GOVERNMENT OF INDIA MINISTRY OF RAILWAYS TECHNICAL … · 2020. 12. 24. · 4.1 The Isolator shall...

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DRAFT TECHNICAL SPECIFICATION NO. TI/SPC/PSI/ISOLTR/0200 FOR 25KV/55kV/66KV/110KV/132KV/220kV AC SINGLE POLE , DOUBLE POLE & TRIPLE POLE MOTORIZED/MANUAL OPERATED ISOLATORS FOR RAILWAYS AC TRACTION SUB-STATIONS

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SPECIFICATION No. TI/SPC/PSI/ISOLTR/0200

GOVERNMENT OF INDIA

MINISTRY OF RAILWAYS

TECHNICAL SPECIFICATION

for

25KV Motorized/Manual operated and

66KV/110KV/132KV/220kV KV Manual operated

Single Pole, Double Pole and Triple Pole Isolators

For

Railway Electric Traction

RESEARCH DESIGNS AND STANDARDS ORGANIZATION LUCKNOW - 226 011

December, 2020

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INDEX

Clause Description

1.0 Scope

2.0 Climatic, Environmental & operating condition

3.0 List of related specifications

4.0 Rating, name plate details and other information

5.0 Design and constructional features

6.0 Test

7.0 Test Method

8.0 Bulk Manufacturing

9.0 Technical data and drawing

10.0 Installation, Testing and Commissioning

11.0 Packing and Dispatch

Annexure-A Schedule of Guaranteed Performance Data Technical And Other Particulars for Isolator.

Annexure-B Information to be furnished by the manufacturer /supplier in case of Motorized Isolator

Annexure-C Definition

Annexure-D-1 General arrangement of motorized isolator

Annexure-D-2 General arrangement of Manual isolator

Annexure-E-1 Schematic Interlocking Arrangement on 132 kV

Annexure-E-2 Schematic Interlocking Arrangement on 25 kV

Annexure-F General arrangement of Bimetallic terminal connector

Annexure-G Sketch of Operating Arrangement of Bus/Line Isolator

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1. SCOPE

1.1 This specification applies to single pole, double pole & triple pole isolators with/without earthing

switch (25KV Motorized/Manual operated and 66KV/110KV/132KV/220kV Manual operated) as

specified by purchases in the particular tender for outdoor use in nominal system voltage of

220/132/110/66/55/25kV ac 50 Hz single phase/2x25kV AT Feeding System/2x25kV New System

for overhead equipment (OHE), Traction Substations and Switching Stations. The Specification also

applies to the operating mechanism of the Isolator and Earthing Switch. The Isolator shall be

mounted on a mast/structure as required.

1.2 In case of motorized isolator in station area, the operation of Motorized Isolators shall be possible

from a remote location at distance about 1 km. The status of Isolators i.e. whether Close or Open

shall be available at the Station Master’s chamber (in case of motorized isolator provided at

station area). However the status of motorized isolator within the TSS and near the SP/SSP, shall

be at RCC in case of motorized isolator provided in 2 x25 kV New system. The DC supply from

battery in TSS/SP/SSP to the motorized isolator through a two core cable shall be made available

in case of 2x25kV New System.

1.3 The isolator shall be complete with all parts, fittings and accessories including mounting frame

work, (battery & battery charger in case of 2x25kV New System), insulators, operating rod,

operating mechanism box, remote control box along with OPEN/CLOSE indication, motor

operating mechanism necessary for its efficient operation. All such parts, fittings and accessories

except cables shall be deemed to be within the scope of this specification, whether specifically

mentioned or not.

1.4 The ‘Make in India’ policy of ‘Government of India’ shall be applicable. 1.5 This Specification supersedes following Specification:-

Sl.No Specification No. Description

1 ETI/PSI/122(3/89) 245kV/145kV/123kV/72.5kV Double Pole and Triple Pole Isolators

2. ETI/PSI/133(8/89) 25kV,ac Double Isolators for 2x25kV AT Feeding System

3. ETI/OHE/16(1/94) 25kV, ac Single Pole and Double Pole Isolators

4. TI/SPC/PSI/ISOLTR/1060 25kV,ac Single Pole and Double Pole Motorized Isolators

2.0 CLIMATIC, ENVIRONMENTAL & OPERATING CONDITION

2.1 The isolator is intended to be used as outdoor line sectioning switches. The isolator shall be used in

normally polluted atmosphere, subject to dust, smoke and effluents from chemical plants. It may

also be used in coastal areas.

2.2 Environmental Conditions

i. Maximum ambient air temperature : 550 C

ii. Minimum Temperature of Air in shade : (-)100 C

iii. Average ambient air temperature over a period of 24 hrs. : 35° C

iv. Maximum Relative Humidity : 100%

v. Annual Rainfall ranging from : 1750 mm to 6250 mm

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vi. Maximum Number of Thunder storm days per annum : 85 days

vii. Maximum number of Dust Storm days per annum : 35 days

viii. Number of Rainy days per Annum : 120 days

ix. Basic Wind Pressure : 200 kgf/m2

x. Altitude above Mean Sea Level : Normally 1000 meters

but some of the places it

may be up to 2500 meter

2.3 The isolator shall 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 with the instances peak going up to 350 microns. These vibrations may become more severe as the speeds and loads of trains increase in future.

3.0 LIST OF RELATED SPECIFICATIONS

3.1 The isolator and earthing switch shall, unless otherwise specified herein, conform to the latest

version of the Indian Standards. Specifications/IEC recommendations/Research designs and Standards Organization (RDSO) specifications as indicated below and the Indian Electricity Rules, wherever applicable:

1. IS 1570 : PART 2 : 1979

(REAFFIRMED 2016) : CARBON STEELS (UNALLOYED STEELS)

2. IS 2071 : PART 1 : 2016 : GENERAL DEFINITIONS AND TEST REQUIREMENTS 3. IS 2108 : 1977 : NOT EXIST

4. IS/IEC 60168 : 2000 : TESTS ON INDOOR AND OUTDOOR POST INSULATORS OF CERAMIC MATERIAL OR GLASS FOR SYSTEMS WITH NOMINAL VOLTAGES GREATER THAN 1 000 V

5. IS/IEC 60273 : 1990 : CHARACTERISTIC OF INDOOR AND OUTDOOR POST INSULATORS FOR SYSTEMS WITH NOMINAL VOLTAGES GREATER THAN 1 000 V

6. IS 5561 : 2018 : ELECTRIC POWER CONNECTORS-SPECIFICATION 7. IS 7608 : 1987 (REAFFIRMED

2016) : PHOSPHOR BRONZE WIRE FOR GENERAL ENGINEERING

PURPOSES 8. IS 7906 : HELICAL COMPRESSION SPRINGS 9. IS/IEC 62271 : PART 102 : 2003

(REAFFIRMED 2018) : ALTERNATING CURRENT DISCONNECTORS AND EARTHING

SWITCHES 10. ETI/OHE/13 : SPECIFICATION FOR HOT DIP ZINC COATING ON STEEL MASTS

(ROLLED AND FABRICATED) TUBES AND FITTINGS USED ON 25 KV AC OHE

11. ETI/OHE/18 : SPECIFICATION FOR STEEL AND STAINLESS STEEL BOLTS, NUTS AND WASHERS

12. ETI/OHE/64 : SPECIFICATION FOR SOLID CORE CYLINDRICAL POST INSULATORS FOR SYSTEM WITH NOMINAL VOLTAGE OF 220KV, 132KV,110KV & 66KV

13. IEC 62505-2 : RAILWAY APPLICATIONS – FIXED INSTALLATIONS – PARTICULAR REQUIREMENTS FOR AC SWITCHGEAR – PART 2: DISCONNECTORS, EARTHING SWITCHES AND SWITCHES WITH NOMINAL VOLTAGE ABOVE 1 KV

14. IEC 62271-102:2018 : SHORT TIME WITHSTAND CURRENT TEST

3.2 Any deviation from this specification proposed by the tenderer, intended to improve upon the

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performance, utility and efficiency of the equipment will be given due consideration, provided full particulars of the deviation with justification thereof are furnished .In such a case, the tenderer shall quote accordingly to this specification and deviation, if any, proposed by him shall be quoted as an alternative(s).

3.3 In case of any contradiction between the provisions of Indian Standards Specification/recommendations of the IEC and this specification, the later shall prevail.

4.0 RATING NAME PLATE DETAILS AND OTHER INFORMATION 4.1 The Isolator shall be designed for the following rating and other technical particulars:-

SI. No

Particulars Motor/Manual Operated, Horizontally Mounted on pole, Vertical Break Type and suitable for outdoor istallation

Manually Operated, single or double break, upright mounting with the movement of blade(s) in a horizontal plane, with or without earthing switch and suitable for outdoor installation

1 Nominal system voltage (kV)

25KV 55 kV 66 kV 110 kV 132 kV 220 kV

2 Number of Phases 1 or 2 (as specified by purchaser) 1 or 2 (as specified by purchaser)

2 or 3 (as specified by purchaser)

3 Type of Isolators

Type-I (SP/DP)

Type-II–A

(SP/DP)

Type-II–B

(SP/DP)

Type-III (SP/DP)

4 Rated Current 1250 A 1600A 2000 A 3150A 2000 A 1250 A 1250 A 1250 A 1250 A

5 No of Poles 1 or 2 (as specified by purchaser) 2 2 or 3 (as specified in the particular specification of tender)

6 Highest System Voltage

52KV 52KV 52KV 52KV 72.5KV 72.5KV 123KV 145KV 245KV

7 Rated Frequency 50Hz ± 3%

8

Isolating Distance in Air (min)

500 mm (min.)

500 mm (min.)

500 mm (min.)

500 mm (min.)

1200 mm

1200 mm

1800 Mm

1800 mm

2800 mm

9 Distance between pole centers

NA/DP 1000 mm-DP

NA/DP 1500 mm-DP

NA/DP 1500 mm-DP

NA/DP 1500- mm-DP

2000 mm

2000 mm

3000 mm

3000 mm

4500 mm

10

Rated one minute Wet power frequency withstand voltage

(i) To earth and between poles

95KV (rms)

95KV (rms)

95KV (rms)

95KV (rms)

140 kV (rms)

140 kV (rms)

230kV (rms)

275kV (rms)

460kV (rms)

(ii) Across isolating distance

110 KV (rms)

110 KV (rms)

110 KV (rms)

110 KV (rms)

160 kV (rms)

160 kV (rms)

265 kv (rms)

315 kV (rms)

530 kV (rms)

11

Rated Lightning impulse (1.2/50 micro- second) withstand voltage

(i) To earth and between poles

250 KV (peak)

250 KV (peak)

250 KV (peak)

250 KV (peak)

325kV (Peak)

325kV (Peak)

550 kV (Peak)

650kVp 1050 kV (Peak)

(ii) Across isolating distance

290 KV (Peak)

290 KV (Peak)

290 KV (Peak)

290 KV (Peak)

375kV (Peak)

375kV (Peak)

630 kV (Peak)

750 kV (Peak)

1200kV (Peak)

12 Rated short time with stand current. for Three second (Both for main & earthing switch)

20 KA (rms)

20 KA (rms)

40 KA (rms)

50 KA (rms)

31.5kA (rms)

31.5kA (rms)

31.5kA (rms)

31.5kA (rms)

31.5kA (rms)

13 Rated peak withstand current (both for main and earthing Switch)

50 KA 50 KA 100 KA 125 KA 80 KA 80 KA 80 KA 80 KA 80 KA

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14 Temperature Rise The temperature of any parts of an isolator shall not exceed the maximum temperature rise given below under the conditions specified in the test clauses- 7.5

S. No

Nature of Parts Temp. in

0 C

Temperature rise at an ambient temperature not exceeding 40

0C

I Copper contacts in air a) Bare copper or

tinned Al alloy b) Silver faced

copper, copper alloy or Al alloy

75

105

35

65

Ii Terminals of isolators to be connected to external conductors by screws or bolts

a) Bare b) Silver- faced

90 105

50 65

iii Metal parts acting as springs

The temperature shall not reach a value where the elasticity of the materials is impaired. For pure copper, this implies a temperature limit of 75

0C

Note:- When applying the temperature rise of 65 0C, care should be taken to ensure that no damage is caused to the surrounding insulating material.

The quality of silver facing shall be such that a layer of silver remains at the points of contact after the mechanical endurance test. Otherwise, the contacts shall be regarded as bare.

The values of temperature and temperature rise are valid whether or not the conductor connected to the terminals is silver faced.

15 Operating Mechanism

The motorized Isolators in station area whose control is with station master should be Operated by 230 V, ac 50 Hz, Single Phase, Motor The motorized isolators provided within TSS and near SP/SSP which are controlled from RCC, should work with 110 V DC supply already available at TSS/SP/SSP.

16 Any other particular The isolator shall be capable of breaking capacitive current of bus bars, bushings, very short lengths of overhead lines, cables and no-load current of the transformer. Such currents are not likely to exceed 6 Amps.

4.2 The earthing switch shall be designed for the following rating and other technical particulars:-

SI. No

Particulars Motor/Manual Operated, Horizontally Mounted on pole, Vertical Break Type and suitable for outdoor

Manually Operated, single or double break, upright mounting with the movement of blade(s) in a horizontal plane, with or without earthing switch and suitable for outdoor installation

1 Nominal system voltage (kV)

25KV 55 kV 66 kV 110 kV 132 kV 220 kV

2 No of Poles 1 or 2 (as specified by purchaser) 2 2 or 3 (as specified in the particular specification of tender)

3 Highest System Voltage

52KV 52KV 52KV 52KV 72.5KV 72.5KV 123KV 145KV 245KV

4 Rated Frequency 50Hz ± 3%

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5 Rated short time with stand current. for Three second (Both for main & earthing switch)

20 KA (rms)

20 KA (rms)

40 KA (rms)

50 KA (rms)

31.5kA (rms)

31.5kA (rms)

31.5kA (rms)

31.5kA (rms)

31.5kA (rms)

6 Rated peak withstand current (both for main and earthing Switch)

50 KA 50 KA 100 KA 125 KA 80 KA 80 KA 80 KA 80 KA 80 KA

Note: The BIL shall be change as per IEC-60071 & IEC-62271-1, for altitude above 1000 meter and

upto 2500 meter.

5.0 DESIGN AND CONSTRUCTIONAL FEATURES

i. The isolator shall be robust in construction and so engineered as to ensure smooth operation at all times. The isolator, single/double/triple pole shall be supplied fully assembled on a suitable rigid frame. For double/triple pole isolators, the cross channels for mounting, shall also form part of supply.

i. All poles of the isolator shall operate simultaneously. Provision shall be made for adjustments, if required, for the proper alignment of the pole after mounting. All movable joints shall be provided with brass bushes/ bearings, which shall be entirely maintenance free.

ii. The blades of the isolator shall be of electrolytic high conductivity copper with the ends silver-plated (min. thickness 10 microns) and of adequate strength and cross section to IS: 191 – 2007 to withstand thermal and bending stresses particularly under short circuit fault conditions. Flexible braided copper, where used, shall have corrosion resistant coating such as tinning or silvering. The connection between the flexible braid and rotating and fixed parts shall be by means of not less than two bolts to prevent any tendency of rotation.

iii. For reasons of safety, the isolator should be so designed that no dangerous leakage current can pass from the terminals of one side to any of the terminals of the other side.

iv. The frame (isolator mounting channel) of each isolator shall be provided with an earthing terminal for connecting to an earthing conductor having clamping screws, suitable for earth fault conditions. The diameter of the clamping screws shall be not less than 12 mm. The connecting point shall be marked with “Earth” ( ) symbol.

v. When installed, the isolator shall be able to bear on terminals the total forces (including wind load and electrodynamics forces on the attached conductors) related to the application and rating without impairing their reliability or current carrying capacity.

vi. The isolator shall be constructed so as to permit it being locked both in the open as well as closed positions. It shall not be possible to lock the isolator in any intermediate position.

vii. The fixed contacts of isolator shall be made out of copper (extruded, rolled or drawn). They shall be silver-plated (min. thickness 10 microns). The contacts shall be spring- loaded. Only non-ferrous or stainless steel components shall be used in the contact assembly.

viii. The springs used in the contact assembly of the isolator shall be of phosphor bronze conforming to IS: 7608-1987 (reaffirmed 2016). To avoid current passing through the springs, nylon strip of suitable size shall be provided for insulation. The characteristics of the springs shall conform to IS: 7906 (Pt. II) - 1975 (reaffirmed 2019) and their mechanical properties shall not be affected in any manner on account of rise in temperature during operation.

ix. Bolts, nuts locknuts and other fasteners of 12 mm dia and less shall be of stainless steel. Fasteners of higher size may be made of hot dip galvanized steel. Spring washers, wherever used shall be of phosphor bronze. All fasteners shall be procured from approved manufacturers, a list of which may

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be obtained from Central Organization for Railway Electrification, Allahabad. The fasteners shall confirm to RDSO specification No. ETI/OHE/18.

x. The Operating pipe shall not have any joint and shall be supplied with four guides unless otherwise specified in the purchase order. The operating pipe shall be obtained only from approve manufacturers, a list of which may be obtained from CORE/ ALD.

xi. All malleable cast iron parts shall be of black heart malleable cast iron grade BM- 340. All ferrous parts shall be hot dip galvanized in accordance with specification No. ETI/OHE/13(4/84).The isolator shall be provided with a terminal pad at each end. The terminal pad shall have holes for being connected to a terminal connector.

5.1 Main contacts

i. The isolator shall have heavy-duty self-aligning and high pressure contacts of modern design. ii. The contact of the isolator shall be in the form of reverse loop so that during passage of short circuit

current they exert additional pressure on the moving contacts. iii. The blade of the isolator shall be of

a. Rotating type at its longitudinal axis by the turn and twist mechanism provided in the moving contact assembly in case of 66/110/132/220 kV isolator.

b. Vertical Break Type in case of 25 kV/55kV isolator iv. The moving and fixed contact assemblies shall be so designed as to ensure –

a. Electrodynamic forces withstandability during short circuit without any risk of dislodging of moving contact from the fixed contact.

b. Thermal withstandability during short circuits. c. Constant contact pressure even when the live parts of the insulator stacks are subjected to

tensile stress due to linear expansion of connected bus-bar conductor, either because of temperature variation or strong winds.

d. Wiping and self-cleaning action during closing and opening and e. Self-aligning ensuring smooth closing of the isolator.

5.2 Earthing Switch

i. The earthing switch shall be manually/motorized operated as the case may be. ii. The moving contact shall be made of electrolytic high-conductivity copper of adequate strength to

withstand all thermal and bending stresses at the time of short circuits. iii. The fixed contacts shall be identical to the main isolator fixed contacts except for silver plating iv. The earthing of the moving contact shall be affected by flexible copper braids of adequate cross-

section to safely carry the short circuit current. v. The earthing switch for all poles of the isolator shall be mounted on the same shaft and operated by

a single and common operating handle, which shall be distinct and separate from that used for operating the isolator.

vi. The moving contacts of the earthing switch shall close home simultaneously in the fixed contacts. vii. Suitable arrangement shall be provided in the operating mechanism of the earthing switch, so that

while opening the moving contact it does not come to rest with a jerk.

5.3 Operating mechanism

i. The isolator and earth switch shall be suitable for being conveniently operated manually from the ground level without any strain. The design shall permit the length of operating rod to be so adjusted that, with the isolator mounted in working position, the rotating shaft of the operating mechanism on which the operating handle would be connected is at a height of 1.1 meter from

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the ground level.

ii. At Traction Sub-Station, the isolator and the earthing switch (wherever provided) shall be mounted rigidly on the support structure. The height of base of the rigid frame shall be 2500 mm (in case of 25kV or 2x25kV isolator) and the height of the support structure from the ground level shall be 3000 mm (for72.5kV & above isolator).

iii. At SP/SSP or any other location in OHE, the height of base of the rigid frame would vary,

depending on the type of mast/ or structure on which the isolator is mounted. The heights for typical masts/ structures are given below:

Location Height of isolator mounting channel from ground level in mm

SP DP

RSJ/BFB mast 8310 8160

RSJ with super mast 9425 9275

R Portal 9535 9385

N Portal 9485 9335

O Portal 9585 9435

Two track cantilever 9560 9410

SS, SSP, SP, FP 3262 ------

5425 5525

(When bus bar height is 5968mm)

iv. The isolator shall be supplied with operating pipe in exact length for the particular mast/

structure, the length being obtained from the purchaser for each type of mast/ structure. v. Operating mechanism shall be provided with a sealed type reduction gear unit so as to facilitate

easy operation and maintenance of the isolator. vi. Suitable ‘OFF’ and ‘ON’ plates shall be provided on the operating handle to indicate when the

isolator/ earth switch is open and closed respectively. vii. The operating mechanism shall be designed in such a way that, with minimum modification, the

isolator can be converted from manual to motor operated. viii. The operating mechanism shall be such that it is possible to fasten the base to which the

‘Operating handle’ is attached, to either of the two mutually perpendicular vertical faces of the supporting structure on which the isolator is mounted.

ix. Two numbers each of earthing terminals shall be provided for earthing the operating mechanism boxes of the isolator and the earthing switch.

x. The operating handle of the isolator shall be so designed as to work in the vertical plane. The isolator shall close when the handle is moved upwards. The free end of moving contact shall be fully housed in the fixed contact when the handle is moved fully upward in which position the isolator can be locked.

xi. The design of the single pole isolator shall be such as to permit coupling of isolator for gang operation from a single operating handle. Not more than two single pole isolators are required to be coupled.

xii. Following are the additional requirement for Motorized Isolator - a. The motorized Isolators in station area whose control is with station master should be

Operated by 230 V, ac 50 Hz, Single Phase, Motor The motorized isolators provided within TSS and near SP/SSP which are controlled from RCC, should work with 110 V DC supply already available at TSS/SP/SSP. The voltage at the battery terminal may vary between 110% and 85% of the normal value.

b. The Isolator shall be able to operate manually in case of failure of motor circuit.

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c. The motor drive unit shall be installed in a weather and corrosion proof, adequately ventilated cubicle made of sheet steel not less than 2 mm thick with adequate stiffeners to prevent deformation during transit and handling. The cubicle shall have a sloping roof. To prevent condensation of moisture in the cubicle, metal clad space heater, controlled by an associated thermostat and switch, shall be provided.

d. The top of the cubicle shall be at a height of about 1.5 m from the rail level. The cubicle shall be so positioned that the hinge of the operating handle - for manual operation - is at a height of about 1.1 m from the rail level.

e. The isolator and its control circuit shall be designed for operation from the remote control center (RCC) by the traction power controller (TPC) as well as from the isolator cubicle. Local/remote spring-loaded switch as well as necessary terminations for tele-signals and tele-commands from and to the isolator- for operation from the RCC- shall therefore be provided in the isolator cubicle. The isolator cubicle shall be provided with motor protection relays.

f. In case power supply goes off, once the opening command has been initiated, Station Master/ Controller shall ensure that Motorized Isolator is actually opened and Open indication has come before issuing ‘Permit to Work’. The same instruction shall also be incorporated by manufacturer in their Operating manual.

g. Control Box -: There should be two separate Control box, One for Local Operation and other for Remote Operation.

1. Control box for Local Operation should contain following things-

i. Selector switch for Local/Remote. ii. Open/Close indicator. Green indicator for open and Red indicator for Close

condition. (All indicator should be of LED type) iii. Push button for Open. iv. Push button for Close

2. Control Box for Remote Operation should contain following things i. Open/Close indicator. Green indicator for open and Red indicator for Close

condition. (All indicator should be of LED type) ii. Push button for Open.

iii. Push button for Close

5.4 Terminal pad and terminal connectors

i. The isolator shall be provided with hard-drawn, extruded or rolled electrolytic copper terminal pad on either end to be connected to the terminal connectors.

ii. The terminal connectors shall be of bimetallic type to prevent electrolytic corrosion.

5.5 Steel structure

i. The support and framework shall be designed for a wind pressure of 200 kgf/m2 acting on 150 % of the projected area in addition to all other loads. During the opening and operations of the isolator there shall be no shock. There shall also not be a backlash tending to open the isolator after closing, due to the jerk, if any.

ii. The mounting arrangement and the operating mechanism shall be such that with the isolators mounted in the working position, the hinge pin of the operating handle is at a height of 1.1m from ground level.

5.6 Insulators

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The support and operating rod insulators shall be of solid core/composite type in accordance with the latest specification of RDSO viz No. ETI/OHE/15 (9/91) with A&C Slip No.1 to 6 or composite type as per RDSO Spec.No.TI/SPC/OHE/INSCOM/0991 and shall be procured, if included in the order, only from the approved manufacturers as per drawings approved by RDSO.

5.7 LOCKING:

i. A bolt type integral lock and /or interlock, as specified by the purchaser, of approved type shall be fitted on the isolator to enable the operating handle of the isolator to be locked effectively in the open as well as in the close position. It shall not be possible to withdraw the key from the integral lock except when the isolator is locked either in the open or in the closed position.

ii. The operating mechanism shall be so designed as to permit padlocking, in addition to the integral lock and or interlock, for locking the operating handle of the isolator both in the open as well as in the closed positions.

iii. The design of operating mechanism shall permit its operation in a predetermined sequence related to the operation of other switchgear with the help of suitable interlocks.

iv. The internal mechanism of integral lock and inter lock shall be of stainless steel or non-ferrous material. It shall be of robust construction. The outer housing of the interlock and integral lock shall be chrome plated steel and the construction shall be such that it is not prone to theft. The integral lock and interlock shall be obtained only from the approved manufacturers. Electrical/mechanical interlocking shall be provided for manual/motorized operation.

v. Each lock shall be supplied with two keys. Key/lock number shall be inscribed on the keys /locks.

5.8 EARTH CONTACT ASSEMBLY: The design of the isolator shall be such that it is possible to incorporate an additional pair of contacts so as to effectively earth the fixed contact of the isolator in open position even at a later date. The design of the isolator frame shall permit the provision of the earth contact assembly without calling for modification to the frame itself. Two holes of 15.5 + 0.5 mm dia shall be provided on the mounting channel for connecting the earthing terminals. The earth contact assembly shall be rated for the short time current specified in clause 4.1 (12) & 4.2 (5).

5.9 ARCING HORN:

The single pole isolator shall be provided with arcing horns which shall be of bright steel to Gr. 20-C-8 of IS: 1570 (Pt. II) - 1979 (reaffirmed 2016). The arcing horns shall make contact before the main contacts close and break contact after the main contacts break.

6.0 TESTS:

6.1 Type tests

Only after all the designs and drawings have been approved and clearance given by RDSO/Chief Electrical Engineer to this effect, the manufacturer shall take up the manufacture of the prototype. It is to be clearly understood that any changes to be done in the prototype as required by RDSO/Chief Electrical Engineer shall be done expeditiously.

Before giving the call to RDSO/Chief Electrical Engineer for inspection and testing of the

prototype, the manufacturer shall submit a detailed test schedule prototype, the manufacturer shall submit a detailed test schedule consisting of schematic circuit diagram for each of the test and the nature of the test, venue and duration of each test and the total number of the days required to complete the test at one stretch. Once the schedule is approved, the test shall

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invariably be done accordingly. However, during the process of type testing or even later, RDSO/ Chief Electrical Engineer’s representative reserves the right to conduct any additional test(s) beside those specified herein, on 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/Chief Electrical Engineer as the case may be, whose decision shall be final and binding.

The following tests shall be carried out on the prototype unit of the isolator and earthing switch at the works of the manufacturer/ sub- contractor or at a reputed testing laboratory, in the presence of RDSO/Chief Electrical Engineer’s representative(s) in accordance with the relevant governing specification and/or as modified or amplified hereunder against each test:

i. Visual examination of isolator and its parts.

ii. Dimensional verification of parts iii. Assembly and interchangeability iv. Measurement of resistance of main circuit and /earth circuit (before and after

mechanical Endurance test) v. Temperature rise test (before and after mechanical endurance test)

vi. Mechanical endurance test vii. Short time rated current test.

viii. One minute wet power frequency test across the isolating distance and to Earth. ix. Impulse voltage withstand test across isolating distance and to earth x. Galvanization test

xi. Chemical analysis of materials – copper contacts, springs, fasteners and bushes xii. Physical tests on springs and fasteners and copper strips.

xiii. 10 closing and 10 opening operations will be carried out by giving the supply at highest voltage as well as at lowest voltage as mentioned under Para no.. 5.3-Xii-a

6.2 Acceptance tests

6.2.1 For the purpose of acceptance, isolators shall be offered for inspection in lots containing

components for not more than 50 assemblies of same type of isolators. The isolators offered for inspection shall first be routine tested by the manufacturer and defective components removed.

6.2.2 The visual examination and measurement of resistance shall be done on all the isolators

offered for inspection .The defective ones shall be either attended to or removed before tests are conducted.

6.2.3 The following shall comprise the acceptance test:

I. Visual examination (on every item of the lot) II. Dimensional verification of parts (on 10% sample of the lot, minimum one Number)

III. Assembly and interchangeability (of minimum 3) IV. Galvanization test (one sample of each item) V. Measurement of resistance (all samples)

6.2.4 The inspector may, at his discretion, conduct any or all of the tests for a particular lot. The

manufacturer shall arrange for the test. 6.2.5 Acceptance Criteria

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I. If during dimensional verification of parts assembly and interchangeability, any component fails

to meet the requirement of this specification, twice the number of the same shall be taken and the tests repeated. If the component(s) fail to meet the requirement again, the lot shall be rejected. The manufacturer may sort out the defective pieces and offer the lot once again, should there be any failure in the lot offered once again, the lot shall be rejected totally.

II. If the sample fails to meet the requirements, twice the number of samples for same

components/ assembly shall be drawn and subjected to the same test. If the sample fails in the re-test, the lot of particular component will be rejected. The manufacturer may reassemble the isolators using the new components and offer once again for inspection.

6.3 Routine tests.

The manufacturer shall carry out the following as routine tests: a. Visual examination. b. Dimensional verification of parts. c. Assembly and interchangeability. d. Power frequency voltage dry withstand tests (on the Isolator only) for72.5kV & above. e. Measurement of contact resistance for 72.5kV & above.

The manufacturer shall offer record of the routine tests and acceptance tests carried out by him to ensure quality of raw materials, to the inspector. Unless these are satisfactory, no acceptance test shall be carried out, Mention of routine tests and acceptance tests carried out by the manufacturer shall be made in the test report and salient extracts reproduced.

7 TEST METHODS

7.1 Visual examination

All components shall be visually examined to check that they are properly manufactured, do not have sharp edges and corners, the tubes are not crooked or bent and galvanization of ferrous components is free from visible defects mentioned in Appendix ‘A’ of RDSO specification No. ETI/OHE/13 or latest version. The finish of stainless steel fasteners and pins shall be smooth and bright.

7.2 Dimension verification

The components of the isolators, particularly –moving contact blade, the spring of the fixed contact, the housing for fixing contact jaws on the post insulators, the fixed and moving contact jaws, the operating shaft for the operating pipe and the contacts shall be checked with respect to the approved drawings. The components shall be in accordance with the approved drawings.

7.3 Assembly and interchangeability

7.3.1 The isolator shall be assembled, using the components picked up at random from different lots.

No adjustments shall be required in any assembly the isolator shall function smoothly without any adjustments.

7.3.2 The components such as the housing for the fixed and moving contacts, the housing for the

earth contact assembly shall then be interchanged to ensure to ensure that the components are fully interchangeable. Fixing of different components shall be without any difficulty and any special adjustment.

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7.3.3 The dimensions of the isolator assembly, particularly the following critical ones shall be verified.

I. Minimum clearance between moving blade and the jaw of the fixed Contact at free end

when the isolator is open. II. The clearance between the earth end of the operating rod insulator with both the live

terminals in closed as well as open positions. III. The travel of the moving blade with full travel of operating pipe. IV. The distance between the centers of all the holes of the isolator Assembly for fixing it on

the masts. V. When the isolator is in fully closed position, the moving contact shall go home fully into

the fixed contact and no portion shall Remain Projecting beyond the fixed contact on the upper side. The main contact shall not exert undue pressure on the stopper.

7.4 Measurement of the resistance of the main circuit/earth circuit.

i. This measurement is made for comparison between the isolator type tested for

temperature rise and all other isolator of the same type subjected to acceptance tests. ii. The direct current of any convenient value between 100 A and the rated normal current

shall be passed through the main circuit /earthing contact circuit as the case may be and the voltage drop between the two terminals of each pole of the isolator shall be measured to obtain the resistance at the ambient temperature. All values measured/obtained shall be recorded.

iii. The measurement of resistance shall be made before the temperature rise test. iv. The test shall also be conducted during acceptance test. The maximum value of resistance

shall not exceed 1.5 times the resistance obtained during type tests or (R x T)/t, whichever is lower. where –

R = Resistance obtained during type test. T = Permissible temperature rise (35 deg. C) t = Temperature rise obtained during type tests at the hottest spot.

v. For the purpose of the acceptance test, the measurement of resistance may be made by using micro-ohm meter calibrated to the satisfaction of the inspector.

7.5 Temperature rise test

i. The test for temperature rise of main circuit shall be made on a new isolator with clean contact pieces. The isolator shall be mounted approximately as under usual service conditions, including all normal covers of any part of the isolator, and shall be protected against undue heating or cooling.

ii. Temporary connections to the main circuit shall be such that no appreciable amount of heat is

conducted away from or conveyed to the isolator during the test. In case of doubt, the temperature rise of the terminals of the main circuit and at temporary connections at a distance of 1 m from the terminals shall be measured. The difference of temperature shall not exceed 50 C.

iii. The test shall be made with the rated normal current of the isolator (i.e. 1250A for isolators

for SSP and SP, 1600 A for isolators to be used at FP, 2000A for Isolators to be used at TSS/SP/SSP of 2x25kV New system and TSS and 3150 A for type III isolators) and at rated frequency (50Hz +/-3%).

iv. The duration of the test shall be made over a period of time sufficient for the temperature to

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reach a steady state i.e. when the variation of temperature does not exceed 1 deg. C per hour over three hours.

v. The temperature of the different parts shall be measured with thermometers, thermocouples

or other suitable means, placed at the hottest accessible spot. The following precautions shall be taken when measuring with thermocouples or thermometers:

a. Thermocouples or the bulbs of thermometers shall be protected against being cooled

from outside during the test. The protected surface area shall, however, be negligible when compared with the cooling surface area of the part under test.

b. Good heat conductivity between the bulb of the thermometers or the thermocouples and the surface of the part under test shall be insured.

c. Alcohol thermometers shall be used as they are accurate for such purposes.

vi. The time for the whole test may be shortened by preheating the circuit with a higher value of current.

vii. In case the temperature rise at any part of the isolator exceeds the values specified in Clause

4.0(14), the isolator shall be deemed to have failed in the test. 7.6 Mechanical Endurance Test

i. The mechanical endurance test shall be conducted in accordance with IS: 62271 but the number of operating cycles shall be 5000 instead of 1000 as specified their n. The condition of all parts shall be satisfactory after the test. On successful completion, the test shall be continued up to 10000 cycles to determine the weak spots.

ii. For this test, the isolator shall be complete with operating and locking mechanism etc.

7.7 Short time withstand current test

7.7.1 The test shall be conducted at the current value specified in Clause 4.0 (12) for 3 s. The ac

component of the test current shall be equal to the ac component of the rated short time withstand current of the isolator or earthing switch. The peak current shall not be less than the rated peak withstand current but shall not exceed it by more than 5% without the consent of the manufacturer.

7.7.2 The value of the test current and its duration shall be such that I1

2 .t1=I2.t Where –

I1= r.m.s. component of test current measured in accordance with IS: 62271 in A. I = r.m.s. component of specified short –time current in A t = Specified short time current duration in seconds (3 s) t1 = Duration of current in s.

Note: This test shall be conducted ‘at the work of the successful tenderer/manufacturer or at CPRI, ERDA or any other NABL accredited testing laboratory in the presence of the representative of the purchaser/DG(TI), RDSO, Lucknow’.

7.7.3 During the test to prove its capability of carrying the rated peak withstand current and the rated

short time withstand current, the isolator or earthing switch shall not show undue stress. After the test, the isolator or earthing switch shall not show any material deterioration and shall be

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capable of operating normally.

7.7.4 Visual inspection and no-load operation of the tested isolator or ear thing switch are usually sufficient to check these requirements.

7.7.5 The test may be considered completed successfully if the isolator can be operated manually

after tests. There should be no damage, which may affect its mechanical and electrical performance.

7.7.6 If after the test, there is any doubt about its current carrying capability; temperature rise test

shall be made before the isolator is reconditioned. The value of temperature rise shall not exceed the figure given in Clause 4.0(14).

7.8 Wet power frequency voltage withstand test

7.8.1 The isolator and earthing switch shall be subjected to wet power frequency voltage withstand

test in accordance with IS: 2071 (Pt. I & II). The test voltage shall be raised for each test condition to the rated withstand voltage, duly corrected for the ambient atmospheric conditions, specified in Cl. 4.0(10) and shall be maintained for 1 min. No disruptive discharge shall take place during the 1 min period.

7.8.2 The wet power frequency voltage withstand test shall be conducted in accordance with IS:

2071 (Pt. I). However, if the water of prescribed resistivity cannot be obtained, water of lower resistivity may be used, provided that the isolator passes the test. The actual value of resistivity of the water and the rate of precipitation (both horizontal and vertical components) shall be stated in the test report.

7.8.3 The test shall be conducted in following conditions:

I. Between isolator and earth: With the isolator in the closed position, the test voltage shall be

applied to one of the 25kV terminals, the support frame – work and the other pole connected together and earthed.

II. Across isolating distance: With the isolator in the open condition, the test voltage duly corrected for ambient conditions, shall be applied at the moving blade(s)and the other two terminals shall be connected to the earth of the testing transformer. The whole isolator shall be adequately insulated from the ground to prevent possibility of direct flashover

Note: If the order is for both single pole and double pole (25 kV) isolators, these tests

would be conducted on a double pole isolator with earthing switch.

7.9 Lightning impulse voltage tests

7.9.1 If the order is for both single pole and double pole isolators, this test shall be conducted on a double pole isolator with earth contact assembly. Isolator and earthing switch shall be subjected to dry lightning impulse voltage test, with both positive and negative polarities using standard 1.2/50 micro- second lightning impulse according to IS: 2071(Pt. I).

7.9.2 Impulse voltage test between isolator and earth

With the isolator in closed opposition and earthing switch open, 15 consecutive impulses of

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voltage as per S.No. 11 (i) of table at Para 4.0, duly corrected for the ambient atmospheric conditions, shall be applied between one terminal and the frame, the other pole being connected to the frame. The isolator shall be considered to have passed the test, if number of disruptive discharges to frame or to the adjacent pole does not exceed two.

7.9.3 Impulse voltage test across isolating distance

The isolator shall be in the open position. The frame – work shall be adequately insulated from earth so as to prevent any disruptive discharges direct to earth. Lightning impulses of voltage as per S.No. 11 (ii) of table at Para 4.0, duly corrected for ambient conditions shall be applied to the moving blade(s). The remaining two terminals shall be connected to the earth .The isolator shall be deemed to have passed the test if there is no disruptive discharge to the opposite terminals.

7.10 Galvanization test

7.10.1 In the type test, at least two samples of each type of component which has been galvanized

shall be tested for ensuring that the galvanizing done conforms to specification no. ETI/OHE/13 in regard to adherence, uniformity and mass of zinc coating .The mass of zinc coating shall be not less than 610 g/m2.

7.10.2 In the acceptance test, one sample of each type of component which has been galvanized shall

be tested for ensuring that the galvanizing done conforms to specification no. ETI/OHE/13 in regard to adherence, uniformity and mass of zinc coating .The mass of zinc coating shall be not less than 610 g/m2.

7.11 Chemical analysis of materials

7.11.1 The chemical analysis of phosphor bronze springs, copper tube/strips of moving and fixed

contacts and stainless steel fasteners shall be conducted in accordance with IS: 7608,IS: 191 and RDSO specification No. ETI/OHE/18 as applicable. The material shall conform to the requirements specified.

7.11.2 Physical tests on fasteners shall be conducted in accordance with RDSO specification No.

ETI/OHE/18. The results shall be in accordance with the requirement laid down in the specification.

7.11.3 Physical tests on the springs and on copper strips/Tubes shall be conducted in accordance with

IS: 7906(Part II)-1985 and IS: 1897-1983 respectively.

8.0 BULK MANUFACTURING

8.1 Only after clear written approval of the results of the tests on the prototype is communicated by RDSO/Chief Electrical Engineer to the manufacturer, shall he take up bulk manufacture of the equipment –which shall be strictly with the same material and process of manufacture as adopted for the prototype .In no circumstances shall material other than those approved in the designs /drawings and/or the prototype be used for bulk manufacture on the plea that they had been obtained prior to the approval of the prototype.

8.2 If the prototype of an isolator or earthing switch conforming to this specification has been approved for earlier supplies to Indian Railways, testing of prototype again may be waived

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provided that no changes in the design or material(s) used or the process of manufacture have made

9.0 TECHNICAL DATA AND DRAWING

9.1 The tenderer shall furnish along with his offer the guaranteed performance data and other

technical particulars of the equipment in the proforma attached at Annexure ‘A’. 9.2 The information furnished in the Schedule of Guaranteed technical, performance, data and

other particulars shall be complete in all respects. If there is any entry like “shall be furnished later” or blanks are left against any item of Schedule of guaranteed particulars, the tender is not likely to be considered as such omissions cause delay in finalizing the tender.

9.3 Reports of the type tests, if conducted on the similar equipment shall also be furnished. 9.4 The tenderer shall specifically indicate in a statement attached with his offer, his compliance

with each clause and sub-clause of this specification. If any vague remark 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 attention to the clause(s) where the tenderer seeks deviation giving detailed remarks/justification thereof. If there are no deviations, a ‘NIL’ statement shall be furnished.

9.5 The tenderer shall furnish along with tender the following drawings: i. General arrangement drawings showing the outline dimensions of isolators and earthing

switch (whenever provided) ii. Drawings for support insulators along with salient technical particulars. iii. Drawings for operating mechanism of main isolator. iv. Drawing for operating mechanism of earthing switch. v. Any additional drawing, if required

9.6 The manufacturer shall be required to submit the following detailed dimensioned drawings

including drawings already mentioned in clause 9.5 above, as per Railways standards in size of 210 mm X 297 mm or in integral multiple thereof, for approval:

i Details of main contacts. ii Details of earthing contacts iii Interlocking arrangement iv Mounting details of isolator v Terminal connector vi Loads exerted by the isolator & earthing switch (wherever provided) for designing the

mounting structure. This drawing should furnish complete information regarding loads and their point of application.

vii Motor Details along with Circuit diagram (in case of motorized isolator)

9.7 After approval, six copies of approved drawings along with two sets of reproducible prints shall be supplied to each consignee. Two copies of drawings along with one set of reproducible prints shall be supplied to the Director General (TI), Research Designs and Standards Organization, Manak Nagar, Lucknow – 226 011.

10.0 INSTALLATION, TESTING AND COMMISSIONING

Twenty sets of installation, operation and maintenance instructions shall be supplied to the Purchaser with every order. Two copies of these instructions shall be supplied to the Director General (TI), RDSO, Lucknow. The information shall necessarily include

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i Procedure for erection and precautions to be taken during the process. The details of maintenance practices to be adopted under normal service conditions. The number of operations (or the period) after which different parts of isolators and/or earthing switch requires to be specifically attended to shall be indicated.

ii Procedure for overhauling of isolator and/or earthing switch. iii Procedure for replacement of parts, like contacts, subject to wear and tear and

deterioration during service. iv List of special tools required for maintenance /replacement. v List of special parts required for 5 years maintenance. vi Lubrication instructions including type of lubricants and quality to be used.

11.0 WARRANTY

11.1 The successful tenderer/ manufacturer shall warrant that all equipment shall be free from defects

and faults in design, material, workmanship and manufacture and of the highest grade consistent with the established and generally accepted standards for the equipment of the type ordered and in full conformity with the specifications and shall operate properly.

11.2 This warranty shall cover inspection of, payment for and acceptance of the equipment, but shall

expire 30 (Thirty) months after the delivery at ultimate destination, or 24(Twenty four) months from the date of commissioning and proving test of the equipment at ultimate destination in India, whichever period expires earlier, except in respect of complaints, defects and/or claims notified to the successful tenderer/manufacturer within 3(Three) months of the expiry of such date. Any approval or acceptance by the Purchaser of the equipment shall not in any way limit the successful tenderer/manufacturer’s liability.

11.3 The successful tenderer/manufacturer’s liability in respect of any complaint, defects and/or

claims shall not be limited to the furnishing and installation of replacement of parts free of any charge or the repair of defective parts only to the extent that such replacement or repairs are attributable to or arise from faulty workmanship or material or design in the manufacture of the goods, provided that the defects are brought to the notice of the successful tenderer/manufacturer within 3(Three) months of their being first discovered during the warranty period of 3(Three) months from the date of expiry of

warranty period, or at the option of the Purchaser, to the payment of the value, expenditure and damage as hereafter mentioned.

11.4 The successful tenderer/ manufacturer shall, if required, replace or repair the equipment of

such portion thereof as is rejected by the Purchaser free of cost at the ultimate destination or at the option of the Purchaser. Successful tenderer/manufacturer shall pay to the Purchaser value thereof at the contract price or in the absence of such price at a price decided by the Purchaser and such other expenditure and damages as may arise by reason of the breach of the conditions herein specified.

11.5 All replacement and repairs that the Purchaser shall call upon the successful

tenderer/manufacturer to deliver or perform under this warranty shall be delivered and performed by the successful tenderer/manufacturer, promptly and satisfactorily and in any case within 2(Two) months of the date of advice to this effect.

11.6 If the successful tenderer /manufacturer so desires, the parts that are removed may be taken

over by him or his representative for disposal as he deems fit at the time of replacement with

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good parts. No claim whatsoever shall lie on the Purchaser thereafter for the parts so removed.

11.7 The warranty herein contained shall not apply to any material which shall have been repaired or altered by the Purchaser or on his behalf in any way without the consent of the successful tenderer/manufacturer, so as to affect the strength, performance or reliability or to any defects to any part due to misuse, negligence or accident.

11.8 The decision of the Purchaser in regard to successful tenderer/manufacturer’s liability and the

amount, if any, payable under this warranty shall be final and conclusive.

12.0 TRAINING OF INDIAN RAILWAY’S ENGINEERS

The offer shall include the training of two engineers of the Indian Railways free of cost at the manufacturer’s works in India or abroad and at the maintenance depots/workshops on a Railway system or other public utility where circuit breakers of similar/identical design are in operation. The total duration of training for each engineer shall be 4 weeks of which approximately two weeks will be at manufacturer’s works and two weeks on a Railway system or other public utility. If the country of manufacturer is not India, the cost of travel to that country and back will be borne by the Indian Railways. Other details shall be settled at the time of finalizing the contract/Purchase Order.

11.0 PACKING AND DISPATCH

11.1 Various components of the isolator and /or earthing switch shall be securely packed in a proper

manner in a wooden crate/box. It shall be ensured that one crate/box does not contain components of more than one complete isolator and/or earthing switch A detailed packing list with weight and overall dimensions of the crate/box shall be furnished for each crate/box indicating the following:

Crate/Box No.

Description of each component in the crate /box

Gross weight in kg

Outside dimensions of crate /box

11.2 The weight of a crate /box containing all components shall be such that it can be manually

handled conveniently by more than two persons.

11.3 Necessary instructions for handling and storage shall also be furnished for use at the receiving end.

12.0 “All the provisions contained in RDSO’s ISO procedures laid down in Document No.-QD-D-7.1-11

dated 19.07.2016 (Titled ‘Vendor-changes in approved status’) and subsequent versions/amendments thereof, shall be binding and applicable on the successful vendor/ vendors in the contracts floted by Railways to maintain quality of products supplied to Railways”

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Annexure – A

SCHEDULE OF GUARANTED PERFORMNCE DATA TECHNICAL AND OTHER PARTICULARS FOR ISOLATOR.

Sl. No.

Description Unit of measurement

Values to be supplied by tenderer

1. Name of manufacturer.

2. Country of origin.

3. Standard specification on which performance is based.

4. Manufacturer’s type designation.

5. Rated voltage. kV

6. Rated current a) Isolator b) Earthing switch

A A

7. Rated frequency Hz.

8. Rated insulation level a) Rated one minute power frequency wet

withstand voltage. i. To earth and between poles ii. Across isolating distance.

b) Rated one minute power frequency dry withstand voltage. i. To earth and between poles ii. Across isolating distance.

c) Standard lightening impulse (1.2/50 micro second) withstand voltage) – i. To earth and between poles ii. Across isolating distance.

kV(rms) kV(rms) kV(rms) kV(rms) kVp kVp

9. Rated short time withstand current (for 3 second)

I. Isolator II. Earthing switch

kA(rms) kA(rms)

10. Dynamic peak withstand current: i. Isolator

ii. Earthing switch

kAp kAp

11. Maximum temperature rise over an ambient temperature of 40 deg.C, When carrying its rated current.

i. Copper contacts ii. Terminal pad of the isolator to be connected

to terminal connectors by both. iii. Metal parts acting as spring.

Deg.C. Deg.C. Deg.C.

12. Breaking capacity of capacitive current at rated voltage.

A

13. Number of poles. Number

14. Number of breaks per pole Number

15. Total length of break per pole mm

16. Centre distance between poles mm

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17. Minimum clearance in air

a. Between poles b. Between the live part and earth c. Between open contacts of the same pole. d. Isolating distance.

mm mm mm mm

18. Contact a) Material of the moving contact. b) Material of the fixed contact. c) Thickness of silver coating. d) Contact pressure.

Micron Kgf.

19. Operating mechanism. a. Type b. Height of the rotating shaft on which operating

handle shall be connected. c. Thickness of the sheet metal for operating

mechanism box. d. Gear ratio e. Number of turns the handle is to be rotated to

fully close the isolator from its fully open position.

f. Weight of the operating Mechanism

M m Number. Kg.

20. Insulator a. Name of manufacturer b. Type designation

c. Standard specification on which performance is based

d. Number of stack e. Weight of one insulator f. Number of insulators used

i. Support

ii. Rotating/operating g. Wet power frequency Withstand voltage (1 min.) h. Dry power frequency withstands voltage (1 min.) i. Visible discharge test voltage j. Impulse withstand voltage k. Wet power frequency flashover voltage l. Dry power frequency flashover voltage m. Puncture voltage n. Minimumfailing load in bending o. Minimum failing load in tension p. Minimum failing load in torsion q. Minimum failing load in compression r. Creepage distance in air s. Shed profile

IS Kg. KV (rms). KV (rms) kV kVp kV(rms) kV(rms) kV(rms) kN kN kN kN mm

21. Type of bearings used in the isolator.

22. Type and material of terminals.

23. Total weight i. Isolator ii. Earthing switch

Kg. Kg.

24. Number of closing and opening operations, the isolator can perform Without deterioration of its contacts.

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Additional Information :-

25. Is contact silver plated? Yes/no

26. Is pad locking arrangement for operating mechanism box provided?

Yes/no

27. Is mounting arrangement for interlock(s) on isolator operating mechanism provided?

Yes/no

28. Is integral lock on earth mechanism provided? Yes/no

29. Is mounting arrangement for interlock with associated isolator provided?

Yes/no

30. Is mechanical interlocking arrangement between earthing switch and the isolator provided?

Yes/no

31. Is material of fasteners of 12mm dia and below stainless steel?

Yes/no

32. Is material of fasteners above 12mm dia galvanized iron?

Yes/no

33. Is framework for the isolator is made out of steel galvanized?

Yes/no

34. Two number each of earthing studs provided for – a. Isolator frame b. Earthing switch frame c. Operating mechanism box d. Earthing symbols provided

Yes/no Yes/no Yes/no Yes/no

35. Is height of operating handle hinge pin in earthing switch from ground level 1.1m?

Yes/no

36. Is arrangement for keeping the operating handle for isolator in the operating mechanism box provided?

Yes/no

37. In case of Manual Isolator, can the isolator be converted to motor operated, with minor modification (if yes, sketch to be shown for modification required)

Yes/no

38. Is the operating mechanism box for the isolator is weather, dust and vermin proof?

Yes/no

39. Is Open/Close indicator provided for– a. Isolator b. Earthing switch

Yes/no Yes/no

40. Is padlocking provided for– a. Main rotating shaft of isolator b. Operating handle for earthing switch c. Lid cover for operating mechanism box

Yes/no Yes/no Yes/no

41 Are the bearings maintenance free Yes/no

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Annexure-B

The following information shall be furnished by the manufacturer /supplier:

Sl.No Description Values to be supplied by tenderer

1. Motor i. Description and type ii. Type designation iii)Make iv)Identification mark iii. Governing specification iv. Rating

a. Voltage b. Wattage c. Power frequency voltage with stand d. Class of insulation e. continuous current f. Mode of protection

2. Motor limit switch i. Description and type ii. Make iii. Type designation iv. Rating

a. Voltage b. Continuous current

4 MCB’s i. Description and type ii. Type designation iii. Make iv. Identification mark v. Governing specification vi. Rating:

a. Voltage b. continuous current c. Breaking and making current d. Electrical & Mechanical life (No. of operations)

5 Heater i. Description and type ii. Type designation iii. Make iv. Identification mark v. Rating:

a. Voltage b. Power

vi. Make and type designation of thermostat (if used)

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6 Interlock: i. Description and type ii. Type designation iii. Make iv. Identification mark v. Governing specification vi. Electrical rating of switch use

7 Power contactor i. Description and type ii. Type designation iii. Make iv. Identification mark v. Governing specification vi. Electrical rating of switch use

=============

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Annexure-C DEFINITIONS

1. Isolator It is a mechanical switching device which provides, in the open position, an isolating distance between the two contacts in accordance with specified requirements.

An isolator is capable of opening and closing a circuit when either negligible current is broken or made, or when no significant change in the voltage across the terminals at each pole of the disconnector (isolator) occurs. It is also capable of carrying currents under normal circuit conditions and carrying, for a specified time, currents under abnormal conditions such as those of short circuit.

2. Earthing switch

A mechanical switching device for earthing part of a circuit, capable of withstanding for a specified time currents under abnormal conditions such as those due to short circuit, but is not required to carry current under normal conditions of the circuit.

3. Main circuit

All the conducting parts of an isolator or earthing switch included in the circuit which is designed to close or open.

4. Pole

The portion of an isolator or earthing switch associated exclusively with one electrically separated conducting path of its main circuit and excluding those portions which provide means of mounting and operating all poles together.

5. Closed position

The position in which the predetermined continuity of the main circuit is secured.

6. Open position The position in which the predetermined clearances between open contacts in the main circuit is secured.

7. Position Indicating Device

A device, which indicates, at the location of the isolator or ear thing switch, whether the contacts of the main circuit are in open or closed position.

8. Interlocking Device

A device, which makes the operation of the isolator or ear thing switch dependent upon the position or operation of one or more other pieces of equipment.

9. Ambient Temperature

The temperature determined under prescribed conditions, of the air surrounding the complete switching device (e.g. for enclosed switching device, it is the air outside the enclosure).

10. Operation Cycle

A succession of operation from one position to another and back to the first position through all other operations, if any.

11. Dependent Manual Operation

An operation solely by means of directly applied manual energy, such that the speed and force of the operation are dependent upon the action of the operator.

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12. Rated value

A stated value of any one of the characteristic value that serve to define the working conditions for which the isolator or ear thing switch is designed and built.

13. Normal current

The current which the main circuit of the isolator is capable of carrying continuously under specified conditions of the use and behavior.

14. Short-time withstand current

The current that an isolator or the ear thing switch can carry in the closed position during a short specified time period under prescribed conditions of the use and behavior.

15. Permissible duration of short –circuit current

The time during which an isolator or ear thing switch in the closed position can carry a short – circuit current of specified value.

16. Permissible peak withstand current

The value of peak current that an isolator or ear thing switch can withstand in the closed position under prescribed conditions of use and behavior.

17. Rated 1 min power frequency withstand voltage

The r.m.s. value of sinusoidal alternating voltage at power frequency which the insulation of the isolator or ear thing switch withstands under specified test conditions.

18. Rated impulse withstand voltage

The peak value of the standard (1.2/50 s) impulse voltage wave which the insulation of the isolator or ear thing switch can withstand under specified test conditions.

19. Clearance

The distance between the conducting parts along a string stretched the shortest way between these conducting parts.

20. Clearance between poles

The clearance between any conducting parts of the adjacent poles.

21. Clearance to earth The clearance between any conducting parts and any parts which are earthed or intended to be earthed.

22. Clearance between open contacts (gap)

The total clearance between the contacts or any conducting parts thereto, of a pole of an isolator or ear thing switch in the open position.

23. Isolating distance

The clearance between open contacts or any conducting parts connected thereto in a pole of an isolator meeting safety requirements.

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Annexure-D-1

The general arrangement of the motorized isolator

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Annexure-D-2

The general arrangement of the manual isolator

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Annexure- E-1

The Schematic Interlocking Arrangement on 132 kV

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Annexure - E-2

The Schematic Interlocking Arrangement on 25 kV

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Annexure-F

The Bimetallic terminal connector

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Annexure-G

The Operating Arrangement of Bus/Line Isolator

GOVERNMENT OF INDIA MINISTRY OF RAILWAYS TECHNICAL … · 2020. 12. 24. · 4.1 The Isolator shall...

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