.
b.Galvanized Steel Junction Box. The box shall be made of galvanized steel, NEMA Type 3R, and be listed. It shall be hot-dip galvanized according to ASTM A 653 (A 653M). When specified for attachment to a structure, the box shall be suitable for surface mounting, complete with external mounting lugs or brackets welded to the box. Galvanizing shall be done after the lugs or brackets are attached. The box shall have an overlapping cover that is secured to the box with a continuous stainless steel hinge and a minimum of four captive stainless steel clamps utilizing captive stainless steel hex-head bolts or deep slotted stainless steel screws. When specified for embedment in structure, the box shall be constructed with the cover arranged to fit flush with the structure surface.
c.Cast Iron Junction Box. The box shall be made of cast iron, be listed, and NEMA Type 4. When specified for attachment to structure, the box shall be suitable for surface mounting, complete with external mounting lugs integral to the casting. Mounting lugs shall be integral with or securely attached to the box, maintaining the NEMA Type 4 rating, and galvanizing shall be done after the lugs are attached. When specified for embedment, the box shall be suitable for encasement in concrete with a flush cover, recessed within an outside flange frame. Covers shall be attached with hex-head un-slotted silicon bronze screws. The Engineer will determine the application of screws based on the box location.
1088.05 Composite Concrete Handhole. Handholes constructed of a
composite concrete shall be designed for off roadway applications subject to occasional, non-deliberate heavy vehicular traffic according to ANSI/SCTE 77 and the following.
a.Material. The handhole box and cover shall be constructed of any special combination of fiberglass reinforced polymer concrete and/or fiberglass reinforced polymer, polyester, or plastic material. The handhole material shall be non-conductive and unaffected by ultraviolet light, moisture, and sub-soil chemicals. The color of the top frame and cover shall be concrete gray to match approximately the color of nearby pavement or sidewalks. Art. 1088.05 Wireway and Conduit System The material shall have the following mechanical properties. Mechanical Property Strength, psi (kPa) Compressive Strength 10,300 (71,000) Tensile Strength 1,700 (11,700) Flexural Strength 7,500 (51,700)
b.Dimensions. The dimensions of the handhole shall be as shown on the plans. The box walls may be smooth or corrugated, straight, or flared, as specified on the plans.
c.Cover. The cover of the handhole shall fit flush with the surrounding top frame surface. The minimum thickness of the cover shall be 3/4 in. (19 mm). The cover shall contain a cast-in-place legend “IDOT TRAFFIC SIGNALS”, “IDOT LIGHTING”, “IDOT TSC”, or “IDOT ITS” as specified on the plans. The cover shall contain either two lifting rings or two lifting slots, as specified on the plans, as follows. The cover shall contain two recessed slots, each with a recessed stainless steel pin to assist in lifting the cover. The cover shall be held down by two or more stainless steel hex head bolts. The cover for a double handhole of either cover type shall be a split lid, two- piece cover.
d.Load Capacity. Handholes shall meet the structural requirements of Section 7 of ANSI/SCTE 77 for Tier 15 loading. Written certification shall be submitted to the Engineer that states the handholes provided meet these requirements.
1088.06 Handhole Frame and Cover. The handhole frame and cover shall be
fabricated from steel according to Section 505 or cast iron according to AASHTO M 105, Class 30 or better. The dimensions of the frame and cover shall be as shown on the plans. The thickness of the frame and the outer rims of the cover shall be a minimum of 3/4 in. (19 mm). The thickness of the cover, at the center, shall be a minimum of 1 in. (25 mm) at the reinforcing ribs. The frame and cover shall have beveled edges to assist in centering the cover. Each cover of a double handhole shall be connected to the frame by a flush hinge. The outside of the cover shall contain a recessed lifting ring attached by a J-bolt and a cast-in-place legend "IDOT TRAFFIC SIGNALS", "IDOT LIGHTING", “IDOT TSC”, or “IDOT ITS” as specified in the plans. Both the lifting ring and J-bolt shall consist of stainless steel according ASTM A 240 (A 240M). The frame and cover shall be designed to withstand AASHTO H-15 loading for a regular handhole and a double handhole, and to withstand AASHTO H-20 loading for a heavy-duty handhole. The frame and cover of a handhole shall have the minimum weight (mass) as follows. Sign Base Art. 1090.02 Frame and Cover Minimum Weight (Mass) Handhole 140 lb (64 kg) Heavy-duty Handhole 260 lb (118 kg) Double Handhole 330 lb (150 kg) The handhole lifting ring shall have the same or better design life than the handhole cover and frame. The attachment of the lifting ring to the lid by a loaded spring mechanism will not be acceptable.
1088.07 Gulfbox Junction. Cast iron and composite concrete junction boxes
shall be as follows.
a.Cast Iron Box. The box and cover shall be made of cast iron according to AASHTO M 105, Class 30 or better. The box shall be bottomless and 14 3/4 in. (375 mm) long, 12 in. (305 mm) wide, and 8 in. (203 mm) deep.
b.Composite Concrete Box. The box and cover shall be composite concrete according to Article 1088.05. The box shall be bottomless and 14 3/4 in. (375 mm) long, 14 3/4 in. (375 mm) wide, and 12 3/4 in. (324 mm) deep. SIGNS SECTION 1090. SIGN BASE
1090.01 Sign Base Material Requirements. The sign base material for Type 1
sign panels shall be sheet aluminum. Type 2 sign panels may be sheet aluminum, bolted aluminum extrusions, or plywood. Type 3 sign panels shall be bolted aluminum extrusions. Sign Type Description Type 1 6 ft (1.8 m) wide or less and 9 sq ft (0.84 sq m) in area or less. Type 2 Over 9 sq ft (0.84 sq m) in area or over 6 ft (1.8 m) wide but less than 24 sq ft (2.22 sq m). (Note 1) (Note 2) Type 3 24 sq ft (2.22 sq m) in area or larger. Note 1. Plywood may be used only when specified. Note 2. On freeways and expressways, Type 2 panels used for guide, information, or service signing shall have the same sign legend as the Type 3 sign panels.
1090.02 Sheet Aluminum. The sign base material shall be flat sheet
aluminum to which a chemical conversion coating has been applied. The material shall comply with ASTM B 209, Alloy 6061-T6 or 5052-H38 and conversion coated according to either MIL-DTL-5541 or ASTM B 449. Art. 1090.02 Sign Base Type 1 sign panels shall be at least 0.080 in. (2.03 mm) thick. Type 2 sign panels shall be at least 0.125 in. (3.17 mm) thick. All panels shall be a flat continuous section of the length, width and shape specified in the plans for Standard Sign Design Criteria of the MUTCD with specified mounting holes and corner radii. Sign panels shall be according to dimensions specified, within ±1/32 in. (±0.794 mm) and shall not be out of square more than 1/16 in. (1.588 mm). Warps and buckles shall not exceed 1/16 in. (1.588 mm) for each foot in length or width when laid on a true flat surface. All fabrication shall be accomplished prior to the chemical conversion coating process. Before retroreflective sheeting is applied to the sign panel, the application surface shall be thoroughly cleaned, prepared, or etched according to the sheeting manufacturer's recommendations. The chemical conversion coating shall remain intact on the backside of the sign panel. There shall be no opportunity for the clean metal surface to oxidize or come in contact with grease, oils, or other contaminants prior to the application of retroreflective sheeting or paint.
1090.03 Bolted Aluminum Extrusions. Sign panels of this type shall be made
of aluminum according to ASTM B 221, Alloy 6063-T6. Panel preparation shall be according to Article 1090.02, except etching may be omitted and holes for demountable sign legend units may be drilled after assembly and reflectorization. Sign molding shall be an aluminum extrusion designed for the sign panel extrusion with which it is to be used and its color shall match the color of the sign background. The sign molding shall be riveted to the sign panel on 2 ft (600 mm) centers. Aluminum dome head rivets shall be used to secure the sign molding, sign panel overlays, demountable legend unit, and supplemental panel to the sign face. The dome head rivets shall be 3/16 x 1/4 in. (4.75 x 6.35 mm) blind made from 5052 aluminum with an aluminum alloy mandrel. The dome head rivets shall have a grip range from 0.126 to 0.250 in. (3.2 to 6.4 mm) with a flange diameter of 0.114 in. (2.9 mm) and a rivet length of 0.450 in. (11.4 mm). The dome head rivets shall be color anodized according to the sheeting color of the unit being installed. All bolts, nuts, and other hardware and material used in assembling aluminum extrusions into sign panels shall be supplied by the manufacturer of the panels. Post clips shall be aluminum according to ASTM B 108 (B 108M), 356-T6. Bolts and washers shall be stainless steel according to ASTM A 276 (A 276M), Type 304. Nuts shall be stainless steel according to ASTM A 240 (A 240M), Type 304.
1090.04 Plywood. Plywood shall be according to AASHTO M 133. Each
panel shall bear the mark of an approved testing agency or independent testing laboratory. If slip sheets are used, they shall not deposit any wax, silicone, or other substance on the surface of the overlays. There shall be no caulk lubricant residue left on the surface of the overlays that will affect the adhesion of retroreflective sheeting.
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Source: Illinois Standard Specifications for Road and Bridge Construction, 2022 Edition. Pages 1084–1091 of 1,217. View official source ↗