GOVERNMENT OF INDIA TECHNICAL SPECFICATION FOR 25kV … · 2020. 8. 25. · Effective From Draft spec No. TI/SPC/PSI/SHUNT/2200 Page 2 of 39 Specification No. ETI/PSI/126(8/89) Specification

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Draft spec No. TI/SPC/PSI/SHUNT/2200 Page 1 of 39

GOVERNMENT OF INDIA

MINISTRY OF RAILWAYS

TECHNICAL SPECFICATION FOR

25kV SHUNT CAPACITOR EQUIPMENT

FOR

2X25 KV AT FEEDING SYSTEM

DRAFT SPECIFICATION No. TI/SPC/PSI/SHUNT/2200

AUGUST 1989

This Specification supersedes the Specification No. ETI/PSI/126(08/1989)

with A&C Slip No. 1 to 3.

ISSUED BY

TRACTION INSTALLATION DIRECTORATE

RESEARCH DESIGNS AND STANDARDS ORGANIZATION

(MINISTRY OF RAILWAY)

MANAK NAGAR, LUCKNOW-226011.

Prepared By Checked By Approved By

Signature

Date

Designation

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Specification No.

ETI/PSI/126(8/89)

Specification for Shunt Capacitor Equipment for 2x 25 kV a Feeding System.

1.0 SCOPE:

1.1 It is to be noted that “The Make in India Policy of Government of India shall be applicable.”

1.2 All the provisions contained in RDSO’s ISO procedures laid down in Document No. - QO - D-8.1-11 Ver. 1.2 dated 22.06.2020 (titled

“Vendor changes in approved status") and subsequent versions/amendments thereof, shall be binding and applicable on the successful vendor/vendors in the contracts floated by Railways to

maintain quality of products supplied to Railways.

1.3 This specification covers design, manufacture supply, testing and

commissioning of shunt capacitor equipment intended for outdoor

installation on 25 kV side a traction sub - station of 2 X 25 kV AT

feeding system on Indian Railways for improvement of power factor

and reduction of maximum demand.

1.4 The shunt capacitor equipment shall be complete with control-gear,

protective relays, series reactors and accessories necessary for its

efficient operation.

1.5 All such items and accessories shall be deemed to be within the scope

of this specification whether specifically mentioned herein or not. The

Shunt capacitor shall be installed by Railways under the supervision of

the contractor, who shall however commission the equipment.

2.0 GOVERNING SPECIFICAIONS:-

2.1 The shunt capacitor and associated items shall, unless otherwise

specified herein, conform to the latest revision of RDSO specification,

Indian Standard specifications/IEC Recommendations as indicated

below and the Indian Electricity Rules, wherever applicable:

i. IS:513 Cold rolled carbon steel sheets.

ii. IS:800 Code of practice for use of structural steel in general building construction.

iii. IS: 1554(pt. II) PVC insulated (heavy duty) electric cable pt. II for voltage above 1 kV.

iv. IS:2099 Bushings for alternating voltages above 1 kV.

v. IS:2834 Shunt capacitor for power systems.

vi. IS:3070 (Pt..I) Lightning arrestor for AC systems,

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Non- Linear resistor type.

vii. IS: 3231 Electrical relays for power system

protection.

viii. IS:5553(Pt.II) Series reactor.

ix. IS:11298(pt.3/sec.1) Specification for plastic films for electrical purposes.

x. IEC-70 Power capacitors.

xi. IS- 12672 Internal fuse and internal over

pressure disconnectors for shunt capacitors.

xii. IEC 871-1 & IEC 871-2.

Shunt capacitor for AC systems having a rated voltage above 660 V.

xiii. RDSO specn. No. ETI/OHE/13(4/84)

with A & C Slip No. 1 to 4.

Specification for hot-dip zinc galvanization.

xiv. RDSO specn. No. ETI/PSI/18(4/84) TI/SPC/OHE/FASTERN

ERS/0120 Rev. 1

Specification for steel and stainless steel bolts, nuts and washers.

xv. RDSO specn. No.

ETI/OHE/27(6/87) TI/SPC/PSI/PROTCT/6

071 with A&C slip no.1

Control and relay board.

Control and Relay panel for 25kV acts including specification for numerical

type protection relays for traction transformer, 25kV shunt capacitor bank and transmission line for 25kV AC

TSS on Indian Railways.

xvi. RDSO specn. No.

ETI/PSI/71/Rev-1(1/87)

ETI/PSI/MOGTLA/0101(02/ 15)

Metal oxide gapless type lightning

arrestors. Metal oxide gap less type lightening

arrester for use on Railway traction substations and switching stations.

xvii. RDSO specn. (CP) No. ETI/PSI/93(5/87)

TI/PSI/SPC/LVCBIN/0120

(Dec,2013), Rev. 0 with A&C Slip No. 1

25 kV outdoor type, single pole, SF6 gas circuit breakers.

25 kV Single pole, Double Pole, Pole mounted, outdoor Vacuum circuit

breaker (VCB) and vacuum Interrupter (BM) for Indian Railway.

xviii. RDSO specn. (CP) No.

ETI/PSI/120(7/87) With A&C Slip No. 1

Code of practice for earthing of power

supply installation for 25 kV A.C., 50 Hz Single Phase traction system.

xix. IEC: 60071 Insulation co-ordination and system engineering of high voltage electrical

power installations above 1.0 kV AC and 1.5 kV DC

xx. IEC: 62271-1

High-voltage switchgear and control gear – Part 1: Common specifications

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2.2 Any deviation from this specification, proposed by the tenderer vendor

calculated to improve the performance, utility and efficiency of the

equipment will be given due consideration provided full particulars of

the deviation with justification therefore are furnished. In such case,

the tenderer vendor shall quote according to this specification and the

deviations, if any, proposed by him shall be quoted as an alternate/

alternatives.

2.3 In case of any conflict between the contents of the above IS and this

specification, the stipulation of this specification shall prevail.

3.0 ENVIRONMENTAL CONDITIONS-

3.1 The shunt capacitor installation shall be suitable for outdoor use in

moist tropical climate and in areas subject to heavy rainfall, pollution

due to industry and marine atmosphere and severe lightning. The

limiting weather conditions which the shunt capacitor and associated

items have to withstand in service are indicated below:

SN Description Vale for altitude up to 1000 m

Vale for altitude above 1000 m

and up to 2500 m

i. Maximum ambient air temperature

45 degree C 45 degree C

ii. Minimum ambient air temperature

0 Deg. C -15 Deg. C

iii. Minimum Average ambient air temperature over a period of 24

hours


iv. Maximum relative

humidity


v. Annual rainfall Ranging from

1750 to 6250 mm

Ranging from

1750 to 6250 mm

vi. Maximum number of thunder storm days per

annum

85 days 85 days

vii. Maximum Number of dust storms days per

annum

35 days 35 days

viii. Number of rainy days

per annum

120 days 120 days

ix. Basic wind pressure 200 kg/sq.m 216 kg/sq.m

x. Altitude Not exceeding 1000 metres.

Above 1000 m and up to 2500

m.

3.2 Vibrations -

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The shunt capacitor installations would also be subjected to vibrations

on account of trains running on nearby railway tracks. The amplitude

of these vibrations which occur with rapidly varying time periods in the

range of 15 to 70 ms lies in the range of 30 to 150 microns at present

with the instantaneous peak going up to 350 microns.

4.0 TRACTION POWER SUPPLY SYSTEM ( 2X 25 KV AT FEEDING SYSTEM)

4.1 GENERAL SCHEME:-

The electric power for railway traction is supplied in AC 50 Hz, single

phase through 2x 25 kV AT feeding system, which has feeding voltage

from the sub-station two times as high ( 2x 25 kV) as catenary

voltage (25 kV) . This high voltage power supplied from the traction

sub-station through catenary wire and feeder wire is stepped down to

the catenary voltage by use of auto transformers installed about every

13 to 17 km along the track and then fed to the locomotives. In other

words, both the catenary voltage and feeder voltage are 25 kV against

the rail, although the sub-station feeding voltage between catenary

and feeder is 50 kV. Therefore, the catenary voltage is the same as

that of the conventional 25 kV system.

Since the power is supplied in two times higher voltage , the 2x

25 kV AT feeding system is suitable for a large power supply, and it

has the following advantages, compared with conventional feeding

systems:

a. Less voltage drop in feeder circuit.

b. Large spacing of traction sub-station.

c. Less telecommunication interference by use of AT installed with

adequate spacing.

The power is obtained from 220/2 x 25 kV Scott connected

traction transformer or 132/2x25 kV Single phase transformers. The

primary windings of the single phase transformers are connected to

two or three phase of 132 kV, three phase, effectively earthed

transmission network of the electricity board, in case of a single phase

transformer or in case of two single phase transformers connected in V

respectively. On the other hand, the primary windings of the Scott

connected transformers are connected to the three phases of 220 kV

three phase, effectively earthed transmission network of the Electricity

Board. The Scott connected transformer and V-connected single phase

transformers are effective in reducing voltage imbalance on the

transmission network of the Electricity Board. The spacing between

adjacent sub-stations is normally between 70 to 100 kms.

One outer side terminal of the secondary windings of traction

transformer is connected to the catenary, the other outer side terminal

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being connected to the feeder. Two inner side terminals are, via series

capacitors or directly, connected to each other and their joint is solidly

earthed and connected to the traction rails.

The load current from the sub-station flows through the

catenary and returns to the sub-station through the feeder. Between

two adjacent ATs, the load current fed from the catenary to the

locomotive flows in the rail and is boosted upto the feeder through the

neutral tap at ATs at left and right sides of the locomotive.

At the points of sub-station and sectioning post, a dead zone

known as neutral section is provided in OHE to avoid a wrong phase

coupling. The power to the catenary and feeder on one side of the sub-

station is fed by one feeder circuit breaker, even if there exist two

breakers for on side, and each track is controlled by an interrupter.

The two breakers are used as a stand by for each other. For

maintenance work and keeping the voltage drop within limits, one or

more sub sectioning and paralleling posts ( known as SSP) are

introduced between traction sub-station and a sectioning and

paralleling post (known as SP). A SSP on a double track section

normally has four sectioning interrupters and one paralleling

interrupter. In case of fault, the feeder circuit breaker of the sub-

station isolates it.

A figure showing the principle of AT feeding system and typical

power supply diagram showing the general feeding arrangement at a

traction sub-station and sections of the OHE are given in the sketch at

the Appendix-I.

4.2 Protection system:-

4.2.1 The following relays are provided for the protection of traction

transformers.

a) Differential relay.

b) Over current relay on 220 kV or 132 kV side.

c) Grounding overcurrent relay on 220 kV or 132 kV side.

d) High speed over current relay on 220 kV or 132 kV side.

e) Phase failure relay (to detect a malfunctions of a feeder

circuit breaker).

4.2.2 The following relays are provided for the protection of OHE:

a) Distance relay (with a parallelogram protection

characteristics).

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b) Delta I type fault selective relay.

c) Under voltage relay.

4.3 25 kV OHE and Traction Transformer-Electric Parameters:

4.3.1 The OHE is made up of a stranded cadmium copper catenary of 65

sq. mm or a stranded aluminium alloy catenary of 116 sq. mm and

a grooved contact wire of 107 sq. mm, making up a total of 150 sq.

mm or 140 sq. mm copper equivalent, respectively. As a feeder wire

stranded aluminium alloy of 240 sq mm is used. The calculated OHE

impedance value of AT feeding circuit ( OHE; Al 116-Cu 107 sq.

mm. feeder wire; al 240 sq. mm ) for a single track line is 0.0601 +

jo.1419 Ohms /km (at 20 kV system impedance).

4.3.2 Traction transformer; the percentage impedance of 2x25 MVA,

220/2 x 25 kV scott connected transformer and 20 MVA, 132/2 x 25

kV single phase transformer are 12 % (at 207 MVA based) and 12%

(at 21.6 MVA base); respectively.

4.3.3 Clearance; Normally a clearance of 500 mm is provided between

any live part at 25 KV and earth.

4.4 Nature of faults on the OHE system

4.4.1 OHE ( including a feeder wire) is subjected to frequent earth faults

caused by failure of insulation, or by the OHE snapping and touching

the rail or earth, or by a piece of wire dropped by birds connecting

the OHE to earthed overlying structure, miscreant activities etc..

These faults are cleared by feeder circuit breaker which operates on

any one or both of the following relays:

a) Distance Relay (with a parallelogram protection characteristics)

b) Delta I type fault selective relay.

4.4.2 Short Circuit level; The 220 kV and 132 kV source impedance may

be, based on a 3 phase symmetrical short circuit level, between

2000 and 10,000 MVA, and between 1000 and 5000 MVA,

respectively. The level of short circuit on the 25 kV side for a fault in

the vicinity of a substation could be around 20 MVA or more. The

exact short circuit level on 25 kV side at each substation will be

indicated in the tender papers.

4.5 Nature of load on the 25 kV system:

4.5.1 Traction load is of frequent and rapidly varying nature and may

fluctuate between no load and overloads, and the system is subject

to frequent short circuits due to earth faults. It is difficult to forecast

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precisely the load cycle of traction service because of the non-

uniform pattern of traffic which is different on different days.

4.5.2 At present AC locomotives are fitted, for conversion of AC to DC,

with single phase bridge connection silicon rectifiers with

smoothening reactor for feeding the DC traction motors. The ripple

current is the region of 25 to 40% which introduces harmonics in

the 25 kV power supply. In the near future, Indian Railways would

be introducing phase controlled a symmetrical thyristor bridges (two

bridges connected in sequential control to improve power factor)

which would further introduce harmonics in the system.

The typical percentage of the current harmonics present in the

traction system with silicon diodes locomotives are given below:

Feeder current. 142 A

Feeder current 480 A

Percentage

3rd harmonics (150 Hz) 38.50 111.50

5th harmonics (250 Hz) 14.35 5.48

7th harmonics (350 Hz) 15.00 2.01

4.5.3 In big yards and loco sheds, a large number of locomotives stand

idle with only the load of their auxiliaries drawing higher reactive

power. The load power factor as therefore, rather low.

4.5.4 The average power-factor of electric locomotive and multiple unit

trains generally varies between 0.7 and 0.8 lagging, without

compensation.

5.0 TECHNICAL SPECIFICATION:

5.1 Rating and other particulars:

i System 2x 25 kV AT feeding system

ii Nominal system voltage 25 kV (phase to earth)

iii Variation in the traction supply voltage

19 kV to 27.5 kV ( sometimes touching 30 kV)

iv Equipment voltage class 52 kV

v Rated voltage

a) Capacitor bank b) reactor

31 kV 4 kV

vi Rated frequency 50 Hz +/- 3%

vii Average power factor of the

traction system

Between 0.7 and 0.8 lagging

viii Power factor desired after 0.9

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installation of the capacitor

ix Rated capacity (for fundamental wave): (Unit: kVar)

Equipment Capacitor Bank Reactor

400 (2 X 200)* 460 (2 X 230) 60 (2 X 30)

600 (2 X 300) 690 (2 X 345) 90 (2 X 45)

800 (2 X 400) 920 (2 X 460) 120 (2 X 60)

1200 (2 X 600) 1380 (2 X 690) 180 (2 X 90)

1,600 (2 X 800) 1,840 (2 X 920) 240 (2 X 120)

2,000 (2 X 1,000) 2,300 (2 X 1,150) 300 (2 x150)

* ( 2 x 200 ) means 2 halves of 200 kVar

x Harmonics in the system as given in para 4.5.2

xi Location of capacitor bank Out-door

5.2 Constitution of Shunt Capacitor Equipment

Shunt capacitor equipment to be installed at traction sub-station for AT

electrification shall consists of two halves shunt capacitor equipment ,

each rating voltage is 31 kV, for one phase. The one shall be

connected to the OHE and rail, and the other to feeder and rail. Each

half shunt capacitor equipment consists of capacitor(s) and series

reactor connected in series. Refer to Appendix-II.

5.3 Resonant condition and inrush current

The rating of capacitor bank shall be such that it does not resonate

with source impedance including transformer impedance and series

reactor (parallel resonance). It shall also not resonate with the series

reactor (series resonance) at any of the harmonic frequencies. It shall

also be ensured that the inrush current of the capacitor banks does not

exceed the maximum guaranteed value. Calculations shall be

furnished with the tender in respect of the inrush current and series/

parallel resonant frequencies.

5.4 Capacitor Unit

5.4.1 The individual capacitor units of the bank shall be self- contained,

outdoor type provided with double bushing protected by external

fuse or internal element fuses. The bushings shall be of porcelain

and shall be jointed to the case by solder sealing or any other

approved technique. The minimum value of creepage distance for

bushings shall be 25 mm per kV of the rated voltage. Each capacitor

unit shall be built up of number of elements having a dielectric of

plastic film (polypropylene) between the aluminium foils.

The capacitor elements shall be assembled in a stack closely

fitted into the container in order to reduce the amount of free

impregnation fluid. The container shall accommodate changes in

fluid volume due to variation in the temperature. Each individual

unit shall consist of a number of elements connected in series

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parallel arrangement. The capacitor unit shall be capable of

withstanding transient over currents of high frequency and

amplitude occurring at the time of their switching in the circuit. In

case of capacitor unit is provided with internal fuse protection, each

element shall be protected by means of an internal fuse connected

in series and each capacitor unit shall have enough parallel elements

in each series group so that failure of 40% of elements in a series

group shall not give rise to more than:

a) 10% over voltage on healthy parallel units.

b) 60% over voltage on healthy parallel elements.

Each capacitor unit shall satisfactorily operate continuously at

rated voltage and shall withstand 30% over current (rms value) due

to over-voltages and harmonics. The unit shall also satisfactorily

operate with traction harmonic currents as indicated in clause 4.5.2.

5.4.2 The polypropylene film conforming to IS: 11298 or latest shall be

checked for proper thickness, roughness, breakdown voltage

besides its physical appearance.

5.4.3 The capacitor shall be impregnated with non PCB (polychlorinated-

Biphenyl) impregnation fluids which have excellent electrical

characteristics, low toxicity, low bio-accumulation and are

biodegradable.

5.4.4 The aluminium foil used shall be of very high purity and free from

materials like rolling oil and such other defects. The thickness of

aluminium foil used shall not be less than 6 microns.

5.4.5 The container of each capacitor unit shall be leak and moisture-

proof. The capacitor containers shall be made of CRCA steel sheets

of drawing quality generally as per IS: 513 or latest. The nominal

thickness of steel shall be 1.25 mm. The inside surface of the

container in contact with the impregnating fluid shall not be painted

and shall only be degreased and made rust free. The steel surface

exposed to weather shall be given a primer coat of zinc-chromate

and two coats of light grey enamel paint as per shade 631 of IS:5 or

latest.

5.4.6 Internal element fuse for capacitor unit shall comprise very high

grade quality special alloy wire. The raw material for fuse shall

comprise fuse wire, press board and insulating paper. These fuse

wire shall be checked for tolerance in dimension and uniformity in

finish and also for compatibility with the impregnating fluids. The

element fuse shall be current limiting type which shall operate in a

very short duration to isolate the faulty elements.

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The fuse shall be capable of carrying both nominal current

continuously and inrush current. It shall operate at the minimum

available energy and should not explode while discharging maximum

available energy.

The construction of internal fuse shall be such that the residue of

fuse operations shall not contaminate the impregnating liquid.

The internal fuse shall be so designed that fuse operation under the

worst conditions will not cause a fire inside a unit. The internal fuse

shall be designed and tested as per IS: 12672 or latest and test

results furnished with each capacitor unit.

5.4.7 Each capacitor unit shall be provided with a directly connected

internal discharge device to drain the residual voltage from the crest

value of the rated voltage to 50 volts or less within 5 minutes of

disconnection of the capacitor from the source of supply.

This device shall be made from carbon resistors without lacquer coating.

5.5 Series Reactor:

A series reactor will be provided to make the resultant reactance of

capacitor- set inductive for 3rd harmonic or other higher harmonics for

the purpose of restraining the distortion of voltage wave form possibly

caused by the shunt capacitor. A series reactor has also another useful

effect on damping a transient phenomenon at the time of switching in/

on of the capacitor bank. Reactance of series reactor is 13 % of that of

capacitor.

5.5.1 The series reactor shall be of the type described below:

a) Oil emerged

b) Hermitically sealed

c) Natural air cooled

d) Magnetic shielding air core with non- load tap changer.

e) Steel tank

5.5.2 Performance Characteristics

i. Tolerance of induction value error 0 to 10 %

ii. Reactance value while passing 5 times

rated current

Not less than

90% of rated value

5.6 Basic insulation level:

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The basic insulation level of the complete capacitor bank and other

associated equipments shall be as follows:

1.2 /50 micro second impulse withstand voltage ( peak) 250 kV (P)

1 minute wet power frequency withstand voltage (rms) 105 kV

For altitude above 1000 m and up to 2500 m, the value of basic

insulation level shall be calculated as per IEC 62271-1 and IEC 60071-

1&2 by multiplying of correction factor (k) in value of insulation level

up to 1000m at the required altitude.

As per IEC 62271-1, the formula for correction factor is

k = e m (H–1000)/8150

Where,

H is the altitude, in meters;

m = 1 for power frequency and lightning impulse voltage;

m = 0.75 for switching impulse voltage.

5.7 Protection:

5.7.1 The capacitor bank shall be provided with following protective relays

and generally as indicated in appendix-II.

i. Over current relay with IDMT element with suitable settings.

ii. Over voltage relay- over voltage protection against system over

voltage shall be provided with an inverse tank characteristics

with suitable settings. The over voltage relay shall be energized

from a PT connected to the main bus bar on the incoming of the

circuit breaker controlling the capacitor bank. If required an IVT

of suitable ratio shall be used for matching the capacitor over

voltage withstand characteristics.

iii. Under voltage relay- in conjunction with the timer to enable the

capacitors to discharge before reclosure. Relay provided for this

purpose should have a high resetting ratio and shall be

connected to the bus PT. Also a time delay relay should be

enclosed with adjustable setting of 0 to 5 minutes to provide a

time lag before the breaker is reclosed. However, this relay

would not be required if a timer is included in the closing circuit

of its associated breaker to prevent its reclosing within 5

minutes.

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iv. Un-balanced voltage protection- relay for unbalanced protection

of capacitor bank shall be provided with residual voltage

transformers. The offer shall include the residual voltage

transformers, of adequate ratio and burden also.

OR

v. The capacitor bank shall be protected by means of unbalanced

current protection. The capacitor bank shall be connected as a

bridge and an unbalanced sensing current transformer provided.

The current transformer ratio shall be chosen so that even one

capacitor element failure can be detected. The relay used shall

be a harmonic insensitive over current relay with fixed time delay

characteristic. The time delay shall be set at approximate 0.1

second. Calculations shall be furnished to establish that

unbalanced protection shall operate before the over voltage

limits as given in clause number 5.4.1 are exceeded.

vi. Each capacitor element shall be protected by means of internal

fuse. The fuse shall be connected in series with each capacitor

element inside the capacitor unit to limit the effects of dielectric

failures. If the puncture of dielectric occurs, only one element

shall be disconnected and the capacitor unit continue to operate.

While selecting the fuse rating, it would be necessary to choose

proper tank current characteristic which in turn significantly

depends upon the cross section and circumference of the fuse.

Fuses chosen shall have adequate thermal capability and comply

with relevant IS, IEC specifications.

OR

vii. - High rupturing capacity fuses for protection of individual unit.

Each capacitor unit shall be individually protected by an HRC

(cartridge) fuse, suitably rated. While selecting the fuse ratings,

it would be necessary to take into account thermal efforts of

transient currents.

5.7.2 The tenderer vendor may propose any other protection which they

consider in their experience to be superior for the installation and

shall give full justification for the same.

6.0 GENERAL ARRANGEMENT OF CAPACITOR BANK AND ASSOCIATED

EQUIPMENT.

6.1 The capacitor bank shall be of outdoor type, installed on a concrete

bed or mounted on steel racks for connection to the 25 kV bus through

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double pole isolator and circuit breaker (both the isolator and the

circuit breaker will be arranged by the purchaser). The capacitor bank

shall consist of groups of individual capacitor units, connected in

series-parallel combination to deliver the rated output, at nominal

rated system voltage, rated frequency and other system conditions

detailed elsewhere. The number of parallel units in each series group

shall be such that failure of one unit shall not create more than the

rated over voltage units in the bank. The capacitor bank shall be

supplied complete with mounting steel rack assembly, inter-connectors

between units, fuses for unit and group protection, insulators, suitable

earthing lugs including terminal connectors but without connecting

jumper to 25 kV bus and any other material required to make the bank

complete in all respects for its satisfactory.

6.2 Mounting Arrangement:

6.2.1 The capacitor bank alongwith external fuses for unit protection if

provided and the series reactor shall be suitable for mounting on

steel racks which in turn shall be mounted on a concrete plinth with

rack insulators and other hardware etc. There shall be an expanded

metal enclosure to the steel racks on which capacitor bank and

reactor are mounted.

6.2.2 The manufacturer will provide an asbestos roof over the capacitor

bank to protect against direct exposure to the sun. The assembly

shall be of two tier arrangement suitable for erection within a floor

area of 3400 x 1100 mm. In case the manufacturer guarantees the

normal functions of a capacitor bank without any roof, it is not

necessary for him to provide the roof.

7.0 CONTROL PANEL

7.1 Control and relay panel for capacitor bank

The control panel having the relays for the capacitor bank shall be

supplied and installed by the tenderer vendor in the control room of

unattended remote control traction sub-station. The control panel

shall be of vertical mounting, self-supporting steel construction back

to back duplex corridor type. The corridor shall be provided with a

lockable door at either end permitting free access to all instruments,

components, wiring, terminal connections, test block etc. Stove

enameled painting shall be done on the panel. The colour of the panel

shall be ‘Eau de Nile green’ conforming to IS:5 or latest Shade 216 on

the exterior and white on the interior surfaces. The overall height

shall be 2300 mm to match with the height of the existing

transformer and feeder control and relay panels.

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7.2 The control panel shall be fabricated from sheet steel of uniform gauge

of at least 10 SWG for front and rear panels, base frame and door

frame, and of at least 14 SWG for side panels, roof and doors. Cable

entries shall be provided from the bottom of the control panel for

which suitable opening shall be provided on the bottom plate. The

control panel shall be suitable for erection flush with the floor by

evenly spaced grouting bolts projecting through the base channel of its

frame. The control panel including the relay housing shall be dust,

vermin and moisture-proof. The overall size of the control panel shall

be subject to the approval of Railways.

There shall be provision for fixing a 240 V incandescent lamp for

interior lightning. The lamp shall be switched ON/OFF with the help of

a door switch mounted at suitable location inside the panel.

The front panel shall have the control switch, indication light emitting

diodes (LEDs), annunciation level, alarm cancellation push button and

a mimic diagram indicating connections of various equipments.

7.3 The protective relays shall be mounted on the rear panel and shall be

of semi-flush mounting type with back connections and provided with

dust-proof covers and test plug or separate test blocks for secondary

injection tests.

7.4 Instrument

A switch-board type, back connected, semi-flush mounted Ammeter

0-200 A of class A industrial grade accuracy, shall be provided for the

indication of capacitor current. All circuits including current coil of the

instrument shall be capable of withstanding 20% overload

continuously. It shall be subjected to a high voltage test of 2 kV rms

for one minute. The instrument shall be provided with dust-tight case

and finished in dull black enamel paint.

7.5 A suitable spring return type control switch with pistol grip handle

having three positions- ON/OFF/Neutral shall be provided on the

control panel. The switch shall have a sequence device to prevent two

successive movements to the same position. Following LEDs shall be

provided for indication of circuit breaker condition:

i Circuit breaker ‘closed’ Red

ii Circuit breaker ‘open’ Green

iii Trip circuit of C.B. healthy Yellow

Low consumption, extra bright, 5 mm dia. Light emitting diodes (LEDs)

shall be used, wherever required. LEDs shall be suitably wired o glow

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off 110 V d.c. supply. LEDs shall be housed in suitable holders with

glazed/ polished surface to act as reflector. The holders shall be

screwed to the panel from inside.

7.6 A suitable two position (local/remote) change over switch shall be

provided on the control panel for operation of circuit breaker from

control panel in ‘local’ mode and from Remote Control Centre in

‘Remote’ mode of this switch.

7.7 Mimic diagram

7.7.1 The scheme of connections at the sub-stations showing the isolator,

circuit breaker, series reactor and the capacitor bank shall be

represented by a single line mimic diagram on the control panel.

The colour of the mimic diagram will be golden yellow to shade No.

356 of IS: 5 or latest. Automatic semaphore relay shall be provided

in the mimic diagram to indicate ON/OFF position of the circuit

breaker.

7.7.2 Open / Close position of the 25 kV isolator shall be represented on

the mimic diagram board by manually operated semaphore

indicator. Push button and yellow indication LED, as mentioned in

clause No. 7.5 above, shall be provided on the control panel to

monitor the healthiness of the trip circuit of the circuit breaker.

7.8 Annunciator

7.8.1 An annunciation level as per sketch at Appendix-VII shall be

provided on the front side of the control panel for visual alarm of

various fault conditions.

7.8.2 The visual alarm shall be of flasher type i.e. concerned LED shall

flicker and will not become stable till the alarm is accepted.

7.8.3 The alarm accepting and annunciation testing buttons shall be

mounted on the control panel at a convenient height under the

annunciator lebel.

7.8.4 Alongwith visual alarm, there shall be provision for an audible

alarm. Audible alarm bell shall work off 110 volts d.c. this bell shall

be mounted inside the control panel. The alarm bell shall

continuously ring when a fault is there and shall not stop ringing till

the alarm is acknowledged. A suitable disconnection switch shall be

provided for disconnection of the bell circuit.

7.9 Remote operation

7.9.1 The capacitor bank shall normally be switched in or out by control

commands issued by Traction Power controller from the Remote

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Control Centre. These telecommands shall be issued with the help of

supervisory Remote Control and Data Acquisition System, hereafter

called SCADA system, provided at Remote Control Centre.

7.9.2 For the purpose of telecommands and telesignalling, suitable

terminals shall be provided on a terminal block, which shall be duly

wired for the following:

i. One telesignal each for supervision of secondary fuse of potential

transformer (P.T.) and residual voltage transformer (RVT).

ii. One telesignal for monitoring the health of capacitor units and

series reactor as recommended by the tenderer vendor.

iii. One telecommand for operation of capacitor circuit breaker.

7.10 Suitable terminal blocks including testing terminal shall be mounted at

a convenient location inside the control panel. The current rating of the

contacts shall be 30 amps. Continuous at 110 V dc. The current

terminals shall be provided with short circuiting links or other suitable

device. The potential terminals shall be housed in a narrow recesses of

the moulded insulation block to prevent accidental short circuit.

Terminals on the blocks shall be stud type for crimpled terminal/lugs,

securely tightened with nuts and spring washers. AC and DC terminals

shall be kept separate. Each terminal shall be completely shrouded.

7.11 All panel wiring shall be done with switch-board type 1100 V grade

PVC insulated single core stranded tinned annealed copper conductor

for service in tropical climate. The wiring shall be flame retardant and

not prone to attach by the vermins, i.e. mice, white ants, cockroaches,

etc.

7.12 Suitable space heaters to operate off 240 V AC single phase, 50 Hz

supply with ‘ON’ and ‘OFF’ switch shall be provided inside the control

panel to prevent condensation of moisture in humid weather.

7.13 One combined three pin switch plug, 5 Amps rating shall be provided

inside the panel for using 240 V hand lamp.

7.14 HRC type cartridge fuses of appropriate rating shall be used in the

control panel at easily accessible places in all potential circuits.

8.0 CURRENT TRANSFORMER AND POTENTIAL TRANSFORMER

Current and potential transformers for the protection of capacitor bank shall

be supplied by the tenderer vendor. Full technical particulars of such

transformers shall be furnished in the tender offer.

9.0 PROTECTION AGAINST LIGHTNING SURGES

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A separate lightning arrestor shall be provided to protect the capacitor bank

against lightning surges. The lightning arrestor shall be metal oxide gapless

type 42 kV class having 10 kA discharge current. The lightning arrestor

shall be designed to withstand the full energy discharge from the capacitor

bank to which it is connected.

10.0 EARTHING

Earthing arrangements shall be provided for capacitor bank installation in

accordance with RDSO specification No. ETI/PSI/120(7/88) (02/91) with

A&C Slip No. 1 or latest code of practice for Earthing of power supply

installation for 25 kV, ac 50 Hz, single phase traction system.

11.0 GALVANISING

All steel supporting frame shall be hot-dip galvanized as per Research

Designs & Standards Organisation’s specification no. ETI/OHE/18(4/84)

TI/SPC/OHE/FASTERNERS/0120 Rev. 1 or latest and the weight of zinc

coating shall be not less than 1000 gm/m sq.

12.0 FASTERNERS

All fasteners of 12 mm diameter and less exposed to atmosphere shall be

of stainless steel and those above 12 mm dia shall be preferably of

stainless steel or mild steel hot dip galvanized to RDSO’s specification No.

ETI/OHE/18(4/84) TI/SPC/OHE/FASTERNERS/0120 Rev. 1 or latest.

13.0 TESTS

13.1 All type and routine tests shall be conducted on the capacitor units,

series reactor, circuit breaker and the complete capacitor bank

installation as per the governing specifications mentioned in clause

2.1. The tests on all the equipments shall be conducted in the

presence of the purchaser’s representative.

13.2 The following tests shall be carried out at the works of manufacturer

or at a reputed testing laboratory at any Government approved

testing laboratory if testing is done in India on the prototype units of

the shunt capacitor as per IS: 2834 and IEC:70 or latest.

13.3 TYPE TESTS

13.3.1 Type tests shall be conducted on the first prototype unit

manufactured after all the design and drawings have been

approved and clearance given by RDSO to this effect.

13.3.2 Before giving the call to RDSO/ The Chief Electrical Engineer for

inspection and testing of the prototype of the system the

manufacturer shall submit a detailed test schedule of proto type

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testing indicating the name of the test with internal test report

(Test report of Routine Test) consisting of schematic circuit

diagrams for each of the tests and nature of the test, venue of the

test and the duration of each test and the total number of days

required to complete the test at one stretch. Once the schedule is

approved, the test shall invariably be done accordingly. However,

during the process of type testing or even later, RDSO

representative reserves the right to conduct any additional tests

besides those specified herein, or any equipment/ sub-system or

system so as to test the system to his satisfaction or for gaining

additional information and knowledge. In case any dispute or

disagreement arises between the manufacturer and RDSO/ The

Chief Electrical Engineer during the process of testing as regards

the type tests and /or the interpretation and acceptability of the

type test results, it shall be brought to the notice of the Director

General (Traction Installations), RDSO/ the Chief Electrical

Engineer as the case may be, whose decision shall be final and

binding.

i. Test for output and capacitance:

The output of the capacitor shall be determined in accordance

with Appendix-F of IS: 2834 or latest and shall be within-5 to +

10% of the rated value of capacitor units for making capacitor

banks but within -0 to 10 % of the rated value in case of

capacitor banks.

ii. Voltage test between terminals and container ( for capacitor

units):

An AC test voltage of the value specified in Col.2 of Table-3 of

IS:2834 or latest shall be applied between the terminals (short

circuited) of each capacitor unit and its container, and

maintained for a period of one minute, except that when one

terminal of the capacitor is connected to the container.

iii. Measurement of tangent dielectric loss angle:

The dielectric loss angle (tan delta) shall be determined by

means of Schering Bridge or other method capable of giving

sufficiently accurate results. The measurements shall be carried

out as per Clause no. 14 of IS: 2834 or latest.

iv. Thermal Stability Test:

This test shall provide thermal stability to capacitor under

overload conditions and prepare the capacitor to give reliable

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loss measurements. The test shall be carried out as per clause

No. 15 of IS: 2834 or latest.

v. Tangent pf dielectric loss angle at elevated temperature:

The dielectric loss angle (tan delta) shall be measured at a

temperature of 70 degree C or as attained in thermal stability

test. The measuring voltage shall be same as in thermal stability

test.

vi. Partial discharge test:

The test shall be carried out as per clause No. 17 of IS: 2834 or

latest.

vii. Impulse voltage test between terminals and container:

Five impulse wages of 1.2/50 micro-second, of each polarity

having a peak value corresponding to the insulation level of the

unit shall be applied between the terminals (joined together)

and the container. The test shall be carried out as per Clause

No. 18 of IS: 2834 or latest.

viii. Capacitor discharge test:

The capacitor shall be charged by means of dc voltage equal to

twice the r.m.s value of the rated voltage of the unit and

discharged through a gap situated as close as possible to the

capacitor as per clause No. 21 of IS: 2834 or latest.

ix. Endurance testing

Capacitor units shall be subjected to an endurance test by the

manufacturer of the capacitors to ascertain that repeated over

voltages stresses do not cause dielectric break down. This test

shall be done in accordance with procedure laid down in IEC

Report 871—2:1987. In case it is not possible to carry out the

test in accordance with IEC report 871-2:1987 or latest, the

capacitor units shall be tested for endurance in accordance with

an alternative procedure which shall be mutually agreed to

between the manufacturer and the purchaser.

13.4 The following type tests shall be carried out on the internal fuses as

per IS: 12672 or latest:

i. Discharge Test:

The fuses shall be subjected to live discharges within 10 minutes

from a dc test voltage equal to 2.5 times the rms value of the

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rated voltage of the capacitor element through a gap situated as

clause as possible to the capacitor without any additional

impedance in the circuit. To prove that the fuses have not

operated, a capacitance measurement shall be made before and

after the test.

ii. Disconnecting test on fuses:

The disconnecting test on fuses shall be performed first at lower

voltage limit equal to 0.9 times rms value of the rated voltage of

the capacitor element and then as soon as possible after blowing

of one fuse at the upper voltage limit equal to 2.2 times the rms

value of rated voltage of the capacitor element until blowing of

another fuse. After the test, Capacitance shall be measured to

prove that the fuse(s) has (have) blown. A measuring method

shall be used that is sufficiently sensitive to detect the capacitance

change caused by the blown fuse.

13.5 Special tests on capacitor units with internal fuses.

i. High voltage discharge test;

Each capacitor unit manufactured shall be tested strictly in

accordance with the IS: 2834-1986 or latest. The special

discharge test shall be performed to check the mechanical

strength of internal fuses and discharge resistors. The internal

element fuses shall be routine tested together with the capacitor

units as per the diagram given below:

1. Low voltage capacitance

measurement. 2. DC Voltage test (4.3 Vn 10

sec.) 3. Direct discharge from 1.7

Vn.

4. Low voltage capacitance measurement.

5. Capacitance and loss measurement (Vn)

(Vn=rated voltage of capacitor)

13.6 Routine tests:

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The following tests shall be carried out as routine tests and shall be

carried out on each and every units.

i. Visual Examination:

All capacitors shall be examined for finish and marking.

Verification of dimension shall also be done as per approved

drawings.

ii. Sealing test:

A sealing test shall be carried out to demonstrate that the

impregnated does not leak from the capacitor. The test shall be

carried out at 80+/- 5 degree C for a period of 3 hours.

iii. Test for output and capacitance:

This test shall be carried out in accordance with clause 13 of IS:

2834 or latest.

iv. Insulation resistance test:

Every capacitor shall be subjected to an insulation test between

terminals and container except when the terminal of the capacitor

is connected to the container. The test shall be made with a dc

voltage (megger) not less than 500 volts. The insulation

resistance so determine shall not be less than 50 mega ohms.

v. Test for efficacy of discharge device:

A test for verifying the requirements of discharge device, as given

in clause 6.1.1 to 5.1.3 of IS: 2834 or latest, shall be made.

Method of test for efficacy of discharge device shall be as per

Appendix-G of IS: 2834 or latest.

vi. Measurement of tangent of dielectric loss angle.

This test shall be carried out in accordance with clause No. 14 of

IS: 2834 or latest.

13.7 Acceptance Tests:

The routine and/or type tests or some of them, may be repeated by

the Purchaser by mutual agreement between the purchaser and the

manufacturer, however, following tests shall be carried out in the

sequence given below:

i. Visual Examination:

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All capacitors shall be examined for finish and marking verification

of the dimension shall also be done as per approved drawing.

ii. Sealing tests:


IS: 2834 or latest.

iii. Insulation Resistance Test:

This test shall be carried out in accordance with clause no. 12 of

IS: 2834 or latest.

iv. Test for efficacy of discharge device;


IS: 2834 or latest.

v. Measurement of tangent of dielectric loss angle.


IS: 2834 or latest.

13.8 Test on Series Reactor:

13.8.1 Type Tests:

i. Temperature –rise test:

This test shall be carried out in accordance with IS: 2026 or

latest.

ii. Short circuit test

This test shall consist of application to the reactor of two

short circuits with specified initial peak current for 10 cycles

as per clause No. 3.5 and 8.11 of IS: 5553 (Part-II) or latest.

iii. Impulse voltage withstand test:


latest.

13.8.2 Routine Tests:

i. Measurement of winding resistance:

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latest.

ii. Measurement of impedance:

This test shall be carried out in accordance with clause No.

8.4 of IS: 5553 or latest.

iii. Measurement of load losses:

This test shall be carried out in accordance with clause No.

8.5 of IS: 5553 or latest.

iv. Separate source voltage withstand test:


latest by applying specified voltage for one minute between

a) The winding and the earth and

b) The windings of different phases.

v. Induced overvoltage withstand test or impulse voltage

withstand test:


latest.

vi. Measurement of insulation resistance:


latest.

13.9 Test on control panel

Following checks and tests shall be carried out on the control panel:

i. Visual checks

General check of control board in respect of construction of

wiring, provision of various equipments and relays.

ii. Operation tests

Operation tests on all the equipments, switches and tests to

prove correctness of wiring of various circuits including

indications, alarms, operation of relays and annunciation.

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iii. Power frequency high voltage withstand test.

Voltage test on the panel with all equipments and wiring for

a withstand voltage of 2000 V (rms) to earth for one minute.

iv. Insulation resistance tests

Measurement of insulation resistance of the complete panel

wiring, circuit by circuit, by using 1000 v megger.

13.10 Following tests shall be conducted at site to verify the performance of

the complete capacitor bank installation:

i. Tests for efficacy of discharge device:

Tests for verifying the requirements of discharge deice as

given in clauses 6.1.1 to 6.1.6 of IS: 2834 or latest.

ii. Test on protection system:

This test shall be carried out by a simulating the fault

conditions and observing the relay operation.

iii. Rise in voltage due to capacitor bank connection:

At different loads, the voltage at the 25 kV busbar shall be

recorded for 24 hours each with and without the capacitor

bank. The rise in voltage due to the capacitor bank shall be

assessed from these observations.

iv. Harmonic analysis:

The harmonic analysis of current and voltage waveform shall

be carried out by the tenderer with and without capacitor

bank in circuit.

v. Surge voltage measurement:

The surge voltage shall be measured by the tenderer at the

time of switching in capacitor bank. This shall be done for 20

times; the voltage peak shall not exceed 70 kVp in any case.

13.11 Schedule of pre-commissioning tests:

The schedule of pre-commissioning tests on the capacitor units,

reactor and the complete bank, control & relay panels, circuit breakers

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and other items shall be mutually agreed upon by the successful

tenderer vendor and the purchaser.

13.12 Bulk manufacture of the shunt capacitor shall be taken up only after

specific written approval given by the purchaser to the successful

tenderer vendor on the basis of the tests conducted on the proto type

units manufactured according to approved design and drawings.

14.0 Capitalization of Losses:

14.1 In evaluating the offer, the price of the capacitors and series reactors

with higher watt losses per/ kVAr shall be compared by increasing the

prices by capitalization of additional losses by the formula given in the

appendix- VIII. The tenderer shall for this purpose clearly indicate the

losses in watts per kVAr rating of the capacitor bank and separately for

the series reactor at the rated voltage.

14.2 The losses of the capacitor bank shall be made up of the losses per

capacitor unit (including fuses and discharge device) multiplied by the

number of units in the bank. The overall losses of a capacitor unit shall

be as low as possible and shall not be more than 0.25 W/kVAr.

15.0 Technical Data and Drawings:

15.1 The tenderer vendor shall furnish guaranteed performance data,

technical and other particulars for the equipments offered in the

Performa at Annexure-A. Technical details of the protection employed

together with detailed calculation for the ratings of the equipment shall

be furnished with the tender.

15.2 The information furnished in schedule of the guaranteed performance,

technical and other particulars (Annexure-A) shall be complete in all

respects. If there is any entry like: “shall be furnished later” or blanks

are left against an item, the tender is not likely to be considered as

such omissions causes delay in finalizing the tender.

15.3 The tenderer vendor shall specifically indicate in a statement attached

with his offer, his compliance with each clause and sub-clause of this

specification. If any vague remarks on any clause or sub-clause of this

specification is given by the tenderer, then the tender submitted by

him is not likely to be considered. A separate deviation statement shall

be furnished with the offer drawing to the clause (s) where the

tenderer seeks the deviation giving detailed remarks/ justification

thereon. If there are no deviation, a ’NIL’ statement shall be furnished.

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15.4 The tenderer vendor shall furnish the following calculations with their

offer.

i. Detailed calculations for rating of shunt capacitor bank series

reactor, inrush current, transient over voltage, parallel and series

resonant frequencies.

ii. Calculations for protection scheme offered

iii. Calculations for design of supporting frame, fixing arrangement

and foundation.

15.5 The following drawings shall be furnished as per IR standard in sizes of

210 mm x 290 mm or any integral multiple thereof:

a. Outline general arrangement drawing giving the overall

dimensions of the capacitor bank installation.

b. Arrangement of capacitor Bank, Series reactor, circuit breaker,

isolator, lightening arrestor, current and potential transformers.

c. Details of capacitor bank showing series parallel arrangement of

capacitor units.

d. Arrangement of core winding and magnetic path of series reactor.

e. General Arrangement of circuit breaker showing mounting

arrangement and over all dimensions.

15.6 The successful tenderer vendor shall be required to submit for

approval the following detailed dimensioned drawings as per Indian

Railway Standard in the sizes of 210 mm x 297mm or any integral

multiple thereof.

a. Outline general arrangement drawing of the capacitor bank

installation indicating necessary dimensions, clearances and

location of equipments/ fittings (all the 3 views), Name and

noting plate with diagram of connections (one in English and

other in Hindi).

b. Internal arrangement of series reactor including cross sectional

views in both plane and elevation.

c. Schematic and wiring diagram.

d. Supporting frame with details of fixing arrangement and

foundations alongwith calculation for their design.

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15.7 After approval of designs and drawings by Director General/TI, RDSO,

Lucknow, the tenderer vendor shall manufacture an acceptable

prototype of shunt capacitor equipment as per approved drawings. The

prototype inspection shall be carried out by the representative of

RDSO. The bulk manufacture shall be taken up only after approval of

prototype by the Director General (TI), RDSO, Lucknow.

15.8 Routine Inspection shall be carried out, by the representatives of

Indian Railways at the manufacturer’s works.

15.9 After approval, 6 copies of approved drawings alongwith two sets of

reproducible prints shall be supplied to each consignee(s). Besides,

two copies of drawing alongwith one set of reproducible prints shall be

supplied to Director General (TI), RDSO, Lucknow.

15.10 The successful tenderer vendor shall supply 10 copies of

instructions/maintenance manual for the capacitor bank installation

and its fittings and accessories, to each consignee(s) and two copies to

Director General (TI), RDSO, Lucknow.

16.0 Erection Testing and Commissioning:

The capacitor bank installation shall be erected by the successful tenderer

vendor under the supervision of a competent engineer of the successful

tenderer vendor/manufacturer/ supplier. The capacitor bank installation

shall be subjected to the specified proving / pre commissioning tests by

the Railway Engineer at site and with which the successful tenderer

vendor/ manufacturer/ supplier shall also be associated. For this purpose

prior intimation regarding the date and location of the tests shall be given

by the purchaser to the successful tenderer vendor/ manufacturer/

supplier.

17.0 SPARES

The tenderer vendor shall furnish alongwith his offer a list of spares, with

cost, recommended by him for maintenance of capacitor bank installation

for a period of 2 years.

18.0 TRAINING OF INDIAN RAILWAYS’ ENGINEERS

The offer shall include the training of two engineers and four technicians of

the Indian Railways free of cost at the manufacturer’s works in India or

abroad and at the traction sub-station of a railway system or other public

utility where capacitor bank installations of similar/ identical design are in

operation. The total duration of training for each engineer/ technician

shall be 4 weeks of which approximately 2 weeks will be a the

manufacturer’s works and 2 weeks on a railway system or other public

utility. The cost of travel to the country of manufacture and back will be

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borne by the Indian Railways. Other details shall be settled at the time of

finalizing the contract or purchase order.

19.0 WARRANTY

Each capacitor bank including all equipment supplied against a purchase

order/ contract in which this specification is quoted, irrespective of origin

(imported or indigenous), shall be guaranteed for trouble free and

satisfactory performance for a period of 24 months from the date of supply

or 18 months from the date of commissioning at the sub-station on the

Indian Railways, whichever period is shorter. Details of warranty clause,

the extent of responsibility and other relevant aspects shall be included in

the purchase order or contract. The tenderer vendor shall furnish detailed

terms and conditions in this regard in his offer.

The successful tenderer vendor shall make necessary arrangement for

closely monitoring the performance of the capacitor bank installation

through periodical visits (preferably once in two months during the

warranty period) to the sub-station for on-the-spot detailed observations.

Arrangements shall be also be made for spare parts to be kept readily

available with the successful tenderer vendor / manufacturer/ supplier to

meet exigencies warranting replacement so as to put back the capacitor

bank installation in service without unduly long interruptions.

*********

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Annexure to Specification No. ETI/PSI/126(8/89)

SCHEDULE OF GUARANTEED PERFORMANCE TECHNICAL AND OTHER

PARTICULARS.

A- Capacitor Unit

S. N. Description Unit of measurement

1. Maker’s Name

2. Country of manufacture

3. Manufacturer’s type designation

4. Location of capacitor bank ( outdoor/indoor)

5. System voltage kV

6. Rated voltage of unit as per IS: 2834 or latest kV

7. Maximum voltage (rms) which the capacitor

unit can withstand continuously

kV

8. Rated frequency Hz

9. No. of phases No.

10. Upper limit of temperature category Deg. C

11. Capacity of individual unit at rated voltage of

unit

KVAr

12. Capacity of capacitor bank at 25 kV kVAr.

13. Continuous current Maximum inrush current at the instant of switching in

Amps Amps

14. Basic insulation level of unit a) Power frequency voltage withstand

b) 1.2/50 microsecond impulse withstand voltage

KV(rms)

kV(peak)

15. Basic insulation level of complete capacitor bank.

a) Power frequency voltage withstand b) 1.2/50 microsecond impulse withstand

voltage

Kv(rms) Kv(peak)

16. Transient current withstand capacity kA

17. Constructional details of capacitor unit. i) Dielectric material ii) Foil material

iii) Impregnating liquid used and its properties.

iv) Discharge resistors. v) Internal fuses.

18. Dielectric loss per kVAr / unit at 25 kV and 50 C/s

watts

19. Capacitor unit- i) No. of elements in series ii) No. of elements in parallel

iii) Capacitance of each unit

No. No.

Micro Farad

20. Capacitor bank

i) Capacitance of bank ii) No. of series groups

Micro Farad No.

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iii) No. of parallel units in each group No.

21. a) Internal fuse

i) Type of internal fuse elements of capacitor unit:

ii) Length of fuse element

iii) Cross section of fuse element iv) circumstance of fuse element

v) It characteristics. vi) Time factor (s) of internal fuse element

b) External fuse:

i) Type of fuse on individual capacitor unit. ii) Rating of the fuse. iii) Reference to time/ current characteristics

of the fuse used.

mm

Sq.mm Mm

Sec. (under max. energy

condition)

Sec. (under min energy condition.)

22. Discharge device.

i) Type ii) Location

iii) Time interval between de-energisation and re-energisation

iv) Residual voltage after an interval of 5

minutes of de-energisation

Minutes

Volts

23. Bushings:

i) Maker’s name ii) Governing Specification

iii) Wet-1 minute power frequency voltage withstand

iv) Impulse voltage withstand 1.2/50

microsecond full wave. v) Creepage distance in air

vi) No. of bushings in each unit

KV(rms) kV(peak)

mm

No.

24. Overall dimensions

i) Capacitor unit ii) Complete capacitor bank

25. Weight per unit Kg

26. Weight of the complete bank Kg

B- Control AND RELAY PANEL

1. Name of manufacturer and address

2. Overall dimensions and weight L-

W- H- Weight

Mm

Mm Mm Kg

3. i. Colour of the panel ii. Colour of the mimic

4. Details of switches provided and their make

5. Annunciations provided

6. Size of wires used for:

i. Control circuit.

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ii. Indication circuit iii. General wiring.

iv. Potential and current transformer circuits. v. Heating circuit. vi. Light circuit.

7. Method of cable entry

8. Details of instruments, if any, provided

C- PROTECTIVE FOR CAPACITOR BANK

1. Over-current protection i) Type and make of relays offered ii) Setting range of current available

2. Over-current protection i) Type and make of relay offered.

ii) Setting range available

3. Unbalance protection

i) Setting range available on current/ voltage operated relay.

ii) Calculations to show overvoltage on other capacitor units due to successive element failures.

iii) Details type and make and setting range of current operated relay.

iv) Values of unbalance currents at which alarm & trip signals shall be given.

4. Under voltage protection i) Type and make of relay used. ii) Resetting ratio of the under voltage

relay. iii) Type and make of the time delay relay.

iv) Setting range of the under voltage relay. v) Setting range of the time delay relay.

Note: - The tender should be complete with three sets (one with each copy) of technical literature and pamphlets of the relays used.

D- SRIES REACTOR

1. Rated current and voltage Amps/ Volts

2. Rated frequency Hz.

3. Inductance of series reactor H

4. Rated impedance Ohms

5. Parallel & Series resonant frequencies of the

system

Hz( parallel)

Hz( Series

6. Value of the peak surge voltage generated at

the time of switching in of shunt capacitor ( calculations shall be appended )

kV

7. Short circuit rating for 3 seconds KA

8. Overall dimensions of the series reactor Mm

9. Total weight of the series reactor Kg

10. Maximum temperature rise: a) At continuous current b) At 130 % loading

Deg. C Deg. C

11. Basic insulation level: a) Power frequency voltage withstand

KV (rms)

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b) 1.2/50 micro-second impulse voltage withstand

KV (peak)

E- INSTRUMENT TRANSFORMER

i. CURRENT TRANSFORMERS

1. Name of the manufacturer

2. Standard governing specification

3. Nominal system voltage kV

4. Rated burden VA

5. Rated secondary current A

6. Rated transformation ratio

7. Accuracy class

8. rated accuracy limit factor

9. Current error at rated primary current %

10. Phase displacement at rated primary current Minute

11. Composite error at the rated accuracy limit primary current

%

12. Rated short time thermal current for one second.

KA(rms)

13. Temperature rise with rated load and with specified overload:

a) Of oil by thermometer

b) Of winding by reisistance (secondary)

Deg. C

Deg. C

14. Overall dimensions of CT:

Height Length

Breadth

Mm Mm

mm

15. Total weight of CT kg

16. a) Is the CT of sealed construction with nitrogen gas at the top? b) Pressure or amount Nitrogen gas.

ii. POTENTIAL TRANSFORMER

1. Name of the manufacturer

2. Rated system voltage kV

3. Rated burden VA

4. a) Rated primary/ secondary voltage

b) Transformation ratio

kV/Volt

5. Accuracy class as per:

a) IS: 3156 (Pt. II)-1978 b) IS: 3156 ( Pt. III)-1978

6. Rated voltage factor

7. Maximum temperature rise after continuous full

load operation: a) Oil by thermometer b) Winding by resistance.

Degree Degree

8. Weight and dimensions a) Overall dimensions

Height Length

Width b) Total weight of potential transformer with

oil

Mm Mm

Mm Kg

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9. Whether the PT is of sealed construction with nitrogen at top

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Appendix-I

(a) Principle of AT Feeding System.

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Appendix-II

Constitution of shunt Capacitor

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Appendix-III

Schematic Diagram of Shunt Capacitor Bank

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Documents

GOVERNMENT OF INDIA TECHNICAL SPECFICATION FOR 25kV … · 2020. 8. 25. · Effective From Draft spec No. TI/SPC/PSI/SHUNT/2200 Page 2 of 39 Specification No. ETI/PSI/126(8/89) Specification