final 26 05 33 Raceways.pdf

OFFUTT AIR FORCE BASE

(092036) 26 05 33-1 (Repair AHU O-Club, B462)

2010 by FEI

SECTION 26 05 33

RACEWAYS

PART 1 - GENERAL

1.1 SUMMARY

A. All wiring shall be installed in continuous raceways.

B. Types of raceways in this section include the following:

1. Electrical metallic tubing.

2. Rigid heavy-wall metal conduit.

3. Flexible metal conduit.

4. Liquid-tight flexible metal conduit.

PART 2 - PRODUCTS

2.1 METAL CONDUIT AND TUBING

A. General: Provide metal conduit, tubing and fittings of types, grades, sizes and weights (wall thicknesses) for each service indicated. Where types and grades are not indicated, provide proper selection determined by Installer to fulfill wiring requirements and comply with applicable portions of

NEC for raceways.

B. Colored Conduit: Route fire alarm conductors in factory-finished red conduit.

C. Rigid Heavy-Wall Steel Conduit: Provide rigid steel, heavy wall, zinc-coated, threaded type conforming to ANSI C80.1 and UL 6. Provide zinc coating fused to inside and outside walls.

1. Rigid Metal Conduit Fittings: Rigid metal conduits shall have threaded couplings.

D. Flexible Metal Conduit: Provide flexible metal conduit conforming to UL 1. Formed from continuous length of spirally wound, interlocked zinc-coated strip steel.

1. Flexible Metal Conduit Fittings: Provide conduit fittings for use with flexible steel conduit of threadless hinged clamp type.

a. Straight Terminal Connectors: One-piece body, female end with clamp and deep slotted machine screw for securing conduit and male threaded end provided with locknut.

b. 45 o or 90 o Terminal Angle Connectors: Two-piece body construction with removable upper section, female end with clamp and deep slotted machine screw for securing conduit and male threaded end provided with locknut.

E. Liquid-Tight Flexible Metal Conduit: Provide liquid-tight flexible metal conduit conforming to UL 360;

construct of single strip, flexible, continuous, interlocked and double-wrapped steel; galvanized inside and outside; coat with liquid-tight jacket of flexible polyvinyl chloride (PVC).

1. Liquid-Tight Flexible Metal Conduit Fittings: Provide cadmium plated, malleable iron fittings with compression type steel ferrule and neoprene gasket sealing rings, with insulated throat.

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F. Electrical Metallic Tubing (EMT): Provide electrical metallic tubing conforming to ANSI C80.3 and UL

797.

1. EMT Fittings: Fittings for EMT shall be steel and may be of the screw or compression type.

Steel compression type shall be used in wet locations. All EMT connectors shall be of the insulated throat type. Cast or indenter fittings are not acceptable. EMT connectors shall be fastened to box or enclosure with locknuts. Snap-in fittings are not acceptable.

2. Steel EMT connectors with male threads on the locknut and female threads on the connector equal to Cooper Crouse-Hinds Space-Saver connectors may be used in lieu of insulated throat type connectors.

G. Conduit Bodies: Provide galvanized cast-metal conduit bodies of types, shapes and sizes as required to fulfill job requirements and NEC requirements. Construct conduit bodies with threaded-conduit-entrance ends, removable covers, either cast or of galvanized steel and corrosion-resistant screws.

2.2 WIREWAYS

A. General: Provide electrical wireways of types, grades, sizes, and number of channels for each type of service as indicated. Provide complete assembly of raceway including, but not limited to, couplings, offsets, elbows, expansion joints, adapters, holddown straps, end caps and other components and accessories as required for complete system.

B. Lay-in Wireways: Construct lay-in wireways with hinged covers, in accordance with UL 870 and with components UL Listed, including lengths, connectors and fittings. Select units to allow fastening hinged cover closed without use of parts other than standard lengths, fittings and connectors.

Construct units to be capable of sealing cover in closed position with sealing wire. Provide wireways with knockouts.

1. Connectors: Provide wireway connectors suitable for "lay-in" conductors, with connector covers permanently attached that removal is not necessary to utilize the lay-in feature.

2. Finish: Protect sheet metal parts with rust inhibiting coating and baked enamel finish. Plate finish hardware to prevent corrosion. Protect screws installed toward inside of wireway with spring nuts to prevent wire insulation damage.

C. Raintight Wireway: Construct raintight lay-in wireways with hinged covers, in accordance with UL 870 and with components UL Listed, including lengths, connectors and fittings. Design units to allow fastening hinged cover closed without use of parts other than standard lengths, fittings and connectors.

Construct units to be capable of sealing cover in closed position with sealing wire. Provide wireway units with knockouts only in bottom of troughs.

D. Raintight Troughs: Construct in accordance with UL 870, with components UL Listed.

1. Construction: 16-gage galvanized sheet metal parts for 4-inch x 4-inch to 6-inch x 6-inch sections, and 14-gage parts for 8-inch x 8-inch and larger sections. Provide knockouts only in bottom of troughs, with suitable adapters to facilitate attaching to other NEMA 3R enclosures.

Do not use gasketing that can rip or tear during installation, or would compromise raintight capability of the trough. Do not use cover screws that will protrude into the trough area and damage wire insulation.

2. Finish: Provide 14-gage and 16-gage galvanized sheet metal parts with corrosion-resistant phosphate primer and baked enamel finish. Plate hardware to prevent corrosion.

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PART 3 - EXECUTION

3.1 INSTALLATION OF RACEWAYS

A. General: Install raceways as indicated; in accordance with manufacturer's written installation instructions, and in compliance with NEC and NECA's "Standards of Installation". Install units plumb and level and maintain manufacturer's recommended clearances.

B. Coordinate with other work including wires/cables, boxes and panel work, as necessary to interface installation of electrical raceways and components with other work.

3.2 INSTALLATION OF CONDUITS

A. General: All conduits shall be concealed unless noted otherwise. Install concealed conduits either in walls, slabs or above hung ceilings. In existing work where conduits can not be concealed in finished areas, surface metal raceways shall be used (Wiremold or conduit at Contracting Officer’s discretion).

1. Mechanically fasten together metal conduits, enclosures, and raceways for conductors to form continuous electrical conductor. Connect to electrical boxes, fittings and cabinets to provide electrical continuity and firm mechanical assembly.

2. Avoid use of dissimilar metals throughout system to eliminate possibility of electrolysis. Where dissimilar metals are in contact, coat surfaces with corrosion inhibiting compound before assembling.

3. Install miscellaneous fittings such as reducers, chase nipples, 3-piece unions, split couplings, and plugs that have been specifically designed and manufactured for their particular application. Install expansion fittings in raceways every 200-feet linear run or wherever structural expansion joints are crossed.

4. Use roughing-in dimensions of electrically operated unit furnished by supplier. Set conduit and boxes for connection to units only after receiving review of dimensions and after checking location with other trades.

B. Conduit Installation:

1. Use rigid steel heavy-wall zinc-coated conduit in spaces where exposed below 4-feet-0-inch height in Mechanical Equipment Rooms, Electrical Equipment Rooms, Boiler Rooms, Penthouses and in service splines. Other areas include warehouse spaces where exposed below 18-feet-0-inch height, on floors of crawl spaces, wet locations, and locations subject to mechanical injury.

2. Where acceptable to all authorities having jurisdiction, intermediate metal conduit may be used in lieu of rigid steel heavy-wall conduit in non-hazardous locations when in compliance with

NEC.

3. Use steel zinc-coated EMT for raceway systems except as specifically specified previously, where not allowed by NEC or noted on drawings. Additionally EMT shall not be acceptable below grade, in or under slabs on grade, or in wet locations.

4. Use flexible conduit in movable partitions and from outlet boxes to devices installed in accessible ceiling tiles. Arrange flexible conduit to allow removal of ceiling tile with installed device without dismantling of connected raceway systems. Use flexible conduit for final 24-

(092036) 26 05 33-4 (Repair AHU O-Club, B462) inches of connection to motors and mechanical equipment, or control items subject to movement or vibration. The maximum length for flexible conduit shall not exceed 6-feet.

5. Use liquid-tight flexible conduit where subjected to one (1) or more of the following conditions:

a. Exterior location.

b. Moist or humid atmosphere where condensate can be expected to accumulate.

c. Corrosive atmosphere.

d. Subjected to water spray or dripping oil, water or grease.

C. Install pull wires in empty raceways. Use No. 14 AWG zinc-coated steel or monofilament plastic line having not less than 200 lb tensile strength. Leave not less than 12-inches of slack at each end of the pull wire.

D. Cut conduits straight, properly ream, and cut threads for heavy wall conduit deep and clean. Use temporary closures to prevent foreign matter from entering raceways.

E. Field-bend conduit with benders designed for purpose so as not to distort nor vary internal diameter.

F. Size conduits to meet NEC requirements and as shown on drawings or specified herein.

G. Fasten rigid conduit terminations in sheet metal enclosures with locknuts inside and outside enclosure or with threadless rigid box connectors and terminate with bushing.

H. Conduit terminations in wet locations shall be of the threaded hub type or other sealing type fittings UL

Listed for use in wet locations.

I. Conduits are not to cross vertical or horizontal openings such as pipe shafts, elevator shafts, ventilating duct openings, etc.

J. Keep conduits a minimum distance of 6-inches from parallel runs of flues, hot water pipes or other sources of heat. Wherever possible, install horizontal raceway runs above water and steam piping.

K. Conduit shall be properly supported as specified herein and as required by NEC. Attach raceways directly to building structure (structural wood, structural concrete, or steel red iron), or to unistrut trapeze supported directly from building structure with 3/8-inch minimum threaded rods. Wire type supports and click-type hangers shall not be allowed. Do not attach to roof decking.

L. Support riser conduit at each floor level with clamp hangers.

M. Use of running threads at conduit joints and terminations is prohibited. Where required, use 3-piece union or split coupling.

N. Complete installation of electrical raceways before starting installation of cables/wires within raceways.

O. Install raceway sealing fittings in accordance with the manufacturer's written instructions. Locate fittings at suitable, approved, accessible locations and fill them with UL Listed sealing compound. For concealed raceways, install each fitting in a flush steel box with a blank cover plate having a finish similar to that of adjacent plates or surfaces. Install raceway sealing fittings at the following points and elsewhere as indicated:

1. Where conduits enter or leave hazardous locations.

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2. Where conduits pass from warm locations to cold locations, such as the boundaries of refrigerated spaces, built-up air handlers, and air-conditioned spaces.

3. Where required by the NEC.

P. Openings around electrical penetrations through fire-resistant-rated walls, partitions, floors or ceilings shall be firestopped using approved methods to maintain the fire resistance rating.

Q. Provide sleeves for conduits passing through foundation or other load bearing walls.

R. All conduits extending through the exterior walls of a building in areas below grade shall be provided with a hydrostatic seal such as Link Seal or equal.

S. Concealed Conduits:

1. Conduits in finished areas shall be installed concealed.

T. Install conduits as not to damage or run through structural members. Avoid horizontal or cross runs in building partitions or side walls.

U. Exposed Conduits:

1. In unfinished areas such as Janitor Closets, Storage, Mechanical Equipment Rooms, etc., conduit may be run exposed. In finished areas with exposed structure, surface raceway may be run exposed (Wiremold or surface conduit at Contracting Officer’s discretion). Prior permission shall be first obtained from the Contracting Officer. All exposed conduit or surface metal raceways shall be installed in a neat manner following the building lines. Horizontal runs shall be close to the ceiling and shall be installed above mechanical piping as much as possible. Multiple hung conduits shall be strapped to the channel to hold it in place.

2. Install exposed conduits and extensions from concealed conduit systems neatly, parallel with or at right angles to walls of building.

3. Install exposed conduit work as not to interfere with ceiling inserts, lights or ventilation ducts or outlets.

4. Support exposed conduits by use of hangers or clamps. Attach raceways directly to building structure (structural wood, structural concrete, or steel red iron), or to unistrut trapeze supported directly from building structure with 3/8-inch minimum threaded rods. Wire type supports and click-type hangers shall not be allowed. Do not attach to roof decking. Support conduits on each side of bends and on spacing not to exceed following: Up to 1-inch: 6-feet-0-inch; 1-1/4-inch and over: 8-feet-0-inch.

5. Run conduits for outlets on waterproof walls exposed. Set anchors for supporting conduit on waterproof wall in waterproof cement.

6. Above requirements for exposed conduits also apply to conduits installed in space above hung ceilings, and in crawl spaces except that spacing of supports for conduits up to 1-inch shall not exceed 8-feet-0-inch.

V. Conduit Fittings:

1. Construct locknuts for securing conduit to metal enclosure with sharp edge for digging into metal, and ridged outside circumference for proper fastening.

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2. Plastic insulating bushings for terminating rigid conduits smaller than 1-1/4-inch are to have ribbed sides, with smooth upper edges to prevent injury to cable insulation.

3. Install metallic insulated type bushings for terminating rigid conduits 1-1/4-inch and larger.

Bushings are to have flared bottom and ribbed sides. Upper edge to have phenolic insulating ring molded into bushing.

4. Miscellaneous fittings such as reducers, chase nipples, 3-piece unions, split couplings and plugs to be specifically designed for their particular application.

END OF SECTION