ATM PROJECT-electromic. work

3.9    CONDUITS, WIREWAYS, SUPPORTING

    SYSTEMS AND   RELATED ACCESSORIES 

Part 1 GENERAL

3.9 .1.1    DESCRIPTION OF WORK

Raceways, including conduits, wire ways and related installations and accessories necessary  to support and protect  cables, feeders, sub-feeders, branch-circuit wiring and  wiring of the low current systems, communications and signal  systems.

3.9 .1.2   REGULATIONS AND STANDARD

Conduits, wire ways and fittings are to be designed, constructed and installed to give a safe installation and reliable mechanical protection for wires and cables in accordance with the Regulations.  Standards are to be as specified under the products.

3.9 .1.3     ‏ TECHNICAL DATA

Submit data including, but not limited to, the following:

-‏        Manufacturers' catalogue cuts with specifications for conduit, trunking etc. and related accessories

-‏        ‏Samples of each type of conduit and accessory

 3.9 .1.4  SHOP AND CONSTRUCTION DRAWINGS:

Submit drawings including, but not limited to the following:

-        ‏Exact routing of conduits, trunking etc. with indication of boxes, accessories and expansion joints; size and type of conduits and boxes are to be indicated

-‏        ‏Typical assembly details of installation of trunking, trays etc.

-‏        ‏Construction details of pull boxes.

-‏        Typical installation details including connection of  conduits to metal enclosure, connection of flexible conduits, vapor-tight installations in cold rooms,  weatherproof installations outdoors etc.

3.9 .1.5     ‏ APPROVED MANUFACTURE

Obtain conduit, wire ways and related accessories from one of the following:

          Byeit Elhandasa             Egypt

          Elrehab  Co.                   Egypt

          Eslon  Co.                       Egypt

or other equal and approve d.

Part 2         ‏      CONDUITS AND ACCESSORIES

3.9 .2.1     ‏‏     ‏ RIGID HEAVY GAUGE STEEL CONDUIT

MATERIAL:

Heavy gauge welded and drawn steel, threaded at both ends.

STANDARD:

Conduit is to be to BS 31 Class B (screwed) with class 4  protection for rigid steel conduit, zinc coated, inside and outside by the hot-dip process/sherardizing and in compliance with BS 4568 Part 1.

FITTINGS GENERALLY:

Threaded type, galvanized or cadmium plated malleable cast iron.  Fittings used in corrosive atmospheres are to be specially treated.  Fittings and components are to comply with BS 4568 Part 2.

LOCKNUTS:

For securing conduit to metal enclosure are to have sharp edges for gripping and ridged outside surface for fastening.

BUSHINGS:

For terminating conduits are to be insulated type with flared bottom and ribbed sides.  Upper edge is to have phenolic insulating ring molded into surface.  Bushing for earth connection is to have screw terminal.

END BELLS:

For terminating conduit in face of concrete or masonry walls are to be cast metal, threaded, and flared type.

MISCELLANEOUS FITTINGS:

Including reducers, chase nipples, three piece unions, split couplings and

plugs are to be designed and manufactured for  the particular application.

3.9 .2.2     ‏‏     FLEXIBLE STEEL CONDUIT

MATERIAL:

Steel, cold  rolled and annealed, non-threaded type, formed  from continuous length of helically wound and interlocked strip steel, with fused zinc coating on inside and outside  and to BS 731.

LIQUID TIGHT FLEXIBLE CONDUIT:

Is to have a PVC jacket extruded over core.

FITTINGS GENERALLY:

Thread less; hinged clamp type, galvanized or cadmium plated malleable cast iron.  Fittings used in corrosive atmospheres are to be specially treated.

STRAIGHT CONNECTORS:

One piece body, female end having hinged clamp and deep  slotted machine screws for securing to conduit, male end  having thread and locknut.

ANGLE CONNECTORS:

Of 45 deg. or 90 deg. and terminal connectors are to be as specified for straight connectors, except that body is to be two-piece with removable upper section.

3.9 .2.3‏     RIGID HEAVY GAUGE PVC CONDUIT

MATERIAL:

Rigid unplasticized polyvinyl chloride with high impact and high temperature resistance, flame retardant, non- hygroscopic and non-porous.

STANDARDS:

To CEE 26, DIN 49026 or other equal and approved standards conforming to IEC 423, 614-1 and 614-2-2.

FITTINGS GENERALLY:

Unbreakable, non-inflammable, self extinguishing, heavy moulded plastic.

ASSEMBLY:

Conduits, boxes and accessories are to be assembled by cementing, using manufacturer's recommended cementing products and appropriate connectors or spouts.  Where no spouts are available use smooth bore male PVC bushes and sockets.

3.9 .2.4     FLEXIBLE PVC CONDUIT

MATERIAL:

Flame retardant, heat resistant, non-hygroscopic PVC, high resistance to impact, ribbed on the circumference.

3.9 .2.5     ‏ STEEL CONDUIT ACCESSORY

SLEEVES THROUGH OUTSIDE WALLS:

Cast iron with end and intermediate integral flanges, internal diameter suitably over-sized to outside diameter of conduit, length to correspond to wall thickness.  Space between sleeve and conduit is to be packed with oakum to within 50 mm of both faces of wall.  Remainder of sleeve is to be packed with plastic compound or lead, held in place by heavy escutcheon plates bolted at both ends to flanged ends of sleeve or other equal and approved.

SUPPORTS AND HANGERS:

Galvanized malleable cast iron straps or structural steel sections with hot dip galvanized bolts and nuts.

EXPANSION JOINT FOR EMBEDDED STEEL CONDUITS:

Watertight, flexible conduit with end fittings to receive fixed conduits.  Length is to allow movement within range of joint and is not to be less than 20 times diameter of conduit.  Conduit is to be covered with thick rubber tubing with 5mm minimum gap all around tube.  Bonding jumper with earth clamp is to electrically connect both sides of joint. 

EXPANSION JOINT FOR EXPOSED STEEL CONDUITS:

Sleeve with fittings to permit telescoping of one conduit into sleeve.  Movable conduit is to be fitted with insulating bushing.  Joint is to be weatherproof.  Joint is to be of malleable iron with corrosion resistant gasket. Bonding jumper with earth clamp is to electrically connect both sides of joint.

EXPANSION JOINT FOR EXPOSED STEEL CONDUITS:

PVC sheathed flexible steel conduit terminating in pull boxes and securely fixed on each side of structural expansion joint.  Bonding jumper is to be electrically connecting both sides of joint.

TAGS:

50 mm diameter steel with indented lettering, rust inhibiting treatment and baked enamel finish.

Part 3        WIREWAYS AND CABLE SUPPORTING SYSTEM

3.9 .3.1     CABLE TRAY

COMPONENTS:

Are to include cable trays, bends, elbows, tees, couplings and plates, rubber grommits, hangers, supports and other accessories.

MATERIAL:

Hot dip galvanized steel ladder type with corrosion resistant coating.  Fittings are to be of same material as tray.

SIZE:

Trays are to be standard metric sizes 100, 150mm, 300, 600 mm, 900 mm wide and100 mm deep.  Size of tray is to be determined by number and sizes of cables in accordance with the Regulations and/or as shown on the Drawings. Tray is to have strength and rigidity to provide support for cables contained within.

3.9 .3.2     ‏ WIRING AND CABLE TRUNKING

COMPONENTS:

Are to include wireway base, 'clip-on' covers, couplings, endplates, wall flanges, panel to trunking rubber grommets, elbows, tees, adaptor plates and necessary hangers, supports and accessories.

STEEL TRUNKING:

Galvanized sheet steel, 1.5 mm minimum thickness, protected internally and externally with corrosion resistant finish such as zinc or cadmium with top coat of enamel. Trunking is to be to BS 4678 Part 1.

SIZE:

As required to accommodate number of conductors permitted by the Regulations and/or as shown on the Drawings.

3.9 .3.3     WEATHERPROOF WIRING AND CABLE TRUNKING(NID)

TYPE:

Trunking and cover, of hot dip galvanized sheet steel, similar to Simplex 'Power Centre' type or other equal and approved.

CONSTRUCTION:

Trunking is to be constructed with outwardly turned flanges  to receive the cover, and are to be provided with an internal sleeve coupling between sections, thus allowing cutting  of trunking on site.

GASKETS:

Neoprene bonded cork gaskets are to be fitted throughout, between any two attached surfaces.

SCREWS:

Removable flanged covers are to be secured with holding screws.  All screws are to be galvanized steel.

Part 4         FIELD AND INSTALLATION WORK 

3.9 .4.1‏     ‏ CONDUIT AND WIREWAYS GENERALLY

USE:

Unless otherwise specifically indicated all light and power circuits, communications, signal and low current systems wiring are to be drawn inside conduits or wire ways up to the various electric power consuming equipment as shown on the Drawings.  Separate conduit and wire way installations are to be used for HV cables, normal light and power circuits, emergency light and power circuits and communication, signal and other low current systems wiring.

BOXES:

Junction, pull and splice boxes of ample capacity are to be provided as indicated or required.  Boxes are to remain permanently accessible.

TOOLS AND ACCESSORIES:

For forming and installing conduit and wire way systems are to be purpose made for the particular application and used in accordance with manufacturers' instructions.

FIXING:

Conceal conduits and wire way installations as much as possible.

SIZES:

Of conduits and wire ways, not shown on the Drawings, are to be selected in accordance with the Regulations and in relation to the number and size of conductors.

MINIMUM SIZE:

Of conduit for all applications is to be 16 mm diameter, unless otherwise shown on the Drawings.

MECHANICAL CONTINUITY:

Conduits and wire ways are to be effectively joined together and connected to electrical boxes, fittings and cabinets to provide firm mechanical assembly.  In the case of steel conduits earthing jumpers are to be installed where required to  ensure effective electrical continuity irrespective of whether a separate protective earth conductor is required or  not.

3.9 .4.2 CONDUIT APPLICATIONS AND INSTALLATION GENERALLY

RIGID HEAVY GAUGE PVC CONDUIT:

Is to be used generally in underground installations and in screed below outdoor pavements.

RIGID HEAVY GAUGE STEEL CONDUIT:

Is to be used for surface mounted main and sub-feeder installations, except where otherwise shown on the Drawings.

RIGID HEAVY GAUGE STEEL CONDUIT:

Is to be used for the following:

-‏        Light and power circuits in surface mounted and conceal installations, or installations embedded in concrete and in masonry

-‏        Low-current installations, including all communication and signal systems Except where otherwise shown on the Drawings or described in other Sections of the Specification.

FLEXIBLE CONDUIT:

Of same material as corresponding rigid conduit system is to be used for connection to motors, vibrating and non-rigidly fixed equipment and to fixtures installed in false ceilings.

EXPOSURE TO DAMAGE:

Where conduit is subject to risk of damage by shock or corrosion, it is to be brought to the attention of the Engineer.  Copper silicone alloy tubes may be used in corrosive atmospheres.

CROSSINGS:

Conduits are not to cross pipe shafts, vents or openings.

CLEARANCES:

Install conduits at least 100 mm clear of and preferably above pipes of other non-electrical services.

SLEEVES:

Obtain approval for positioning sleeves where conduits pass through reinforced concrete.  Additional openings may be allowed in finished slabs but are to be drilled and not broken.  Rigidly fix sleeves to maintain position and alignment during construction work.

EXPANSION FITTINGS:

Provide expansion fittings in each conduit run at a crossing of an expansion joint in the structure.

WATERPROOF CONSTRUCTION:

Conduits are not to cross waterproof construction unless permitted by the Engineer. Specially designed and approved fittings are to be used.

MAKE GOOD:

All holes for conduits passing through walls, floors and ceilings with cement or similar fire-resisting material to full thickness.

BENDS:

Conduit runs between outlet and outlet, fitting and fitting or outlet and fitting are not to contain more than the equivalent of 2 quarter bends (180 deg. totals).

BENDING:

Is to be made without damaging conduit or tubing and without reducing internal diameter.  Methods of field bending are to be approved.

CUT ENDS:

Are to be reamed to remove burrs and sharp edges.

 

DRAINING:

Arrange conduits so that condensed moisture can drain to screwed plug at lowest point.

BEFORE WIRING:

Conduits are to be swabbed through.  Do not draw cables into any section of system until conduit and draw boxes are fixed in position.

CAPPING:

Conduits are to be properly capped until wiring conductors are drawn in.

CONDUIT AND FITTINGS INSTALLED OUTDOORS:

Are to be watertight and highly resistant to corrosion. Use appropriate fittings, threaded cast boxes, gaskets and the like.

TERMINATIONS:

Do not terminate or fasten rigid conduits to motor frame or base.

LENGTH AND RADIUS OF FLEXIBLE CONDUIT:

Used for motors and vibrating equipment are to permit bending of feeder cables without damage to conductor or insulation.

FLEXIBLE CONDUIT:

For slide rail mounted motor is to have sufficient slack to allow for movement of motor over entire slide rail length.

PULLING WIRE:

Install 3 mm galvanized stranded steel wire or equivalent strength cord with wooden blocks fastened at ends, in empty service conduits (power, low current and signal).

 STANDARD ELBOWS:

Are to be used for conduit sizes over 40 mm.  For smaller sizes, field bends may be used provided no damage occurs to conduit.

 FIT TAGS:

To conduits entering or leaving floors, walls or ceilings for identification of conduit and circuits.  Tags are also to be placed at suitable intervals throughout the system.

3.9 .4.3‏    ‏ STEEL CONDUIT

TERMINATION:

Conduit entering sheet metal enclosure or outlet boxes, when not terminated in a threaded hub, is to be securely held in place by two lock-nuts and terminated with an insulating bushing.  Place lock-nuts inside and outside enclosure.

RUNNING THREADS:

Do not use running threads at joints and terminations but use 3-piece unions or split couplings.

ADDITIONAL THREADED CUTS:

On galvanized steel conduits are to be painted with zinc based coating resistant to corrosion.

 DAMAGE:

To protective coating of conduits is to be repaired to original degree of protection.

 GALVANIZED CONDUIT RUNS IN SCREED:

Is to be painted with heavy coat of emulsified bitumen

.

GALVANIZED STEEL CONDUITS BURIED IN GROUND:

Or placed in wet or damp locations are to be coated with two heavy coats of hot bitumen.  They are to be covered by at least 600 mm of earth if buried in planting soil and by 300 mm if under walkway.

3.9 .4.4     PVC CONDUIT

COUPLING:

Of conduit and/or termination into spouted fittings are to be made watertight and permanent using special cement.

TERMINATION:

Connect conduits terminating in switchgear, fuse boards,   trunking, adaptable boxes or other non-spouted enclosures etc. with smooth bore male PVC bushes and sockets.

 ENDS OF CONDUIT:

And conduit fittings are to be cleaned and jointed using PVC cement recommended by manufacturer.

SEMI-PERMANENT ADHESIVE:

Use in joints requiring expansion couplers.

 BENDS:

Conduits not exceeding 25 mm in diameter may be cold bent using bending springs.  Conduits over 25 mm are to be hot bent by an approved method.

3.9 .4.5     EMBEDDED CONDUIT

CONDUITS IN CONCRETE SLABS:

Place parallel to main reinforcing steel.

HORIZONTAL OR CROSS RUNS:

In partitions or side walls are to be avoided.

PULL-BOXES:

Are to be avoided.  If unavoidable, such installation may be approved if located inconspicuously.

CONDUITS IN FLOOR OF SLABS ON GRADE:

Encase in concrete, minimum thickness 50 mm or to thickness allowed by the architectural detail.

PVC CONDUITS:

Embedded in reinforced concrete structures are to be well protected against damage, and installed after completing all steel reinforcement work.

3.9 .4.6     EXPOSED CONDUIT

 CONDUITS ON WALLS:

Run neatly, horizontally or vertically fixed to walls.

 SUPPORTS:

Use approved clamps, hangers or clips fastened by machine screws to expansion sleeves in inserts or to lead anchors.

 SPACING OF CLAMPS OR CLIPS:

For supporting steel conduits is not to be greater than:

Conduit Size‏                                                   Maximum Spacing of Support‏ts   

‏ mm (inches)‏                                                                    ‏      ‏meters

‏          ‏               20 (3/4)                                                            3

                        25 (1)                                                               3.6

‏          ‏               32-38 (1 1/4 - 1 1/2)                                        4.25

                         50-63 (2 - 2 1/2)‏                                             5          ‏           

                        ‏ 75 (3) and larger                                            6‏

                   ‏     ‏

BENDS AND FITTINGS:

Firmly fasten conduit at each side of bends and within 900 mm of each outlet box, junction box, cabinet or fitting.

 OBSTRUCTIONS:

Run conduit without interfering with ceiling inserts, lights or ventilation outlets.

 OUTLETS:

Do not run more than one conduit to any wall outlet.  Install junction box near ceilings to act as a pull box in which vertical conduit is to terminate.

 OUTDOOR MOUNTED CONDUIT:

Apply anti-corrosion coating of zinc-chromate based paint and two weather resistant finish coats of enamel, of approved color, or other equal and approved coating.

3.9 .4.7     CABLE TRAY

 INSTALLATION:

Each run of cable tray is to be completed before installation of cables.

 SUPPORTS AND BARRIERS:

Provide supports to prevent stress on cables entering or leaving tray.  Cable trays extending through partitions and walls are to be protected by fire-proof non-combustible barriers.

 SECURE CABLES:

With purpose made straps or saddles and arrange in one layer only, evenly spaced at least one diameter between one circuit and another.

 FINISH:

Remove sharp edges, burrs and projections and finish trays smooth.

 FIX:

Trays using approved suspension rods or steel angle brackets at spacing not exceeding.

 CONNECTION FITTINGS:

 Such as tees, bends and crossing are to be purpose made with radius to permit cable bending standards.

 MINIMUM CLEARANCE:

Of 250 mm is to be maintained between top of tray and ceiling, beams and other service ducts and between trays.

 EARTHING:

Do not use metal trays as earth continuity conductor.  Connect trays by flexible tinned copper straps to nearest bare earthing conductor and at maximum 30 m spacing.

END OF THIS SECTION