Tech Specification for LT MCC

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: TECHNICAL SPECIFICATION FOR LT SWITCHGEAR

TECHNICAL SPECIFICATIONS FOR LT SWITCHGEAR & PANEL

CONCEPT ENGINEERING PROJECTS PVT. LTD.

DOCUMENT NO. : CEPL/20082/EL/TS ‐04

REV.

DESCRIPTION

CEPL/20082/EL/TS ‐04

TOTAL SHEETS : 24

REV. 0

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CONTENTS 1.0

SCOPE…………………………………………………………………………….…………3

2.0

CODE AND CODE AND STANDARD………………………………………………….…………..3

3.0

GENERAL REQUIREMENTS………… REQUIREMENTS………………………………… ………………………………….………… ………….………….4 .4

4.0

OPERATING CONDITIONS…..……… CONDITIONS…..……………………………… ………………………………….………… ………….………….6 .6

5.0

PERFORMANCE……….………………………………………………………..……….6

6.0

CONSTRUCTION DETAILS……………………………………………….…….……8

7.0

MISCELLANEOUS ACCESSORIES………… MISCELLANEOUS ACCESSORIES……………………………… ……………………………………..12 ………………..12

8.0

NOISE LEVEL…………….………………………………………………………………13

9.0

MOTOR VIBRATION……………………………..………………………..............14

10.0

INSPECTION AND INSPECTION AND TESTING…………..………………………… TESTING…………..…………………………………………..20 ………………..20

11.0

CERTIFICATION….…………………………………………………………………….23

12.0

PACKING AND PACKING AND DESPATCH…………………………………………………………24

2.0

CODE AND CODE AND STANDARD

2.1

The equipment shall comply with the requirement of latest editions of following standards issued BIS (Bureau of Indian Standards) unless otherwise specified:


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IS: 5

Colors for ready mixed paints enamels.

IS: 772

AC Electricity Meters.

IS: 1248

Directing acting electrical indicating instruments.

IS: 2705

Current transformers.

IS: 2824

Method for determining the comparative tracking index of solid insulating materials under moist conditions.

IS: 3156

Voltage transformers.

IS: 3231

Electrical relays for power systems protections.

IS: 3618

Phosphate treatment of iron and steel for protection against corrosion.

IS: 5082

Material data for aluminium bus bars.

IS: 5578

Guide for marking of insulated conductor.

IS: 6005

Code of practice of phosphate of iron and steel.

IS: 8623

Factory Built assemblies of switchgear and control gear for voltage up to and including 1000V AC and 1200V DC Part‐II particular requirements for bulbar trucking system (bus ways).

IS: 11353

Guide for information system marking and identification of conductors and apparatus terminals.

IS: 13706

Low voltage fuses.

IS: 13947

LV switchgear and control gear

IS: 3043

Code of practice for earthing.

2.2

In case of imported equipment, standards of the country of origin shall be applicable if these standards are equivalent or stringent than the applicable Indian Standards.

2.3

The equipment shall also confirm to the provision of Indian Electricity rules and other statutory regulations currently in force in the country.

2.4

In case Indian Standards are not available, Standard IEC/BS/VDE/IEEE/NEMA IEC/BS/VDE/IEEE/NEMA or equivalent agency shall be applicable.

2.5

In case of any contradiction between various referred standards / Specification / data sheets and sta tutory regulations, the following order of priority shall govern: ‐ ‐ ‐ ‐

Statutory regulations Data sheets Job specifications This specification

‐

Codes and standards


issued

by

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3.0

GENERAL REQUIREMENTS

3.1

The offered equipment shall be brand new with state of the art technology and proven field track record. No prototype equipment shall be offered.

3.2

Vendor shall ensure availability of spare parts and maintenance support services for the offered equipment at least for 5 years from the date of supply.

3.3

Vendor shall give a notice of at least one year to the end user of equipment and EPC contractor before phasing out the product/spares to ensure the end user for placement of order for spares and services.

4.0

SITE CONDITIONS.

4.1

The switchboard shall be suitable for installation and satisfactory operation in a pressured substation or in substation with restricted natural air ventilation in a tropical, humid and corrosive atmosphere

4.2

The switchboard shall be designed to operate under specified site conditions. If not specifically mentioned a design ambient temperature of 40°C and altitude not exceeding 1000 meters above mean sea level shall be considered.

4.3

All the equipment described in this specification is intended for continuous duty at the specified ratings under the specified ambient conditions.

5.0

PROJECT INFORMATION Owner

:

M/s. NMDC Limited, Hyderabad

Project

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Donimalai Iron Ore Mine, Lump Ore Stacker Machine

Site Location

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Donimalai, Near Sander, Bangalore – 360 Km. , Hyderabad – 460 Km.( Bellary district)

Elevation

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‐

Nearest Railway

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Toranagallu, 22 kMS from Donamalai

Nearest Harbour

:

-

Nearest road (National/State Highway) : ‐

6.0

CLIMATE CONDITIONS The climate of area is mild and pleasant during summer months and moderately cold during winter.


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Max. Ambient Temperature

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450C

Min. Ambient temperature Rain fall Relative humidity

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150C to 80C

: :

Height above Mean sea level

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600mm to 800mm per annum during monsoon 100% not occurring Simultaneously with maximum temperature More than 1000M above MSL

7.0

DESIGN AND DESIGN AND FABRICATION REQUIREMENTS

7.1

Panel Design Requirement

7.1.1

Low voltage switchboard shall be metal enclosed non draw out, free standing, floor mounting, compartmentalized, Modular type suitable for indoor installation.

7.1.2

The switchboard enclosure shall be dust and vermin proof and shall provide a degree of protection not less than IP‐42

7.1.3

The switchboard switchboard enclosure enclosure shall be assembled assembled out of vertical panels of uniform height in single line up.

7.1.4

It shall be possible to extend extend the switchboards, in either direction at a later date. 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, Details drilled holes in busbar and openings in the panels, provided for future extension shall be clearly shown in th e vendor drawings.

7.1.5

The switchboard switchboard shall shall be designed to ensure maximum safety during operation, inspection, connection of cables, relocation of outgoing circuits and maintenance, with the bus bar system energized and without taking any special precautions.

7.1.6

Adequate means shall be provided to prevent prevent shorting shorting of power and / or control control terminals due to accidental dropping of maintenance tools etc. inside the switchboard. Checking and removal of components shall be possible without disturbing adjacent equipment.

7.1.7

All identical equipment and corresponding parts shall be fully interchangeable.

7.1.8

The frame, of individual vertical vertical panels panels shall shall be fabricated using pressed and 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. Wherever required, stiffeners shall be provided to increase stiffness of large size doors and covers.

7.1.9

The switchboard shall be provided provided with integral base frame frame for each vertical vertical


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panel. The switchboard integral base frame shall be suitable for tack welding. 7.1.10 All opening, covers and doors doors shall be provided provided with neoprene Gaskets. Removable blanking plates shall be provided to cover th e openings in the event of withdrawing the feeder modules. Numbers of blanking plates shall be 10% of each module size with minimum of one number. 7.1.11 All hardware shall be corrosion resistant. resistant. All joints and connections of the panel members shall be made by zinc passivity cadmium plated high quality steel bolt, nut and washers. 7.1.12 Suitable removable type eyebolts shall be provided for the lifting of the panel/shipping section. These bolts, when removed shall not leave any opening in the panels. 7.1.13 Non‐magnetic cable gland gland plates shall be provided for termination termination of single core core cables. 7.1.14 The switchboard shall be formed using distinct vertical panels each comprising of following compartments. 



  



A completely metal enclosed horizontal busbar compartment running horizontally at top unless otherwise specified. Individual feeder modules in multitier mode In 415V Panels, the no. of tiers per vertical section shall be restricted, as per SLD Drg. Vertical bus bars serving all feeder modules in the vertical panel. Cable termination compartment. Perforated sheet steel/Insulating material enclosed horizontal auxiliary bus bars for control, interlock, indication and metering wiring running horizontally. Metal sheets shall be provided between two adjacent vertical panels running up to full useful height of the switchboard.

7.1.15 Metal sheets shall be provided between two adjacent vertical panels running to the full width of the wider panel and up to full use ful height of the switchgear. 7.1.16 The depth of the MCC MCC panel shall be uniform throughout section and shall not not be less than 1400 mm 7.1.17 A separate vertical vertical bus bar chamber shall be provided at the front of the panel for the bottom ACB feeders. 7.1.18 Adequate space shall be planned for the the outgoing cable termination. termination. Necessary shrouding shall be provided for the outgoing cable termination. Accessing a single ACB feeder shall be easier and it shall not disturb the functioning of the other feeder. 7.1.19 A separate vertical vertical bus bar chamber shall be provided at the front of the panel for the bottom ACB feeders.


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7.1.20 Adequate space shall be planned for the the outgoing cable termination. termination. Necessary shrouding shall be provided for the outgoing cable termination. Accessing a single ACB feeder shall be easier and it shall not disturb the functioning of the other feeder. 7.1.21 The front of the board shall comprise of individually enclosed Air‐ break Circuit Breakers, Starters, MCCB & MPCB modules. 7.1.22 All auxiliary devices for control, indication, indication, measurement and protection such as control and selector switches, indicating lamps, ammeters, voltmeters, energy meters and protective relays shall be mounted on the front side of the respective compartment only. 7.1.23 The design shall be such that unless required for maintenance maintenance / inspection purpose, all power on / off or start / stop and relay reset operations shall be performed without opening the panel door. 7.1.24 Busbar rating of all the panels shall be not less than the incomer rating. 7.1.25 Mechanical Castel key and Electrical interlock between incomers shall be provided, wherever MCCs / Distribution Boards are provided with more than one incomer. 7.2

Construction

7. 2.1

The complete board shall be of coordinated design so that shipping groups groups of the board are easily assembled together at site into a continuous line up. Necessary standard connecting material shall be supplied.

7.2.2

Name plates of elegant and durable design and quality shall be fixed to the individual compartments, feeder modules etc.

7.2.3

The boards covered by this enquiry shall be designed, manufactured and tested in accordance with the latest revisions of the related applicable standards listed elsewhere in this document.

7.2.4

The frame work of the boards, except incomer panels and main busbar section, shall be constructed of preformed steel channels, angles and side sheets bolted together and suitably reinforced to form a rigid, self supporting, compact assembly to function properly under both normal and short circuit conditions. All busbars and components of the switchboard shall be adequately supported suitable for transportation, handling at site in assemble condition.

7.2.5

The bus compartments shall comprise of one main horizontal TPN in the bus unit with vertical risers for connection to the individual modules.

7.2.6

The board shall be of totally metal‐enclosed ventilated multiple unit construction. End unit shall include provisions for future main bus extensions and installation of additional units on either side with the framework suitably drilled to receive the additional modules and the busbars fitted with fishplates


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and associated hardware enabling f uture extension without involving major fabrication work on the panel in service. 7.2.7

Metallic barriers shall be provided provided between vertical vertical sections sections and also between adjacent modules to ensure prevention of accidental contact with live parts during routine inspection / maintenance of functional units or cable terminations of one or more functional units when working on those of adjacent units. These barriers shall have insulating inserts as necessary for taking the interconnections etc.

7.2.8

Doors and covers shall be be of sheet steel of thickness not less than 1.6 mm cold rolled and the edges shall be reinforced against distortion by rolling / bending / or by addition of welded reinforcement members. The doors shall have concealed type of hinges, and shall be of removable type for the rear doors. Wherever the door length is more than 600mm, necessary stiffeners shall be provided and shall be split into two halves. All module doors shall be provided with a minimum of two locks with the travel angle of 90 degrees. All the locks shall be operated with a single key.

7.2.9

Cut outs shall be true in shape and free from sharp edges.

7.2.10 The panel shall be provided with a separate metal metal base channel 75 mm in height for facilitating grouting on the floor, in addition to the integral base channels, if considered. 7.2.11 Dust preventing gaskets of neoprene neoprene shall be used on all doors to ensure dust 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 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‐ screened brass meshes to prevent entry of vermin. If ventilation louvers are provided on top, suitable canopy / cover shall be provided. 7.2.12 The hardware shall shall be zinc plated and passivated. These shall be of the captive type to obviate loss of these bolts / screws etc., when the doors / covers are opened for servicing / inspection. 7.2.13 Cold Rolled Sheet Steel Steel of 2.0 mm. thickness shall be used for all members. 7.2.14 All components components including the busbars shall be capable capable of being removed from 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 415V panels. 7.2.15 All the doors doors for the feeder modules in the front front shall have individual sheet steel 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 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


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also have interlock facility, with defea t provision, to ensure that the door is not opened when feeder is in ON position. 7.2.16 The bus bar chamber shall have screwed covers covers at the front, on the sides and for the top. 7.2.17 The covers for the cable chambers and other compartments shall have covers screwed on with captive screws so that these do not fall off when the panel is in use while the operating / maintenance personnel have occasion to open and replace these covers. 7.2.18 The panels shall be suitable for cable entry entry at bottom. Undrilled, removable removable 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 clamping arrangements shall be provided in the cable alley. 7.2.19 The switchboards shall have uniform height of not more than 2400 mm. The 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 not more than 1950 mm from the finished operating level on the floor so that these are easily accessible for the operating / maintenance personnel without having to take recourse to ladders / steps etc., 7.2.20 The minimum operating height of the switch switch handles shall not be less than 400 mm from the finished floor level including the safety rubber mat. 7.2.21 All live parts shall be suitably shrouded with non deteriorating deteriorating insulating barriers so as to prevent any a ccidental contact with these by the operating / maintenance personnel while the panel is in service and the modules are opened for inspection / servicing etc. 7.2.22 The switchgear panels shall be provided provided with space heaters to prevent moisture moisture condensation and maintain cubicle temperature 5 Deg.C above the ambient 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 provided with a manually operated rotary switch and controlled through a thermostat. A separate space heater shall be provided for each vertical panel. The space heaters shall be fed from control transformer of respective panel. 7.2.23 18W CFL Lamps shall be provided in the cable chamber and also also in the marshalling compartment unit. The supply for the same shall be derived from the control supply through door limit switches. 7.2.24 Specific requirements requirements to be met for 2000A and higher rating feeders: a.

Ventilation louvers with fine screened brass meshes to meet IP52 requirement, on side covers of main busbar chambers and rear covers shall be provided.

b. Ventilation hoods on top of the panel shall be provided.


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c.

8.0

Thickness of busbars at the incomer panels shall not be more than ¼”.

SPACE HEATER 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 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 double pole miniature circuit breaker.

9.0

AUXILIARY BUS AUXILIARY BUS BARS Auxiliary bus bars each of minimum size 18‐mm2 coppers shall be provided for following applications. Exact number of bus bars shall depend on various controls, metering and auxiliary power distribution requirement.   

 

Panel space heater supply and motor space heater supply. Control supply for breaker tripping, closing and indication circuits. Control supply for breaker spring charging motors, motor starter control and indication circuit. AC potential supply for energy meters, voltage operated relay tec. Provision to hook up of external DC control supply to be provided wither in bus PT panel or bus coupler panel.

10.0

BUS BARS

10.1

The busbars shall be of hard drawn high conductivity electrolytic grade Aluminum conforming to IS / IEC Standards. The busbars shall be of uniform cross section along its entire length. No tapering of the busbar cross section is allowed. The busbar shall have smooth round edges.

10.2 Horizontal and vertical busbars shall be provided with PVC sleeves of high quality. 10.3

• • • • •

The joints in the busbars busbars shall be of of the the bolted bolted type and it shall be be ensured that the following precautions are observed: The contact contact pressure must be ample ample and this shall be be maintained during the time the panel is in service. The surfaces of the conductors must be clean. With flat conductors, the overlap overlap should be equal to or greater than the width of the bars or ten times the bar thickness whichever is greater. The joints shall be treated by the application application of of joint compound to render the joints moisture‐proof. For the joints joints cadmium cadmium plated plated high tension MS bolts having expansion characteristics due to temperature change similar to the conductor may be used with steel nuts.


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10.4

The efficiency of the joints shall be preserved by smearing the surfaces with oxide inhibiting grease just prior to making the joint.

10.5

The switchboard shall be provided with power busbars for the 3 phases and neutral. The Busbars fed by the incomer shall run continuously throughout the length of the switchboard.

10.6

The power busbars shall have a short circuit withstanding capacity of 50 kA for 1 Sec.

10.7

The busbars shall be phase identified by colour, throughout the length or identification of busbars at regular intervals. Colour code for busbars shall be as per IEC practices. Busbars shall be rated for 40 Deg.C temperature rise over an ambient of 45 Deg.C as measured by thermometer.

10.8

However, the main bus bars for panels shall not be less than the sizes furnished below for various ratings. The main bus bar rating for the panels shall be as indicated in the single line diagram.

10.9

The cross section of the other bus bars shall be uniform throughout. In any case, the current density shall be not more than 0.8 A/Sq.mm for panels, on the rated current of switchgear.

10.10 Busbars shall be supported supported on tough, non‐hygroscopic, non‐hygroscopic, resin bonded self extinguishing fire retardant insulators of SMC / DMC with ribbed construction to prevent tracking due to dust accumulation and to have larger creepage paths. All the phases are individually supported. If a common support is provided for all the three phases, anti‐tracking barriers shall be incorporated. Busbars and supports shall withstand the maximum stresses that are likely to be induced by the short circuit currents specified. 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 mm respectively. 10.12 All busbar joints shall be of the bolted type. Ring washers shall be used for joints to prevent loosening of the nuts and over heating. Lock nuts shall be 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 shall have adequate cover of the protective cadmium coating to obviate corrosion while the board is in service. 10.13 The busbar chambers at the the top shall be totally segregated from the rest of compartments and rendered totally inaccessible under normal circumstances. No equipment / instrument shall be mounted on the busbar chamber. 10.14

Power shall be distributed to each module or compartment by a set of vertical busbars. The vertical busbars shall run behind the modules.


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10.15

All busbars, links etc., shall be PVC sleeved and adequately shrouded to prevent accidental contact. The sleeve used shall be of the heat shrinkable type. Shrouds at outgoing terminals shall be with transparent sheets.

10.16

Auxiliary busbars busbars of minimum 18 Sq.mm copper shall be provided for panel space heater supply, control supply for breaker tripping, closing and indication circuits, breaker spring charging motor and motor starter control and indication circuits.

10.17

The busbars shall run horizontally in a separate enclosure but may run in an enclosure located within the power busbar compartment.

10.18

Necessary tee off connectors connectors shall be used for distributing auxiliary supply supply to each vertical panel. Rubber grommets shall be used for all wire entries to make the entries dust and vermin proof.

11.0

EARTHING

11.1

The panel shall be connected to an earth busbar running throughout the length of the switchboard.

11.2 11.3

The minimum earth bus size shall be 300 Sq.mm Sq.mm copper with lead coating. All doors and movable movable parts shall be connected to the earth earth bus with flexible flexible copper connections. Provision shall be made to connect the earthing busbar to the plant earthing grid at two ends.

11.4

All non‐current carrying metallic parts of the mounted equipment shall be earthed. Earthing bolts shall be provided to ground cable armours.

12.0

SPECIFIC REQUIREMENT TO AIR TO AIR CIRCUIT BREAKERS PANELS

12.1

The breaker panel shall have distinct bus bar, breaker and cable compartments.

12.2

The design of each compartment shall be such as as to prevent movement of vermin from a particular compartment to any other compartment of the panel when the breaker is withdrawn and compartment door is closed.

12.3

Blanking plates shall be provided for each circuit breaker compartments, which would be used after installation, to cover the openings in the event of taking out the breaker outside the compartment.

12.4

In order to minimize accidental access and avoid accidents due to falling tools, all the outgoing links shall be shrouded.

12.5

outgoing Air circuit breaker cab be mounted in a maximum of two –tier execution while the incoming/bus coupler Air circuit breaker shall be single tier execution only.

12.6

Cable Compartment


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12.6.1 Separate compartment compartment totally enclosed from from all sides shall shall be provided for cable termination, on the front side. 12.6.2 The incoming /outgoing /outgoing cable termination termination shall be staggered staggered for each circuit and barriers of sheet steel or insulating material shall be provided between termination of two circuits such that maintenance on one circuit could be carried out while the other circuit is live, suitable clamping arrangements shall be provided for cable and cable termination. Te rminal blocks shall not be used for supporting the cables. 12.6.3 The incoming supply supply for MCC/PMCC panels panels shall be through through top entry bus ducts or through bottom entry cables unless specified otherwise. The outgoing cables shall have bottom entry unless specified otherwise. 12.6.4 The cable terminations shall shall be suitably sized sized for receiving specified specified number of cable per termination and provision shall be made for terminating each outgoing cable with a separate bolted connection. In case the total number of cables entering a particular panel cannot be accommodated in the cabling compartment of the panels an extension panel of full height shall be added to the cabling compartment for accommodating extra cables.

12.7

Circuit Breaker Circuit Breaker Compartments

12.7.1 Spring actuated and gravity operated safety shutters shall be provided for for isolating the busbars and other live parts when the breaker is completely withdrawn. The design of compartment shall be such as to prevent movement 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. 17.7.2 The circuit breaker compartment enclosure shall be IP31 with the circuit breaker in position or withdrawn from the compartment. 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 contacts (it shall be possible to draw out the with draw able trolley without having to unbolt or unscrew any power and control connections). Suitable guides shall be provided to facilitate easy withdrawal of the trolley. All identical feeder compartments shall be interchangeable without having to carryout modifications. 12.7.4 The draw out breaker shall be earthed by means of a scraping earth system of silver plated copper such that the earth connection is broken after the breaker main contacts disengage during withdrawal and the earth connection is made before the main contacts engage du ring insertion. 12.7.5 The earth connection shall remain connected connected in "test" and "isolated" "isolated" positions also. 12.7.6 The draw‐out compartments shall have the following interlocks:


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•

Compartment doors shall be interlocked against opening when breaker is in closed or ON condition. However, it shall be possible to bypass this interlock for inspection purposes.

•

It shall not be possible to push "in" a drawn out circuit breaker in closed condition or withdraw a circuit breake r in closed condition.

•

It 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 the breaker in intermediate position while inserting or withdrawing a circuit breaker or while in "Full Out" position inside the panel.

•

It shall be possible to open / close close the circuit breaker in “test” position bypassing bypassing the closing interlocks.

•

All the circuit breakers shall be provided with a TNC switch for local electrical electrical operation and a Local / Remote Re mote selector switch for selecting the mode o f operation.

12.7.7 The breaker shall be of draw‐out type and shall be suitable for motor / manual spring charged closing. 12.7.8 Mechanical Castell key type interlocks shall be provided between between feeders, wherever specified. Electrical interlocks shall also be device, wherever specified.

13.0

SPECIFIC REQUIREMENT OF NON‐ AIR CIRCUIT BREAKER FEEDERS

13.1

The design of draw out feeder module shall not change for single front execution. Separate vertical bus bars shall be provided for each front side modules.

13.2

All identical feeder modules shall be interchangeable.

13.3

Each vertical vertical panel shall have a separate cable alley. The width of this cable alley shall be sufficient to accommodate all the cables and shall have free access for cable terminations and in any case shall not be less than 200mm minimum. Cable alleys shall be provided with suitable doors.

13.4

Sheet steel barriers shall be provided between individual compartments and cable alley. This barrier shall be provided with opening for power and control connections and it shall be possible t o safely carryout maintenance work on cable connections to any one circuit in the cable alley with the busbars and the adjacent circuits live.

13.5

Maintenance and connection of cables to any modules shall be possible without having to take out the modules from its position from the panel.

13.6

The outgoing feeder trolleys for drawout type switchboard shall be fully drawout and shall have the following features.


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13.6.1 It shall be possible to withdraw the trolley without having to unbolt or unscrew any power and control connections to the equipment mounted on the withdraw able trolley. 13.6.2 Both power and control connections connections shall be be drawout type. All line and bus PT’s shall be in drawout execution only. However, outgoing modules having size more than half of the useful vertical height of the panel may be in mixed combination of drawout/fixed type. 13.6.3 Control supply supply transformer modules with burden higher than 2.5KVA may be in fixed execution. 13.6.4 The trolley withdrawal shall be by means of crank and screw arrangement. Alternatively movement on guided rollers may also be acceptable. Plug in operation shall be independent of manual force. 13.6.5 For drawout type type feeders of size equal to or greater than half the useful vertical vertical height of panel, positive clamping arrangement shall be provided on the top portion of the trolley in addition to clamping arrangement at the bottom, to ensure all round positive pressure on the power drawout contacts once the trolley is plugged in. 13.6.6 Power drawout contacts contacts shall preferably be located towards the bottom portion portion of each trolley. The trolley shall be lockable in fully plugged in position a nd devices shall be provided to ensure positive plugging in. in test position, power contacts shall be totally isolated and device shall be provided for indication of test position. 13.7

The incomer and bus tie feeders with load break switches rated 800A and above may be in fixed execution.

13.8

Various compartment sizes in a vertical panel shall be multiples of a basic 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 specification. Vertical bus bars shall be pre‐drilled at regular intervals for complete flexibility for changes in size of modules.

13.9

All switch drives other than rotary rotary control switches, shall be lockable in both ‘ON’ and ‘OFF’ positions.

13.10 The switches/Moulded case circuit breakers/MCB shall be interlocked with with the compartment door to prevent opening of the door when the switch/moulded 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. 13.11 The maximum height of the operating handle and switches shall not exceed 1900 mm and the minimum height not below 300 mm. 13.12 Unused modules in the panel shall be fully equipped with hinged door, power and control terminals for starter modules and cradle for future use.


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14.0

SWITCHGEAR MODULES

14.1

Switchboard shall be completely completely lined up in one one straight straight row row with with the type and 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 starters and switch fuse.

14.2

Starter modules required for motor control shall be of following types and internal control wiring of all starter modules of each type shall be id entical for all ratings.

14.2.1 FVNR Full voltage non‐reversing starter with minimum 18 control terminals. 14.2.2 FVR Full voltage reversing starter with minimum 24 control terminals. 14.2.3 FVNR‐HD Full voltage non‐reversing heavy duty starter with long starting time such as for compressors and fans etc. with minimum 18 control terminals 14.3

Switch fuse/contactor feeder modules shall be of following types and internal control wiring of all modules of each type shall be identical for all ratings.

14.3.1 SFU

Switch fuse modules with no control terminals.

14.3.2 SFUC

Switch fuse contactor modules with 18 control terminals.

14.4

Type of modules for fixed type switchboard shall be similar to above specified drawout modules except that the modules shall be of fixed type.

14.5

Minimum 2000 VA control transformer shall be provided provided for each bus section of the PMCC/MCC switchboard having contactor control feeders and each transformer shall be sized for the entire switchboard. For switchboard having two bus sections and coupled by bus tie shall have manual changeover switch for the control transformers.

14.6

To facilitate site modification due to to changes in motor KW ratings and to minimize spares inventory, overload relays and power fuse links shall meet the following requirements.

14.6.1 All bimetal overload overload relays shall be separately mounted type with connecting connecting links rated for the maximum rating of the contactor in a starter module. 14.6.2 Bimetal overload relays relays of various current ranges required for motors likely to be connected to a contactor must be identical in dimension for inter‐ changeability. In case offered relays are with different dimension for any particular starter module, special mounting plate suitable for mounting different relays shall be provided in all the modules of that size. 14.7

Heavy duty starters shall be provided with saturable type current transformer operated overload relays only, which shall be s uitable for motor starting time of 15‐60 seconds.


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14.8

All contactor controlled starter feeders shall meet the requirements of type‐2‐ co‐ordination as per IS: 13947.

15.0 SWITCHBOARD COMPONENTS 15.1

Circuit Breakers Circuit Breakers

15.1.1 Circuit breakers shall be air break, 3 pole and drawout type. type. However Circuit breaker for generator incomer shall be with four poles unless specified otherwise. 15.1.2 The circuit breakers shall be provided with mechanically operated operated emergency tripping device. This device shall be available on the front of the panel. Mechanically operated ‘closing’ device shall be provided for all breakers. However mechanical closing shall be inhibited for all breakers in service position. 15.1.3 The circuit breakers breakers shall be provided with minimum 4 NO + 4 NC contacts, wired and available for purchaser’s use. 15.1.4 Circuit breakers Open and Closed positions; Service and test locations and spring spring charged condition shall also be indicated mechanically in addition to electrical indications. 15.1.5 Unless otherwise specified, all circuit circuit breakers in the switchboard shall be provided with electrical power operating mechanism. Wherever circuit breakers are provided in place of Isolators, Breaker can be manually operated type. 15.1.6 Operating Mechanism a) Electric power operating mechanism shall be motor wound spring charged stored energy type. However, manual‐operating mechanism may be of the spring charging stored energy type or the spring assisted type. For circuit breakers with electrical power operating mechanism, provision shall also be made for manual spring charging. Closing time of circuit breakers with manual operating mechanism shall be independent of the speed of the operating handle. b) All stored energy operating mechanism shall be equipped with following features. i)

Failure of springs, vibrations or shocks shall not cause unintended operation of breaker or prevent intended tripping operation.

ii) Closing of circuit breakers shall be prevented unless the spring is fully charged. c) All electrical power operating mechanisms shall be suitable for remote operation and shall be equipped with following features. i)

Provided with universal motor operable on AC or DC control supplies.


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ii) Provided with emergency manual charging facility. The motor shall be automatically, decoupled (mechanically) once the manual‐charging handle is inserted. iii) Closing operation of circuit breaker shall automatically initiate charging of the spring for the next closing operation without waiting for tripping circuit breaker. iv) Closing operation shall be completed once the closing impulse is given and the first device in the control scheme has responded even though the control switch / Push Button is released provided no counter trip impulse is present. 15.1.7 Circuit breaker trip and closing coils in case of electrically electrically operated breakers breakers and trip coil in case of mechanically operated breakers and circuit breaker i ndication shall be suitable for satisfactory operation on a control supply system indicated in data sheets/job specification. 15.1.8 Circuit breakers shall be provided provided with anti pumping & trip free feature. 15.1.9 Circuit breakers breakers shall be provided provided with operation operation counters. counters. 15.1.10 Releases are not required to be provided with breakers where relays are used. However breaker‐having AC control supply voltage shall be provided with under voltage release unless specified otherwise. 15.2

Switches

15.2.1 All switches or fuse switches shall be air break type provided provided with quick make/break manual operating mechanism. The operating handle shall be mounted on the door of the compartment having the switch. 15.2.2 Rating of switches for starter module shall meet the requirements of of AC23 duty as per IS: 13947 and minimum rating shall be as specified in job specification/data sheets. 15.3

Fuses

15.3.1 Fuses shall be non‐deteriorating non‐deteriorating HRC cartridge link type. 15.3.2 Power fuses shall be pressure fitted type and shall preferably have ribs on the contact blades to ensure good line contact. 15.3.3 It shall be possible to handle fuses during off load conditions with full voltage available on the terminals. Wherever required fuse pullers shall be provided. The fuse base shall be so located in the modules to permit insertion of fuse pullers and removal of fuse links without any problem. 15.4

Contactors

15.4.1 The contactors shall be air break type, type, equipped with three main contacts and CEPL/20082/EL/TS ‐04

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minimum 1 NO + 1 NC auxiliary contacts. The main contacts of a particular contactor for motor starter module shall have AC‐3 or AC‐4 ratings as specified in data sheet. 15.4.2 Unless specified otherwise, otherwise, the coil of the contactor shall be suitable for operation on 240 V, 1 Phase, AC supply and shall work satisfactorily between 65 to 100 % of the rated value.

15.5

Thermal overload relay

15.5.1

Bimetal relays shall be provided for protecting the

motor from thermal overload.

15.5.2 Bimetal relays shall be manually reset reset type with the reset reset push button brought out on the front of the panel. The reset push button shall be capable of being operated without opening the compartment door. 15.5.3 Bimetal relays shall be positive positive acting ambient temperature compensated type with adjustable setting range. 15.5.4 Bimetal relays shall have built‐in built‐in single phasing prevention feature, which operate even with 50% rated current at the time of single phasing. 15.6

Moulded case circuit breakers circuit breakers

15.6.1 MCCBs shall be provided with spring assisted quick make/break manually operated trip free mechanism. Wherever specified, MCCB shall be suitable for remote tripping operation and the tripping device shall be suitable for the specified control supply voltage. 15.6.2 MCCBs shall be provided tripping device with inverse time characteristic for over load protection and instantaneous characteristics for short circuit protection and MCCB rated above 125A shall preferably have adjustable settings. 15.6.3 ‘ON’ and ‘OFF’ position position of the operating operating handle of MCCB shall be displayed and the operating handle shall be mounted on the door o the compartment housing MCCB. 15.6.4 Each MCCB shall be provided with minimum 1 NO + 1 NC auxiliary contact and 1 NO contact for tripping indication/alarm for purchaser’s use. 15.6.5 MCCBs shall be provided with with solenoid/Motorised closing mechanism mechanism to make make them suitable for remote closing operation if specified. The closing solenoid/motor shall be suitable for specified control supply voltage. 15.6.6 MCCB’s as part of motor starter starter module shall be current current limiting type type and type tested for type‐2 co‐ordination as per IS: 13947. 15.7

Relays


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15.7.1 Type of relay shall be electromagnetic, electromagnetic, static or numerical numerical type as specified specified in the data sheet / job specification. 15.7.2 All electromagnetic electromagnetic protective relays relays shall be back‐connected, back‐connected, of drawout type, type, suitable for flush mounting, and fitted with dust‐tight covers. Alternatively, “plug‐in” type relays will also be acceptable. Auxiliary relays are acceptable in fixed execution. 15.7.3 The protective relay cases shall have provision provision at the front front for “testing and calibration” purposes. It shall be possible to test the relays without disconnecting the wiring and without withdrawing the relays. The insertion of the test plug shall automatically short circuit th e CTs and permits extension of external power supply to the relay. 15.7.4 Each protective relay shall be provided provided with minimum 2 nos. potential free free contacts of required configuration. 15.7.5 Each tripping relays relays shall be of lockout type with hand reset coil cut‐off contacts. The tripping relay shall be sui table for satisfactory operation from 50% to 110% of the specified control supply voltage. 15.7.6 Protective relays shall shall be preferably mounted on the front side and upper part of the panel and mounting of relays on the lower portion shall be avoided.

15.8

Instrument Transformers Instrument Transformers (CTs/PTs)

15.8.1 Current transformers shall generally conform conform to IS: IS: 2705 and any special requirement with respect to Numerical relay shall be taken care by the vendor. 15.8.2 For general guidance the vendor shall note that the protective protective current transformers shall have an accuracy class of “5P” and an accuracy limit factor greater than “10”. However CTs for restricted earth fault shall be of class “PS”. Vendor shall co‐ordinate the knee point voltage, magnetizing current for PS class CTs to avoid saturation and mismatching of CTs provided at other end by other vendor. 15.8.3 Current transformers for instruments shall shall have an accuracy class 1.0 and accuracy limit factor less than 5.0. However accuracy class of 3.0 is acceptable for CT’s meant for remote ammeters. 15.8.4 The current transformers transformers in breaker feeders shall be capable of with with standing the applicable peak momentary short circuit and the symmetrical short circuit current for 1.0 second. 15.8.5 The voltage transformers transformers shall be cast resin type transformers transformers and PT shall generally conform to Is: 3156. PT shall be provided with HRC fuses on primary side and Miniature circuit breakers with auxiliary contact on the secondary side.

15.9

Measuring Instruments

15.9.1 All analogue analogue instruments instruments shall be of 96 × 96 mm and 72 × 72 mm square CEPL/20082/EL/TS ‐04

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pattern, flush‐mounting type for incomer and outgoing feeders respectively in the switchboard. 15.9.2 All auxiliary equipment equipment such as shunts transducers, CTs, VTs, etc. as required shall be included in the supply of the switchboard. 15.9.3 All AC ammeters ammeters and voltmeters shall be of moving moving iron type with accuracy class of 1.5 as per IS: 1248. Ammeters for motor feeders shall have a non‐linear compressed scale at the end to indicate motor starting current and red mark for the full load current. 15.9.4 The KW/KWH meters shall be suitable to measure unbalanced loads on 3 phases 4‐wire system. Test terminal block shall be provided for KWH meters. The accuracy class of KW/KWH meters shall be a minimum of 2.5. 15.9.5 Digital meters shall be provided if specified specified in job specification/data specification/data sheets. All digital meter shall be high reliable, accurate, compact and self powered. Digital meter data shall be saved in case of power failure. Field programming from front of the meter shall be possible and shall be RS232/485 port in case specified in the job specification/data sheet. 15.10 Control Switches 15.10.1 All control switches shall be rotary type, having a cam‐operated contact mechanism. Switch shall have pistol‐grip handles for circuit breaker control and knob type handle for other applications. 15.10.2 Ammeter selector switches shall have a make‐before‐break feature on its contacts. The selector switch shall generally ha ve four positions: three for reading 3‐phase currents and the fourth for the OFF. The voltmeter selector switch shall also have four positions: three shall be used to measure phase‐to‐ phase voltages, and the fourth shall be for the OFF position. 15.11 Push Buttons: Push button colours shall be as f ollows: Stop/Open/Emergency

:

Red

Start/ Close

:

Green

Reset/ Test

:

Yellow/ Black/ White

15.12 Indications 15.12.1 Clustered LED type indicating light with minimum 8mm diameter size shall be provided for indications. 15.12.2 Breaker positions (CLOSE, OPEN, spring‐charged, test position, service service position) electrical indications, with colours as given below, shall also be provided:


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Breaker ‘CLOSE’

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Red lamp

Breaker ’OPEN’

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Green lamp

Breaker auto‐trip

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Amber lamp

Trip circuit healthy

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White lamp

Spring charging

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Blue lamp

15.12.3 Outgoing feeder (CLOSE, OPEN, TRIP) electrical indications, with colours as given below, shall also be provided: ‘CLOSE’

:

Red lamp

’OPEN’

:

Green lamp

Trip

:

Amber lamp

15.13 Auxiliary relays /contactors Auxiliary relays/contactors shall generally be used for inter‐locking and multiplying contacts. Auxiliary contacts shall be capable of carrying the maximum anticipated current. 15.14 Timers For re‐acceleration duty, timers unless otherwise stated, shall be pneumatic type and shall have adjustable time setting of 0‐60 seconds. Alternatively static timer may be considered. The time settings, where specified, shall be accurately set before dispatch of the switchboard. Timer provided for control of capacitor feeder shall have minimum setting of 0‐5 minutes. 15.15 Miniature circuit breaker circuit breaker MCB shall provide high mechanical and electrical life, reliable protection of circuits against overload and short circuit and s hall have minimum breaking capacity of 9KA unless otherwise specified. Positive ON/OFF indication shall be provided. Earth leakage circuit breaker shall have earth sensitivities range 30mA to 300mA unless otherwise specified.

16.0

INSPECTION, TESTING AND TESTING AND ACCEPTANCE ACCEPTANCE

16.1

During fabrication, switchgear shall be subject subject to inspection by EIL / Owner, or by an agency authorized by th e Owner. Manufacturer shall furnish all necessary information concerning the supply to EIL/Owner’s inspectors.


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16.2

All routine tests shall be carried carried out as per per IS: IS: 12729 at the manufacturer’s manufacturer’s works under his care and expense.

16.3

Type tests, if specified specified shall be performed. performed. Short circuit and internal arc test shall shall be performed at CPRI or equivalent approved testing agency and heat run test may be performed at manufacturer’s works. Heat run test shall be performed at least on one incomer and two outgoing vertical panels of the ordered switchboard.

16.4

Type and shop tests shall be witnessed by an inspector of EIL / Owner, or of an agency authorized by Owner. Prior notice of minimum 4 weeks shall be given to the inspector for witnessing the tests.

16.5

Acceptance Tests Acceptance tests shall be as follows:

16.5.1 A general visual check shall be carried out. This shall cover cover measurement of overall dimensions, location, number and type of devices, and connection of terminals, etc. 16.5.2 Manual and electrical operation operation of Circuit breakers breakers / Relays shall be checked under the worst conditions of auxiliary supply voltage. 16.5.3 Dry insulation test with power‐frequency voltage voltage shall be conducted conducted for the main and auxiliary circuits. 16.5.4 Insulation resistance of the main main and auxiliary circuits shall be be checked before and after power frequency voltage withstand test . 16.5.5 Operation check shall shall be carried out for every control control function / interlocks as per the schematic diagrams by manually simulating fault conditions and operation of control switches/relays, etc. 16.5.6 For equipment bought bought from other sub‐suppliers, certified test reports of the the tests reports of the tests carried out at the manufacturer’s works shall be submitted. Normally, all routine tests as specified i n the relevant standards shall be conducted by the sub‐supplier at his works. 16.5.7 Interchange ability of of similar modules shall be checked on random basis. This may be done on one module of each size.

17.0 PACKING AND PACKING AND DISPATCH All the equipment shall be di vided into several shipping sections for protection and ease of handling h andling during transportation. The equipment shall be properly packed for selected mode of transportation i.e. ship/rail or trailer. The panels shall be wrapped in polyethylene sheets before being placed in wooden crates/cases to prevent damage to the finish. Crates/cases shall have skid bottoms for handling. Special Special precaution notations such as ‘Fragile’, ‘Fragile’, This side up, center of gravity, Weight, Owner’s particulars, Purchase number etc. shall be CEPL/20082/EL/TS ‐04

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clearly marked on the package together with other details as per purchase order. The equipment may be stored outdoors for long periods before installation. The packing should also be suitable for outdoors storage areas with heavy rains and high ambient temperature unless otherwise agreed.

7.0 MCCB Modules

7.1 MCCB modules shall be provided with components, as furnished in the schedule and the drawings. 7.2 The module shall comprise of the of the following: • Three pole MCCB with neutral link • Set of cluster of cluster type LED lamps for ON, OFF and TRIP • Meters, as specified • Current transformers • Terminal blocks, interconnection bars / wires, ferrules etc., as per requirement. 7.3 The modules shall have doors made out of 1.6 of 1.6 mm steel or heavier. Doors shall be mounted on adjustable and removable pin type concealed hinges and so arranged that unit doors may be removed without disturbing the unit doors above or below. 7.4 The operating handles shall be capable of being of being padlocked in the ‘OFF' position. 7.5 For the purpose of standardisation, of standardisation, similar components in the switch board shall be of the of the same make / brand, identical and interchangeable. 7.6 Only the operating handle of the of the MCCB shall be accessible for operation with the related door closed. 7.7 The doors shall be interlocked with associated MCCB so that the door can be opened only when the MCCB is in the deenergised (off) position and the doors shall not be capable of being of being closed with the MCCB in the energised (on) position. Provision shall also be available to defeat the interlock. 7.8 Each compartment shall have suitable name plate which shall be fixed on the cover in distinct colour to designate the feeder number, feeder designation, current rating and HP/kW of the of the related equipment. 7.9 Mechanical Castell key and Electrical interlock between incomers shall be provided, wherever MCCs / Distribution Boards are provided with more than one incomer. CEPL/20082/EL/TS ‐04

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8.0 Motor Feeder Starter Modules

8.1 Basic scheme to be adopted for various types of starters of starters shall be as shown in the drawing, corresponding to the specified feeders in the schedule. 8.2 The starter modules shall comprise of the of the following: • Three pole MCCB / MPCB, as applicable • Air‐break contactor(s) • Microprocessor based over load relay, as specified in the respective drawings. • MCB for the control circuits. • Selector switch, as shown in the drawings. • Set of cluster of cluster type LED lamps for ON / OFF / TRIP. • Set of pilot of pilot devices comprising of oil of oil tight 'RESET' button complete with actuator and necessary linkages. • Timer settable up to 60 sec. for star‐delta starters. • Meters, as specified • Current transformers for metering and protection • Terminal blocks, interconnection bars / wires, ferrules etc., as per requirement 8.3 The starter modules shall have doors made out of 1.6 of 1.6 mm steel or heavier. Doors shall be mounted on adjustable and removable pin type concealed hinges and so arranged that unit doors may be removed without disturbing the unit doors above or below. 8.4 Only the operating handle of the of the MCCB / MPCB set, and the RESET push buttons shall be accessible for operation with the related doors closed. 8.5 The ratings of the of the MCCB / MPCB and over load relays shall be suitably coordinated with the main contactor rating to meet type ‘2’ requirement in accordance with relevant IS Standards. However, the over sizing requirements as specified elsewhere in this document shall be complied with. 8.6 The selected MCCB rating in all the cases shall be not less than the ratings specified in the drawings. 8.7 AC3 duty rating of the of the contactor in all the cases shall be at least 30% more than the corresponding FLC of the of the motor. Minimum contactor rating shall be 9A. 9.0 Marshalling Compartments 9.1 A common Marshalling compartments / cabinets, as an extension for the switchboards shall be provided, for connection of multi of multi‐core cables from DCS CEPL/20082/EL/TS ‐04

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racks. A Marshalling Compartment of adequate of adequate size shall be provided in each 415V panels common for all feeders in a particular switchboard) to house the interposing relays, contact multiplying relays. The terminal blocks shall be mounted in such a way that FIELD terminal blocks / terminations and DCS terminal blocks / terminations are coming on either side (Front and Rear). All inter‐panel wiring between the individual modules, marshalling compartment shall be through metallic troughs with cover. The inter panel wiring between the individual modules and the marshalling compartment shall be done only with screened cables. 9.2 Marshalling cabinets shall house terminal blocks and transducers for connection to 415V Pcc Auxiliary Switchboard and MCC compartments / DCS racks, as shown in the drawings. However, local push button stations and other field instrument cables shall be directly connected to the respective motor feeder compartments. 9.3 The terminal block arrangement shall be arranged as below: • All digital inputs (DIs) from different feeders to be terminated at a separate array of terminal of terminal blocks. • All digital outputs (DOs) from different feeders to be terminated at a separate array of terminal of terminal blocks. • All analog inputs (AIs) from different feeders to be terminated at a separate array of terminal of terminal blocks. 9.4 All terminal blocks shall be identified with the respective feeder names. 9.5 The communication port of all of all the Tri Vector Meters / kWH meters in the 415V PCC shall be connected in series through Screened, twisted pair cable of 0.5 of 0.5 Sq. mm. and a single point connectivity shall be provided in the marshalling compartment for hooking up these signals to the Energy Management System. However, there shall be an independent terminal block individually for all the Tri Vector Meter / kWH meter. 10.0 TB Details at Marshalling Compartment

10.1 All the terminal blocks, which will be hooked up to DCS, shall be arranged as specified. Each wire at the terminal block shall be terminated with sleeve ferrules as indicated below: XXX ‐ YYY‐ ZZZ XXX – XXX – Feeder Module Number YYY – YYY – Signal type (DI/DO/AI/AO) CEPL/20082/EL/TS ‐04

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ZZZ – ZZZ – TB number 10.2 Protective sleeve shall be provided for cable packing between movable cover and panel/ terminal blocks. 11.0 Air‐break Circuit Breakers

11.1 The breakers shall be of three of three pole type, unless otherwise specifically mentioned elsewhere and all the breakers shall be of draw of draw‐out type. The ratings of the of the circuit breaker shall be as indicated in the schedules. All the air circuit breakers shall be rated for 50 kA, 1 sec short circuit rating. 11.2 The operating mechanism shall be of manual of manual wound spring charged type, unless otherwise specifically mentioned, where it shall be of motor of motor operated spring charged type. 11.3 The circuit breakers shall be provided with mechanically operated emergency tripping device. This device shall be available on the front of the of the panel. 11.4 The circuit breakers shall be provided with minimum 6 Nos. normally open and 6 Nos. normally close spare auxiliary contacts wired and available for PURCHASER’s use. If spare If spare auxiliary contacts are not available, lock‐out relay of approved make and type shall be used to multiply the available spare auxiliary contact. However, auxiliary contactors may be used for multiplication purpose, but only in outgoing feeders. 11.5 Circuit Breaker positions shall be indicated electrically. The following indicating colours shall be used. Breaker 'Close' ‐ Red Breaker 'Open' ‐ Green Breaker 'Auto Trip' – Trip' – Amber 11.6 In addition, if available if available as a manufacturer's standard design, the following positions / conditions shall also be indicated electrically. The colours to be used shall be as indicated below: Breaker Spring 'Charged' ‐ White Breaker Test Position – Position – Blue 11.7 Circuit Breaker positions (Open and Close), location (Service and Test) and spring charged conditions shall also be indicated mechanically.


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11.8 The circuit breaker closing time shall be approximately in the range of 100 of 100 to 150 msecs, and the tripping time shall not exceed 100 msecs. 11.9 The breakers shall be trip free. If available If available as manufacturer's standard feature, the breakers shall be provided with a release trip to the breakers instantaneously if closed if closed on to a fault. 11.10 The circuit breakers shall be provided with an anti‐pumping feature. If an If an electrical relay is used for this feature, the relay shall be located on the breaker chassis. The anti‐pumping feature shall be maintained even if the if the bus voltage disappears during a fault. 11.11 Circuit breaker trip and closing coils shall be rated for satisfactory operation under the following conditions of supply of supply voltage variation: a. Trip Coil: 70% to 110% of rated of rated voltage. b. Closing coil: 85% to 110% of rated of rated voltage. c. Rated coil voltage shall be 240V AC for trip coils and closing coils. 11.12 Operating Mechanism: a. Electrical power operating mechanism shall be motor wound spring charged stored energy type. However, manual operating mechanism may be of the of the spring charging stored energy type or the spring assisted type. Provision shall be made for manual spring charging also. Closing time of circuit of circuit breakers with manual operating mechanism shall be independent of the of the speed of the of the operating handle. b. All stored energy operating mechanisms shall be equipped with following features: of springs, vibrations or shocks shall not cause unintended operation of ‐ Failure of springs, breaker or prevent intended tripping operation.

‐ Closing of circuit of circuit breaker shall be prevented unless the spring is fully charged. c. All electrical power operating mechanisms shall be suitable for remote operation and shall be equipped with following features:

‐ Provided with AC motor operating on 240V AC control supply designed to operate satisfactorily from 85% to 110% of rated of rated voltage.

‐ Provided with emergency manual charging facility. The motor shall be automatically, (mechanically) delinked once the manual charging handle is inserted.


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‐ Closing operation of circuit of circuit breaker shall automatically initiate charging of the of the spring for the next closing operation.

‐ One complete closing operation shall be completed once the closing impulse is given and the first device in the control scheme has responded even though the control switch / PB is released provided no counter trip impulse is present. 12.0 Releases

12.1 Releases for over load, short circuit and earth fault shall be provided, wherever specified. The releases shall be of microprocessor of microprocessor based type and self powered self powered with micro switches. Flag / indication shall be made available for all types of protections. Reset buttons shall also be available at the front panel. 12.2 U/V releases shall be provided in the feeders, wherever called for, with built‐in timer with adjustable setting ranging from 0.1 to 1 Sec. time delay. Alternatively, discrete under voltage relay with timer relay may be provided along with shunt trip coil. 13.0 Moulded Case Circuit Breaker (MCCB) and Motor Protection Circuit Breaker (MPCB)

13.1 The circuit breakers shall meet IS: 13947 requirements, and shall be rated for system short time rating of 50 of 50 kA for 1 sec with Ics = 100% Icu 13.2 The breaker shall be designed to carry the rated current continuously without overheating. 13.3 Barriers shall be provided to prevent interphase arcing and live terminals shall be shrouded to avoid accidental contact. 13.4 Alarm and auxiliary switches shall be provided for MCCB & MPCB with sufficient NO & NC contacts, to meet the scheme requirements. 13.5 The breakers shall be of 'trip of 'trip‐free'. 13.6 MCCBs for all outgoing feeders shall be provided with microprocessor based type over load and earth fault protections along with magnetic type short circuit protection. The releases should not be sensitive for harmonic currents, and shall be temperature compensated. In case earth fault protection is not available as a part of main of main releases, a separate earth fault module shall be considered. 13.7 MCCBs for motor protection and control transformer controls can be with thermal based overload releases and magnetic based short circuit protection. CEPL/20082/EL/TS ‐04

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13.8 MCCBs shall have adjustable settings, with min.50% for over load for microprocessor based type releases and 80% for thermal based releases. 13.9 MPCBs shall have single phase prevention feature. 13.10 Accessories like rotary handles, door interlock arrangement and shrouds / barriers shall form part of supply. of supply. 13.11 Fuses shall be non‐deteriorating HRC cartridge link type. ‘Diaze’ fuses are not acceptable. 13.12 The fuses shall be provided with operation indicator which shall be visible without removal of fuses of fuses from service. 13.13 Fuses shall be pressure fitted type and shall preferably have rims on the contact blades to ensure good line contact. 13.14 It shall be possible to handle fuses during off load off load conditions with full voltage available on the terminals. Wherever required, fuse pullers shall be provided. 14.0 Contactors

14.1 The contactors shall be air break type, equipped with three main contacts and minimum 2 NO + 2 NC auxiliary contacts. The main contacts of a of a particular contactor shall have AC3 ratings for general AC motor circuits, AC4 for RDOL feeders, AC5a for AC lighting circuits and DC6 for DC lighting circuits, as per IEC 60947. 14.2 The auxiliary contacts shall be rated for minimum 5 Amps at 230 V AC. 14.3 Unless specified otherwise, the coil of the of the contactor shall be suitable for operation on 230V AC supply and shall work satisfactorily between +10% and ‐ 15% of the of the rated voltage. 14.4 The contactor drop‐off voltage off voltage shall be between 30% to 65% of the of the rated coil voltage. 14.5 Auxiliary contactors shall generally be used for interlocking and multiplying contacts. Auxiliary contacts shall be capable of carrying of carrying the maximum estimated current, but not less than 5A at 230V AC. 15.0 Over Load Relays


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15.1 Over load relays will be of microprocessor of microprocessor based. Heavy duty relays shall be considered, wherever the starting time is expected to be very high (all fan feeders and conveyor feeders). The overload relays shall be properly selected, based on the FLC and starting currents, for RDOL feeders, used in actuator motor circuits. 15.2 Microprocessor type overload relays shall have motor stalling, single phasing, locked rotor, earth fault and overload protections, as a minimum and shall be suitable for the ambient that will be prevalent in the switchboard. Necessary core balancing current transformers, as required for earth fault protection shall be arranged. The relay shall have in‐built time delay setting facility for tripping. The relays shall preferably be of CT of CT operated type. 16.0 Automatic Power Factor Relay:

16.1 In PCC for power factor improvement load sensing CTs (3 Nos.) with 0.5 class accuracy in all three phases along APFC relay shall be considered. 16.2 The APFC relay shall be provided with following minimum features:

‐ Micro‐processor controlled measurements. ‐ All measurements with 0.5 class accuracy ‐ Minimum control of 12 of 12 Capacitor Banks. ‐ RS 485 communication port with MODBUS protocol. ‐ Monitoring facility for capacitor healthiness. of Nth capacitor bank with reset facility. ‐ Utilization counter for ON/OFF operations of Nth ‐ Harmonic compensation algorithm to maintain the set power factor. of capacitor values at a regular interval for each step. ‐ Auto correction of capacitor ‐ Auto sensing of connected of connected capacitor rating. 17.0 Miniature Circuit Breakers and Earth Leakage Circuit Breakers

17.1 MCBs shall be used in all the AC control circuits and DC control circuits and lighting feeders, as specified. However, control fuses may be used in the ACB feeders for DC circuit. 17.2 MCBs shall be of self of self ‐extinguishing type with rupturing capacity of not of not less than 10 kA, and shall be selected with appropriate characteristics, as per IEC Standards. 17.3 Earth leakage circuit breakers shall be provided as specified in the drawings. 18.0 Timers


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18.1 Static / Electronic timers of range of range (0‐60 secs) shall be used in the star‐delta starter. 18.2 Off ‐delay static / Electronic timers of (0 of (0‐120 secs) shall be used in the capacitor circuits 18.3 Timers to be used in the lighting circuits shall be of digital of digital type with 24 hr setting range and battery back‐up for dawn and dusk control of the of the lighting feeders. 19.0 Relays

19.1 All protective relays shall be back connected, draw out type, suitable for flush mounting and fitted with dust tight covers. All relays shall be mounted on the front of the of the panel and shall be specified as per requirement. The current and the voltage coils shall be rated as specified. 19.2 All relays shall have built‐in flag / indicator to indicate operation. All tripping relays shall be suitable to operate on the specified DC voltage. 19.3 Automatic power factor correction relay shall be provided wherever specified to maintain the power factor in a particular bus section at pre‐set value. This relay shall be of micro of micro processor based type. The number of steps of steps to switch ON / OFF the capacitor feeders shall be provided in this relay as specified in the drawings. 19.4 Timer relay of static of static type with 0‐1sec time delay shall be provided for discrepancy function, wherever applicable. 20.0 Meters and Transducers

20.1 Trivector meters shall be capable of indicating of indicating all phase instantaneous PARAMETERS and recording kWH, kVARH and kVAH. These should be suitable for 3 phase, 4 wire 50 Hz circuits with unbalanced loading and with three sets of elements connected to current and potential transformers of specified of specified ratio. The trivectormeter shall be digital type, class 0.5 or better with communication port, RS 485 interface– MODBUS‐RTU protocol, for hooking up to PC / DCS. The meter shall have data retention facility in the event of supply of supply source failure for minimum one month period. The meters shall also be capable of indicating of indicating the total harmonic levels up to 25th harmonic in the system for current as well as in voltage parameters. 20.2 Digital energy meters shall be capable of indicating of indicating all phase INSTANTANEOUS parameters and recording kWh. These should be suitable for 3 phase, 4 wire 50 CEPL/20082/EL/TS ‐04

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Hz circuits with unbalanced loading and with three sets of elements of elements connected to current and potential transformers of specified of specified ratio. The energy meter shall be of digital of digital type, class 0.5 or better, with RS 485 communication port and suitable for communicating to ‘Energy Management System’ with MODBUS‐RTU Protocol. The meter shall have data retention facility, as specified. 20.3 Test terminal blocks shall be provided in the incomer panels for TVM meter. 20.4 The analog meters, wherever provided, shall be of flush of flush mounting type with square pattern of size of size 144 mm for incomer feeders and 96 mm dial size for outgoing feeders. The dial shall have black numerals with a white background and shall be free from parallax errors. The meters shall have provision for zero adjustment outside the cover. 21.0 Current Transformers

21.1 The current transformers shall be of bar of bar primary wound secondary cast resin type and have a short time withstand rating equal to that of the of the associated switchgear for one second. It shall be the responsibility of the of the vendor to co‐ ordinate the burden of the of the CTs with the actual requirement of relays, of relays, instruments, and leads etc., associated with the particular CTs. The minimum requirement shall be 5 VA burden, accuracy class 1.0 and an instrument safety factor of 5. of 5. CTs with 0.5 / 0.2 accuracy class shall be provided, wherever specified. 21.2 The CTs shall be provided with the following: • Test links in both secondary leads to carry out phase angle and current measurement tests. • Earth link to which the leads of the of the CTs shall be connected so as to facilitate easy measurement of Insulation of Insulation Resistance of the of the CTs. 22.0 Potential Transformer

22.1 The potential transformer shall be cast‐resin insulated type. Insulation of PT of PT shall be suitable for unearthed system. It shall be draw out type and easily accessible so that the same can be attended to or replaced when the panels are in service condition. The Potential transformers shall be of single of single phase type, no three phase type shall be used. 22.2 The potential transformers shall be protected through HRC fuses on primary side and MCBs on secondary side. They shall have ratios, outputs and accuracies specified.


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23.0 Control Transformers

23.1 In main PCC panels two numbers of control of control transformers with one as standby shall be provided. The rating of these of these transformers shall be sized to feed to ACB closing coils, ACB spring charging motor coil and also for under voltage release of the of the incomers and tie feeders. Separate reducant transformers with changeover arrangement shall also be provided for feeding to the control device requirements of the of the panel, panel illumination. 23.2 In case of MCC of MCC panels, minimum two (2) numbers control transformers, with one as standby, shall be provided in each switch board for meeting control and auxiliary supply requirement of the of the individual modules. Rating of control of control transformer shall be sized to feed all control device requirement of panel, of panel, panel illumination space heater of motor of motor circuits. 23.3 The transformers shall be provided with independent MCCB / SFU at primary with arrangement to select one at time. The transformers shall be adequately sized to deliver 240V AC. Supply shall be protected against short circuits and over loads on primary as well as secondary side. Control transformers, SFU, selector switches and contactors shall be sized to feed instrument loads and space heaters, as specified technical specification. The control transformer change over switches shall be of door of door mounted type. Also the control transformer shall be sized to feed single phase motor feeders, wherever specified 24.0 Push Buttons, Control Switches and Pilot Lamps

24.1 The push buttons shall be of shrouded of shrouded type with actuator provided with escutcheon plates marked with its function on it. 24.2 Control switches shall be of the of the heavy duty rotary type with name plates clearly marked to show the operation. They shall be semi‐flushed mounting with only the front plate and operating handle projecting. Circuit breaker control switches shall be of the of the spring return to neutral type, while local / remote selector switches and instrument selector switches shall be of the of the stay‐put type. 24.3 The indicating lamps shall be of cluster of cluster LED type of low of low watt consumption. They shall be provided with series resistors.

25.0 Interconnections CEPL/20082/EL/TS ‐04

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25.1 All switchgear cubicles shall be supplied completely wired internally to equipment and terminal blocks and ready for PURCHASER's external connections at the outgoing terminal blocks. Interconnection between all compartments and marshalling cabinets shall also be completed. 25.2 The wiring shall be complete in all respects so as to ensure proper functioning of control, of control, protection and interlocking schemes. 25.3 Power interconnections inside the panel shall be done with 650/1100 V grade single core PVC insulated copper conductor up to 63 Amps rating and above 63 Amps rating by copper flats. Wherever copper with Copper dirt’s are made bi‐ metallic connectors / contactors should be used. Control wiring shall be done with 650/1100 V grade PVC single core copper conductor of minimum of minimum cross section 2.5 Sq.mm for CT wiring and 1.5 Sq.mm. for others. 25.4 The cabling chamber of adequate of adequate size for accommodation, support and termination of copper of copper cables shall be provided at the rear. Facility to extend cabling area by additional cable chamber shall be preferred. 25.5 All wirings and cables at the terminations at the switchboard shall have distinct marking by means of ferrules of ferrules with letters / numerals printed corresponding to the wiring diagram to be furnished by the successful SUPPLIER. 26.0 Terminal Blocks

26.1 The terminal blocks provided in the switchboard shall be mounted vertically near the bottom side of each of each module unit, in the cable chamber at a slightly upward angle, to provide clear and easy access to the terminals. 26.2 Each wire at terminal blocks shall be distinctly identified with appropriate number / letter ferrules at each end in accordance with the schematics. 26.3 Wiring to the door shall be done by flexible cable and the cables shall be bunched, sleeved and cleated so that no mechanical damage can occur to the cables when the door swings. 26.4 Not more than 2 wires shall be terminated at one control terminal. 26.5 All terminations shall be of adequate of adequate current rating and size to suit individual feeder requirement.


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26.6 All the termination ends shall be provided with hardware’s like cadmium coated bolts, nuts, spring washers and twin brass washers of 2mm of 2mm thick and having an equivalent contact area of the of the terminating lug. 26.7 Outgoing power terminations shall be designed for connecting PVC copper cables. Suitable provision shall be made for termination of higher of higher size cables. 26.8 Each control terminal block shall have 20% spare terminals. 26.9 Inter module wiring in the same panel shall be through vertical cable alley. 26.10 The rating of the of the terminal blocks shall be minimum 10A. 26.11 Terminal blocks for all CT connections to be of sliding of sliding contact type suitable for terminating ring type sockets. 26.12 Different coloured terminal blocks shall be provided for various applications like DI, DO, CT, PT, Power, Control, etc. 27.0 Name Plate

Name plate shall contain all details regarding the drives / equipment controlled by the particular module. 27.6 The switchboard shall carry the following distinct markings / name plates. • The manufacturers' name / brand name. • The module nos. with the load designation and rating of the of the module in kW/Amps. • Danger boards as per the IEC standards and as per standard practices27.1 A name plate with the switchgear designation shall be fixed at the top of the of the central panel. 27.2 A separate name plate giving feeder details shall be provided for each compartment. A separate nameplate giving details of bus of bus section shall also be provided for switchgears having more than one bus section. 27.3 Name plate shall be provided for each equipment (lamps, push buttons, switches, relays, auxiliary contactors etc. mounted on the switchboard. Special warning plates one each on each front of a of a shipping section shall be provided on removable covers of doors of doors giving access to cable terminals and busbars. Special warning labels shall be provided inside the switchboard also, wherever considered necessary. Identification tags shall be provided inside the panels matching with those shown on the circuit diagram. CEPL/20082/EL/TS ‐04

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27.4 Reverse engraved nameplates made up of acrylic of acrylic sheets shall be provided. Name plates shall be fastened by screws and not by adhesives. 27.5 The name plates for feeder compartments shall be in two parts. One part shall have necessary details pertaining to the switchboard. The other parts shall be removable and. 28.0 Painting

28.1 All sheet steel surfaces shall be chemically cleaned, degreased and pickled in acid to produce a smooth, clean surface free of scale, of scale, grease and rust. After cleaning, the surface shall be given a phosphate coating followed by a coat of high quality primer and baking in the oven. 28.2 After the initial preparation of the of the panels, the final assembly shall be spray painted with two coats of final of final paint. Painting process shall be with SKPS grey colour primer and two coats of polyurethane. of polyurethane. The colour shade of the of the final paint shall be of pebble of pebble grey, Shade RAL 7032 with Texture Finish. 28.3 Sufficient quantity of touch of touch up paint shall be furnished for application at site. 29.0 Drawings and Manual

29.1 The drawings and manual shall be submitted as per the ‘List of Drawings of Drawings / Documents to be submitted’. 30.0 Tests

30.1 Switchgear assembly shall be subjected to the tests as per latest revision of IS of IS / IEC Standards. 30.2 The SUPPLIER should submit the following type test certificates for having carried‐out in the past: a. Heat run test for 4000 A rating. b. Short circuit test for 50 kA rating. c. Degree of protection of protection 30.3 Test Certificates shall be submitted for the PURCHASER’S / CONSULTANT's approval before dispatch of the of the switch‐gear. 30.4 All major components incorporated in the switchgear, such as circuit breakers, shall have undergone type tests as per their respective standards. CEPL/20082/EL/TS ‐04

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Tech Specification for LT MCC

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