TECHNICAL
TECHNICAL SPECIFICATIONS
SPECIFICATIONS FOR
FOR
LT
LT SWITCHGEAR
SWITCHGEAR &
& PANEL
PANEL
CONCEPT
CONCEPT ENGINEERING
ENGINEERING
PROJECTS
PROJECTS PVT.
PVT. LTD.
LTD.
DOCUMENT
DOCUMENT NO.NO. :: CEPL/20082/EL/TSCEPL/20082/EL/TS
‐
‐
0404REV.
CUSTOMER
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DOC.NAME
DOC.NAME
:: TECHNICAL
TECHNICAL SPECIFICATION
SPECIFICATION FOR
FOR LT
LT SWITCHGEAR
SWITCHGEAR
CONTENTS
CONTENTS
1.0
1.0
SCOPE……….…………3
SCOPE……….…………3
2.0
2.0
CODE
CODE AND
AND STANDARD……….…………..3
STANDARD……….…………..3
3.0
3.0
GENERAL
GENERAL REQUIREMENTS…………
REQUIREMENTS………
……….…………
………….………….4
.4
4.0
4.0
OPERATING
OPERATING CONDITIONS…..………
CONDITIONS…..………
……….…………
………….………….6
.6
5.0
5.0
PERFORMANCE……….………..……….6
PERFORMANCE……….………..……….6
6.0
6.0
CONSTRUCTION
CONSTRUCTION DETAILS……….…….……8
DETAILS……….…….……8
7.0
7.0
MISCELLANEOUS
MISCELLANEOUS ACCESSORIES…………
ACCESSORIES………
………..12
………..12
8.0
8.0
NOISE
NOISE LEVEL……….………13
LEVEL……….………13
9.0
9.0
MOTOR
MOTOR VIBRATION………..………...14
VIBRATION………..………...14
10.0
10.0
INSPECTION
INSPECTION AND
AND TESTING…………..……
TESTING…………..………
………..20
………..20
11.0
11.0
CERTIFICATION….……….23
CERTIFICATION….……….23
12.0
12.0
PACKING
PACKING AND
AND DESPATCH………24
DESPATCH………24
2.0
2.0
CODE
CODE AND
AND STANDARD
STANDARD
2.12.1 The The equipment equipment shall shall comply comply with with the the requirement requirement of of latest latest editions editions of of followingfollowing standards issued BIS (Bureau of Indian Standards) unless otherwise specified: standards issued BIS (Bureau of Indian Standards) unless otherwise specified:
IS:
IS: 5 5 Colors Colors for for ready ready mixed mixed paints paints enamels.enamels. IS:
IS: 772 772 AC AC Electricity Electricity Meters.Meters. IS:
IS: 1248 1248 Directing acting Directing acting electrical electrical indicating indicating instruments.instruments. IS:
IS: 2705 2705 Current transformers.Current transformers. IS:
IS: 2824 2824 Method Method for for determining determining the the comparative comparative tracking tracking indexindex of solid insulating materials under moist
of solid insulating materials under moist conditions.conditions. IS:
IS: 3156 3156 Voltage transformers.Voltage transformers. IS:
IS: 3231 3231 Electrical relays Electrical relays for for power power systems systems protections.protections. IS:
IS: 3618 3618 Phosphate treatment Phosphate treatment of of iron iron and and steel steel for for protectionprotection against corrosion.
against corrosion. IS:
IS: 5082 5082 Material data Material data for for aluminium aluminium bus bus bars.bars. IS:
IS: 5578 5578 Guide Guide for for marking marking of of insulated insulated conductor.conductor. IS:
IS: 6005 6005 Code of Code of practice practice of of phosphate phosphate of of iron iron and and steel.steel. IS:
IS: 8623 8623 Factory Built Factory Built assemblies assemblies of of switchgear switchgear and and control control geargear for voltage up to and including 1000V AC and 1200V DC for voltage up to and including 1000V AC and 1200V DC Part‐II particular requirements for bulbar trucking Part‐II particular requirements for bulbar trucking system (bus ways).
system (bus ways). IS:
IS: 11353 11353 Guide Guide for for information information system system marking marking and and identificationidentification of conductors and apparatus terminals.
of conductors and apparatus terminals. IS:
IS: 13706 13706 Low Low voltage voltage fuses.fuses. IS:
IS: 13947 13947 LV LV switchgear switchgear and and control control geargear IS:
IS: 3043 3043 Code of Code of practice practice for for earthing.earthing. 2.2
2.2 In In case case of of imported imported equipment, equipment, standards standards of of the the country country of of origin origin shall shall bebe applicable if these standards are equivalent or stringent than the applicable applicable if these standards are equivalent or stringent than the applicable Indian Standards.
Indian Standards. 2.3
2.3 The The equipment equipment shall shall also also confirm confirm to to the the provision provision of of Indian Indian Electricity Electricity rules rules andand other statutory regulations currently in force in the country.
other statutory regulations currently in force in the country. 2.4
2.4 In In case case Indian Indian Standards Standards are are not not available, available, Standard Standard issued issued byby IEC/BS/VDE/IEEE/
IEC/BS/VDE/IEEE/NEMA or equivalent NEMA or equivalent agency shall be agency shall be applicable.applicable. 2.5
2.5 In In case case of of any any contradiction contradiction between between various various referred referred standards standards / / Specification Specification // data sheets and sta
data sheets and sta tutory regulations, the following order of priority shalltutory regulations, the following order of priority shall govern:
govern: ‐
‐ Statutory Statutory regulationsregulations ‐
‐ Data Data sheetssheets ‐
‐ Job Job specificationsspecifications ‐
‐ This This specificationspecification
‐
CUSTOMER
CUSTOMER
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EPC
EPC CONTACTOR
CONTACTOR
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DOC.NAME
DOC.NAME
:: TECHNICAL
TECHNICAL SPECIFICATION
SPECIFICATION FOR
FOR LT
LT SWITCHGEAR
SWITCHGEAR
3.0
3.0
GENERAL
GENERAL REQUIREMENTS
REQUIREMENTS
3.13.1 The The offered offered equipment equipment shall shall be be brand brand new new with with state state of of the the art art technology technology andand proven field track record. No prototype equipment shall be offered.
proven field track record. No prototype equipment shall be offered. 3.2
3.2 Vendor Vendor shall shall ensure ensure availability availability of of spare spare parts parts and and maintenance maintenance support support servicesservices for the offered equipment at least for 5 years from the date of supply.
for the offered equipment at least for 5 years from the date of supply. 3.3
3.3 Vendor Vendor shall shall give give a a notice notice of of at at least least one one year year to to the the end end user user of of equipment equipment andand EPC contractor before phasing out the product/spares to ensure the
EPC contractor before phasing out the product/spares to ensure the end user forend user for placement of order for spares and services.
placement of order for spares and services.
4.0
4.0
SITE
SITE CONDITIONS.
CONDITIONS.
4.14.1 The The switchboard switchboard shall shall be be suitable suitable for for installation installation and and satisfactory satisfactory operation operation in in aa pressured substation or in substation with restricted
pressured substation or in substation with restricted natural air ventilation in anatural air ventilation in a tropical, humid and corrosive atmosphere
tropical, humid and corrosive atmosphere 4.2
4.2 The The switchboard switchboard shall shall be be designed designed to to operate operate under under specified specified site site conditions. conditions. IfIf not specifically mentioned a design ambient temperature of 40°C and altitude not specifically mentioned a design ambient temperature of 40°C and altitude not exceeding 1000 meters above mean sea level shall be considered.
not exceeding 1000 meters above mean sea level shall be considered. 4.3
4.3 All All the the equipment equipment described described in in this this specification specification is is intended intended for for continuous continuous dutyduty at the specified ratings under the specified ambient conditions.
at the specified ratings under the specified ambient conditions.
5.0
5.0
PROJECT
PROJECT INFORMATION
INFORMATION
OwnerOwner : : M/s. M/s. NMDC NMDC Limited, Limited, HyderabadHyderabad Project
Project : : Donimalai Donimalai Iron Iron Ore Ore Mine, Mine, Lump Lump Ore Ore StackerStacker Machine
Machine Site
Site Location Location : : Donimalai, Donimalai, Near Near Sander, Sander, Bangalore Bangalore – – 360 360 Km. Km. ,, Hyderabad
Hyderabad – – 460 460 Km.( Km.( Bellary Bellary district)district) Elevation
Elevation : : ‐‐ Nearest
Nearest Railway Railway : : Toranagallu, Toranagallu, 22 22 kMS kMS from from DonamalaiDonamalai Nearest
Nearest Harbour Harbour ::
-
-Nearest road (National/State Highway) : ‐ Nearest road (National/State Highway) : ‐
6.0
6.0
CLIMATE
CLIMATE CONDITIONS
CONDITIONS
The climate of area is mild and pleasant during summer months and moderately The climate of area is mild and pleasant during summer months and moderately cold during winter.
Max. Ambient Max. Ambient Temperature Temperature : 450C : 450C Min. Ambient Min. Ambient temperature temperature : : 150C 150C to to 80C80C Rain
Rain fall fall : : 600mm 600mm to to 800mm 800mm per per annum annum during during monsoonmonsoon Relative
Relative humidity humidity : : 100% not 100% not occurring occurring Simultaneously Simultaneously withwith maximum temperature
maximum temperature Height above Mean sea
Height above Mean sea level
level
:
: More More than than 1000M 1000M above above MSLMSL
7.0
7.0
DESIGN
DESIGN AND
AND FABRICATION
FABRICATION REQUIREMENTS
REQUIREMENTS
7.17.1 PanelPanel DesignDesign Requirement Requirement 7.1.1
7.1.1 Low voltage switchboard shall be metal enclosed Low voltage switchboard shall be metal enclosed non draw out, free standing,non draw out, free standing, floor mounting, compartmentalized, Modular type suitable for indoor
floor mounting, compartmentalized, Modular type suitable for indoor installation.
installation. 7.1.2
7.1.2 The switchboard The switchboard enclosure enclosure shall be shall be dust and dust and vermin vermin proof proof and shall and shall provide provide aa degree of protection not less than IP‐42
degree of protection not less than IP‐42 7.1.3
7.1.3 The switchboThe switchboard encard enclosure losure shall shall be assembe assembled out bled out of of vertical vertical panels panels of of uniformuniform height in single line up.
height in single line up. 7.1.4
7.1.4 It shall It shall be possible be possible to exto extend the tend the switchboards, switchboards, in either in either direction at direction at a later a later date.date. End of bus bars shall be suitably drilled for this purpose. Panel at extreme ends End of bus bars shall be suitably drilled for this purpose. Panel at extreme ends shall have openings, which shall be covered with plates screwed to the panel, shall have openings, which shall be covered with plates screwed to the panel, Details drilled holes in busbar and openings in the panels, provided for future Details drilled holes in busbar and openings in the panels, provided for future extension shall be clearly shown in th
extension shall be clearly shown in th e vendor drawings.e vendor drawings. 7.1.5
7.1.5 The sThe switchboard shawitchboard shall ll be designed be designed to to ensure ensure maximum maximum safety during safety during operation,operation, inspection, connection of cables, relocation of outgoing circuits and
inspection, connection of cables, relocation of outgoing circuits and
maintenance, with the bus bar system energized and without taking any special maintenance, with the bus bar system energized and without taking any special precautions.
precautions. 7.1.6
7.1.6 Adequate means Adequate means shall be shall be provided provided to prto prevent shorevent shorting of ting of power power and / and / or conor controltrol terminals due to accidental dropping of maintenance
terminals due to accidental dropping of maintenance tools etc. inside thetools etc. inside the switchboard. Checking and removal of components shall be possible without switchboard. Checking and removal of components shall be possible without disturbing adjacent equipment.
disturbing adjacent equipment. 7.1.7
7.1.7 All All identical identical equipment equipment and and corresponding corresponding parts parts shall shall be be fully fully interchangeable.interchangeable. 7.1.8
7.1.8 The frame, The frame, of of individual verindividual vertical ptical panels sanels shall be hall be fabricated using fabricated using pressed pressed andand cold rolled sheet steel. The sheet steel used for panel shall be of minimum 2mm cold rolled sheet steel. The sheet steel used for panel shall be of minimum 2mm (14swg) CRCA except that the doors and covers may be made of 1.6mm CRCA. (14swg) CRCA except that the doors and covers may be made of 1.6mm CRCA. Wherever required, stiffeners shall be provided to increase stiffness of large size Wherever required, stiffeners shall be provided to increase stiffness of large size doors and covers.
CUSTOMER
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EPC
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DOC.NAME
DOC.NAME
:: TECHNICAL
TECHNICAL SPECIFICATION
SPECIFICATION FOR
FOR LT
LT SWITCHGEAR
SWITCHGEAR
panel. The switchboard integral base frame shall be suitable for tack welding. panel. The switchboard integral base frame shall be suitable for tack welding. 7.1.10
7.1.10 All opening, All opening, covers and doorcovers and doors shall be provs shall be provided with neoprene Gaskets.ided with neoprene Gaskets. Removable blanking plates shall be provided to cover th
Removable blanking plates shall be provided to cover th e openings in the e openings in the eventevent of withdrawing the feeder modules. Numbers of blanking plates shall be 10% of of withdrawing the feeder modules. Numbers of blanking plates shall be 10% of each module size with minimum of one number.
each module size with minimum of one number. 7.1.11
7.1.11 All hardware shall All hardware shall be corrosion resistanbe corrosion resistant. All joints t. All joints and connections of and connections of the panelthe panel members shall be made by zinc
members shall be made by zinc passivity cadmium plated high quality steel passivity cadmium plated high quality steel bolt,bolt, nut and washers.
nut and washers. 7.1.12
7.1.12 Suitable removable Suitable removable type eyebolts shall type eyebolts shall be provided for the be provided for the lifting of thelifting of the panel/shipping section. These bolts, when removed shall not leave
panel/shipping section. These bolts, when removed shall not leave any openingany opening in the panels.
in the panels. 7.1.13
7.1.13 Non‐magnetic cable glNon‐magnetic cable gland plates shall be and plates shall be provided for terminprovided for termination of single coation of single corere cables.
cables. 7.1.14
7.1.14 The switchboard shall The switchboard shall be formed using distinct be formed using distinct vertical panels vertical panels each comprisingeach comprising of following compartments.
of following compartments.
A completely metal enclosed horizontal busbar A completely metal enclosed horizontal busbar compartment runningcompartment running horizontally at top unless otherwise specified.
horizontally at top unless otherwise specified.
Individual feeder modules in multitier modeIndividual feeder modules in multitier modeInIn415V Panels, the no. of tiers per415V Panels, the no. of tiers per vertical section shall be restricted, as per
vertical section shall be restricted, as per SLD Drg.SLD Drg.
Vertical bus bars serving all feeder modules in the vertical panel.Vertical bus bars serving all feeder modules in the vertical panel.
Cable termination compartment.Cable termination compartment.
Perforated sheet steel/Insulating material enclosed horizontal auxiliary bus Perforated sheet steel/Insulating material enclosed horizontal auxiliary bus barsbars for control, interlock, indication and
for control, interlock, indication and metering wiring running horizontally.metering wiring running horizontally.
Metal sheets shall be provided between two adjacent vertical panels running upMetal sheets shall be provided between two adjacent vertical panels running up to full useful height of the switchboard.
to full useful height of the switchboard. 7.1.15
7.1.15 Metal sheets shall be Metal sheets shall be provided between two adjacent provided between two adjacent vertical panels running vertical panels running toto the full width of the wider panel and up to full use
the full width of the wider panel and up to full use ful height of the switchgear.ful height of the switchgear. 7.1.16
7.1.16 The depth of the MCThe depth of the MCC panel shall C panel shall be uniform throughout be uniform throughout section and shall nosection and shall not bet be less than 1400 mm
less than 1400 mm 7.1.17
7.1.17 A separate vertA separate vertical bus bar chamber ical bus bar chamber shall be provided at shall be provided at the front of the front of the panelthe panel for the bottom ACB feeders.
for the bottom ACB feeders. 7.1.18
7.1.18 Adequate space shall Adequate space shall be planned for tbe planned for the outgoing cable terhe outgoing cable termination. Necessarymination. Necessary shrouding shall be provided for the
shrouding shall be provided for the outgoing cable termination. Accessing aoutgoing cable termination. Accessing a single ACB feeder shall be easier and it shall not disturb the functioning of the single ACB feeder shall be easier and it shall not disturb the functioning of the other feeder.
other feeder. 7.1.19
7.1.19 A separate vertA separate vertical bus bar chamber ical bus bar chamber shall be provided at shall be provided at the front of the front of the panelthe panel for the bottom ACB feeders.
7.1.20
7.1.20 Adequate space shall Adequate space shall be planned for tbe planned for the outgoing cable terhe outgoing cable termination. Necessarymination. Necessary shrouding shall be provided for the
shrouding shall be provided for the outgoing cable termination. Accessing aoutgoing cable termination. Accessing a single ACB feeder shall be easier and it shall not disturb the functioning of the single ACB feeder shall be easier and it shall not disturb the functioning of the other feeder.
other feeder. 7.1.21
7.1.21 The front The front of the of the board shall board shall comprise of comprise of individually enclosed individually enclosed Air‐ break Air‐ break CircuitCircuit Breakers, Starters, MCCB & MPCB modules.
Breakers, Starters, MCCB & MPCB modules. 7.1.22
7.1.22 All auxiliary devices All auxiliary devices for control, infor control, indication, measurement and dication, measurement and protection such protection such asas control and selector switches, indicating lamps, ammeters, voltmeters, energy control and selector switches, indicating lamps, ammeters, voltmeters, energy meters and protective relays shall be mounted on the front side of the respective meters and protective relays shall be mounted on the front side of the respective compartment only.
compartment only. 7.1.23
7.1.23 The design The design shall be shall be such that such that unless required unless required for maintenafor maintenance / nce / inspectioninspection purpose, all power on / off or start
purpose, all power on / off or start / stop and relay reset operations shall / stop and relay reset operations shall bebe performed without opening the panel door.
performed without opening the panel door. 7.1.24
7.1.24 Busbar rating of Busbar rating of all the panels all the panels shall be not shall be not less than the incomer less than the incomer rating.rating. 7.1.25
7.1.25 Mechanical Castel Mechanical Castel key and Electrical key and Electrical interlock between interlock between incomers shall incomers shall bebe provided, wherever MCCs / Distribution Boards are
provided, wherever MCCs / Distribution Boards are provided with more thanprovided with more than one incomer.
one incomer. 7.2
7.2 ConstructionConstruction 7. 2.1
7. 2.1 The complete The complete board shall board shall be of be of coordinated design coordinated design so that so that shipping groupshipping groups of s of thethe board are easily assembled together at site into a continuous line up. Necessary board are easily assembled together at site into a continuous line up. Necessary standard connecting material shall be supplied.
standard connecting material shall be supplied. 7.2.2
7.2.2 Name Name plates plates of of elegant elegant and and durable durable design design and and quality quality shall shall be be fixed fixed to to thethe individual compartments, feeder modules etc.
individual compartments, feeder modules etc. 7.2.3
7.2.3 The The boards boards covered covered by by this this enquiry enquiry shall shall be be designed, designed, manufactured manufactured and and testedtested in accordance with the latest revisions of the related applicable standards listed in accordance with the latest revisions of the related applicable standards listed elsewhere in this document.
elsewhere in this document. 7.2.4
7.2.4 The The frame frame work work of of the the boards, boards, except except incomer incomer panels panels and and main main busbar busbar section,section, shall be constructed of preformed steel channels, angles and side sheets bolted shall be constructed of preformed steel channels, angles and side sheets bolted together and suitably reinforced to form a
together and suitably reinforced to form a rigid, self supporting, compactrigid, self supporting, compact assembly to function properly under both normal and short circuit conditions. assembly to function properly under both normal and short circuit conditions. All busbars and components of the switchboard shall be
All busbars and components of the switchboard shall be adequately supportedadequately supported suitable for transportation, handling at site in assemble
suitable for transportation, handling at site in assemble condition.condition. 7.2.5
7.2.5 The The bus bus compartments compartments shall shall comprise comprise of of one one main main horizontal horizontal TPN TPN in in the the busbus unit with vertical risers for connection to the
unit with vertical risers for connection to the individual modules.individual modules. 7.2.6
7.2.6 The The board board shall shall be be of of totally totally metal‐enclosed metal‐enclosed ventilated ventilated multiple multiple unitunit construction. End unit shall include provisions for future main
construction. End unit shall include provisions for future main bus extensionsbus extensions and installation of additional units on either side with the framework suitably and installation of additional units on either side with the framework suitably
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:: TECHNICAL
TECHNICAL SPECIFICATION
SPECIFICATION FOR
FOR LT
LT SWITCHGEAR
SWITCHGEAR
and associated hardware enabling f
and associated hardware enabling f uture extension without involving majoruture extension without involving major fabrication work on the panel in
fabrication work on the panel in service.service. 7.2.7
7.2.7 Metallic Metallic barriers barriers shall shall be prbe provided ovided between vbetween vertical sectertical sections ions and also and also betweenbetween adjacent modules to ensure prevention of accidental
adjacent modules to ensure prevention of accidental contact with live partscontact with live parts during routine inspection / maintenance of functional units or
during routine inspection / maintenance of functional units or cablecable terminations of one or more functional units when
terminations of one or more functional units when working on those of adjacentworking on those of adjacent units. These barriers shall have insulating inserts as necessary for taking the units. These barriers shall have insulating inserts as necessary for taking the interconnections etc.
interconnections etc. 7.2.8
7.2.8 Doors Doors and covers and covers shall bshall be of e of sheet steel sheet steel of thickness of thickness not not less than less than 1.6 mm 1.6 mm coldcold rolled and the edges shall be reinforced against distortion by rolling / bending / rolled and the edges shall be reinforced against distortion by rolling / bending / or by addition of welded reinforcement members. The doors shall have
or by addition of welded reinforcement members. The doors shall have concealed type of hinges, and shall
concealed type of hinges, and shall be of removable type for the be of removable type for the rear doors.rear doors. Wherever the door length is more than 600mm, necessary stiffeners shall be Wherever the door length is more than 600mm, necessary stiffeners shall be provided and shall be split into
provided and shall be split into two halves. All module doors shall be two halves. All module doors shall be providedprovided with a minimum of two locks with the travel angle of 90 degrees. All the locks with a minimum of two locks with the travel angle of 90 degrees. All the locks shall be operated with a single key.
shall be operated with a single key. 7.2.9
7.2.9 Cut Cut outs outs shall shall be be true true in in shape shape and and free free from from sharp sharp edges.edges. 7.2.10
7.2.10 The panel shall The panel shall be provided with be provided with a separate ma separate metal base channel etal base channel 75 mm in 75 mm in heightheight for facilitating grouting on the floor, in addition to the integral base channels, if for facilitating grouting on the floor, in addition to the integral base channels, if considered.
considered. 7.2.11
7.2.11 Dust preventing Dust preventing gaskets of ngaskets of neoprene shall eoprene shall be used on be used on all doors all doors to ensure to ensure dustdust tightness of the interior while the board is in service. Suitable ventilating louvers tightness of the interior while the board is in service. Suitable ventilating louvers designed in such a way as to prevent entry of falling dust shall be provided at the designed in such a way as to prevent entry of falling dust shall be provided at the sides and top so that a free circulation of air through the equipment under
sides and top so that a free circulation of air through the equipment under thermal cycling conditions is ensured. The louvers shall be provided with fine‐ thermal cycling conditions is ensured. The louvers shall be provided with fine‐ screened brass meshes to prevent
screened brass meshes to prevent entry of vermin. If ventilation louvers areentry of vermin. If ventilation louvers are provided on top, suitable canopy / cover shall be
provided on top, suitable canopy / cover shall be provided.provided. 7.2.12
7.2.12 The hardware shalThe hardware shall be l be zinc plated zinc plated and passivated. and passivated. These shall These shall be of be of the captivethe captive type to obviate loss of these bolts /
type to obviate loss of these bolts / screws etc., when the screws etc., when the doors / covers aredoors / covers are opened for servicing / inspection.
opened for servicing / inspection. 7.2.13
7.2.13 Cold Rolled Sheet SCold Rolled Sheet Steel of 2.0 mm. teel of 2.0 mm. thickness shall be used thickness shall be used for all members.for all members. 7.2.14
7.2.14 All compoAll components including nents including the busbars the busbars shall be cshall be capable of being apable of being removed fromremoved from front. The cable alleys shall also be at the front of the board for MCCs &
front. The cable alleys shall also be at the front of the board for MCCs &
Distribution Boards. However, cable access may be arranged at the rear side in Distribution Boards. However, cable access may be arranged at the rear side in 415V panels.
415V panels. 7.2.15
7.2.15 All the doAll the doors for ors for the feeder modules the feeder modules in the froin the front shall nt shall have individual sheet have individual sheet steelsteel hinged doors with concealed hinges; these doors shall be capable of being
hinged doors with concealed hinges; these doors shall be capable of being
physically lifted off the main base shell and fixed back in position while the panel physically lifted off the main base shell and fixed back in position while the panel is in service without necessitating removal of any screws or welding etc. and is in service without necessitating removal of any screws or welding etc. and with the adjacent modules in service with their doors closed. The doors shall with the adjacent modules in service with their doors closed. The doors shall
also have interlock facility, with defea
also have interlock facility, with defea t provision, to ensure that the door t provision, to ensure that the door is notis not opened when feeder is in ON position.
opened when feeder is in ON position. 7.2.16
7.2.16 The bus bar The bus bar chamber shall chamber shall have screwed covhave screwed covers at the ers at the front, on front, on the sides and the sides and forfor the top.
the top. 7.2.17
7.2.17 The covers The covers for the for the cable chambers cable chambers and other and other compartments compartments shall have shall have coverscovers screwed on with captive screws so that these do not fall off when the panel is in screwed on with captive screws so that these do not fall off when the panel is in use while the operating /
use while the operating / maintenance personnel have occasion to open andmaintenance personnel have occasion to open and replace these covers.
replace these covers. 7.2.18
7.2.18 The panels The panels shall be shall be suitable for suitable for cable entrcable entry at y at bottom. bottom. Undrilled, remoUndrilled, removablevable gland plates not less than 3 mm thick shall be provided at the bottom for the gland plates not less than 3 mm thick shall be provided at the bottom for the switchboards to suit entry of the cables as furnished in the schedules. Cable switchboards to suit entry of the cables as furnished in the schedules. Cable clamping arrangements shall be provided in the
clamping arrangements shall be provided in the cable alley.cable alley. 7.2.19
7.2.19 The switchboards The switchboards shall have shall have uniform height uniform height of not of not more than more than 2400 mm. 2400 mm. TheThe height of the operating handle for the feeder modules, indicating lamps, MCBs height of the operating handle for the feeder modules, indicating lamps, MCBs etc., in the top most tier which may need adjustment / replacement shall all be etc., in the top most tier which may need adjustment / replacement shall all be not more than 1950 mm from the finished operating level on the floor so that not more than 1950 mm from the finished operating level on the floor so that these are easily accessible
these are easily accessible for the operating / maintenance personnel withoutfor the operating / maintenance personnel without having to take recourse to ladders
having to take recourse to ladders / steps etc.,/ steps etc., 7.2.20
7.2.20 The minimum The minimum operating height operating height of the switcof the switch handles shall h handles shall not be not be less than 400less than 400 mm from the finished floor level including the safety rubber mat.
mm from the finished floor level including the safety rubber mat. 7.2.21
7.2.21 All live All live parts shall parts shall be suitably be suitably shrouded with shrouded with non deterioratnon deteriorating insulatinging insulating barriers so as to prevent any a
barriers so as to prevent any a ccidental contact with these by the ccidental contact with these by the operating /operating / maintenance personnel while the panel is in service and the modules are opened maintenance personnel while the panel is in service and the modules are opened for inspection / servicing etc.
for inspection / servicing etc. 7.2.22
7.2.22 The switchgear The switchgear panels shall panels shall be provbe provided with space ided with space heaters to heaters to prevent mprevent moistureoisture condensation and maintain cubicle temperature 5 Deg.C
condensation and maintain cubicle temperature 5 Deg.C above the ambientabove the ambient temperature. The space heater shall be located at the bottom of the switchboard temperature. The space heater shall be located at the bottom of the switchboard and shall be supplied from 230 V AC control supply. The space heater shall be and shall be supplied from 230 V AC control supply. The space heater shall be provided with a manually operated
provided with a manually operated rotary switch and controlled through arotary switch and controlled through a thermostat. A separate space heater shall be
thermostat. A separate space heater shall be provided for each vertical panel.provided for each vertical panel. The space heaters shall
The space heaters shall be fed from control transformer of respective panel.be fed from control transformer of respective panel. 7.2.23
7.2.23 18W CFL Lamps shall 18W CFL Lamps shall be provided in be provided in the cable chamber and althe cable chamber and also in theso in the marshalling compartment unit. The supply for the same shall
marshalling compartment unit. The supply for the same shall be derived frombe derived from the control supply through door limit switches.
the control supply through door limit switches. 7.2.24
7.2.24 Specific requirementSpecific requirements to s to be met be met for 2000A for 2000A and higher and higher rating feeders:rating feeders: a.
a. Ventilation louvers with fine screened brass meshes to meet IP52 requirement,Ventilation louvers with fine screened brass meshes to meet IP52 requirement, on side covers of main busbar
on side covers of main busbar chambers and rear covers shall be provided.chambers and rear covers shall be provided. b.
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c.
c. Thickness of busbars at the incomer panels shall not be more than ¼”.Thickness of busbars at the incomer panels shall not be more than ¼”.
8.0
8.0 SPACESPACE HEATERHEATER
The switchboard panel shall be provided with space heaters to prevent moisture The switchboard panel shall be provided with space heaters to prevent moisture condensation. The space space heater shall be located in the bottom part of each condensation. The space space heater shall be located in the bottom part of each panel and shall be supplied from 240V AC auxiliary bus for space heater. The panel and shall be supplied from 240V AC auxiliary bus for space heater. The space heater shall be provided with a thermostat having adjustable setting and space heater shall be provided with a thermostat having adjustable setting and double pole miniature circuit breaker.
double pole miniature circuit breaker.
9.0
9.0 AUXILIARY AUXILIARY BUSBUS BARSBARS
Auxiliary bus bars each of minimum size 18‐mm2 coppers shall be provided for Auxiliary bus bars each of minimum size 18‐mm2 coppers shall be provided for following applications. Exact number of bus bars shall depend
following applications. Exact number of bus bars shall depend on variouson various controls, metering and auxiliary power distribution requirement.
controls, metering and auxiliary power distribution requirement.
Panel space heater supply and motor space Panel space heater supply and motor space heater supply.heater supply.
Control supply for breaker tripping, closing and indication circuits.Control supply for breaker tripping, closing and indication circuits.
Control supply for breaker spring charging Control supply for breaker spring charging motors, motor starter control andmotors, motor starter control and
indication circuit. indication circuit.
AC potential supply for energy meters, voltage operated relay tec.AC potential supply for energy meters, voltage operated relay tec.
Provision to hook up of external DC control supply to be Provision to hook up of external DC control supply to be provided wither in busprovided wither in bus
PT panel or bus coupler panel. PT panel or bus coupler panel.
10.0
10.0 BUSBUS BARSBARS
10.1
10.1 The The busbars busbars shall shall be be of of hard hard drawn drawn high high conductivity conductivity electrolytic electrolytic gradegrade Aluminum conforming to IS / IEC Standards. The
Aluminum conforming to IS / IEC Standards. The busbars shall be of uniformbusbars shall be of uniform cross section along its entire length. No tapering
cross section along its entire length. No tapering of the busbar cross section isof the busbar cross section is allowed. The busbar shall have smooth round edges.
allowed. The busbar shall have smooth round edges. 10.2
10.2 Horizontal Horizontal and and vertical vertical busbars busbars shall shall be be provided provided with with PVC PVC sleeves sleeves of of highhigh quality.
quality. 10.3
10.3 The joints The joints in in the busbarthe busbars shall s shall be obe of tf the bohe bolted type lted type and it and it shall bshall be ensured e ensured thatthat the following precautions are observed:
the following precautions are observed: •
• The cThe contact ontact pressure pressure must must be ambe ample and ple and this this shall bshall be maintained e maintained during during thethe time the panel is in service.
time the panel is in service.
•• The surfaces of the conductors must be clean.The surfaces of the conductors must be clean. •
• With flat With flat conductors, conductors, the overthe overlap should lap should be equal be equal to or to or greater than greater than the width the width ofof the bars or ten times the bar thickness whichever is greater.
the bars or ten times the bar thickness whichever is greater. •
• The joints shall be The joints shall be treated by treated by the appthe application olication of joint f joint compound compound to render to render thethe joints moisture‐proof.
joints moisture‐proof. •
• For For the jothe joints cadmints cadmium pium plated high lated high tension tension MS MS bolts bolts having having expansionexpansion
characteristics due to temperature change similar to the conductor may be used characteristics due to temperature change similar to the conductor may be used with steel nuts.
10.4
10.4 The The efficiency efficiency of of the the joints joints shall shall be be preserved preserved by by smearing smearing the the surfaces surfaces withwith oxide inhibiting grease just prior to making the joint.
oxide inhibiting grease just prior to making the joint. 10.5
10.5 The The switchboard switchboard shall shall be be provided provided with with power power busbars busbars for for the the 3 3 phases phases andand neutral. The Busbars fed by
neutral. The Busbars fed by the incomer shall run continuously throughout thethe incomer shall run continuously throughout the length of the switchboard.
length of the switchboard. 10.6
10.6 The The power power busbars busbars shall shall have have a a short short circuit circuit withstanding withstanding capacity capacity of of 50 kA 50 kA forfor 1 Sec.
1 Sec. 10.7
10.7 The The busbars busbars shall shall be be phase phase identified identified by by colour, colour, throughout throughout the the length length oror identification of busbars at regular intervals. Colour code
identification of busbars at regular intervals. Colour code for busbars shall be asfor busbars shall be as per IEC practices. Busbars shall be rated for 40 Deg.C temperature rise over an per IEC practices. Busbars shall be rated for 40 Deg.C temperature rise over an ambient of 45 Deg.C as
ambient of 45 Deg.C as measured by thermometer.measured by thermometer. 10.8
10.8 However, However, the the main main bus bus bars bars for for panels panels shall shall not not be be less less than than the the sizes sizes furnishedfurnished below for various ratings. The main bus bar rating for the panels shall be as below for various ratings. The main bus bar rating for the panels shall be as indicated in the single line diagram.
indicated in the single line diagram. 10.9
10.9 The The cross cross section section of of the the other other bus bus bars bars shall shall be be uniform uniform throughout. throughout. In In any any case,case, the current density shall be
the current density shall be not more than 0.8 A/Sq.mm for panels, on the not more than 0.8 A/Sq.mm for panels, on the ratedrated current of switchgear.
current of switchgear. 10.10
10.10 Busbars shall Busbars shall be supporbe supported on ted on tough, non‐hygrtough, non‐hygroscopic, oscopic, resin bonded resin bonded selfself extinguishing fire retardant insulators of SMC
extinguishing fire retardant insulators of SMC / DMC with ribbed construction to/ DMC with ribbed construction to prevent tracking due to dust accumulation and
prevent tracking due to dust accumulation and to have larger creepage paths. to have larger creepage paths. AllAll the phases are individually
the phases are individually supported. If a common support is provided for allsupported. If a common support is provided for all the three phases, anti‐tracking barriers shall
the three phases, anti‐tracking barriers shall be incorporated. Busbars andbe incorporated. Busbars and supports shall withstand the maximum stresses that are likely to be induced by supports shall withstand the maximum stresses that are likely to be induced by the short circuit currents specified.
the short circuit currents specified.
10.11 The clearance between the individual bare phase power busbars and between the 10.11 The clearance between the individual bare phase power busbars and between the
phase and earth busbars in air shall be not less than 25 mm and 16 phase and earth busbars in air shall be not less than 25 mm and 16 mmmm respectively.
respectively. 10.12
10.12 All busbar All busbar joints shall joints shall be of the be of the bolted type. bolted type. Ring washers Ring washers shall be used shall be used for jointsfor joints to prevent loosening of the nuts and
to prevent loosening of the nuts and over heating. Lock nuts shall beover heating. Lock nuts shall be
incorporated for the bolts besides the main nuts. The bolts and nuts used in the incorporated for the bolts besides the main nuts. The bolts and nuts used in the current carrying paths shall all be of steel cadmium plated and the hardware current carrying paths shall all be of steel cadmium plated and the hardware shall have adequate cover of
shall have adequate cover of the protective cadmium coating to obviatethe protective cadmium coating to obviate corrosion while the board is in service.
corrosion while the board is in service. 10.13
10.13 The busbar The busbar chambers at tchambers at the top shall he top shall be totally be totally segregated from segregated from the rest ofthe rest of compartments and rendered totally inaccessible under normal circumstances. compartments and rendered totally inaccessible under normal circumstances. No equipment / instrument shall be
No equipment / instrument shall be mounted on the busbar chamber.mounted on the busbar chamber. 10.14
10.14 Power shall Power shall be distributed be distributed to each to each module or module or compartment compartment by a by a set of set of verticalvertical busbars. The vertical busbars shall run behind
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10.15
10.15 All All busbars, links busbars, links etc., shall etc., shall be PVC be PVC sleeved and sleeved and adequately shrouded adequately shrouded to to preventprevent accidental contact. The sleeve used shall be of the heat shrinkable type. Shrouds accidental contact. The sleeve used shall be of the heat shrinkable type. Shrouds at outgoing terminals shall be with
at outgoing terminals shall be with transparent sheets.transparent sheets. 10.16
10.16 Auxiliary bAuxiliary busbars of usbars of minimum minimum 18 Sq.mm 18 Sq.mm copper copper shall be shall be provided for provided for panelpanel space heater supply, control supply for breaker tripping, closing and indication space heater supply, control supply for breaker tripping, closing and indication circuits, breaker spring charging motor and motor starter control and indication circuits, breaker spring charging motor and motor starter control and indication circuits.
circuits. 10.17
10.17 The busbars The busbars shall run shall run horizontally horizontally in a in a separate enclosure separate enclosure but may but may run in run in anan enclosure located within the power busbar compartment.
enclosure located within the power busbar compartment. 10.18
10.18 Necessary tee Necessary tee off cooff connectors nnectors shall be shall be used for used for distributing distributing auxiliary suppauxiliary supply toly to each vertical panel. Rubber grommets shall be used for all wire entries to make each vertical panel. Rubber grommets shall be used for all wire entries to make the entries dust and
the entries dust and vermin proof.vermin proof.
11.0
11.0
EARTHING
EARTHING
11.111.1 The The panel panel shall shall be be connected connected to to an an earth earth busbar busbar running running throughout throughout the the lengthlength of the switchboard.
of the switchboard. 11.2
11.2 The The minimum minimum earth earth bus bus size size shall shall be be 300 S300 Sq.mm q.mm copper copper with with lead lead coating.coating. 11.3
11.3 All All doors doors and moand movable vable parts parts shall shall be be connected connected to to the earthe earth bus th bus with flexibwith flexiblele copper connections. Provision shall be made to connect the earthing busbar copper connections. Provision shall be made to connect the earthing busbar toto the plant earthing grid at two ends.
the plant earthing grid at two ends. 11.4
11.4 All All non‐current non‐current carrying carrying metallic metallic parts parts of of the the mounted mounted equipment equipment shall shall bebe earthed. Earthing bolts shall be provided
earthed. Earthing bolts shall be provided to ground cable armours.to ground cable armours.
12.0
12.0
SPECIFIC
SPECIFIC REQUIREMENT
REQUIREMENT TO
TO AIR
AIR CIRCUIT
CIRCUIT BREAKERS
BREAKERS PANELS
PANELS
12.112.1 The The breaker breaker panel panel shall shall have have distinct distinct bus bus bar, bar, breaker breaker and and cable cable compartments.compartments. 12.2
12.2 The The design design of of each each compartment compartment shall shall be be such asuch as s to to prevent prevent movement movement ofof vermin from a particular compartment to any other compartment of the panel vermin from a particular compartment to any other compartment of the panel when the breaker is
when the breaker is withdrawn and compartment door is closed.withdrawn and compartment door is closed. 12.3
12.3 Blanking Blanking plates plates shall shall be be provided provided for for each each circuit circuit breaker breaker compartments, compartments, whichwhich would be used after installation, to cover the openings in the event of taking out would be used after installation, to cover the openings in the event of taking out the breaker outside the
the breaker outside the compartment.compartment. 12.4
12.4 In In order order to to minimize minimize accidental accidental access access and and avoid avoid accidents accidents due due to to falling falling tools,tools, all the outgoing links shall be shrouded.
all the outgoing links shall be shrouded. 12.5
12.5 outgoing outgoing Air Air circuit circuit breaker breaker cab cab be be mounted mounted in in a a maximum maximum of of two two –tier–tier execution while the incoming/bus coupler Air circuit breaker
execution while the incoming/bus coupler Air circuit breaker shall be single tiershall be single tier execution only.
execution only.
12.6
12.6.1
12.6.1 Separate compartmSeparate compartment totally enclosed frent totally enclosed from all sides shaom all sides shall be provided for ll be provided for cablecable termination, on the front side.
termination, on the front side. 12.6.2
12.6.2 The incoming /The incoming /outgoing cable termoutgoing cable termination shall be stagination shall be staggered for each circuit gered for each circuit andand barriers of sheet steel or insulating material shall be provided between
barriers of sheet steel or insulating material shall be provided between termination of two circuits such that
termination of two circuits such that maintenance on one circuit could be carriedmaintenance on one circuit could be carried out while the other circuit is live, suitable clamping arrangements shall be
out while the other circuit is live, suitable clamping arrangements shall be provided for cable and cable termination. Te
provided for cable and cable termination. Te rminal blocks shall not be used forrminal blocks shall not be used for supporting the cables.
supporting the cables. 12.6.3
12.6.3 The incoming supplThe incoming supply for MCC/PMCC pany for MCC/PMCC panels shall be threls shall be through top entry ough top entry bus ductsbus ducts or through bottom entry cables unless specified otherwise. The
or through bottom entry cables unless specified otherwise. The outgoing cablesoutgoing cables shall have bottom entry unless specified
shall have bottom entry unless specified otherwise.otherwise. 12.6.4
12.6.4 The cable terminations sThe cable terminations shall be suitably sizhall be suitably sized for receiving sped for receiving specified number ofecified number of cable per termination and provision shall be made
cable per termination and provision shall be made for terminating each outgoingfor terminating each outgoing cable with a separate bolted connection. In case the total number of cables
cable with a separate bolted connection. In case the total number of cables entering a particular panel cannot be accommodated in
entering a particular panel cannot be accommodated in the cabling compartmentthe cabling compartment of the panels an extension panel of full height shall be added to
of the panels an extension panel of full height shall be added to the cablingthe cabling compartment for accommodating extra cables.
compartment for accommodating extra cables.
12.7
12.7
Circuit
Circuit Breaker
Breaker Compartments
Compartments
12.7.112.7.1 Spring actuated Spring actuated and gravity and gravity operated safety operated safety shutters shall shutters shall be provided fobe provided forr isolating the busbars and other
isolating the busbars and other live parts when the breaker live parts when the breaker is completelyis completely withdrawn. The design of
withdrawn. The design of compartment shall be such as to prevent movement ofcompartment shall be such as to prevent movement of vermin from a particular circuit breaker compartment to any other portion of vermin from a particular circuit breaker compartment to any other portion of the panel when the breaker is withdrawn and the compartment door is closed. the panel when the breaker is withdrawn and the compartment door is closed. 17.7.2 The circuit breaker compartment enclosure shall be IP31 with the circuit breaker 17.7.2 The circuit breaker compartment enclosure shall be IP31 with the circuit breaker
in position or withdrawn from the compartment. in position or withdrawn from the compartment.
12.7.3 The circuit breaker compartment shall be fully draw out, i.e., bus side and 12.7.3 The circuit breaker compartment shall be fully draw out, i.e., bus side and
outgoing power and control connections shall be through draw out
outgoing power and control connections shall be through draw out contacts (itcontacts (it shall be possible to draw out the with draw able trolley without having to unbolt shall be possible to draw out the with draw able trolley without having to unbolt or unscrew any power and control connections). Suitable guides
or unscrew any power and control connections). Suitable guides shall beshall be provided to facilitate easy withdrawal of the trolley. All identical feeder provided to facilitate easy withdrawal of the trolley. All identical feeder compartments shall be interchangeable without having to carryout compartments shall be interchangeable without having to carryout modifications.
modifications.
12.7.4 The draw out breaker shall be earthed by means of a scraping earth system of 12.7.4 The draw out breaker shall be earthed by means of a scraping earth system of
silver plated copper such that the
silver plated copper such that the earth connection is broken after the earth connection is broken after the breakerbreaker main contacts disengage during withdrawal and the earth connection is made main contacts disengage during withdrawal and the earth connection is made before the main contacts engage du
before the main contacts engage du ring insertion.ring insertion. 12.7.5
12.7.5 The earth connection The earth connection shall remain connshall remain connected in "test" and "isoected in "test" and "isolated" positionslated" positions also.
also. 12.7.6
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•• Compartment doors shall be interlocked against opening when breaker Compartment doors shall be interlocked against opening when breaker is inis in closed or ON condition. However, it shall
closed or ON condition. However, it shall be possible to bypass this interlock forbe possible to bypass this interlock for inspection purposes.
inspection purposes.
•• It shall not be possible to push "in" a drawn out circuit breaker in closedIt shall not be possible to push "in" a drawn out circuit breaker in closed condition or withdraw a circuit breake
condition or withdraw a circuit breake r in closed condition.r in closed condition.
•• It shall be possible to operate a circuit breaker only in the defined "Full In" orIt shall be possible to operate a circuit breaker only in the defined "Full In" or "Service" and "test" position inside the panel. It shall not be possible to operate "Service" and "test" position inside the panel. It shall not be possible to operate the breaker in intermediate position while inserting or withdrawing a circuit the breaker in intermediate position while inserting or withdrawing a circuit breaker or while in "Full Out" position inside the panel.
breaker or while in "Full Out" position inside the panel. •
• It shall It shall be possible be possible to open to open / clos/ close the e the circuit breaker circuit breaker in “test” in “test” position byposition bypassingpassing the closing interlocks.
the closing interlocks. •
• All All the circuit the circuit breakers breakers shall be shall be provided with provided with a TNC a TNC switch for switch for local electlocal electricalrical operation and a Local / Re
operation and a Local / Remote selector switch for selecting the mode omote selector switch for selecting the mode o ff operation.
operation. 12.7.7
12.7.7 The breaker shall be The breaker shall be of draw‐out type of draw‐out type and shall be suitable and shall be suitable for motor / for motor / manualmanual spring charged closing.
spring charged closing. 12.7.8
12.7.8 Mechanical Castell Mechanical Castell key type key type interlocks interlocks shall be shall be provided bprovided between feeders,etween feeders, wherever specified. Electrical interlocks shall also be device, wherever specified. wherever specified. Electrical interlocks shall also be device, wherever specified.
13.0
13.0
SPECIFIC
SPECIFIC REQUIREMENT
REQUIREMENT OF
OF NON
NON
‐
‐
AIR
AIR CIRCUIT
CIRCUIT BREAKER
BREAKER FEEDERS
FEEDERS
13.1
13.1 The design The design of of draw out draw out feeder module feeder module shall shall not not change change for for single single front front execution.execution. Separate vertical bus bars shall be provided for each front side modules.
Separate vertical bus bars shall be provided for each front side modules. 13.2
13.2 All All identical identical feeder feeder modules modules shall shall be be interchangeable.interchangeable. 13.3
13.3 Each vEach vertical ertical panel panel shall shall have have a separate a separate cable cable alley. alley. The width The width of of this this cable alleycable alley shall be sufficient to accommodate all the cables and shall have free access for shall be sufficient to accommodate all the cables and shall have free access for cable terminations and in any case
cable terminations and in any case shall not be less than shall not be less than 200mm minimum.200mm minimum. Cable alleys shall be provided with suitable doors.
Cable alleys shall be provided with suitable doors. 13.4
13.4 Sheet Sheet steel steel barriers barriers shall shall be be provided provided between between individual individual compartments compartments andand cable alley. This barrier shall
cable alley. This barrier shall be provided with opening for power and be provided with opening for power and controlcontrol connections and it shall be possible t
connections and it shall be possible t o safely carryout maintenance work ono safely carryout maintenance work on cable connections to any one circuit in the cable alley with the busbars and the cable connections to any one circuit in the cable alley with the busbars and the adjacent circuits live.
adjacent circuits live. 13.5
13.5 Maintenance Maintenance and and connection connection of of cables cables to to any any modules modules shall shall be be possible possible withoutwithout having to take out the modules from its position from the panel.
having to take out the modules from its position from the panel. 13.6
13.6 The The outgoing outgoing feeder feeder trolleys trolleys for for drawout drawout type type switchboard switchboard shall shall be be fullyfully drawout and shall have the following features.
13.6.1
13.6.1 It shall be It shall be possible to withdraw the possible to withdraw the trolley without trolley without having to unbolt having to unbolt or unscrewor unscrew any power and control connections to the equipment mounted on the
any power and control connections to the equipment mounted on the withdrawwithdraw able trolley.
able trolley. 13.6.2
13.6.2 Both power and Both power and control concontrol connections shall bnections shall be drawout type. All e drawout type. All line and bus PT’sline and bus PT’s shall be in drawout execution
shall be in drawout execution only. However, outgoing modules having sizeonly. However, outgoing modules having size more than half of the useful vertical height of the panel may be in mixed more than half of the useful vertical height of the panel may be in mixed combination of drawout/fixed type.
combination of drawout/fixed type. 13.6.3
13.6.3 Control supControl supply transformer ply transformer modules with burden higher modules with burden higher than 2.5KVA may be than 2.5KVA may be inin fixed execution.
fixed execution. 13.6.4
13.6.4 The trolley withdrawal The trolley withdrawal shall be by means shall be by means of crank and of crank and screw arrangement.screw arrangement. Alternatively movement on guided rollers may also be acceptable. Plug Alternatively movement on guided rollers may also be acceptable. Plug inin operation shall be independent of manual force.
operation shall be independent of manual force. 13.6.5
13.6.5 For drawout typFor drawout type feeders of size equal e feeders of size equal to or greater to or greater than half the useful verthan half the useful verticaltical height of panel, positive clamping arrangement shall be
height of panel, positive clamping arrangement shall be provided on the topprovided on the top portion of the trolley in addition to clamping arrangement at
portion of the trolley in addition to clamping arrangement at the bottom, tothe bottom, to ensure all round positive pressure on the
ensure all round positive pressure on the power drawout contacts once thepower drawout contacts once the trolley is plugged in.
trolley is plugged in. 13.6.6
13.6.6 Power drawout conPower drawout contacts shall preferably tacts shall preferably be located towards the be located towards the bottom portiobottom portionn of each trolley. The trolley shall be
of each trolley. The trolley shall be lockable in fully plugged in position alockable in fully plugged in position a ndnd devices shall be provided to
devices shall be provided to ensure positive plugging in. in test position, powerensure positive plugging in. in test position, power contacts shall be totally isolated and device shall be provided for indication of contacts shall be totally isolated and device shall be provided for indication of test position.
test position. 13.7
13.7 The The incomer incomer and and bus bus tie tie feeders feeders with with load load break break switches switches rated 800A rated 800A and and aboveabove may be in fixed execution.
may be in fixed execution. 13.8
13.8 Various Various compartment compartment sizes sizes in in a a vertical vertical panel panel shall shall be be multiples multiples of of a a basicbasic
dimension. However the minimum module size for switch fuse feeder and motor dimension. However the minimum module size for switch fuse feeder and motor starter/contactor feeder shall not be less than that defined in data sheet/job starter/contactor feeder shall not be less than that defined in data sheet/job specification. Vertical bus bars shall be
specification. Vertical bus bars shall be pre‐drilled at regular intervals forpre‐drilled at regular intervals for complete flexibility for changes in size of
complete flexibility for changes in size of modules.modules. 13.9
13.9 All All switch switch drives drives other other than rthan rotary otary control control switches, switches, shall be shall be lockable lockable in in bothboth ‘ON’ and ‘OFF’ positions.
‘ON’ and ‘OFF’ positions. 13.10
13.10 The switches/Moulded The switches/Moulded case circuit case circuit breakers/MCB breakers/MCB shall be shall be interlocked winterlocked with theith the compartment door to prevent opening of the door when the
compartment door to prevent opening of the door when the switch/mouldedswitch/moulded case circuit breaker is in ‘ON’ position and to prevent switching on when the case circuit breaker is in ‘ON’ position and to prevent switching on when the door is open. A defeat mechanism for this interlock shall also be provided. door is open. A defeat mechanism for this interlock shall also be provided. 13.11
13.11 The maximum The maximum height of height of the operating the operating handle and handle and switches shall switches shall not exceed not exceed 19001900 mm and the minimum height not below 300 mm.
mm and the minimum height not below 300 mm. 13.12
13.12 Unused modules Unused modules in the in the panel shall panel shall be fully be fully equipped with equipped with hinged door, hinged door, powerpower and control terminals for starter modules and cradle
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14.0
14.0
SWITCHGEAR
SWITCHGEAR MODULES
MODULES
14.114.1 Switchboard Switchboard shall shall be cobe completely mpletely lined up lined up in oin one stne straight rraight row wow with the ith the type type andand quantities of feeders as defined in switchboard data sheet. Generally the feeders quantities of feeders as defined in switchboard data sheet. Generally the feeders of the three main categories are identified as identified as circuit breaker, motor of the three main categories are identified as identified as circuit breaker, motor starters and switch fuse.
starters and switch fuse. 14.2
14.2 Starter Starter modules modules required required for for motor motor control control shall shall be be of of following following types types andand internal control wiring of all starter modules of
internal control wiring of all starter modules of each type shall be ideach type shall be id entical forentical for all ratings.
all ratings. 14.2.1
14.2.1 FVNR FVNR Full voltage Full voltage non‐reversing non‐reversing starter starter with with minimum minimum 18 18 controlcontrol terminals.
terminals. 14.2.2
14.2.2 FVR FVR Full voltage Full voltage reversing reversing starter starter with with minimum minimum 24 24 control control terminals.terminals. 14.2.3
14.2.3 FVNR‐HD FVNR‐HD Full Full voltage voltage non‐reversing non‐reversing heavy heavy duty duty starter starter with with long long starting starting timetime such as for compressors and fans etc.
such as for compressors and fans etc. with minimum 18 controlwith minimum 18 control terminals
terminals 14.3
14.3 Switch fuse/contactor Switch fuse/contactor feeder feeder modules modules shall shall be be of of following following types types and and internalinternal control wiring of all modules of each type shall be identical for all ratings. control wiring of all modules of each type shall be identical for all ratings. 14.3.1 SFU
14.3.1 SFU Switch Switch fuse fuse modules modules with with no no control control terminals.terminals. 14.3.2
14.3.2 SFUC SFUC Switch Switch fuse fuse contactor contactor modules modules with with 18 18 control control terminals.terminals. 14.4
14.4 Type Type of of modules modules for for fixed fixed type type switchboard switchboard shall shall be be similar similar to to above above specifiedspecified drawout modules except that the modules shall be of fixed type.
drawout modules except that the modules shall be of fixed type. 14.5
14.5 Minimum Minimum 2000 VA 2000 VA control control transformer transformer shall shall be probe provided for vided for each bus each bus section section ofof the PMCC/MCC switchboard having contactor control feeders and
the PMCC/MCC switchboard having contactor control feeders and eacheach transformer shall be sized for the
transformer shall be sized for the entire switchboard. For switchboard havingentire switchboard. For switchboard having two bus sections and coupled by bus tie shall have manual changeover switch for two bus sections and coupled by bus tie shall have manual changeover switch for the control transformers.
the control transformers. 14.6
14.6 To To facilitate facilitate site site modification modification due tdue to o changes changes in in motor motor KW KW ratings ratings and and toto minimize spares inventory, overload relays and power fuse links
minimize spares inventory, overload relays and power fuse links shall meet theshall meet the following requirements.
following requirements. 14.6.1
14.6.1 All bimetal overAll bimetal overload relays shall load relays shall be separately mounted be separately mounted type with connectype with connectingting links rated for the maximum rating of the contactor in a starter module. links rated for the maximum rating of the contactor in a starter module. 14.6.2
14.6.2 Bimetal overload relBimetal overload relays of various ays of various current ranges required current ranges required for motors likely for motors likely toto be connected to a contactor must be
be connected to a contactor must be identical in dimension for inter‐identical in dimension for inter‐ changeability. In case offered relays are with different dimension for any changeability. In case offered relays are with different dimension for any particular starter module, special mounting plate suitable for
particular starter module, special mounting plate suitable for mounting differentmounting different relays shall be provided in all the modules of that size.
relays shall be provided in all the modules of that size. 14.7
14.7 Heavy Heavy duty duty starters starters shall shall be be provided provided with with saturable saturable type type current current transformertransformer operated overload relays only, which shall be s
operated overload relays only, which shall be s uitable for motor starting time ofuitable for motor starting time of 15‐60 seconds.