SECTION CONDUITS AND BOXES

Transcription

1 PART 1 GENERAL 1.01 DESCRIPTION A. Work covered by this section includes the furnishing and installation of conduits and boxes and the testing of the completed electrical systems 1.02 SUBMITTALS A. The Contractor shall submit shop drawings, in accordance with Section Shop Drawing submittals shall clearly show the following: 1. Materials 2. Ratings (voltage, phase, current) 3. Manufacturer s name, address and telephone number 4. Product data including manufacturer s technical data 5. Applicable manufacturer specifications 6. Installation instructions 1.03 QUALITY ASSURANCE A. Set all conduits and boxes plumb and level. B. All conduits and boxes shall be straight, free from blisters and defects, and shall bear the Underwriter s label PENETRATIONS A. Waterproofed surfaces Except where absolutely necessary, do not penetrate roofs and waterproofed surfaces. Where required, make penetrations prior to the application of roofing and waterproofing materials and furnish all sleeves, pitch pockets and other approved items. B. Hazardous areas Seal all conduits and penetrations entering or leaving hazardous areas in accordance with NEC. C. Other gases and corrosive atmospheres Seal all conduits and penetrations which enter or leave a room or structure which will or may contain a corrosive atmosphere or a potentially lethal atmosphere. Seals shall be gas and vapor tight to prevent gases and vapors from escaping or from being communicated from such areas. TALL OAKS STP

2 PART 2 - PRODUCTS 2.01 CONDUIT A. All conduits shall be run exposed unless run in earth, or specifically noted as concealed on plans. B. In hazardous areas and in poured concrete slabs, conduit shall be PVC coated heavy wall rigid galvanized steel. Conduit shall have expansion fittings where passing expansion joints. No conduit shall be run in tank walls or in slabs on grade. Conduits in concrete slabs outdoors shall exit slab with a factory applied PVC coating to the nearest box or joint. C. Schedule 80 PVC with ground wires shall be used per code in all other locations, unless otherwise indicated on plans. PVC conduit must be sunlight resistant. D. Conduits shall be placed at right angles or parallel to walls and securely held by galvanized iron or PVC hangers or straps. No conduit shall be smaller than ¾. All conduits shall be secured with backstraps to structural members. E. The ends of all conduits where entering outlet boxes shall be fitted with locknuts and bushings. At other locations where not entering boxes, the conduit ends shall be equipped with conduit fittings with covers. Provide ground bushings per code and at all motor control centers, with ground wire. F. Provide all necessary hangers, angle iron or channel frames for support of conduit and boxes. G. For all sizes of conduit larger than 1, large radius elbows and offsets made for the purpose shall be used. In smaller sizes the contractor shall be permitted to make bends instead of using the manufactured elbows and offsets, but care must be taken not to damage the conduit. In general, conduit bends shall be made in accordance with Article No. 346 of the National Electric Code. H. Conduit shall be as manufactured by Carlon, Scepter, Robroy or approved equal. I. All buried PVC conduit for vertical to horizontal transitions shall utilize a rigid galvanized PVC coated rise elbow in areas subject to vehicle traffic LIQUID-TIGHT FLEXIBLE CONDUITS A. Make terminal connections to motors and equipment with liquid tight, flexible conduit of the same size as the rigid conduit run. B. Maximum length of liquid tight flexible conduit 18. C. Liquidtight Flexible Non-Metallic Conduit: IL 1660, Non-metallic, liquid-tight conduit with a polyvinyl chloride reinforced core. Conduit must conform to NEC 351B. Acceptable Manufacturers: Electri-Flex Liquatite, Kellems Polytuff I or approved equal TALL OAKS STP

3 2.03 CONDUIT FITTINGS A. Fittings and couplings shall be PVC. Manufacturer approved solvent cement shall be used for joining all PVC conduit. B. For liquid tight flexible conduits, fittings shall have body and gland nut of cast malleable iron, cadmium plated, a one piece brass grounding bushing which threads to interior or conduit spiral, and molded vinyl sealing ring between flange nut and bushing GENERAL A. Conduits shall be sized per NFPA 70 (National Electric Code). Unless otherwise noted, minimum size shall be ¾. B. Each length of conduit shall bear the UL label and the manufacturer s name or trademark. C. Provide No. 12 galvanized pulling wire in each empty conduit and duct, continuous. D. In areas normally enclosed and exposed to raw sewage, provide explosion proof construction in compliance with NEC requirements for Class 1, Division 1, Group D, hazardous locations. E. Provide all unions, reducers, conduit caps and all other fittings and hardware required to complete all conduit runs. F. Use locknuts and proper insulating type bushings, as required. G. Provide conduit expansion fittings, complete with bonding jumpers, at all concrete expansion joints, between concrete structures and where conduits are firmly attached to two independent structures OUTLET BOXES A. The contractor shall furnish and install at all outlets a standard one piece outlet box. Boxes and cover shall be in every instance of such form and dimensions as to be adapted to its specific use and location, kind of fixtures to be used and the number, size and arrangement of conduits connecting thereto. Outlet boxes shall be PVC. B. Outlet boxes shall be as manufactured by the conduit manufacturer. C. Care shall be taken to open such holes as are to be used for the conduits entering the boxes. Those holes not used shall be closed with snap-in blanks or equivalent. D. Concealed outlet boxes shall be firmly anchored in place and shall be provided with approved fixture supports where required. Suitable expansion screws, wood screws with lead plugs, or approved toggles shall be used in all cases for securing to stone, brick or transite walls and partitions. TALL OAKS STP

4 E. All boxes for exterior and interior surface mounted work shall be PVC equipped with gaskets and shall be vaporproof or watertight where required. F. Surface mounted wiring devices shall be mounted in conduit boxes type FS, or FD PULLBOXES, JUNCTION BOXES AND WIREWAYS A. Interior STP non-process area Ppull or junction boxes shall be NEMA 12 cabinet type construction unless noted. Interior pullboxes in non-process areas larger than 6 inches square shall be JIC or NEMA 12 construction. Interior STP process area pull or junction boxes shall be NEMA 4X at all times. Exterior pullboxes and troughs shall be NEMA 4X construction. B. Junction boxes, pullboxes and cable support boxes of proper size and design shall be furnished and installed to facilitate pulling of wires. C. Pullboxes required for main lighting and power conduits shall be located to suit building conditions and clearances. Approved supports shall be provided. D. All interior wireways and troughs shall be NEMA 12 construction of JIC spec type, with hinged covers, unless they are in process areas, where they shall be NEMA 4X UNDERGROUND CONDUIT A. Unless otherwise specified or shown on the drawings, all underground conduits shall not be encased in concrete. B. Encasements, all around conduit, shall be a minimum of 2 for concrete, unless otherwise specified or shown on the drawings. C. Plastic warning tape shall be buried 6 above all underground conduits and duct banks. PART 3 - EXECUTION 3.01 INSPECTIONS VERIFICATIONS A. The drawings indicate the general locations of outlets. Fixtures, equipment, wiring and other electrical devices and the general details for the complete electrical and telephone installations. B. Conduit locations are diagrammatic only and do not necessarily indicate the exact location or routing. C. Prior to locating and installing conduits and boxes, check the contract drawings and the work to be sure that the locations of all conduits and boxes will not interfere with or be covered by TALL OAKS STP

5 doors, casework, heating, and process equipment, or the like, and the conduit stubs for motors and equipment will be placed in the proper locations INSTALLATION OF CONDUITS A. Conform to NEC requirements. B. Unless otherwise directed by the engineer or shown on the drawings, all conduits shall be run exposed. C. For exposed work, conduit shall be supported by one hole straps and clamp backs. Secure tightly with screws, bolts or other approved means. Size of bolts shall be commensurate with supported weight. Maximum separation between supports shall be as outlined in NEC. D. For parallel groups of exposed conduits, provide trapeze hangers or other approved method of installation. E. All exposed conduits shall be neat and symmetrical and run parallel with adjacent walls, partitions and ceilings. Diagonal runs are not permitted. F. Perforated strap hangers are not permitted. G. Running thread type conduit connections are not permitted. H. Provide conduit insulating bushings with ground legs on all conduits terminating in or under motor control centers and ground to control center and system ground. Provide insulating bushings at all other locations required by NEC. I. Unless otherwise specified or directed by the engineer, the minimum depth of cover over underground conduits shall be 18, except under roads, parking lots and other traveled areas where it shall be 24 inches. J. Underground conduit runs shall be pitched for drainage, away from the level of entry to buildings or equipment. K. Where two (2) or more underground conduit runs are banked together, separate them by not less than two (2) inches. L. Holes through concrete wall for conduit installation shall be made with a core drill. Position holes to avoid reinforcing steel. After installation, fill remaining annular space with an approved material. Do not penetrate reinforcing bars. M. The use of wooden plugs inserted into concrete or masonry as a base to fasten conduits is not permitted. N. Avoid bends and offsets where possible. Where necessary, use a conduit manufacturer approved conduit bending machine. No bends greater than 90 degrees are permitted in any one run of conduit. Provide pullboxes where more bends are necessary. O. Deformed, crushed, or cracked conduit is not permitted. TALL OAKS STP

6 P. Cut conduit with powered hacksaw. Cut ends square. Q. Maintain six (6) inch minimum separation between all conduits and water lines. R. All couplings shall be pulled up tight. Ends of conduits terminating in a pressed steel box shall be provided with a galvanized locknut and bushing inside and a locknut outside. Fiber or hardwood bushings are not permitted at termination of feeder conduits. S. Plug and cap all conduits until ready to pull wires and make connections INSTALLATION OF BOXES A. Locate special function outlets where shown on the drawings. B. Make dimension between door openings and wall switches uniform throughout the work. C. Boxes shall be supported independently of all conduits and shall be rigidly secured in place. D. On concrete, brick or other masonry surfaces, secure surface mounted boxes with machine screws or bolts and expansive type shield. E. On buildings steel, secure boxes by means of clamp type supports and provide rigid vibration proof installation. F. Surface mounted pull and junction boxes, one foot square or more in area shall be installed to provide a minimum air space between box and mounted surface on one (1) inch. G. Tape all joints in outlet and junction boxes in such manner and thickness that the insulating value of the joints or splice will be at least equal to the insulating value of the conductor to which it is applied. Tape shall be varnished cambric and electrical tape. H. Unless otherwise shown on the drawings or required by the engineer, the mounting height of all boxes shall be as follows: (from the floor to the centerline of box). Local switches 44 Convenience receptacles - above grade areas below grade areas Clock outlets 7-0 Safety and disconnect switches Panels to top breaker Telephone outlets I. Do not install junction boxes in structural slab less than 4 thick. Junction boxes in slabs 4 and thicker shall not exceed 4-1/2 in width and length, and 2 in depth. When placed flush with the bottom in the middle half of the span of 1-way slabs, the boxes shall be separated by at least 6 inches of concrete. When placed outside the middle of the span, they shall be separated by at least 2 of concrete. TALL OAKS STP

7 3.04 ADJUST AND CLEAN A. Adjust all work to provide a rigid, neat, and clean conduit system. B. Clear conduits of all obstructions and dirt prior to pulling wires of cables. Use ball mandrel, with a diameter equal to approximately 85% of the inside diameter of the conduit, followed by a close fitting wire brush and wad of felt or similar material. This assembly may be pulled together with, but ahead of, the cable being installed. C. Clean empty conduits, as specified above. END OF SECTION TALL OAKS STP

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