SECTION 16111 CONDUITS
PART 1 GENERAL
1.1 RELATED REQUIREMENTS
A. Applicable requirements of Division 0 and Division 1 shall govern work in this Section.
1.2 SCOPE
A. Provide conduit systems for all power, control, and communications systems wiring as specified. Flexible, modular wiring systems shall not be used unless expressly accepted by the Engineer.
1.3 QUALITY ASSURANCE
A. National Electrical Contractor's Association (NECA) Standard of Installation.
B. National Electrical Code (NEC) Including State of Wisconsin and local supplements.
PART 2 PRODUCTS
2.1 GALVANIZED RIGID CONDUIT (GRC)
A. Manufactured lengths, full weight, heavy wall, rigid steel conduit, protected inside and out by hot-dipped galvanized or electro-galvanized coating.
B. Minimum conduit size shall be 3/4 inch.
2.2 POLYVINYL CHLORIDE CONDUIT (PVC)
A. Standard lengths and sizes.
B. Minimum size 3/4" with the exception that the minimum size conduit for underground site lighting circuits shall be 1".
C. Schedule 40 or 80, heavy wall rigid plastic (PVC) conduit manufactured to NEMA TC-2 standards, UL listed, and as required by NEC. Sunlight resistant.
D. Rated for 90 degrees C. cable.
2.3 PVC COATED RIGID METAL CONDUIT
A. Per NEMA Standards Publication No. RN 1 - 1980 and ANSI C80.1. Shall be ETL Verified PVC-001 or shall meet UL Adhesion Test per ASTM B 117-94.
B. Rigid steel galvanized conduit with PVC coating.
C. Full weight 40 mil thick PVC coating, bonding to galvanized metal shall be stronger than plastic tensile strength.
D. Minimum conduit diameter shall be 3/4 inch.
2.4 RIGID ALUMINUM CONDUIT
A. Standard lengths and sizes.
B. Minimum size 3/4”.
C. UL 6A listed and manufactured to ANSI C80.5.
2.5 LIQUIDTIGHT FLEXIBLE METAL CONDUIT
A. Galvanized spiral strip flexible steel.
B. Standard conduit sizes.
C. Heavy wall sunlight resistant PVC jacket.
D. Minimum size 3/4 inch.
2.6 FLEXIBLE METAL CONDUIT
A. Galvanized spiral strip flexible steel.
B. Standard conduit sizes.
C. Minimum size 3/4" with the exception that 3/8" diameter may be used to serve individual lighting fixtures installed in a suspended accessible ceiling system.
PART 3 EXECUTION
3.1 GENERAL
A. Interior conduits for wiring systems rated to 600 volts shall be galvanized rigid conduit (GRC). Exceptions to the requirements stated above are as follows:
1. Flexible conduit where required by other paragraphs in this section.
2. Conduits in corrosive areas.
B. Exterior underground conduit in direct contact with the earth and conduits embedded in concrete lighting fixture pole bases shall be heavy wall schedule 40 PVC except as follows:
1. Underground conduit runs which enter or exit the building envelope shall utilize PVC-coated rigid metal conduit from the point of penetration of the building envelope and the next 5' portion of the run in direct contact with the earth.
2. Underground conduit runs which contain adjustable frequency drive conductors shall be PVC-coated rigid metal.
C. Exterior exposed conduit (i.e. outside of building wall or above roof) shall be GRC. Exception: Conduit for aeration basin walkways and RAS Denitrification Tank walkways shall be aluminum. Transformation from rigid galvanized steel conduit to aluminum conduit shall begin from the pull boxes and junction boxes. Direct coupling of aluminum conduit and rigid steel shall not be permitted.
D. Conduits encased in concrete as part of an underground electrical duct package shall be schedule 40 HW PVC except that conduits within 5' of a manhole or within 5' of the building envelope shall be PVC-coated rigid metal.
E. Conduits installed in corrosive areas shall be PVC coated rigid metal conduit. Corrosive areas are identified on the drawings.
F. Conduits containing only electrical service bare copper grounding conductors shall be HW PVC.
3.2 DIRECT BURIED UNDERGROUND CONDUIT
A. Exterior underground direct buried conduits shall be buried at a depth of not less than 30 inches below grade.
B. Provide conduits or ducts terminating below grade with means to prevent entry of dirt or moisture.
C. Underground conduits shall slope 1/8" per foot for proper drainage. Conduits shall drain toward manholes and junction boxes, not the electrical equipment.
3.3 PROCEDURES AND PRACTICES
A. All conduit shall be routed concealed in finished spaces and shall not be visible at any point within the finished space or from the building's exterior. This requirement also applies to new conduits installed in existing construction. Exposed raceway may be used on remodeling projects only where physically impossible to route concealed in existing construction. In each case the specific raceway type and routing shall be submitted to the Engineer for approval. Where allowed, the general installation requirements are as follows.
1. Raceways shall be routed horizontally along the corners of walls and ceilings, directly above edges of base molding at floors, or along the tops of window and door frames.
2. Raceways shall be routed vertically along corners of adjacent walls and along the edges of window and door frames.
3. Raceways shall not be routed down or across open wall surfaces except in portions of runs not exceeding 12" in length.
4. Raceways shall be painted to match wall finishes, in finished spaces.
5. Fittings and boxes used with raceways shall be specifically designed and approved for use with the raceways.
6. Raceways may not be routed on or across finished floors.
B. Cut joints shall be square, reamed smooth, and drawn up tight.
C. Keep conduit plugged, clean, and dry during construction.
D. Install No. 12 pull wire in empty conduit.
E. Cap spare conduits.
F. Provide riser clamps around all conduits 1-1/4" or larger that are routed between floors.
G. Provide a watertight conduit system where installed in wet locations such as outdoors, underground, in wash-down areas, or where embedded in concrete.
H. Conduits may be routed exposed in mechanical equipment, electrical, and utility rooms.
I. Route all conduits (including conduits routed above ceilings) parallel to or at right angles with lines of the building construction and structural members except conduit runs routed concealed in poured-in-place concrete floor slabs may be run in a direct line from source to load.
J. Make bends and offsets without kinking or destroying smooth bore of conduit. Arrange bends and offsets in parallel conduits to present a neat symmetrical appearance.
K. Secure conduits in place with malleable corrosion-proof alloy straps or hangers. Conduit straps used in corrosive areas shall be PVC coated.
L. The use of perforated strapping as a conduit hanging method is not approved.
M. Conduit runs that extend through areas of different temperature or atmospheric conditions shall be sealed using approved seal off devices, drained, and installed in a manner that will prevent drainage of moisture or gas migration into cabinets, and equipment enclosures.
N. Conduits routed within poured concrete construction poured walls, floor slabs, topping slabs, etc.) shall comply with the following requirement.
1. Conduits shall be parallel to each other, spaced on center to center distance of at least three times conduit trade diameter, and provided with a minimum of 2 inches concrete covering. Contractor shall note that precast planks below topping slabs may camber. Topping slab thickness will be less at the high point of the camber.
2. Conduits larger than 1¼ inches ID shall not be installed in floor slabs. Conduits over 3/4 inches ID shall not be installed in topping slabs.
3. Conduits embedded in a structural frame slab shall comply with applicable provisions of American Concrete Institute (ACI), Standard 318. Refer to structural drawings for locations of structural frames.
4. Conduits used for feeders shall not be embedded in concrete floor slabs or concrete topping slabs.
5. Conduits in poured concrete construction shall not cross other conduits or other piping.
6. Unless specifically indicated on the electrical plans, conduits installed in (or under) the poured concrete construction shall be approved by the Engineer prior to conduit installation. The contractor will be required to submit drawings showing conduit sizes and routings to the Engineer for his review. Approval may not be given prior to bidding. Contractors who base their bid on the assumption that conduits will be allowed in concrete construction do so at their own risk. No changes will be made to the contract if, during construction, the Engineer prohibits the installation of conduit in concrete construction.
O. In areas constructed of precast concrete conduits may be run in cores of planks.
P. Connections to Motors and Equipment Subject to Vibration:
1. Flexible steel conduit not over 3 ft. long for connection to motorized equipment.
2. Liquid-tight flexible conduit not over 3 ft. long where exposed to moisture, dirt, fumes, oil, corrosive atmosphere, with connectors to assure a liquid-tight, permanently grounded connection. Locate so it is least subject to physical abuse. Corrosive areas are identified on the floor plans.
3. Use double locknuts and insulated bushings with threads fully engaged.
Q. Install bushings with ground lugs and integral plastic linings at equipment with open- bottom conduit entrances.
R. Install conduit expansion fittings where conduits cross expansion joints.
3.4 FIRESTOPPING
A. Provide firestopping at conduit penetrations through fire rated construction in accordance with section 16010.
3.5 CUTTING AND PATCHING
A. Provisions for openings, holes, and clearances through walls, floors, ceilings, and partitions shall be made in advance of construction.
B. Provide cutting, patching and painting necessary for the installation of electrical systems.
C. Where conduits need to penetrate concrete or masonry construction the contractor shall install 22 gauge galvanized steel pipe sleeves, 1 in. larger in diameter than the conduit being installed. Sleeves shall extend 2" above and below the floor slab or wall penetrated. Install sleeves before walls and/or slabs are poured or constructed.
D. The contractor shall prepare drawings indicating size and location of all anticipated floor sleeves for the installation of electrical conduits. Such drawings shall be made available 10 days prior to any scheduled concrete work.
3.6 RESTRICTIONS
A. Conduits routed parallel to steam lines, hot water pipes, flues, high temperature piping or ducts shall be routed at least 12" from such and shall be a minimum 12" clear when crossing same.
B. Do not route conduit over boiler, incinerator, or other high temperature equipment.
C. Where conduits must cross or follow the same path as water, steam or other fluid piping, run electrical conduits above such piping wherever possible.
3.7 ADJUSTMENT AND CLEANING
A. Restore damaged areas on PVC jacketed, rigid conduit with spray type touch-up coating compound or as directed by manufacturer
B. Pull cleaning plug through conduits to clear of dirt, oil, and moisture.
3.8 CONDUIT SYSTEMS
A. Separate raceways shall be provided for each wiring category as follows;
1. 120/208 volt or 120/240 volt normal power wiring systems.
2. 480 volt normal power wiring systems.
3. I&C: analog
4. I&C: 120VAC control
5. I&C: 24VAC control
6. I&C: pulsed frequency
7. I&C: field instrument signal
B. Fiber-optic cables shall always be routed in conduit and these raceways shall include sweeping elbows. Fiber-optic cables may be combined with other I&C wiring categories (listed above), but the raceways shall include sweeping elbows.
END OF SECTION
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