CABLE TRAYS
PART 1 - GENERAL
1.01 RELATED DOCUMENTS:
A. Drawings and general provisions of Contract, including General and
Supplementary Conditions and Division 1 Specification Sections, apply to this
Section.
B. Requirements of the following Division 16 Sections apply to this section:
1. Division 7 Section "Fire Stopping" where indicated.
2. Division 16 Section "Basic Electrical Materials and Methods".
3. Division 16 Section "Wires and Cables".
1.02 SUMMARY:
A. This section includes metallic cable trays. Types of cable trays & trunking in
this section include the following:
1. Ventilated (perforated) side.
2. Ladder.
3. Trunking
B. Cable tray support devices are specified here and in Division 16 Section
"Supporting Devices".
1.03 SUBMITTALS:
A. General: submit the following in accordance with Conditions of Contract and
Division 1 Specification Sections:
1. Product Data: manufacturer' catalogues and data for cable tray and trunking
products and accessories.
2. Shop Drawings: layout floor plans and elevations showing cable tray system.
Designate components and accessories including clamps, brackets, hanger
rods, splice plates connectors, expansion joint assemblies, straight lengths,
and fittings. Show accurately scaled components and spatial relationships to
adjacent equipment. Show tray types, dimensions, and finishes.
3. Factory Test Reports: certified copies of factory test reports performed in
conformance with Standard approved on cable trays of types and size
specified for this project.
4. Samples:- Submit 50 cm length of each size of cable tray and trunking
compelte with its accessories and fittings.
2
5. Submit a detailed calculations of capacity of cables installed inside the tray
and the trunking assuring a maximum 30% occupancy for power labels &
25% for I.T cables.
6. Adequate supports shall be provided to prevent stress on cables where they
enter or leave the tray. Where cable trays extend transversely through
partitions and wall additional protection in the form of fire proof ¡V noncombustible
barriers shall be provided.
7. Cables tays must be specially reinforced to have high load bearing
capabilities across wide spans, maximum deflection should not exceed 0.5%
in the longest span. Also it shall be mechanically designed to give high
torsional rigidity and good resistance against lateral loading.
8. Bends in either vertical or horizontal directions should be dimensioned such
that cables may not be curved less than 15 times its diameter.
9. Ladder ¡Vtype cable tray shall be used to support heavy cabling in electrical
and mechanical plant rooms or as directed by the Engineer. The tray shall be
designed ladder-like, offering free circulation of air around cable and
minimum moisture and dust-gathering surfaces. Rungs shall be welded to the
ladder profiles. Run width shall not be less than 30mm, and center distance
between rungs shall not exceed 250 mm.
10. Cables are to be prevented from falling down the ladder system by 50mm
height edges along the whole length of the ladder.
11. All components and accessories shall be hot-dip galvanizxed steel after
manufacturer to give resistance to corrosion.
12. Cable tray width shall be chosen by the contractor according to the number
and diameter of cables laid on the tray. Main feeders shall be laid such that
their outer radius are spaced a distance equal to the diameter of the largest
cable.
13. Field Test Reports: in compliance with "Field Quality Control" Article of
this section.
14. Maintenance data for inclusion in "Operating and maintenance Manual".
1.04 QUALITY ASSURANCE:
A. Manufacturers: firms regularly engaged in manufacture of cable trays and fittings
of types and capacities required, whose products have been in satisfactory use in
similar service for not less than 5 years.
B. Single-Source Responsibility: all cable tray components shall be the product of a
single manufacturer.
C. Coordination Drawings: include cable tray systems in coordination drawings.
D. B.S. Compliance: comply with EN ISO 1449, Part 1: 1991 or equivalent for sheet
steel and EN ISO 1461:1999 for galvanizing.
3
1.05 DELIVERY, STORAGE, AND HANDLING:
A. Deliver cable tray systems and accessories packaged in factory-fabricated
fiberboard type containers.
B. Handle cable tray systems and components carefully to avoid breakage, denting
and scoring finishes. Do not install damaged equipment; replace and return
damaged units to manufacturer.
C. Store cable trays and accessories in original cartons and in clean dry space;
protect from weather and construction traffic.
PART 2 - PRODUCTS
2.01 MANUFACTURERS:
A. Available Manufacturers: subject to compliance with requirements,
specifications, drawings and regulations.
B. Manufcturer to be selected from the list of recommended manufacturers.
2.02 CABLE TRAYS, GENERAL REQUIREMENTS:
A. Cable tray systems are to be of indicated types, sizes, and standard classes and
shall be complete with manufacturer's recommended covers, barrier strips,
dropouts, fittings, conduit adaptors, hold-down devices, grommets, and blind
ends as required and indicated.
B. Cable tray products shall have rounded edges and smooth surfaces.
C. Perforated type trays are to be heavy duty, heavy gauge perforated sheet steel,
hot-dip galvanised after manufacture, minimum 1.5 mm thick, with sides not
less than 45 mm deep, and as shown on dramings. Fitting are to be same
material as tray. Covers, where shown on the drawings, are to be minimum 1.0
mm thick galvanised sheet steel, Snap-On or type, forming a rigid assembly
with the tray.
D. Ladder type trays are to be heavy duty, hot dip galvanised after manufacture,
fabricated from 2 mm mild carbon steel. Ladder side channels are to be
minimum 127 x 23 mm, strengthened by reinforcing inserts for torsional
rigidity. Rungs are to be slotted to take cable cleats or ties and conduit clamps.
Rungs are to be minimum 50 x 25 mm channels, spaced at 300 mm centers.
E. Except as otherwise indicated, provide metal cable trays, with splice plates,
bolts, nuts and washers for connecting units; capable of supporting concentrated
loads of 90kg at any point, over and above full cable load.
F. Provide cable tray covers, where indicated; construct of metals and finishes
which mate and match cable trays.
4
G. Provide cable tray supports and connectors, including bonding jumpers, as
indicated and as recommended by cable tray manufacturer.
H. Steel Galvanizing: is to be in accordance with EN ISO 1461 applied after
fabrication, with a local coat thickness of 45 ƒÝm and mean coat thickness of 55 ƒÝm.
I. Sizes: trays and ladders are to be standard metric sizes, and at least 2,44 m (8
ft.) length of section. Size of tray or ladder is to be determined by number and
sizes of cables in accordance with the Regulations and/or as shown on the
Drawings. Tray or ladder is to have strength and rigidity to provide support for
cables contained within. Deflection between supports is not to exceed 1/350
under full loading capacity.
J Earthing Connector: for plastic coated trays or ladders, provide earthing
connector on each coupling between adjacent sections.
K. Adequate supports shall be provided to prevent stress on cables where they
enter or leave the tray. Where cable trays extend transversely through partitions
and walls additional protection in the form of fire-proof non-combustible
barriers shall be provided.
L. Cable trays must be specially reinforced to have high load bearing capabilities
across wide spans, maximum deflection should not exceed 0.5% in the longest
span. Also it shall be mechanically designed to give high torsional rigidity and
good resistance against lateral loading.
M. Bends in either vertical or horizontal directions should be dimensioned such that
cables may not be curved less than 15 times its diameter.
N. Ladder-type cable tray shall be used to support heavy cabling in electrical and
mechanical plant rooms or as directed by the Engineer. The tray shall be
designed ladder-like, offering free circulation of air around cable and minimum
moisture and dust-gathering surfaces. Rungs shall be welded to the ladder
profiles. Rung width shall not be less than 30mm, and center distance between
rungs shall not exceed 250 mm.
O. Cables are to be prevented from falling down the ladder system by 50mm height
edges along the whole length of the ladder.
P. All components and accessories shall be hot-dip galvanized steel after
manufacture to give resistance to corrosion.
Q. Cable tray width shall be chosen by the contractor according to the number and
diameter of cables laid on the tray. Main feeders shall be laid such that their
outer radius are spaced a distance equal to the diameter of the largest cable.
2.03 MATERIALS AND FINISHES:
A. Cable Trays, Fittings, and Accessories: steel, hot-dipped galvanized after
fabrication.
5
2.04 CABLE TRAY ACCESSORIES:
A. Covers: ventilated-hat type, of same materials and finishes as cable trays.
2.05 SUPPORTS AND CONNECTORS:
A. Cable tray supports and connectors, including bonding jumpers shall be as
recommended by cable tray manufacturer.
B. Bolts and screws shall be cadmium plated or electrolytically galvanized.
2.06 FASTENERS FOR SUPPORTS:
Fasteners to connect cable tray supports to the building structure shall be as
follows:
A. Expansion Anchors: carbon steel wedge or sleeve type.
B. Toggle Bolts: all steel springhead type.
C. Powder-Driven Threaded Studs: heat-treated steel, designed specifically for
the intended service.
2.07 FIRE STOPPING:
A. General: materials shall be approved for fire ratings consistent with penetrated
barriers.
B. General: materials shall be labeled by Manufacturer for fire ratings consistent
with penetrated barriers.
C. Sleeves: galvanized steel pipe sleeves. Sizes as indicated or minimum
required size for cable or cable group to be installed. Provide details.
D. Sealing Fittings: Suitable for sealing cables in sleeves or core drilled holes.
2.08 WARNING SIGNS:
A. Lettering: 37.5 mm (1-1/2-inch) high, black on yellow background with
legend "WARNING! NOT TO BE USED AS WALKWAY, LADDER, OR
SUPPORT FOR LADDERS OR PERSONNEL".
B. Materials and Fastening: conform to Section "Electrical Identification".
2.09 SAFETY FACTOR:
1. Cable tray at 3.0 meters Span:Capable of sustaining a working (allowable)
load of 82 kg per linear 30cm with a safety factor of 2, when tested as a
simple beam and in accordance with approved load test method, test
specimen to be a single section of cable tray.
2. In addition to and concurrent with the above working load, a 90kg
concentrated load applied at mid span to result in no permanent deformation
of the tray.
6
3. Design to be such that all like parts are interchangeable and that trays may be
readily assembled and joined without the use of special tools.
A. Fittings: at least the same thickness and cross sectional area of side members
and (rungs, bottom) as straight sections.
B. Connectors: High pressure rigid plate type connected by ribbed-neck or squareneck
plated steel bolts and free-spinning lock type nuts not requiring a washer,
ribbed-neck or square-neck portion of bolt to grip the tray side member and
connector plate metal to prevent bolt from rotating tightening of nut.
C. Where necessary, provide expansion guides and connectors per manufacturer's
thermal contraction and expansion table, install fixed hold down clamps
approximately midway between expansion connectors, install expansion guides
at all other support locations to allow thermally induced movement of the tray.
D. Resistance of the connection between adjacent sections of cable trays: Not
more than 0.0003 ohms, use bonding jumpers of suitable ampacity at all
expansion connections and at all adjustable points.
2.10 CABLE TRUNKING:
A. GENERAL
1. Lengths of trunking shall be efficiently bonded to each other using strip
copper links not less than 12mm wide x 1.5 mm thick and fixed with brass
nuts, bolts and gasked serrated washers.
2. Lids shall be lipped and fixed at intervals not exceeding 1 meter by means
of quick release can fasteners. Steel screws and fasteners shall be protected
against corrosion by a finish at least equivalent to zinc coating.
3. Metal partitions in trunking shall be a minimum thickness of 1.2 mm and
the finish shall be of the same standard as the trunking. The method of
fixing partitions to the trunking shall not cause long term corrosion or
electrolytic action and shall be such that the partitions cannot be
inadvertently displaced.
4. Connectors shall span the complete internal surface of the trunking and shall
be designed so that the trunking sections mate with butting joints.
5. Vertical trunking shall be supplied with a cable support unit with insulated
pins at intervals not exceeding 3 meters.
6. Horizontal trunking sizes exceeding 100mm x 50mm shall be supplied with
cable separators with insulated pins at intervals not exceeding 2 meters.
7. Trunking shall consist of base, screw-on covers, coupling end plates, wall
flanges, panel to trunking rubber grommet, elbows, tees, adaptor plates and
all necessary hangers supports and accessories.
8. Trunking shall be constructed of steel. All stell units shall be protected
inside and outside with a corrosion resistant finish such as zinc or cadmium,
with a top coat of enamel.
7
9. All trunkings parts shall be mechanically and electrically coupled while
protecting wires from abrasion.
B. Where any cutting or damage is caused during erection, the finish shall be
made good. All burrs and rough edges shall be removed. Where any
corrosion has occurred it shall be removed and the area treated with a rustproofing
agent. After this it shall be treated by the application of either a zinc
rich epoxy primet or equal alternative followed by a coat of color matching
paint.
C. Any fixing used for securing or fitting shall not cause any long term
corrosion or electrolytic action-black japanned fixing screws shall not be
used. Where brackets are used they shall be constructed of mild steel angle or
channel iron finished to the same standard as the trunking.
D. Connections to conduit, multiple box, switchgear and distribution boards
shall be made with flanged units.
E. Where trunking crosses settlement and expansion joints a trunking joints
shall be made. The connector at this point shall be made with slotted fixing
holes to permit a movement of 10 mm in both the horizontal and vertical
planes. The earth continuity links across such joints shall be of braided
copper tape not less than 15mm wide x2 mm thick having a resistance from
fixing to fixing equal to or less than the links used for the standard trunking
joints.
F. the braid shall be long enough to allow for the maximum movement of the
trunking. The braid ends shall be folded, and sweated soiled.
PART 3 - EXECUTION
3.01 INSTALLATION OF CABLE TRAY SYSTEMS:
A. Install cable trays in accordance with equipment manufacturer's written
instructions.
B. Install cable tryas and trunkings and accessories as indicated in accordance
with the requiremtns of applicable standards and in accordance with
recognized industry practices to ensure that installation complies with
requirements and serves intended function.
C. Conform to manufacturer's recommendations for selection and installation of
supports.
D. Strength of each support including fastenings to the structure shall be adequate
to carry present and future load multiplied by a safety factor of at least four or
the calculated load plus 90 kg ( 200 lbs), whichever is greater. Spacing of
supports is not to exceed 2 m.
E. Installation of supports shall be in accordance with cable tray manufacturer's
written instructions and recommendations.
8
F. Fastening Supports: unless otherwise indicated, fasten cable tray supports
securely to the building structure as specified in Division 16 Section
"Supporting Devices".
G. Support at Connections to Equipment: where cable trays connect to equipment,
provide flanged fittings fastened to the tray and to the equipment. Support the
tray separately. Do not carry the weight of the tray on the equipment
enclosure.
H. Thermal Contraction and Expansion: install expansion connectors in cable tray
runs that exceed the following length:
1. Steel Tray: 52.5 m (175 feet).
2. Spacings and gap settings for expansion connectors shall not exceed
recommendations of approved applicable standards.
I. Direction Changes: make changes in direction of cable tray with standard cable
tray fittings.
J. Locate cable tray above piping except as required for tray accessibility and as
otherwise indicated.
K. Firestopping: where cable trays penetrate fire and smoke barriers including
walls, partitions, floors, and ceilings, install fire-stopping at penetrations after
cables are installed.
L. Sleeves For Future Cables: install capped sleeves for future cables through
firestopped cable tray penetrations of fire/smoke barriers.
M. Working Space: install cable trays with sufficient space to permit access for
installing cables.
N. Barriers: where cable trays carry conductors of different systems such as
power, communication and data, or different insulation voltage levels, separate
cable trays are to be used. In case of absolute necessity, obtain the Engineer¡¦s
approval on installing cables of different systems or voltages on the same cable
tray, use proper insulating barriers to separate the systems¡¦ cables and maintain
the proper spacing between them according to the requirements of the codes
and recommendations of the manufacturers.
O. Coordinate as necessary to interface installation of cable trays and trunkings
work with other work.
P. Install intergral fire stops where cable trays and trunkings penetrates fire-rated
walls and floors. Seal between cable trays and trunkings and opening and
around opening with fire-rated sealant not less than wall, or floor, fire ratings.
Q. At floor openings provide concrete curb, 10cm wide and 10cm high, around
cable trays and trunkings and seal with non-combustible material.
R. Provide electrical bonding and equipment earthing connections for cable trays
and trunking. Tighten connections to comply with tightening torques specified
by manufacturers to assure permanent and effective connections and grounds.
9
S. Anchor mounting hardware firmly to walls, floors, or ceilings, to ensure
enclosures are permanently and mechanically secured. Provide all hardware
and accessories for proper mounting.
T. Route cable trays and trunkings as required and make final measurements
before ordering cable tray.
U. Where there is insufficient elevation or lateral change in direction to
accommodate fittings directly connected, adjustable vertical connectors or
adjustable horizontal connectors with straight section in between may be used.
Avoid slopes that would cause cable to bend on smaller radii, than that allowed
by cable manufacturer.
V. Provide hangers, rods, straps, special brackets, and other means of supporting
cable tray and trunkings as requited.
W. Cables shall not occupy more than 30% of the trunking cross sectional area.
3.02 EARTHING:
A. Electrically earth cable trays and ensure continuous electrical conductivity of
cable tray system. Use tray as an equipment earthing conductor for itself
only, not for connected equipment.
3.03 FIELD TESTING:
A. Earthing: test cable trays to ensure electrical continuity of bonding and
earthing connections.
B. Anchorage: test pull-out resistance of one of each type, size, and anchorage
material for toggle bolts and powder-driven threaded studs and as requested
by the Engineer on site.
1. Furnish equipment, including jacks, jigs, fixtures, and calibrated indicating
scales required for reliable testing. Obtain the Engineer's approval before
transmitting loads to the structure. Test to 90 percent of rated proof-load for
fastener. If fastening fails test, replace fastener and retest until satisfactory
results are achieved.
3.04 CLEANING AND FINISH REPAIR:
A. Upon completion of installation of cable trays, inspect trays, fittings, and
accessories. Remove burrs, dirt, and construction debris and repair damaged
finish including chips, scratches, and abrasions.
B. Galvanized Finish: repair damage with a zinc-rich paint recommended by the
tray manufacturer.
C. PVC or Paint Finish: repair damage with matching touch-up coating
recommended by the tray manufacturer.
END OF SECTION 16111
PART 1 - GENERAL
1.01 RELATED DOCUMENTS:
A. Drawings and general provisions of Contract, including General and
Supplementary Conditions and Division 1 Specification Sections, apply to this
Section.
B. Requirements of the following Division 16 Sections apply to this section:
1. Division 7 Section "Fire Stopping" where indicated.
2. Division 16 Section "Basic Electrical Materials and Methods".
3. Division 16 Section "Wires and Cables".
1.02 SUMMARY:
A. This section includes metallic cable trays. Types of cable trays & trunking in
this section include the following:
1. Ventilated (perforated) side.
2. Ladder.
3. Trunking
B. Cable tray support devices are specified here and in Division 16 Section
"Supporting Devices".
1.03 SUBMITTALS:
A. General: submit the following in accordance with Conditions of Contract and
Division 1 Specification Sections:
1. Product Data: manufacturer' catalogues and data for cable tray and trunking
products and accessories.
2. Shop Drawings: layout floor plans and elevations showing cable tray system.
Designate components and accessories including clamps, brackets, hanger
rods, splice plates connectors, expansion joint assemblies, straight lengths,
and fittings. Show accurately scaled components and spatial relationships to
adjacent equipment. Show tray types, dimensions, and finishes.
3. Factory Test Reports: certified copies of factory test reports performed in
conformance with Standard approved on cable trays of types and size
specified for this project.
4. Samples:- Submit 50 cm length of each size of cable tray and trunking
compelte with its accessories and fittings.
2
5. Submit a detailed calculations of capacity of cables installed inside the tray
and the trunking assuring a maximum 30% occupancy for power labels &
25% for I.T cables.
6. Adequate supports shall be provided to prevent stress on cables where they
enter or leave the tray. Where cable trays extend transversely through
partitions and wall additional protection in the form of fire proof ¡V noncombustible
barriers shall be provided.
7. Cables tays must be specially reinforced to have high load bearing
capabilities across wide spans, maximum deflection should not exceed 0.5%
in the longest span. Also it shall be mechanically designed to give high
torsional rigidity and good resistance against lateral loading.
8. Bends in either vertical or horizontal directions should be dimensioned such
that cables may not be curved less than 15 times its diameter.
9. Ladder ¡Vtype cable tray shall be used to support heavy cabling in electrical
and mechanical plant rooms or as directed by the Engineer. The tray shall be
designed ladder-like, offering free circulation of air around cable and
minimum moisture and dust-gathering surfaces. Rungs shall be welded to the
ladder profiles. Run width shall not be less than 30mm, and center distance
between rungs shall not exceed 250 mm.
10. Cables are to be prevented from falling down the ladder system by 50mm
height edges along the whole length of the ladder.
11. All components and accessories shall be hot-dip galvanizxed steel after
manufacturer to give resistance to corrosion.
12. Cable tray width shall be chosen by the contractor according to the number
and diameter of cables laid on the tray. Main feeders shall be laid such that
their outer radius are spaced a distance equal to the diameter of the largest
cable.
13. Field Test Reports: in compliance with "Field Quality Control" Article of
this section.
14. Maintenance data for inclusion in "Operating and maintenance Manual".
1.04 QUALITY ASSURANCE:
A. Manufacturers: firms regularly engaged in manufacture of cable trays and fittings
of types and capacities required, whose products have been in satisfactory use in
similar service for not less than 5 years.
B. Single-Source Responsibility: all cable tray components shall be the product of a
single manufacturer.
C. Coordination Drawings: include cable tray systems in coordination drawings.
D. B.S. Compliance: comply with EN ISO 1449, Part 1: 1991 or equivalent for sheet
steel and EN ISO 1461:1999 for galvanizing.
3
1.05 DELIVERY, STORAGE, AND HANDLING:
A. Deliver cable tray systems and accessories packaged in factory-fabricated
fiberboard type containers.
B. Handle cable tray systems and components carefully to avoid breakage, denting
and scoring finishes. Do not install damaged equipment; replace and return
damaged units to manufacturer.
C. Store cable trays and accessories in original cartons and in clean dry space;
protect from weather and construction traffic.
PART 2 - PRODUCTS
2.01 MANUFACTURERS:
A. Available Manufacturers: subject to compliance with requirements,
specifications, drawings and regulations.
B. Manufcturer to be selected from the list of recommended manufacturers.
2.02 CABLE TRAYS, GENERAL REQUIREMENTS:
A. Cable tray systems are to be of indicated types, sizes, and standard classes and
shall be complete with manufacturer's recommended covers, barrier strips,
dropouts, fittings, conduit adaptors, hold-down devices, grommets, and blind
ends as required and indicated.
B. Cable tray products shall have rounded edges and smooth surfaces.
C. Perforated type trays are to be heavy duty, heavy gauge perforated sheet steel,
hot-dip galvanised after manufacture, minimum 1.5 mm thick, with sides not
less than 45 mm deep, and as shown on dramings. Fitting are to be same
material as tray. Covers, where shown on the drawings, are to be minimum 1.0
mm thick galvanised sheet steel, Snap-On or type, forming a rigid assembly
with the tray.
D. Ladder type trays are to be heavy duty, hot dip galvanised after manufacture,
fabricated from 2 mm mild carbon steel. Ladder side channels are to be
minimum 127 x 23 mm, strengthened by reinforcing inserts for torsional
rigidity. Rungs are to be slotted to take cable cleats or ties and conduit clamps.
Rungs are to be minimum 50 x 25 mm channels, spaced at 300 mm centers.
E. Except as otherwise indicated, provide metal cable trays, with splice plates,
bolts, nuts and washers for connecting units; capable of supporting concentrated
loads of 90kg at any point, over and above full cable load.
F. Provide cable tray covers, where indicated; construct of metals and finishes
which mate and match cable trays.
4
G. Provide cable tray supports and connectors, including bonding jumpers, as
indicated and as recommended by cable tray manufacturer.
H. Steel Galvanizing: is to be in accordance with EN ISO 1461 applied after
fabrication, with a local coat thickness of 45 ƒÝm and mean coat thickness of 55 ƒÝm.
I. Sizes: trays and ladders are to be standard metric sizes, and at least 2,44 m (8
ft.) length of section. Size of tray or ladder is to be determined by number and
sizes of cables in accordance with the Regulations and/or as shown on the
Drawings. Tray or ladder is to have strength and rigidity to provide support for
cables contained within. Deflection between supports is not to exceed 1/350
under full loading capacity.
J Earthing Connector: for plastic coated trays or ladders, provide earthing
connector on each coupling between adjacent sections.
K. Adequate supports shall be provided to prevent stress on cables where they
enter or leave the tray. Where cable trays extend transversely through partitions
and walls additional protection in the form of fire-proof non-combustible
barriers shall be provided.
L. Cable trays must be specially reinforced to have high load bearing capabilities
across wide spans, maximum deflection should not exceed 0.5% in the longest
span. Also it shall be mechanically designed to give high torsional rigidity and
good resistance against lateral loading.
M. Bends in either vertical or horizontal directions should be dimensioned such that
cables may not be curved less than 15 times its diameter.
N. Ladder-type cable tray shall be used to support heavy cabling in electrical and
mechanical plant rooms or as directed by the Engineer. The tray shall be
designed ladder-like, offering free circulation of air around cable and minimum
moisture and dust-gathering surfaces. Rungs shall be welded to the ladder
profiles. Rung width shall not be less than 30mm, and center distance between
rungs shall not exceed 250 mm.
O. Cables are to be prevented from falling down the ladder system by 50mm height
edges along the whole length of the ladder.
P. All components and accessories shall be hot-dip galvanized steel after
manufacture to give resistance to corrosion.
Q. Cable tray width shall be chosen by the contractor according to the number and
diameter of cables laid on the tray. Main feeders shall be laid such that their
outer radius are spaced a distance equal to the diameter of the largest cable.
2.03 MATERIALS AND FINISHES:
A. Cable Trays, Fittings, and Accessories: steel, hot-dipped galvanized after
fabrication.
5
2.04 CABLE TRAY ACCESSORIES:
A. Covers: ventilated-hat type, of same materials and finishes as cable trays.
2.05 SUPPORTS AND CONNECTORS:
A. Cable tray supports and connectors, including bonding jumpers shall be as
recommended by cable tray manufacturer.
B. Bolts and screws shall be cadmium plated or electrolytically galvanized.
2.06 FASTENERS FOR SUPPORTS:
Fasteners to connect cable tray supports to the building structure shall be as
follows:
A. Expansion Anchors: carbon steel wedge or sleeve type.
B. Toggle Bolts: all steel springhead type.
C. Powder-Driven Threaded Studs: heat-treated steel, designed specifically for
the intended service.
2.07 FIRE STOPPING:
A. General: materials shall be approved for fire ratings consistent with penetrated
barriers.
B. General: materials shall be labeled by Manufacturer for fire ratings consistent
with penetrated barriers.
C. Sleeves: galvanized steel pipe sleeves. Sizes as indicated or minimum
required size for cable or cable group to be installed. Provide details.
D. Sealing Fittings: Suitable for sealing cables in sleeves or core drilled holes.
2.08 WARNING SIGNS:
A. Lettering: 37.5 mm (1-1/2-inch) high, black on yellow background with
legend "WARNING! NOT TO BE USED AS WALKWAY, LADDER, OR
SUPPORT FOR LADDERS OR PERSONNEL".
B. Materials and Fastening: conform to Section "Electrical Identification".
2.09 SAFETY FACTOR:
1. Cable tray at 3.0 meters Span:Capable of sustaining a working (allowable)
load of 82 kg per linear 30cm with a safety factor of 2, when tested as a
simple beam and in accordance with approved load test method, test
specimen to be a single section of cable tray.
2. In addition to and concurrent with the above working load, a 90kg
concentrated load applied at mid span to result in no permanent deformation
of the tray.
6
3. Design to be such that all like parts are interchangeable and that trays may be
readily assembled and joined without the use of special tools.
A. Fittings: at least the same thickness and cross sectional area of side members
and (rungs, bottom) as straight sections.
B. Connectors: High pressure rigid plate type connected by ribbed-neck or squareneck
plated steel bolts and free-spinning lock type nuts not requiring a washer,
ribbed-neck or square-neck portion of bolt to grip the tray side member and
connector plate metal to prevent bolt from rotating tightening of nut.
C. Where necessary, provide expansion guides and connectors per manufacturer's
thermal contraction and expansion table, install fixed hold down clamps
approximately midway between expansion connectors, install expansion guides
at all other support locations to allow thermally induced movement of the tray.
D. Resistance of the connection between adjacent sections of cable trays: Not
more than 0.0003 ohms, use bonding jumpers of suitable ampacity at all
expansion connections and at all adjustable points.
2.10 CABLE TRUNKING:
A. GENERAL
1. Lengths of trunking shall be efficiently bonded to each other using strip
copper links not less than 12mm wide x 1.5 mm thick and fixed with brass
nuts, bolts and gasked serrated washers.
2. Lids shall be lipped and fixed at intervals not exceeding 1 meter by means
of quick release can fasteners. Steel screws and fasteners shall be protected
against corrosion by a finish at least equivalent to zinc coating.
3. Metal partitions in trunking shall be a minimum thickness of 1.2 mm and
the finish shall be of the same standard as the trunking. The method of
fixing partitions to the trunking shall not cause long term corrosion or
electrolytic action and shall be such that the partitions cannot be
inadvertently displaced.
4. Connectors shall span the complete internal surface of the trunking and shall
be designed so that the trunking sections mate with butting joints.
5. Vertical trunking shall be supplied with a cable support unit with insulated
pins at intervals not exceeding 3 meters.
6. Horizontal trunking sizes exceeding 100mm x 50mm shall be supplied with
cable separators with insulated pins at intervals not exceeding 2 meters.
7. Trunking shall consist of base, screw-on covers, coupling end plates, wall
flanges, panel to trunking rubber grommet, elbows, tees, adaptor plates and
all necessary hangers supports and accessories.
8. Trunking shall be constructed of steel. All stell units shall be protected
inside and outside with a corrosion resistant finish such as zinc or cadmium,
with a top coat of enamel.
7
9. All trunkings parts shall be mechanically and electrically coupled while
protecting wires from abrasion.
B. Where any cutting or damage is caused during erection, the finish shall be
made good. All burrs and rough edges shall be removed. Where any
corrosion has occurred it shall be removed and the area treated with a rustproofing
agent. After this it shall be treated by the application of either a zinc
rich epoxy primet or equal alternative followed by a coat of color matching
paint.
C. Any fixing used for securing or fitting shall not cause any long term
corrosion or electrolytic action-black japanned fixing screws shall not be
used. Where brackets are used they shall be constructed of mild steel angle or
channel iron finished to the same standard as the trunking.
D. Connections to conduit, multiple box, switchgear and distribution boards
shall be made with flanged units.
E. Where trunking crosses settlement and expansion joints a trunking joints
shall be made. The connector at this point shall be made with slotted fixing
holes to permit a movement of 10 mm in both the horizontal and vertical
planes. The earth continuity links across such joints shall be of braided
copper tape not less than 15mm wide x2 mm thick having a resistance from
fixing to fixing equal to or less than the links used for the standard trunking
joints.
F. the braid shall be long enough to allow for the maximum movement of the
trunking. The braid ends shall be folded, and sweated soiled.
PART 3 - EXECUTION
3.01 INSTALLATION OF CABLE TRAY SYSTEMS:
A. Install cable trays in accordance with equipment manufacturer's written
instructions.
B. Install cable tryas and trunkings and accessories as indicated in accordance
with the requiremtns of applicable standards and in accordance with
recognized industry practices to ensure that installation complies with
requirements and serves intended function.
C. Conform to manufacturer's recommendations for selection and installation of
supports.
D. Strength of each support including fastenings to the structure shall be adequate
to carry present and future load multiplied by a safety factor of at least four or
the calculated load plus 90 kg ( 200 lbs), whichever is greater. Spacing of
supports is not to exceed 2 m.
E. Installation of supports shall be in accordance with cable tray manufacturer's
written instructions and recommendations.
8
F. Fastening Supports: unless otherwise indicated, fasten cable tray supports
securely to the building structure as specified in Division 16 Section
"Supporting Devices".
G. Support at Connections to Equipment: where cable trays connect to equipment,
provide flanged fittings fastened to the tray and to the equipment. Support the
tray separately. Do not carry the weight of the tray on the equipment
enclosure.
H. Thermal Contraction and Expansion: install expansion connectors in cable tray
runs that exceed the following length:
1. Steel Tray: 52.5 m (175 feet).
2. Spacings and gap settings for expansion connectors shall not exceed
recommendations of approved applicable standards.
I. Direction Changes: make changes in direction of cable tray with standard cable
tray fittings.
J. Locate cable tray above piping except as required for tray accessibility and as
otherwise indicated.
K. Firestopping: where cable trays penetrate fire and smoke barriers including
walls, partitions, floors, and ceilings, install fire-stopping at penetrations after
cables are installed.
L. Sleeves For Future Cables: install capped sleeves for future cables through
firestopped cable tray penetrations of fire/smoke barriers.
M. Working Space: install cable trays with sufficient space to permit access for
installing cables.
N. Barriers: where cable trays carry conductors of different systems such as
power, communication and data, or different insulation voltage levels, separate
cable trays are to be used. In case of absolute necessity, obtain the Engineer¡¦s
approval on installing cables of different systems or voltages on the same cable
tray, use proper insulating barriers to separate the systems¡¦ cables and maintain
the proper spacing between them according to the requirements of the codes
and recommendations of the manufacturers.
O. Coordinate as necessary to interface installation of cable trays and trunkings
work with other work.
P. Install intergral fire stops where cable trays and trunkings penetrates fire-rated
walls and floors. Seal between cable trays and trunkings and opening and
around opening with fire-rated sealant not less than wall, or floor, fire ratings.
Q. At floor openings provide concrete curb, 10cm wide and 10cm high, around
cable trays and trunkings and seal with non-combustible material.
R. Provide electrical bonding and equipment earthing connections for cable trays
and trunking. Tighten connections to comply with tightening torques specified
by manufacturers to assure permanent and effective connections and grounds.
9
S. Anchor mounting hardware firmly to walls, floors, or ceilings, to ensure
enclosures are permanently and mechanically secured. Provide all hardware
and accessories for proper mounting.
T. Route cable trays and trunkings as required and make final measurements
before ordering cable tray.
U. Where there is insufficient elevation or lateral change in direction to
accommodate fittings directly connected, adjustable vertical connectors or
adjustable horizontal connectors with straight section in between may be used.
Avoid slopes that would cause cable to bend on smaller radii, than that allowed
by cable manufacturer.
V. Provide hangers, rods, straps, special brackets, and other means of supporting
cable tray and trunkings as requited.
W. Cables shall not occupy more than 30% of the trunking cross sectional area.
3.02 EARTHING:
A. Electrically earth cable trays and ensure continuous electrical conductivity of
cable tray system. Use tray as an equipment earthing conductor for itself
only, not for connected equipment.
3.03 FIELD TESTING:
A. Earthing: test cable trays to ensure electrical continuity of bonding and
earthing connections.
B. Anchorage: test pull-out resistance of one of each type, size, and anchorage
material for toggle bolts and powder-driven threaded studs and as requested
by the Engineer on site.
1. Furnish equipment, including jacks, jigs, fixtures, and calibrated indicating
scales required for reliable testing. Obtain the Engineer's approval before
transmitting loads to the structure. Test to 90 percent of rated proof-load for
fastener. If fastening fails test, replace fastener and retest until satisfactory
results are achieved.
3.04 CLEANING AND FINISH REPAIR:
A. Upon completion of installation of cable trays, inspect trays, fittings, and
accessories. Remove burrs, dirt, and construction debris and repair damaged
finish including chips, scratches, and abrasions.
B. Galvanized Finish: repair damage with a zinc-rich paint recommended by the
tray manufacturer.
C. PVC or Paint Finish: repair damage with matching touch-up coating
recommended by the tray manufacturer.
END OF SECTION 16111
No comments:
Post a Comment