DISTRIBUTION PANEL BOARDS
PART I -GENERAL
1.01 RELATED DOCUMENTS:
A. Drawings and general provisions of Contract, including General and
Supplementary Conditions and Division-1 Specification sections, apply to
work of this section.
B. Division-16 "Basic Electrical Materials and Methods " and other sections
apply to work specified in this section.
1.02 SUMMARY:
A. This section includes panelboards for distribution and subdistribution of
electric power and for protection of circuits, including fixing and supporting
materials and materials for termination of feeders, sub circuits and branch
circuits.
B. Types of panelboards and enclosures required for the project include the
following:
LP: Final branch circuit Lighting Panelboard.
PP: Final branch circuit power panelboard.
DB: Distribution panelboard.
Note 1 : Final branch circuit lighting panelboards, and power
panelboards for secondary lighting and power distribution are
designated with moulded case circuit breaker (MCCB) protection
on subfeeder or branch circuits, as shown on the drawings.
Note 2: Panelboards supplied from emergency source are prefixed with
the letter E.
Note 3: Panelboards supplied from UPS are prefixed with "UPS".
C. Refer to other Division-16 sections "Wires/Cables", "Electrical Enclosures,
Boxes and Fittings", and "Raceways" required in conjunction with
installation of panelboards and enclosures.
D. Refer to Division 16 section "Circuit Breakers" for circuit breaker applications
and recommended types and frames for this project.
E. Refer to Division 15 section "Building Management System" for connection to
BMS.
1.03 SUBMITTALS:
A Product Data: submit manufacturer's data and catalogues on panelboards and
enclosures.
B. Dimensions and contents of each panelboard.
2
C. Coordinated tabulations of series short circuit combination of circuit breakers.
D. Wiring Diagrams: submit wiring diagrams for panelboards showing
connections to electrical power feeders and distribution branches.
E. Typical mounting details, labels, tags.
F. Tests and certificates: submit complete certified manufacturer's type test and
routine test records in accordance with the Standards applicable.
G. Submit to the Engineer a relay and C.B. selectivity study.
The Current-time characteristics must be plotted on a log-log papers showing
that the choice of the C.B. settings are correct for full selective system.
H. Submit a comprehensive short circuit study as well as voltage drop
calculation based on the actual impedance values of the electrical components
such as supply short circuit level at the 11 KV (shall not be less than 500
MVA), transformer per unit impedance, bus bars and cables
impedances…etc.
I. Submit a detailed load list verifying the load balance across the phased of
each board.
1.04 QUALITY ASSURANCE:
A. Manufacturer's Qualifications: firms regularly engaged in manufacture of
panelboards and enclosures, of types, sizes, and ratings required, whose
products have been in satisfactory use in similar service for not less than 5
years.
B. Installer's Qualifications: a firm with at least 3 years of successful installation
experience on projects utilizing panelboards similar to those required for this
project.
C. Codes and Standards:
1. IEC 439 & IEC 947, Factory Built Assembles of Low Voltage Switch
gear and Control gear.
2. Electrical Code Compliance: comply with applicable local code,
regulations and requirements of the authority having jurisdiction, as
applicable to installation, and construction of electrical panelboards and
enclosures in this project.
1.05 . SEQUENCING AND SCHEDULING:
A. Coordinate installation of panel boards and enclosures with civil/architectural
program and installation of wires/cables, electrical boxes and fittings, and
raceway work.
PART 2-PRODUCT:
2.01 MANUFACTURERS:
A. Available Manufacturers: subject to compliance with requirements,
specifications, drawings and regulations.
B. For approved manufacturers refer to the recommended manufacturers list.
3
2.02 PANELBOARDS -GENERAL
A. Schedules on drawings indicate type and requirements of each panelboard.
These are defined by the following criteria:-
1. type of construction (MCB or MCCB), referring to type of branch circuit
breakers required.
2. voltage, number of phases and wires
3. branch circuit breaker trip rating and wire size
4. main circuit breaker trip rating and frame size (maximum continuous
rating) for MCCB
5. short circuit interrupting capacity (IC) in kA.
6. special arrangement or provisions.
B. Rated insulation voltage is to be in accordance with the respective Standards.
C. Panelboards are to be totally enclosed, dead front type, protection code IP42
for indoor installations and IP 65 for outdoor installations, in accordance with
IEC 529 and are to be factory designed and assembled.
D. Earthing bar is to be provided in every panelboard and to be half size the
phase busbars.
E. Neutral bar is to be provided in every panelboard and to be full size as per the
phase busbars.
F. Protection is to be fully rated though-out the systems.
G. Circuit breakers are to be non-fused type.
H. Circuit breaker arrangement: panelboards are to have one main incoming
circuit breaker or switch and the required number of branch circuit breakers,
arranged as shown on the Schedules, including spare circuit breakers and
spaces for future expansion. Three-phase panelboards are to be designed for
sequence phase connection of branch circuit devices.
I. Branch circuit numbering: on 3-phase panelboard schedules, circuits land 2
are J to be connected to red (R) phase, 3 and 4 to yellow (V) phase, 5 and 6 to
blue (B) phase etc., to conform with branch circuit numbering shown on the
Drawings.
J. Connection to Building Management System (BMS): coordinate with the
BMS supplier and provide all necessary interface devices, instruments, dry
contacts for connection of all required points to the BMS as specified or
indicated in the BMS schedules (If required).
K. Distribution boards shall be type tested and shall fully comply with the
requirements of IEC 60947, standards.
L. Distribution boards shall have a side-hung hinged front cover, attached by
means of lift-off hinges and fitted with cylinder type locking handles. Covers
shall be braced or folded in such a manner as to prevent distortion or whip,
and shall be fitted with dust-proofing gaskets or edge seals.
4
M. Distribution board cases shall be of such dimensions that adequate space is
available for maneuvering and connecting the incoming and outgoing cables.
N. Each distribution board shall be provided with a durable circuit chart fixed to
the inside of the cover or immediately adjacent and bearing typewritten
details in plain language, of the circuits supplied by each of the ways. The
chart shall be on heavy weight paper or thin card and shall be protected by
means of rigid transparent plastic cover, it shall be mounted in such a way that
it can easily be removed for correction or alteration then replaced. The size of
the chart shall be such that there is adequate space of recording all of the
required information and in any case, shall not be less than A5
(210mmx148mm).
O. Each distribution board shall be provided with an engraved plastic label on
the outside of the front cover, bearing the designation of the board and its
reference number, if any, as given on the drawings or in the schedules. The
label shall be fixed in position by chromium –plated set screws. Each such
label shall be not less in size than 100mmx30 mm, and shall bear the required
inscription in white on a black background, using letters and/or digits not less
than 5mm high.
P. PDUs shall be equipped with isolation transformers, spike suppressions&
surge arrestors.
2.03 PANELBOARD ENCLOSURES
A. Type: general purpose type, suitable for relevant ambient conditions, flush or
surface mounted as shown on the Drawings, comprising box, trim or trim and
door to approved manufacturer's standards and sizes.
B. Construction: recessed mounting box with multiple knockouts, trim and
doors where required, are to be electro-galvanized sheet steel of gauges not
less than specified in accordance with the Standards, minimum 2.0 mm
thickness. Welded joints are to be galvanized after manufacture. Gutter
spaces are to conform to the Standards, but are not to be less than 100 mm on
all sides. Enclosure is to have predesigned angles or threaded end studs to
support and adjust mounting of interior panelboard assembly.
C. Trims are to cover and overlap front shield, covering all terminals and bus
compartments, to form a dead front panel. Trims are to be fixed to
cabinet/box by adjustable quarter-turn clamps engaging flange of box (use of
screws engaging holes in flange box is not acceptable). Screws where used
are to be oval-head, countersunk and flush. Trims for flush mounted
panelboards are to overlap box and front shields by at least 20 mm. Trims for
surface mounted panelboards are to be exactly sized to form flush fit to box.
D. Doors are to have piano type concealed hinges integral with trim, and flush
combination cylinder lock and catch. Doors over 1000 mm high are to have
vault-type handle and multiple point latch mechanism. Locks are to be flush
and keyed alike.
E. Finish: inner and outer surfaces of cabinet/boxes, trims, doors etc. are to be
cleaned, phosphatized, chrome passivated and treated with final
thermosetting epoxy powder modified by polyester resins providing high
5
resistance to mechanical injury , heat, acid and alkali solvents, grease, aging
and corrosion and of standard grey colour to the approval of the Engineer .
F. Directories under glassene with directory frame, or an approved alternative
durable arrangement, are to be provided on inside face of doors, or in metal
label holders when trim without doors is specified. Directories are to be typed
to identify panelboards and clearly indicate circuit number and description of
load.
G. Outdoor enclosures are to be heavy duty sheet steel cabinets, minimum 2.0
thick, fully weatherproofed (IP 65), without knockouts, but with removable
sealed/gasketed bottom gland plates and gasketed doors.
2.04 BUSBARS
A. Type: one piece, 98% pure electrolytic copper, based on a total maximum
operating temperature of 90 deg. C at full continuous rating (50 °C
temperature rise above 40 °C ambient). Bolted or clamped contact surfaces
are to have I maximum current density not exceeding requirements of the
approved standards. Aluminum is not to be used for busbars or panelboard
parts.
B. Design: busbars are to be shrouded/insulated and rigidly designed so that If
branch circuit devices can be removed without disturbing adjacent units or I
changed without additional machining, drilling or tapping. Busing is to be full
size without reduction. Busing and blank plates are to allow installation of
future circuit devices, where indicated on the Drawings.
C. Rating: bustar rating is to be at least equal to main circuit breaker frame size.
Where no main circuit breaker is required, busbars are to have main lugs or
disconnect switch, and to have nominal rating not less than 1.25 times the I
upstream circuit breaker trip rating.
D. Short-Circuit Duty: busbars are to carry maximum short-circuit duty of main
protective device, which is to be at least maximum short-circuit at point of
application for one second, without showing any signs of degradation.
E. Terminals and connections are to be anti-turn, solderless screw-pressure type.
Screws and bolts used for making copper/copper connections are to be hard
copper alloy with lock washers (riveted bus connections are not acceptable).
F. Neutral bar is to be solid and fully insulated from cabinet or box. One
solderless box type set-screw connector is to be provided for neutral wire of
each branch circuit and one bolted clamp-type connector or anti-turn lug with
set-screw for main incoming neutral wire. Neutral is to be fully sized and
rated as for phase busbars.
G. Earthing bar is to copper, brazed to panelboard cabinet, with bolted pressure
connector for main conductor and one set-screw-type tunnel terminal for each
outgoing conductor, to provide secure and reliable contact with all metal parts
and enclosure.
2.05 DISTRIBUTION PANELBOARDS (DB)
A. DB: to have a rated insulation voltage of 1000 V, rated operational voltage of
600 a.c. or d.c., and to be conforming to IEC 439: Part 1, Form 3a, similar to
6
Cutler Hammer Pow-R-Line 4, or Merlin-Germ type Prisma P or G, floor or
wall surface mounted, suitable for ratings of main breaker or switch and
busbars ranging from 160 A to 1200 A, 3-phase, 4-wire (or 3-wire where
specifically indicated), suitably and orderly arranged for any selected
combination of branch MCCBs ranging from 100 A to 1200 A frame size and
short-circuit interrupting ratings as shown on the Drawings.
B. Construction: sheet steel, minimum 1.5 mm thick for cabinet/box and
minimum 2 mm thick for trim or trim and door. Fronts are to be single or twin
covers to shield circuit breakers, terminals and live ends.
C. Interior of panelboard is to be pan assembly consisting of galvanized sheet
steel chassis minimum 2 mm thick, folded, flanged and reinforced, with
busbars vertically arranged and mounted on moulded insulators.
D. Moulded insulators are to have minimum temperature rating of 130 deg. C
and insulation grade of 3.5 kV for one minute.
E. Circuit breakers are to be mounted in twin arrangement ( except for larger
circuit breakers) and bolted rigidly to copper cross and centre bus connectors.
2.06 FINAL BRANCH CIRCUIT. AND POWER PANELBOARDS (LP&PP).
GENERALLY
A. Arrangement: to comprise set of homogeneous branch circuit breakers with
unified profile and base, and one main circuit breaker. Single and multi-pole
circuit. breakers or other devices are to occupy modular spaces.
Accommodation of contactors and split-bus arrangement or other devices is
not to change regularity of standard box width.
B. Indoor Enclosure: sheet steel, minimum 1.5 mm thick for box/cabinet and
minimum 1.5 mm thick for front shield, trim and door. Fixings for flush trim
are to be adjustable to allow for miss-alignment between box and wall
surface. Wiring spaces (gutters) are to be at least 100 mm wide. Larger gutters
are to be provided where tap-off insulated split connectors are required.
Knockouts are to be provided in top or bottom of enclosure~ and are to
provide a neat and uniform conduit/cable terminal arrangement.
2.07 FINAL BRANCH CIRCUIT AND POWER P ANELBOARDS -TYPE
MCCB
A. Type: to have a rated insulation of 600 V and rated operation Voltage of 440
V a.c. and 240 V d.c., lighting and distribution type (tighting and appliance
type, to N.E.C.), single-phase and neutral (SPN) or 3-phase and neutral
(TPN), with bolted I, 2, or 3-pole MCB’s on branch circuits and 2,3 or 4-pole
MCCB on main incoming.
B. Internal Assembly: to comprise removable back plate or back pan of rigid
construction, attached to enclosure by four captive screws through keyhole
fixings, and provided with DIN rails in horizontal arrangement for SPN
panels, and in vertical arrangement for TPN panels. Assembly is to be
complete with neutral terminal block, earthing bar and one piece insulated
bolt-on/comb-type 'Phase busbars. Busbars are to be single-phase or 3-phase
with spade connectors for fixing by tightening a single screw on circuit
breaker. Insulation is to be high thermal rating, capable of carrying maximum
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short-circuit current for one second without overheating beyond acceptable
limits required by the Standards. Panelboards are to comply with BS 5486
Part 12.
C. SPN type panelboards are to be, single-phase and neutral, with MCBs on
branch circuits and 2 pole MCCB as main incoming.
D. Single pole and double pole MCBs, are to have trip ratings between 6A and
50A, with ICs as required in the Schedules.
E. TPN type panelboards are to have MCBs on branch circuits and 3 or 4-pole
MCCB as main incoming, as shown 6n the drawings.
F. Triple-pole branch circuit breakers are to have trip ratings between 5 A and
100A, with IC as required in the Schedules.
G. TPN type panelboard main circuit breakers are to be MCCB, 100A,
continuous current rating with trip range 16A to 100A, 160A MCCB with trip
range 16A to 160A or 250 A MCCB with trip range 70A to 250A, normal (N)
or high-break (H) duty with/without RCD as shown on the Drawings.
2.08 WORKS TESTS
A. All assemblies shall be tested in accordance with the requirements of IEC
60439 standard part 1, plus requirements of associated standards.
B. Works tests shall include inspection of all wiring and a complete electrical
functioning test.
C. Protection relays shall be tested by primary current injection with currents
equal to overload, short-circuit and earth fault conditions.
D. Works tests shall be done in the presence of the engineer.
2.09 FIELD TESTING
A. ASSEMBLES
All assemblies shall be subjected to the routine tests as defined in IEC,
standards. After installation on site. Test Certificates shall be provided.
B. All functional units shall be checked for correct mechanical operation.
C. All protection circuits with in relays used shall be tested for correct operation
by secondary injection of test currents. This shall be carried out at currents
equivalent to overload, short-circuit and earth fault conditions.
D. Where specified in the schedules, protection circuits using current
transformer (CT) operated relays shall be tested by primary injection of
current to prove the transformer ratio.
2.10 COMMISSIONING
A. Following the satisfactory conclusion of inspections and tests on completed
sections of the works, each switchgear assembly shall be duly commissioned
and left in full working order. The term "Commissioning" shall be deemed to
include:
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i. The energizing of functional device circuits and equipment which have
previously been inspected, tested found to be satisfactory and capable of
being energized with compete safety.
ii. The starting up of all electrically powered plant and equipment including
that supplied and installed under other contracts, and as specified in the
schedules.
iii. The verification of the performance of each distribution board relative to
all such plant and equipment by the carrying out where required of further
tests and the making of all necessary adjustments so as to obtain optimum
performance.
iv. The proving of all interlock operations in all possible combinations and
the operation of all control systems metering and indications to meet the
performance requirements specified.
PART 3- EXECUTION
3.01 EXAMINATION: -
A. Examine areas and conditions under which panelboards and enclosures are to
be installed, notify Engineer and correct conditions detrimental to proper
completion of work. Do not proceed with work until unsatisfactory
conditions have been corrected in a manner acceptable to the Engineer.
3.02 INSTALLATION OF PANELBOARDS:
A. Install panelboards and enclosures as indicated, in accordance with
manufacturer's written instructions, requirements of applicable standards of
Installation, and in compliance with recognized industry practices to ensure
that products fulfill requirements.
B. Align, level and securely fasten panelboards to structure, ensuring that they
are permanently and mechanically anchored.
C. Fix surface mounted outdoor panelboards at least 25 mm from wall ensuring
supporting members do not prevent flow of air.
D. Do not use connecting conduits to support panelboards.
E. Close unused openings in panelboard cabinets.
F. Do not install interior of panelboards in cabinets until all conduit connections
to cabinet have been completed.
G. Wiring inside panelboards to be neatly arranged, accessible and strapped to
prevent tension on circuit breaker terminals. Tap-off connections on a riser
feeder are to be split and bolted type, fully insulated.
H. Trim: fix plumb and square prior to painting. Fix trim for flush mounted
cabinets flush with wall surface finish.
I. Protection: treat concealed- surfaces of recessed cabinets with heavy field
application of waterproof compound prior to installation.
J. Tighten connectors and terminals, including screws and bolts, in accordance
with equipment manufacturer's published torque tightening values for
equipment connectors. Where manufacturer's torquing requirements are not
indicated, tighten connectors and terminals to comply with tightening torques
specified in the approved standards.
K. Fill out panel board's circuit directory card upon completion of installation
work in a proper and neat manner acceptable to the Engineer.
9
L. Coordinate as necessary to interface installation of distribution boards with
other works.
M. Fasten enclosures firmly to walls and structural surfaces ensuring that they
are permanently and mechanically anchored. Provide all angle units and
accessories for proper mounting.
N. Double lugging is not permitted.
3.03 EARTHING:
A. Provide equipment earthing connections for panelboard enclosures as
indicated and as recommended in the Regulations and Codes applicable.
3.04 FIELD OUALITY CONTROL:
A. Prior to energization of electrical circuitry, check all accessible connections
to manufacturer's tightening torque specifications.
B. Prior to energization of panelboards, check with earth resistance tester phaseto-
phase and phase-to-earth and neutral to earth insulation resistance levels to
ensure requirements are fulfilled. Record all readings, using 500 V megger
for equipment on 240V systems, 1000V megger for equipment on systems up
to 600V for I minute with CBs in open position.
C. Prior to energization, check panelboards for electrical continuity of circuits,
and for short-circuits.
D. Ensure and test earth continuity and resistance in accordance with Section
"Earthing" .
E. Carry out circuit breaker tests as required in Division 16 Section "L V Circuit
Breakers" and as required by the Engineer.
F. Routine tests on site are to be carried out, in accordance with the Standards,
on I all panelboards assembled from standardized components of the
manufacturer outside the works of the manufacturer.
G. Equipment shall be tested and full type test certificate issued by an approved
independent test laboratory shall be submitted.
3.05 ADJUSTING AND CLEANING:
A. Adjust operating mechanisms for free mechanical movement.
B. Touch-up scratched or marred surfaces to match original finishes.
3.06 DEMONSTRATION:
A. Subsequent to wire and cable hook-ups, energize panelboards and
demonstrate functioning in accordance with requirements. Where necessary,
correct malfunctioning units, and then retest to demonstrate compliance.
END OF SECTION 16470
PART I -GENERAL
1.01 RELATED DOCUMENTS:
A. Drawings and general provisions of Contract, including General and
Supplementary Conditions and Division-1 Specification sections, apply to
work of this section.
B. Division-16 "Basic Electrical Materials and Methods " and other sections
apply to work specified in this section.
1.02 SUMMARY:
A. This section includes panelboards for distribution and subdistribution of
electric power and for protection of circuits, including fixing and supporting
materials and materials for termination of feeders, sub circuits and branch
circuits.
B. Types of panelboards and enclosures required for the project include the
following:
LP: Final branch circuit Lighting Panelboard.
PP: Final branch circuit power panelboard.
DB: Distribution panelboard.
Note 1 : Final branch circuit lighting panelboards, and power
panelboards for secondary lighting and power distribution are
designated with moulded case circuit breaker (MCCB) protection
on subfeeder or branch circuits, as shown on the drawings.
Note 2: Panelboards supplied from emergency source are prefixed with
the letter E.
Note 3: Panelboards supplied from UPS are prefixed with "UPS".
C. Refer to other Division-16 sections "Wires/Cables", "Electrical Enclosures,
Boxes and Fittings", and "Raceways" required in conjunction with
installation of panelboards and enclosures.
D. Refer to Division 16 section "Circuit Breakers" for circuit breaker applications
and recommended types and frames for this project.
E. Refer to Division 15 section "Building Management System" for connection to
BMS.
1.03 SUBMITTALS:
A Product Data: submit manufacturer's data and catalogues on panelboards and
enclosures.
B. Dimensions and contents of each panelboard.
2
C. Coordinated tabulations of series short circuit combination of circuit breakers.
D. Wiring Diagrams: submit wiring diagrams for panelboards showing
connections to electrical power feeders and distribution branches.
E. Typical mounting details, labels, tags.
F. Tests and certificates: submit complete certified manufacturer's type test and
routine test records in accordance with the Standards applicable.
G. Submit to the Engineer a relay and C.B. selectivity study.
The Current-time characteristics must be plotted on a log-log papers showing
that the choice of the C.B. settings are correct for full selective system.
H. Submit a comprehensive short circuit study as well as voltage drop
calculation based on the actual impedance values of the electrical components
such as supply short circuit level at the 11 KV (shall not be less than 500
MVA), transformer per unit impedance, bus bars and cables
impedances…etc.
I. Submit a detailed load list verifying the load balance across the phased of
each board.
1.04 QUALITY ASSURANCE:
A. Manufacturer's Qualifications: firms regularly engaged in manufacture of
panelboards and enclosures, of types, sizes, and ratings required, whose
products have been in satisfactory use in similar service for not less than 5
years.
B. Installer's Qualifications: a firm with at least 3 years of successful installation
experience on projects utilizing panelboards similar to those required for this
project.
C. Codes and Standards:
1. IEC 439 & IEC 947, Factory Built Assembles of Low Voltage Switch
gear and Control gear.
2. Electrical Code Compliance: comply with applicable local code,
regulations and requirements of the authority having jurisdiction, as
applicable to installation, and construction of electrical panelboards and
enclosures in this project.
1.05 . SEQUENCING AND SCHEDULING:
A. Coordinate installation of panel boards and enclosures with civil/architectural
program and installation of wires/cables, electrical boxes and fittings, and
raceway work.
PART 2-PRODUCT:
2.01 MANUFACTURERS:
A. Available Manufacturers: subject to compliance with requirements,
specifications, drawings and regulations.
B. For approved manufacturers refer to the recommended manufacturers list.
3
2.02 PANELBOARDS -GENERAL
A. Schedules on drawings indicate type and requirements of each panelboard.
These are defined by the following criteria:-
1. type of construction (MCB or MCCB), referring to type of branch circuit
breakers required.
2. voltage, number of phases and wires
3. branch circuit breaker trip rating and wire size
4. main circuit breaker trip rating and frame size (maximum continuous
rating) for MCCB
5. short circuit interrupting capacity (IC) in kA.
6. special arrangement or provisions.
B. Rated insulation voltage is to be in accordance with the respective Standards.
C. Panelboards are to be totally enclosed, dead front type, protection code IP42
for indoor installations and IP 65 for outdoor installations, in accordance with
IEC 529 and are to be factory designed and assembled.
D. Earthing bar is to be provided in every panelboard and to be half size the
phase busbars.
E. Neutral bar is to be provided in every panelboard and to be full size as per the
phase busbars.
F. Protection is to be fully rated though-out the systems.
G. Circuit breakers are to be non-fused type.
H. Circuit breaker arrangement: panelboards are to have one main incoming
circuit breaker or switch and the required number of branch circuit breakers,
arranged as shown on the Schedules, including spare circuit breakers and
spaces for future expansion. Three-phase panelboards are to be designed for
sequence phase connection of branch circuit devices.
I. Branch circuit numbering: on 3-phase panelboard schedules, circuits land 2
are J to be connected to red (R) phase, 3 and 4 to yellow (V) phase, 5 and 6 to
blue (B) phase etc., to conform with branch circuit numbering shown on the
Drawings.
J. Connection to Building Management System (BMS): coordinate with the
BMS supplier and provide all necessary interface devices, instruments, dry
contacts for connection of all required points to the BMS as specified or
indicated in the BMS schedules (If required).
K. Distribution boards shall be type tested and shall fully comply with the
requirements of IEC 60947, standards.
L. Distribution boards shall have a side-hung hinged front cover, attached by
means of lift-off hinges and fitted with cylinder type locking handles. Covers
shall be braced or folded in such a manner as to prevent distortion or whip,
and shall be fitted with dust-proofing gaskets or edge seals.
4
M. Distribution board cases shall be of such dimensions that adequate space is
available for maneuvering and connecting the incoming and outgoing cables.
N. Each distribution board shall be provided with a durable circuit chart fixed to
the inside of the cover or immediately adjacent and bearing typewritten
details in plain language, of the circuits supplied by each of the ways. The
chart shall be on heavy weight paper or thin card and shall be protected by
means of rigid transparent plastic cover, it shall be mounted in such a way that
it can easily be removed for correction or alteration then replaced. The size of
the chart shall be such that there is adequate space of recording all of the
required information and in any case, shall not be less than A5
(210mmx148mm).
O. Each distribution board shall be provided with an engraved plastic label on
the outside of the front cover, bearing the designation of the board and its
reference number, if any, as given on the drawings or in the schedules. The
label shall be fixed in position by chromium –plated set screws. Each such
label shall be not less in size than 100mmx30 mm, and shall bear the required
inscription in white on a black background, using letters and/or digits not less
than 5mm high.
P. PDUs shall be equipped with isolation transformers, spike suppressions&
surge arrestors.
2.03 PANELBOARD ENCLOSURES
A. Type: general purpose type, suitable for relevant ambient conditions, flush or
surface mounted as shown on the Drawings, comprising box, trim or trim and
door to approved manufacturer's standards and sizes.
B. Construction: recessed mounting box with multiple knockouts, trim and
doors where required, are to be electro-galvanized sheet steel of gauges not
less than specified in accordance with the Standards, minimum 2.0 mm
thickness. Welded joints are to be galvanized after manufacture. Gutter
spaces are to conform to the Standards, but are not to be less than 100 mm on
all sides. Enclosure is to have predesigned angles or threaded end studs to
support and adjust mounting of interior panelboard assembly.
C. Trims are to cover and overlap front shield, covering all terminals and bus
compartments, to form a dead front panel. Trims are to be fixed to
cabinet/box by adjustable quarter-turn clamps engaging flange of box (use of
screws engaging holes in flange box is not acceptable). Screws where used
are to be oval-head, countersunk and flush. Trims for flush mounted
panelboards are to overlap box and front shields by at least 20 mm. Trims for
surface mounted panelboards are to be exactly sized to form flush fit to box.
D. Doors are to have piano type concealed hinges integral with trim, and flush
combination cylinder lock and catch. Doors over 1000 mm high are to have
vault-type handle and multiple point latch mechanism. Locks are to be flush
and keyed alike.
E. Finish: inner and outer surfaces of cabinet/boxes, trims, doors etc. are to be
cleaned, phosphatized, chrome passivated and treated with final
thermosetting epoxy powder modified by polyester resins providing high
5
resistance to mechanical injury , heat, acid and alkali solvents, grease, aging
and corrosion and of standard grey colour to the approval of the Engineer .
F. Directories under glassene with directory frame, or an approved alternative
durable arrangement, are to be provided on inside face of doors, or in metal
label holders when trim without doors is specified. Directories are to be typed
to identify panelboards and clearly indicate circuit number and description of
load.
G. Outdoor enclosures are to be heavy duty sheet steel cabinets, minimum 2.0
thick, fully weatherproofed (IP 65), without knockouts, but with removable
sealed/gasketed bottom gland plates and gasketed doors.
2.04 BUSBARS
A. Type: one piece, 98% pure electrolytic copper, based on a total maximum
operating temperature of 90 deg. C at full continuous rating (50 °C
temperature rise above 40 °C ambient). Bolted or clamped contact surfaces
are to have I maximum current density not exceeding requirements of the
approved standards. Aluminum is not to be used for busbars or panelboard
parts.
B. Design: busbars are to be shrouded/insulated and rigidly designed so that If
branch circuit devices can be removed without disturbing adjacent units or I
changed without additional machining, drilling or tapping. Busing is to be full
size without reduction. Busing and blank plates are to allow installation of
future circuit devices, where indicated on the Drawings.
C. Rating: bustar rating is to be at least equal to main circuit breaker frame size.
Where no main circuit breaker is required, busbars are to have main lugs or
disconnect switch, and to have nominal rating not less than 1.25 times the I
upstream circuit breaker trip rating.
D. Short-Circuit Duty: busbars are to carry maximum short-circuit duty of main
protective device, which is to be at least maximum short-circuit at point of
application for one second, without showing any signs of degradation.
E. Terminals and connections are to be anti-turn, solderless screw-pressure type.
Screws and bolts used for making copper/copper connections are to be hard
copper alloy with lock washers (riveted bus connections are not acceptable).
F. Neutral bar is to be solid and fully insulated from cabinet or box. One
solderless box type set-screw connector is to be provided for neutral wire of
each branch circuit and one bolted clamp-type connector or anti-turn lug with
set-screw for main incoming neutral wire. Neutral is to be fully sized and
rated as for phase busbars.
G. Earthing bar is to copper, brazed to panelboard cabinet, with bolted pressure
connector for main conductor and one set-screw-type tunnel terminal for each
outgoing conductor, to provide secure and reliable contact with all metal parts
and enclosure.
2.05 DISTRIBUTION PANELBOARDS (DB)
A. DB: to have a rated insulation voltage of 1000 V, rated operational voltage of
600 a.c. or d.c., and to be conforming to IEC 439: Part 1, Form 3a, similar to
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Cutler Hammer Pow-R-Line 4, or Merlin-Germ type Prisma P or G, floor or
wall surface mounted, suitable for ratings of main breaker or switch and
busbars ranging from 160 A to 1200 A, 3-phase, 4-wire (or 3-wire where
specifically indicated), suitably and orderly arranged for any selected
combination of branch MCCBs ranging from 100 A to 1200 A frame size and
short-circuit interrupting ratings as shown on the Drawings.
B. Construction: sheet steel, minimum 1.5 mm thick for cabinet/box and
minimum 2 mm thick for trim or trim and door. Fronts are to be single or twin
covers to shield circuit breakers, terminals and live ends.
C. Interior of panelboard is to be pan assembly consisting of galvanized sheet
steel chassis minimum 2 mm thick, folded, flanged and reinforced, with
busbars vertically arranged and mounted on moulded insulators.
D. Moulded insulators are to have minimum temperature rating of 130 deg. C
and insulation grade of 3.5 kV for one minute.
E. Circuit breakers are to be mounted in twin arrangement ( except for larger
circuit breakers) and bolted rigidly to copper cross and centre bus connectors.
2.06 FINAL BRANCH CIRCUIT. AND POWER PANELBOARDS (LP&PP).
GENERALLY
A. Arrangement: to comprise set of homogeneous branch circuit breakers with
unified profile and base, and one main circuit breaker. Single and multi-pole
circuit. breakers or other devices are to occupy modular spaces.
Accommodation of contactors and split-bus arrangement or other devices is
not to change regularity of standard box width.
B. Indoor Enclosure: sheet steel, minimum 1.5 mm thick for box/cabinet and
minimum 1.5 mm thick for front shield, trim and door. Fixings for flush trim
are to be adjustable to allow for miss-alignment between box and wall
surface. Wiring spaces (gutters) are to be at least 100 mm wide. Larger gutters
are to be provided where tap-off insulated split connectors are required.
Knockouts are to be provided in top or bottom of enclosure~ and are to
provide a neat and uniform conduit/cable terminal arrangement.
2.07 FINAL BRANCH CIRCUIT AND POWER P ANELBOARDS -TYPE
MCCB
A. Type: to have a rated insulation of 600 V and rated operation Voltage of 440
V a.c. and 240 V d.c., lighting and distribution type (tighting and appliance
type, to N.E.C.), single-phase and neutral (SPN) or 3-phase and neutral
(TPN), with bolted I, 2, or 3-pole MCB’s on branch circuits and 2,3 or 4-pole
MCCB on main incoming.
B. Internal Assembly: to comprise removable back plate or back pan of rigid
construction, attached to enclosure by four captive screws through keyhole
fixings, and provided with DIN rails in horizontal arrangement for SPN
panels, and in vertical arrangement for TPN panels. Assembly is to be
complete with neutral terminal block, earthing bar and one piece insulated
bolt-on/comb-type 'Phase busbars. Busbars are to be single-phase or 3-phase
with spade connectors for fixing by tightening a single screw on circuit
breaker. Insulation is to be high thermal rating, capable of carrying maximum
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short-circuit current for one second without overheating beyond acceptable
limits required by the Standards. Panelboards are to comply with BS 5486
Part 12.
C. SPN type panelboards are to be, single-phase and neutral, with MCBs on
branch circuits and 2 pole MCCB as main incoming.
D. Single pole and double pole MCBs, are to have trip ratings between 6A and
50A, with ICs as required in the Schedules.
E. TPN type panelboards are to have MCBs on branch circuits and 3 or 4-pole
MCCB as main incoming, as shown 6n the drawings.
F. Triple-pole branch circuit breakers are to have trip ratings between 5 A and
100A, with IC as required in the Schedules.
G. TPN type panelboard main circuit breakers are to be MCCB, 100A,
continuous current rating with trip range 16A to 100A, 160A MCCB with trip
range 16A to 160A or 250 A MCCB with trip range 70A to 250A, normal (N)
or high-break (H) duty with/without RCD as shown on the Drawings.
2.08 WORKS TESTS
A. All assemblies shall be tested in accordance with the requirements of IEC
60439 standard part 1, plus requirements of associated standards.
B. Works tests shall include inspection of all wiring and a complete electrical
functioning test.
C. Protection relays shall be tested by primary current injection with currents
equal to overload, short-circuit and earth fault conditions.
D. Works tests shall be done in the presence of the engineer.
2.09 FIELD TESTING
A. ASSEMBLES
All assemblies shall be subjected to the routine tests as defined in IEC,
standards. After installation on site. Test Certificates shall be provided.
B. All functional units shall be checked for correct mechanical operation.
C. All protection circuits with in relays used shall be tested for correct operation
by secondary injection of test currents. This shall be carried out at currents
equivalent to overload, short-circuit and earth fault conditions.
D. Where specified in the schedules, protection circuits using current
transformer (CT) operated relays shall be tested by primary injection of
current to prove the transformer ratio.
2.10 COMMISSIONING
A. Following the satisfactory conclusion of inspections and tests on completed
sections of the works, each switchgear assembly shall be duly commissioned
and left in full working order. The term "Commissioning" shall be deemed to
include:
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i. The energizing of functional device circuits and equipment which have
previously been inspected, tested found to be satisfactory and capable of
being energized with compete safety.
ii. The starting up of all electrically powered plant and equipment including
that supplied and installed under other contracts, and as specified in the
schedules.
iii. The verification of the performance of each distribution board relative to
all such plant and equipment by the carrying out where required of further
tests and the making of all necessary adjustments so as to obtain optimum
performance.
iv. The proving of all interlock operations in all possible combinations and
the operation of all control systems metering and indications to meet the
performance requirements specified.
PART 3- EXECUTION
3.01 EXAMINATION: -
A. Examine areas and conditions under which panelboards and enclosures are to
be installed, notify Engineer and correct conditions detrimental to proper
completion of work. Do not proceed with work until unsatisfactory
conditions have been corrected in a manner acceptable to the Engineer.
3.02 INSTALLATION OF PANELBOARDS:
A. Install panelboards and enclosures as indicated, in accordance with
manufacturer's written instructions, requirements of applicable standards of
Installation, and in compliance with recognized industry practices to ensure
that products fulfill requirements.
B. Align, level and securely fasten panelboards to structure, ensuring that they
are permanently and mechanically anchored.
C. Fix surface mounted outdoor panelboards at least 25 mm from wall ensuring
supporting members do not prevent flow of air.
D. Do not use connecting conduits to support panelboards.
E. Close unused openings in panelboard cabinets.
F. Do not install interior of panelboards in cabinets until all conduit connections
to cabinet have been completed.
G. Wiring inside panelboards to be neatly arranged, accessible and strapped to
prevent tension on circuit breaker terminals. Tap-off connections on a riser
feeder are to be split and bolted type, fully insulated.
H. Trim: fix plumb and square prior to painting. Fix trim for flush mounted
cabinets flush with wall surface finish.
I. Protection: treat concealed- surfaces of recessed cabinets with heavy field
application of waterproof compound prior to installation.
J. Tighten connectors and terminals, including screws and bolts, in accordance
with equipment manufacturer's published torque tightening values for
equipment connectors. Where manufacturer's torquing requirements are not
indicated, tighten connectors and terminals to comply with tightening torques
specified in the approved standards.
K. Fill out panel board's circuit directory card upon completion of installation
work in a proper and neat manner acceptable to the Engineer.
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L. Coordinate as necessary to interface installation of distribution boards with
other works.
M. Fasten enclosures firmly to walls and structural surfaces ensuring that they
are permanently and mechanically anchored. Provide all angle units and
accessories for proper mounting.
N. Double lugging is not permitted.
3.03 EARTHING:
A. Provide equipment earthing connections for panelboard enclosures as
indicated and as recommended in the Regulations and Codes applicable.
3.04 FIELD OUALITY CONTROL:
A. Prior to energization of electrical circuitry, check all accessible connections
to manufacturer's tightening torque specifications.
B. Prior to energization of panelboards, check with earth resistance tester phaseto-
phase and phase-to-earth and neutral to earth insulation resistance levels to
ensure requirements are fulfilled. Record all readings, using 500 V megger
for equipment on 240V systems, 1000V megger for equipment on systems up
to 600V for I minute with CBs in open position.
C. Prior to energization, check panelboards for electrical continuity of circuits,
and for short-circuits.
D. Ensure and test earth continuity and resistance in accordance with Section
"Earthing" .
E. Carry out circuit breaker tests as required in Division 16 Section "L V Circuit
Breakers" and as required by the Engineer.
F. Routine tests on site are to be carried out, in accordance with the Standards,
on I all panelboards assembled from standardized components of the
manufacturer outside the works of the manufacturer.
G. Equipment shall be tested and full type test certificate issued by an approved
independent test laboratory shall be submitted.
3.05 ADJUSTING AND CLEANING:
A. Adjust operating mechanisms for free mechanical movement.
B. Touch-up scratched or marred surfaces to match original finishes.
3.06 DEMONSTRATION:
A. Subsequent to wire and cable hook-ups, energize panelboards and
demonstrate functioning in accordance with requirements. Where necessary,
correct malfunctioning units, and then retest to demonstrate compliance.
END OF SECTION 16470
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