SPECIFICATIONS FOR DC SUPPLY UNIT () PART - I

Page 1 of 39

CONTENTS

1. SCOPE OF WORK ...... 3 2. INSTRUCTIONS TO BIDDERS: ...... 3 3. CRITERIA FOR ACCEPTANCE OF TECHNOCOMMERCIAL OFFER: ...... 5 4. PRE-QUALIFICATION CRITERIA FOR BIDDER ...... 5 5. SERVICES & EQUIPMENT TO BE EXCLUDED ...... 7 6. BATTERY LIMIT: ...... 7 7. GENERAL DESCRIPTION: ...... 8 8. STANDARDS: ...... 9 9. TECHNICAL REQUIREMENTS: ...... 11 10. OPERATIONAL REQUIREMENT: ...... 13 11. RECTIFIER: ...... 16 12. VCB PANEL: ...... 18 13. TRANSFORMER: ...... 20 14. DC FILTER ...... 21 15. HARMONIC FILTER: ...... 21 16. DC CURRENT MEASUREMENT: ...... 21 17. PANELS: ...... 22 18. BUS BAR SYSTEM ...... 24 19. DC ISOLATOR: ...... 26 20. PRINTED CIRCUIT BOARD ...... 26 21. FACTORY, ONSITE TESTS AND ACCEPTANCE CRITERIA: ...... 26 22. DRAWINGS AND DOCUMENT ...... 28 23. TRAINING : ...... 29 24. GUARANTEE: ...... 29 25. SPARES: ...... 29 26. DATA SHEET: ...... 30 27. CONTRADICTIONS / DEVIATIONS / EXCLUSION STATEMENT: ...... 34 28. SCHEDULE OF QUANTITY: ...... 35 29. PLACE OF DELIVERY: ...... 35 30. APPENDIX ...... 37

Page 2 of 39

1. SCOPE OF WORK

a) This sections describes the scope of design, manufacture, pre-dispatch inspection, testing, packing, delivery, installation & commissioning, training at project site (HWP (Baroda)), submission of technical documents and performance guarantee of one no. of 12 pulse (minimum), 900 KW (max. power rating, 25 V 36 KA) solid state variable DC power supply unit along with bus bar up to load terminal and specified spares. The power supply unit shall be as per the relevant Indian standards (IS) and of proven design by way of actual field operation without any deficiencies and the problem whatsoever. b) The scope of the bidder shall be deemed to include all such items which although are not specifically mentioned in the tender documents and/or in contractor’s proposal but are needed to make the system complete in all respects for its safe, reliable, efficient and trouble free operation and the same shall be furnished and erected unless otherwise specifically excluded as per Section ‘services & equipment to be excluded’. c) Bidders shall confirm total compliance to the specification without any deviation from the technical/ quality assurance requirements stipulated.

2. INSTRUCTIONS TO BIDDERS:

a) The Bidder shall submit a brief list of works executed by him in past for designing, manufacturing and installing similar equipment as per the standards and quality specified in this tender document as a proof of capability along with the tender. The work must involve experience in designing, manufacturing, testing and commissioning of large size (20 KA and above) DC power supply unit. b) The Bidder shall comply with each and every condition specified in the Tender Document. Bidder must be prepared to carry out the work within the time prescribed in the tender document. c) The bids will first be scrutinized to determine whether they are complete & meet the essential and important requirements, conditions etc. as prescribed in the tender

Page 3 of 39

document. The tender that does not meet the basic requirements, is liable to be treated as unresponsive and ignored. d) The shipment of the equipment shall not be effected before the written "Shipping Release" is obtained from purchaser or his authorized representative. e) Bidder should note that each and every person of contractor, who enters inside premises of site (HWP (Baroda)) must have a valid police verification certificate (PVC). f) Electricity required for erection, testing and commissioning at site will be made available at one place convenient to the Department, free of cost. All arrangements to distribute the same at the required places shall be done by the Supplier. g) The drawings / specifications prepared by the purchaser and included in this tender document are the property of the purchaser and have been made available to the bidder / supplier for the specific purpose of this tender. No exploitation or transfer of any information contained herein is permitted in the absence of an agreement with the purchaser and neither the document nor any such information shall be used for any purpose other than that for which the document is issued. h) No party shall disclose any information to any third party concerning the matter under this contract generally. In particular, any information identified as “Proprietary” in nature by the disclosing party shall be kept strictly confidential by the receiving party and shall not be disclosed to any third party without the prior written consent of the original disclosing party. This clause shall apply to the sub-suppliers, Supplier, adviser or the employees engaged by a party with equal force. i) Loading, unloading, shifting etc. at site of all equipment under the scope of vendor shall be done by vendor. Any material handling machinery like crane, hydra, fork lift etc. shall be in the scope of vendor. j) The bidder or his representatives may examine the site and surroundings before submission of the tender and they should familiarize regarding all the risk / problem associated with the work which may influence or affect his time & cost and accordingly he should take these factors while quoting. Our site can be inspected with prior intimation between 0900 Hrs. to 1500Hrs on 23/05/2018. The contact detail of the person for site visit is General Manager, HWP(Baroda) (0265-2242036).

Page 4 of 39

3. CRITERIA FOR ACCEPTANCE OF TECHNOCOMMERCIAL OFFER:

Following are the criteria for acceptance of techno-commercial offer of the bidder: a. Inspection, verification and checking of qualifying claims & documents of the bidders, submitted under prequalifying criteria of the tender, at bidder’s office as well as at customer’s site. Bidder should facilitate onsite verification and checking of performance of the rectifier system supplied and installed by them. b. Compliance to technical requirement including total scope of work of the tender. c. Compliance to commercial term of the tender. NOTE: Information submitted under contradictions / deviations / exclusion statement, if not found acceptable to purchaser, should be withdrawn by bidder, non-compliance to this could result into dis-qualification at technical evaluation stage.

4. PRE-QUALIFICATION CRITERIA FOR BIDDER

Bidders are required to compulsorily meet the following requirements to get qualified for consideration of the technical offer for execution of the job as specified in the scope of work. a) Only Rectifier (DC power supply unit) manufacturer or their authorized dealer can quote for this power supply unit .In case of authorized dealers, they should submit the latest authorization certificate from the respective OEM on behalf of whom they are quoting. b) Only those OEM or their authorized dealer who have supplied and commissioned of following rating in India in last seven years ending up to previous day of last date of submission of tender. I. One no. of rectifier of minimum current rating 20 KA and same is in operation. Bidder must enclose PO, completion certificate and performance certificates (from client as evidence for trouble free /

Page 5 of 39

smooth operation). If desired by purchaser the bidder shall also arrange necessary permission for site visit to ascertain the satisfactory working of the system. c) The bidder should submit the documentary evidence for fulfilling the requirement specified above (at sr. no. (b) I). In case of authorized dealer the documentary evidence of OEM will be considered. d) The Proposal, proposed to be submitted by groups of two or more firms, not meeting the following joint venture/ consortia requirements will be rejected: I. Mere association of parties to participate in this tender is not permitted. It may be noted that Consortium / JV should be in existence for last three years. II. Each partner of the joint venture/ consortia must submit the complete documentation required of a firm applying for individual qualification. However, all the correspondences will be channeled through the Lead Partner. III. One of the Consortium / JV partners who will be responsible on behalf of the Consortium shall be designated as the lead member. Necessary “Power of Attorney” and “Deed of Agreement” shall be executed in this regard. IV. Bidder / Lead partner should be registered in India. V. Bidder shall also indicate a description of the proposed participation and responsibility of each partner of the joint venture/ consortium. VI. Confirm that Proposal, as well as in case of award resulting contract, would be signed so as to be legally binding on all partners jointly and severally. VII. Submit joint venture/ consortia agreement, together with title Proposal, providing the joint and several liabilities on all partners in respect to the contract.

Page 6 of 39

Bidder failing to meet the above criteria fully or partly shall be disqualified. Offer shall be not considered for further evaluation.

5. SERVICES & EQUIPMENT TO BE EXCLUDED

a) Earthing riser / earthing pit shall be provided by purchaser up to battery limit, however further taping or extension of earthing connection within battery limit shall be in the scope of bidder. b) Main I/C cable (3.3 KV) up to terminal point of VCB panel shall be provided by purchaser, however glanding and termination of same is in the scope of bidder. c) Purchaser shall provide the control supply (110 V DC) for 3.3 KV VCB panel at one point; further distribution shall be in the scope of bidder. d) Utility like cooling water (DM water) / chilled water supply shall be made available up to battery limit, further taping and distribution using heat exchanger etc. shall be in the scope of bidder. However bidder has to specify the requirement of utility. e) Water sprinkler / fire detection / hydrant / deluge and firefighting system as required for transformer or electrical panel shall not be in the scope of vendor. However vendor has to specify the such requirement as per applicable standards. f) Building shall be provided by purchaser. However Base channel grouting for panel installation, anchoring / mounting of bus bar supports, foundation job for installation of transformer tank etc. shall be in the scope of vendor. 6. BATTERY LIMIT: Battery limit is indicated as below

Page 7 of 39

7. GENERAL DESCRIPTION:

a) Proposed rectifier unit (DC Power supply unit) shall be used for supply to the electrolytic cell of 36 KA. Initially (in phase –I) only one cell (known as test cell) will connect to DC power supply unit. After establishment of operation process parameter same DC power supply unit shall be used for three nos. of cell connected in series. It is envisaged that test cell operation shall remain for two years. During normal operation the voltage requirement of one cell is 6.5 V to 7.5 V for electrolysis, therefore cumulatively 22.5 Volt is required for combination of three cells connected in series and after considering bus voltage drop final supply voltage requirement shall be 24.75 V or say 25 Volt. The rating of DC power supply unit is defined on the basis of three cell in operation. However under this tender of scope bus bar length to be supplied should be sufficient for connection of one no. of cell only. b) Current / power regulated rectifier (one no.) each rated for 36KA and 25 V DC output shall consists of thyristor based rectifier bridges / hexa-phase rectifier (12 Pulse) and step down rectifier transformer, Harmonic filter, electronic controllers, metering, inter phase transformer, indications / alarms, protective and output isolating devices, DC current sensors, Auto / conventional transformer etc. complete in all respect to meet the specified performance and operational requirements. The DC power supply shall be work independently & continuously with all controls and logics. The current set shall be provided for

Page 8 of 39

setting the output current in the range of 0 A to 36 KA and voltage set from 3 V to 25 Volts DC. c) The DC supply power unit may fed the power to cell in any of the following combination : i. One cell : 8.5 V, 36 KA (inclusive DC bus volt drop) ii. Two cell in series 17 V, 36 KA (inclusive DC bus volt drop) iii. Three cell in series 25 V, 36 KA (inclusive DC bus volt drop) d) The output voltage and current shall also be transmitted to remote station for data acquisition purpose. The unit shall be suitable for overload capability of 100% continuous and 150 % for 1 minute after continuous load. Constant Voltage and constant current as per the selection mode shall be maintained. The ripple content at load terminal shall be ≤ 3% at rated conditions. 11th & 13th harmonic filter shall be provided at input side to reduce the harmonics and total harmonics (THDv) should not be more than 5%. e) DC Regulated power Supply (Rectifier) shall be used for pre electrolysis and electrolysis of molten salt mixture. Pre electrolysis of melted salt shall require 3 Volt / cell. DC power supply unit shall be capable to supply the power at required voltage for pre electrolysis. Rectifier shall be operated on constant voltage mode during pre-electrolysis and during electrolysis the rectifier shall be operated at constant voltage/current mode. f) It may please be noted that following technical documents (provisional) of the DC power supply unit shall be submitted by bidder along with tender document for purchaser’s evaluation: i. General arrangement of drawing along with BOQ. ii. Single Line Diagram (SLD) schematic of the power supply unit. iii. Design data sheet of the power supply unit along with transformer, VCB panel etc.

8. STANDARDS:

Page 9 of 39

The DC power supply system shall conform to the currently applicable standards and codes of practice and reports currently applicable statues, regulations and safety codes in the locality where the equipment will be installed. The equipment shall also conform to the latest editions of the codes and standards as listed below: as of date of Bidding. CODES AND STANDARDS SR. STANADARD NO. TITLE NO 1. IS-5 Colours for ready mixed paints and enamels 2. IS: 191 for electrical purposes 3. IS – 11171 Dry type transformer 4. IS: 513 Cold rolled low carbon steel sheets and strips 5. IS: 613 Copper rods and bars for electrical purposes 6. IS: 694 PVC insulated cables for working voltages upto and including 1100 V 7. IS: 1271 Thermal evaluation and classification of electrical insulation 8. IS: 1477 Code of practice for painting of ferrous metals 9. IS: 1554 PVC insulated electric cables: For working voltages upto & including 1100V 10. IS: 1897 Copper strip for electrical purposes 11. IS: 2026 (part 1 & 2) – Power transformers 12. IS: 2062 Steel for general structural purposes 13. IS: 2147 Degree of protection to enclosure 14. IS: 2629 Recommended practice for hot dip galvanizing on iron and steel 15. IS: 2705 Current transformers (CT) 16. IS: 3136 Semiconductor rectifier equipment 17. IS: 3156 Potential transformers (PT) 18. IS: 3231 Electrical relays for power system protection 19. IS: 5082 High conductivity aluminium alloy of grade WP 63401 for 20. IS: 5469 Code of practice for use of semiconductor junction devices 21. IS: 6005 Code of practice for epoxy painting of panels 22. IS: 6297 Transformers for electronic equipment: Pulse and switching transformers 23. IS: 6553 Environmental requirements for semiconductor devices and integrated circuits 24. IS: 6619 Safety code for semiconductor rectifier equipment 25. IS: 8084 Bus duct design

Page 10 of 39

26. IS: 8588 (part 1) Thermostatic bimetals, general requirements & methods of tests 27. IS: 8623 Procedure for short circuit withstand test of power panels 28. IS: 9000 Basic environmental testing procedures for electronic and electrical items 29. IS: 9224 (part 4) Specification for HRC : Requirement for fuse link for the protection of semiconductor devices 30. IS: 10118 Code of practice for selection, installation & maintenance of switchgear & control gear 31. IS: 13703 Low voltages fuses for voltages not exceeding 1000 V AC or 1500 V DC 32. IS: 13947 (part 2) & IEC: 947 (part II) – L.V. switchgear & control gear: General rules, etc. 33. IEC: 60146 Semiconductor converters: Semiconductor self commutated converters 34. IEC: 60326 Printed circuit boards 35. IEEE: 428 IEEE standard definitions and requirements for thyristorised AC power controllers 36. IEEE: 519 IEEE Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems 37. ASME: Section IX Welding and brazing qualifications 38. BS: 6493 (Section Recommendation for rectifier diodes 1.2) 39. BS: 6493 (Section Recommendation for use of thyristors 1.6) 40. Indian Electricity Rules 41. IS: 3043 Code of Practice for Earthing 42. IS: 10028 (part- Transformer installation II), 1981

9. TECHNICAL REQUIREMENTS:

AC Input System Particulars. Input supply 3.3 KV, 3 phase, 50 Hz. Steady State Variation Voltage As per IS 12360-1988 Frequency Combined Voltage and Frequency Max. input supply voltage unbalance 3%

Page 11 of 39

Input supply short circuit level 26.2 KA Type of input supply earthing Solidly earthed Power factor at the input Bidder shall ensure p.f shall not be less than 0.9 (lag). DC Output Particulars

Rated output voltage 8.5V / 17 V / 25 V (at different taps) Rated output current 36KA Stability of output current/power at set point ± 1%. Maximum ripple in voltage at rated condition Maximum 3% RMS at rated full load at load terminal. condition. Maximum ripple in current at rated condition Maximum 3% RMS at rated full load at load terminal. condition.

Response time 200 msec. or better Rectifier Thyristor based 12 pulse ( Either 2 X 6 pulse bridge rectifier or 2 x hexa phase rectifier) Rectifier step down transformer Oil immersed Type and mode of control Constant voltage/current during electrolysis And constant voltage during pre-electrolysis Duties / overload: 150% for 1 minute 110% for 5 minutes Cooling system: & forced cooling for 1. Forced water cooled for Thyristor cabinets. however bidder shall indicate the quantity & quality of water . required. 2. Transformer shall be ONAN.

The rectifier panel shall be able to work satisfactorily under the following site conditions:

Max. ambient temperature : 500 C Min. ambient temperature : 50 C Relative humidity : 90% Climate : Tropical Altitude (above MSL) : 39 mtr. Installation : Indoor

Page 12 of 39

10. OPERATIONAL REQUIREMENT:

The DC Rectifier unit should have minimum following features. Any other requirement, which are not considered below but required for smooth & safe operation of system to be provided by vendor and same, shall be finalized during detailed engineering

a) Controls on the front control panel :

I. Pushbutton for ON/OFF operation.

II. Emergency stop

III. Mode selection for Constant Voltage & Constant Current.

IV. Set V (Output) multi turn potentiometer lockable type dial.

V. Set Current (Output) multiturn potentiometer with lockable type dial.

VI. DC isolator ON / OFF

VII. Local & Remote Selection .

VIII. Push button for alarm acknowledgement, Reset, Lamp Test

b) Metering on front panel:

I. 3 ½ digit DPM for DC Output Voltage measurement (0-100V), with 0.1V resolution.

II. Five digits DPM for DC Output Current (0-99999A), with 1A resolution.

III. 3 ½ digit DPM for Input AC Voltage for three phases with SS / scroll button.

IV. 3 ½ digit DPM for Input Current, for three phases with SS/scroll button.

V. Heat Sink temperature.(Multi channel control cum indicator/identification of each heat sink LED based on PCB).

c) LED Indications / Annunciations on the front

I. Mains R, Y, B ON lamps.

II. Ready to start

III. DC ON lamp.

Page 13 of 39

IV. Constant Voltage Mode.

V. Constant Current Mode.

VI. Fuse failure for semiconductor fuses of Thyristor. (provision of LED for identify each fuse on fuse failure card)

VII. DC output overload tripped.

VIII. DC output isolator/ ON.

IX. (Heat sink) Over temperature (common identification from PCB).

X. DC over current (solid state)

XI. Temperature of rectifier transformer high.( common from multi channel scanner)

XII. Rectifier cooling circuit healthy.

XIII. Display panel for key parameters.

XIV. Panel Fan running

The common window annunciation panels (having test/accept/reset) shall be supplied as per relevant DIN standard. The DC Rectifier power supply unit will work independently with all controls and logics however the 4-20 mA / 0-10 V output signals through instrument cable to the PLC for the following will be provided for remote monitoring. d) Control from (Remote Control)

I. Output Voltage Indication (Analog)

II. Output Current Indication (Analog)

III. Selection of Mode Constant Current & Constant Voltage ( selector switch, Digital)

IV. Set point control DC Current & Voltage. (Analog)

V. ON / OFF Control of DC power supply unit. (Analog)

e) The local control panel shall have the following interlock and subsequent annunciation in the front of module:

I. Rectifier process trip:

Page 14 of 39

II. SCR bridge fuse failure

III. SCR high temperature alarm

IV. SCR very high temperature trip

V. SCR very high temperature trip

VI. SCR Heat sink cooling failed

VII. DC overload trip

VIII. Thyristor rectifier cubicle and local control panel door opened during operation, etc.

IX. Short circuit protection at DC output

X. Overload at AC side

XI. Rectifier transformer winding temperature very high

XII. Any additional recommended by OEM w.r.t. safety of system.

f) The interlock for the above parameters shall be designed in such a way that if one of the above interlock condition is not cleared, power supply unit shall not get ‘ON’, and if the power supply is already in operation, any incoming abnormal condition shall trip the power supply unit. The logic shall be designed for ‘fail safe mode’. The power supply unit shall get ‘ON’ only after resetting the interlock. On resetting if all the interlock parameters/conditions are clear, a ready lamp (amber in colour) shall glow indicating that the power supply unit can be put ‘ON’ (Ready to Start).

g) Common window audio annunciation shall be provided for the above-mentioned interlocking parameters in addition to the visual indication as per general engineering practice. Each parameter mentioned above assigned with one annunciation window. Each window of the annunciation panel shall have two nos of indicating lamps and a common buzzer for the entire annunciation panel. Annunciation panel shall have 20% spare blank window for future use.

Page 15 of 39

h) The power supply shall be designed to be put ‘ON’ and output current/power shall be controlled only from the selected position of the local/remote selector switch, whereas power supply ‘OFF’ shall be possible from both local as well as from remote, irrespective of the position of local/remote selector switch.

i) There shall be a provision of remote communication from computer through RS 232 port (or as specified during detailed engineering) with the availability of all the controls from remote.

11. RECTIFIER:

a) The rectifier circuit shall be thyristor based 12 pulse (minimum) and consists of any of the following configuration:

a. Two. Nos. of 3 phase bridge rectifier

b. Two Nos. Hexa Phase rectifier.

b) These devices shall be mounted on liberally designed, good quality heat sink for adequate heat dissipation.

c) Water cooled thyristor panel can be considered, however cooling water requirement (specification and quantity) to be specified by the vendor, Purchaser will provide the same at one point of the system.

d) In the case of number of devices are used in parallel, high speed current limiting fuse in series with each device shall be used which offers excellent protection. Each thyristor shall be protected by a current limiting fuse with adequate interrupting capacity and current limiting ability to isolate faulty thyristor without damage to the other thyristors. The individual thyristor rectifier shall be protected from the over voltage surges by connecting RC snubber across them.

e) The Thyristor paralleling shall be done appropriately for equal current distribution through parallel thyristor. N +1 thyristor to be used in each limb.

Page 16 of 39

f) Suitably rated semiconductor fuses shall be provided to protect the individual semiconductor device with fuse fail indication / alarm in combination with trip indicating fuse and micro switch.

g) The suitable protection shall be provided to protect individual Thyristor device against high voltage surges.

h) Multipoint scanner for monitoring of temperature for rectifier heat sink and at different location of rectifier panel to be provided with alarm and trip set point.

i) The rectifier should have soft start features so that rectifier can be turn ON/OFF directly irrespectively the position of the potentiometer.

j) The unit should be suitable to operate in Auto / manual mode. In manual mode the output voltage/current should be controlled by potentiometer. In auto mode the output voltage/current should be controlled by 4-20mA signal generated by Purchaser’s PLC /DCS panel.

k) The current sharing difference between two six pulse rectifier should not be more than 5%.

l) The unit should be suitable to operate from local control panel or from remote location. The rectifier can be put ON and the output current can be controlled as per selected position of local / remote switch. The rectifier can be put OFF from both local as well as remote location irrespective of the position of the L/R switch. Current to be controlled by potentiometer in manual mode and by PLC signal in auto mode.

m) Isolated analogue outputs, proportional for voltage and current to be provided for interfacing with Purchaser’s PLC system. Potential free contacts to be provided for remote ON / OFF / Trip indication.

n) One no. of control desk / plate / box having major selector , major indication lamps and displays to be provided in the control room for manual operation from control room. Selector switch and indication lamp to be provided shall be finalized during detailed engineering. However minimum requirement are listed below:

Page 17 of 39

a. Auto / Manual selector switch

b. Raise / lower operating push button

c. Rectifier On indication lamp

d. Auto / manual indication lamp

e. Voltage and current display

f. Emergency stop

g. Rectifier start / stop operating switch

o) All the bus bars shall be fabricated from electrolytic grade tinned copper.

p) The bolts and nuts used shall be of high quality non-corrosive zinc plated.

q) The arrangement to indicate thyristor failure shall be provided along with potential free annunciation contact.

r) Thyristor shall be provided with the following minimum protections:

I. Over voltage i.e. dv/dt for SCRs

II. Over current i.e. di/dt for SCRs

III. Under voltage

IV. Input short circuit

V. Output short circuit

VI. Over temperature

VII. Phase loss

VIII. Input & output surge suppression

12. VCB PANEL:

Page 18 of 39

a) The I/C VCB panel along with CT, PT ( draw able type), Control, indication, meter & relay shall be suitable for indoor Installations with vacuum as interrupting media incorporating separate interrupters of 630 A rating for each phase mounted on single frame to be provided. There shall be a common drive mechanism actuating for interrupters, which must work in synchronism. These breakers shall be provided with suitable local control while provision shall be made for remote control. b) The operating mechanism of the shall be motor wound spring charged type. It shall be electrically and mechanically trip free with anti-pumping device. All working parts in the mechanism shall be of corrosion resistant material. Self-lubricating, wearing resistant bearings shall be provided in the mechanism. c) The mechanism shall fully close the circuit breaker and sustain it in the closed position against the forces of the rated making current and shall fully open the circuit breaker without undue contact bounce at a speed commensurate with that shown by tests to be necessary to achieve the rated breaking capacity in accordance with IEC:56 or IS:13118. The mechanism shall be capable of being locked in either the open or closed position. The mechanism shall be capable of fully closing and opening again after the auto-reclose time interval specified as 0.3 second in this specification d) The entire circuit breaker with its operating mechanism shall be mounted on a horizontal draw out type trolley mounted inserted into a floor standing sheet steel enclosure suitable for withstanding electromagnetic/ electro-dynamic forces of both symmetrical and asymmetrical faults. It shall have plug-in off load type isolating main and auxiliary contacts with all necessary safety features, door limit switch etc. e) The vacuum circuit breaker panels shall be enclosed in sheet steel independent floor mounting cubicle made of minimum 2 mm thick CRCA Sheet for outer walls and 2 mm thick for partition/ inside walls, However gland plate or load bearing member shall be 3 mm CRCA sheet. VCB panel shall have separate chamber

Page 19 of 39

for incoming cable, outgoing cable & CTs, VCBs, Relay & control ckt, drawable PTs chamber etc. f) O/G cable from VCB to transformer / Auto transformer shall be in the scope of vendor. Laying of same along with accessories like & structural support, excavation of earth, Hume pipe etc. as per site requirement shall also in the scope of vendor. g) PVC rubber mat for all panels (VCB, Harmonic filter, rectifier panel, etc.) of suitable rating shall be in the scope of vendor.

13. TRANSFORMER:

a) Rectifier transformer, Auto / conventional transformer & inter phase transformer (IPT) shall be of oil filled out door type. It shall be designed for ONAN cooling. Common tank or separate tank design is left on the discretion of designer. However approval of purchaser is required. b) Primary voltage to the transformer is 3.3kV ± 10% 3 phase 3 wire. Suitable winding configuration for the purpose of 12 pulse rectifier to be used. c) Winding for all transformers shall be considered of copper only. d) An autotransformer with (minimum) three tapings to be considered at I/P for operation of rectifier at approximate O/P voltage 8.5V / 17 V / 25 V so that ripples can be minimized for each case of operation. e) Oil immersed transformer shall have class-A insulation and temperature rises are limited to corresponding to class-A insulation. f) The transformer shall be suitable for rectifier / thyristor duty and continuous operation g) It shall be complete with all accessories including pressure relief devices, winding temperature indicator (WTI), Oil temperature indicator (OTI) etc. The transformer oil tank shall be tested for leakage by applying a pressure of 0.3 kg/cm2 for 60 minutes as mentioned in the relevant standards. The supplier shall install the transformer by following appropriate procedures mentioned in the relevant standards.

Page 20 of 39

h) Rectifier transformer and auto transformer shall be installed outdoor. The foundation to be designed and its construction shall be in the scope of vendor. i) The transformer foundation shall be surrounded by a suitable soak pit as per provision of applicable standards. j) The transformer and accessories shall be designed to facilitate operations, inspection, maintenance and repairs. All apparatus shall also be designed to ensure satisfactory operation under such sudden variations of load and voltage as may be met with under working conditions on the system, including those due to short circuit. k) Minimum 15% over margin to be considered for sizing of the rectifier transformer after considering all losses and de-rating factor. Sizing calculation to be furnished during detailed engineering.

14. DC FILTER

The installation of DC filter and power factor improvement capacitor bank is left on the discretion of designer, However at rated condition (8.5 V / 17 V / 25 V, 36 KA) ripple at load terminal should not be go beyond 3 % RMS and power factor should not be lower than 0.9 at 100% load. In case if DC filter is considered then it should be rated for continuous rated current. The insulation should be class-H and the temperature rise to be limited to Class-F.

15. HARMONIC FILTER:

Suitable LC filter at I/C side to be considered to limit the THDv (5%) as per recommendation of IEEE 519.

16. DC CURRENT MEASUREMENT:

a) The DC current measuring device (clamp on construction) should be capable to measure the current. b) DC CTs are to be provided for individual bridges (for each six pulse).

Page 21 of 39

c) The system shall include hall-effect sensors ICs, metering unit, signal conditioning electronics etc. d) Accuracy: ± 0.25 % measurement accuracy (full scale) e) Construction: Clamp-on type f) Window size: Suitable to the output DC copper bus bars.

17. PANELS:

a) The rectifier power cubicle and the local control panel shall be of flush front metal enclosed sheet (CRCA) cubicle, indoor floor mounting, free standing type and shall be made out of minimum 2 mm thick CRCA sheets. Rectifier panel shall be IP 42 . The cubicle shall be provided with ventilation louvers on the doors rendered dust proof using fine brass/stainless steel wire mesh at suitable locations. All the components inside the cubicle shall be located in such a manner that the maintenance of any component does not interfere with other component. All power cubicle and control panel shall be provided with 25 mm × 6 mm copper strip throughout the length of the panel with two terminals at ends for grounding purposes. All the metallic, non-current carrying components of the panels shall be connected to the earth by suitable size of copper strip. A base channel of minimum 3 mm thick hot rolled sheet steel painted black shall be provided to prevent corrosion of sheet steel cubicles and to facilitate cleaning of the floors. All the structural steel material like plates, strips, sections, flats etc. to be used for the fabrication of the cubicles shall conform to IS: 2062. A standard good engineering practice shall be followed strictly during the execution of the sheet metal constructional work. b) All steel work shall undergo seven tanks process of degreasing, pickling in acid, cold rinsing, phosphate, and passivity and then sprayed with high corrosion resistant primer. The primer shall be baked in oven. The finishing treatment shall be application of synthetic enamel of approved shade and stove. Powder coating procedure shall be applied to obtain the final finish in accordance with IS: 1477. c) Neoprene rubber gasket shall be provided all around the perimeter of the removable covers, doors, gland plates, cutouts, etc

Page 22 of 39

d) Panel doors shall be provided with concealed type hinges, with lockable handles. Doors shall be provided with locking facility to prevent unauthorized opening of the door. Appropriate earthed metal barrier or insulated barrier shall be provided to ensure that the operator does not accidentally come in contact with the live parts on opening of doors. e) Florescent tube with switch fuse and 5 amps, three pin receptacle shall be provided. f) 100% standby fan to be provided on the panel. g) The panel shall have the hooks on the top for easy lifting of the power supply unit as a whole. h) The entire power supply unit shall be constructed in a manner such that it is very easy and comfortable to work, operate, maintain, etc. till its service life. i) The power supply unit shall be of completely factory wired, ready for connecting to the input. All cables used in panels shall be FRLS type. Control wiring shall be done by 1100 volts grade, armoured, PVC insulated single core stranded copper conductor wire of size 1.5 mm2 minimum. j) All the control circuits shall be properly wired with ferrule numbered at each terminal. The wiring shall be neatly bunched, adequately supported, properly routed and finally crimpled to allow for easy access and maintenance. The numbered ferrules at either end shall identify all the wires. The terminal block shall be clamp type with barrier terminals and shall be numbered. More than one wire shall not be terminated on either side of the terminal block. Whenever termination of more than one wire is required on the same point, they shall be terminated in adjacent terminal block with suitable shorting links. All the terminals required for remote operation shall be terminated to the Elmex type terminal blocks of adequate capacity and be located at suitable locations. All the spare contacts of relays, devices, etc. for our use shall be terminated into the terminal blocks. At least 20 % spare terminals shall be provided. All the inter panel wiring shall be taken through PVC sleeves with rubber grommets. Slotted type PVC channels shall be provided for laying the control wiring. The detailed scheme for interlocking with the process parameter and the remote control will be furnished to the successful bidders at the time of detailed engineering. The power supply unit shall be designed for the control cable entry from the bottom of the panel.

Page 23 of 39

18. BUS BAR SYSTEM

There shall be A.C. bus bar and D.C. bus bar system. Both shall be made up of copper. The A.C. bus bar runs from the secondary (LV) of the step down rectifier transformer to the thyristor rectifier cubicle. The D.C. bus bars run from the rectifier cubicle to the load electrolytic cell. Indicative available area for transformer, rectifier and its accessories is shown in appendix-I for reference; however bidder may also visit at site before submitting the bid for accessing the requirement of quantity of AC & DC bus system. The minimum requirements for bus duct are specified below: a) AC Bus duct system: I. LV AC bus duct of suitable size (110% of the rated current at AC side) to be provided for extension of power supply from transformer to rectifier panel. II. The 3mm thick extruded aluminum alloy enclosure (suitable bus duct) to be provided. III. Copper of Electrolytic Tough Pitch (ETP) grade as per IS:191- 1981 (IS 613- 2000) to be used as a bus bar material. IV. Suitable current density to be considered for bus bar sizing, however current density to be considered should not be more than 1.2 A / mm2. V. The bus bars shall be provided with the minimum clearances in air as per the applicable standards for a 500 volts system. VI. The bus bars shall be provided with heat shrinkable PVC sleeves or better. VII. The maximum permissible temperature rise (over ambient) of external surface of enclosure of bus bar shall be 25 deg C. VIII. The bus bar connections and bus bar supports shall have sufficient strength to withstand the thermal and mechanical stresses and electromagnetic forces during short circuit. IX. The bidder shall give details of bus bar sizing during detail engineering.

b) DC bus Bar system:

Page 24 of 39

I. The DC supply from rectifier to electrolytic cell to be extended through DC bus bar system. II. Copper of Electrolytic Tough Pitch (ETP) grade as per IS: 191- 1981(IS -613- 2000) to be used as a bus bar material. III. The bus bars shall be air cooled and adequately sized for the continuous current rating of 36 KA in various series & parallel connections, considering allowable temperature rise at the given ambient temperature with due consideration to different de-rating factors and they are made out of copper conforming to IS: 8084. The bus bars shall be provided with heat shrinkable PVC sleeves. IV. The maximum permissible temperature rise (over ambient) of external insulating surface of bus bar shall be 15 deg C. V. Suitable current density to be considered for bus bar sizing, however current density to be considered should not be more than 1.2 A / mm2. VI. The D.C. bus bars run from the rectifier cubicle to the electrolytic cell but elevation of termination may be at different heights. VII. Flexible copper bradding type connection can be used at termination point (Cathode & Anode) to prevent the load stresses at cathode and anode. Indicative termination arrangement at cathode and anode cell side is shown in appendix –II & III for reference. VIII. The bus bars shall be supported with non-hygroscopic glass fiber reinforced SMC supports/insulators and run inside the suitable duct arrangements, the structural support for duct arrangement (vertically from bottom or hanging from top for running of the bus bar at regular interval shall be provided by purchaser, and however quantity, dimension and design of structural support for duct arrangement shall be provided by vendor. Positive & Negative bus- bar shall be arranged separately. IX. The bus bars shall be provided with the minimum clearances in air as per the applicable standards for a 500 volts system.

Page 25 of 39

X. The bus bar connections and bus bar supports shall have sufficient strength to withstand the thermal and mechanical stresses and electromagnetic forces during short circuit. XI. The bidder shall give details of bus bar sizing during detail engineering.

19. DC ISOLATOR:

a) Main DC isolator / disconnector/ of minimum 110 % of rated current (36 KA) shall be considered. b) It shall be single pole type for isolation of positive and negative bus individually at O/P of the rectifier panel. c) The Isolator shall be motorized so that close and open operation shall be done from rectifier control panel also. d) Sufficient nos. of auxiliary contact is to be provided for indication and interlock. e) It is preferably that disconnector need no supporting frame and can be mounted self- supported directly into the bus bar system.

20. PRINTED CIRCUIT BOARD

a) The PCBs required for control of the unit will be segregated in the form of cards according to function/system and will have printed name for function of PCB on both sides. b) It is preferably PCBs shall be in modular detachable form using Jaw connectors for easy replacement and maintenance. c) PCB housing will be provided with suitable guides so that insertion of correct PCB in right manner is possible. d) The PCBs will be stacked properly within cubicles. e) Double sided PCBs (if any) of epoxy based, copper laminated type will be used with high quality soldering and will be suitably enamel coated for protection against moisture and dust to ensure longer life.

21. FACTORY, ONSITE TESTS AND ACCEPTANCE CRITERIA:

Page 26 of 39

a) Compliance to technical requirement including total scope of work of the tender. b) The manufacturer shall be responsible for satisfactorily working of complete integrated system and guaranteed performance c) The components used in the DC power supply units shall be of high quality and their manufacture and testing shall be done as per relevant standards, which are mentioned above. The action plan for quality surveillance is as follows. a. The bidder shall submit a detailed QA plan for approval. b. The purchaser or his authorized representative shall have at all reasonable times access to the supplier’s works to inspect and examine the materials and workmanship during manufacture. c. The supplier shall provide all reasonable inspection facilities such as necessary tools, instruments, equipment and qualified operators. d. The complete equipment shall be inspected / tested during various manufacturing stages and final stage at the supplier’s works in the presence of the representatives of the purchaser. The supplier shall provide test certificates for the semiconductor devices used in the rectifier and other brought out items. The supplier shall provide valid type test and routine test report of major brought out items like VCB, transformer, CT etc. Purchaser can also witness the routine test of major brought out items. Reputed make of brought out items to be used. All major brought out items are proven and have history of in service in India, bidder has to obtain prior approval for the same during detailed engineering. The supplier shall carry out the following tests under PDI (pre dispatch Inspection). It may also be noted that some tests specified below may be required to perform at full load condition, but due to load constraint at manufacturer works performing of test at full load is not possible in such cases, same can be performed at partial load (but not less than 1/3 of rated current), however such test has to be performed at site after its installation. I. Visual check and verification of BOQ. II. Dimensional checks III. No load Test / Open circuit Test IV. Short Circuit Test

Page 27 of 39

V. Insulation Resistance (IR) Test VI. High Voltage Test VII. Functional Tests VIII. Performance Tests, IX. Ripple measurement X. Heat run test of rectifier. XI. Simulation of faults, annunciation, alarm & indication. XII. Routine test on transformer XIII. Routine test on VCB Panel Tests to be carried out at site during erection and commissioning on DC supply unit are listed below :

I. Visual Inspection II. No load Test III. Insulation Test IV. HV Test V. On load performance test VI. Ripple measurement VII. Efficiency measurement VIII. Harmonic Content measurement IX. Functional test like: constant current / voltage operation, simulation of protection system, interlocking system, annunciation, alarm & indication system etc. It may possible performing of test at site on all the full load rating conditions (i.e. 8.5 V / 17 V / 25 V, 36 KA) is not possible in such cases, same can be performed at maximum possible load available at site.

22. DRAWINGS AND DOCUMENT

All the following drawings and documents shall be submitted for the approval. The fabrication of the unit shall start only after getting approval of drawings.

Page 28 of 39

a) Power circuit diagram. b) Control circuit diagram. c) Control & indicating instruments on front panel d) General arrangement drawings indicating dimensions, mounting, foundation and installation details e) Sizing section of transformer, thyristor, heat sink, fuse, fan size calculation, bus bar. f) Power factor & harmonic calculation g) Operation & Maintenance Manual h) General arrangement drawing i) Electrical control schematic diagram j) Schematic and wiring diagram k) Bill of material , incoming & outgoing cables details l) Test report/ certificates m) Card details containing card drawing with component details and PCB layout. n) List of spare parts and maintenance tools Three copies of above documents and drawings including operation, maintenance and installation manuals shall be supplied prior to the transportation of the equipment.

23. TRAINING : Bidder at no extra cost shall provide the training for at least two engineers, two supervisors & two technicians of purchaser on operation & maintenance aspects of new rectifier at manufacturing works. The duration, contents of training shall be subject to approval of purchaser.

24. GUARANTEE: The consignment should be guaranteed at site for trouble free performance for the period of 12 months from the date of commissioning or 18 months from the date of delivery whichever is earlier and free replacement of defective parts, if any, during the guarantee period.

25. SPARES: Following spares are to be supplied along with the equipment:

Sl. Description Minimum

Page 29 of 39

No. Quantity

A Thyristors and snubber circuit Minimum 10% of BOM

B Semi Conductor fuses of each rating used in Min.10% of each rating

C One set of Firing card (one no.), rectifier One each control card (one no.), power card (one no.), fuse failure card, Heat sink card.

D Indication lamp & HRC fuse Min.10% of each type

D Cooling fan of each type used in rectifier and 2 Nos of each control panel type

26. DATA SHEET: Following data sheet to be filled and submitted along with technical bid.

a) Guaranteed Technical particular

Sr. No. Particular To be filled by bidder

1. OEM

Rectifier

Transformer

2. Type of rectifier (nos. of pulse)

3. Hexa phase rectifier / bridge rectifier

4. O/P voltage rating (at all the three taps of auto transformer)

5. O/P current rating (at all the three taps of auto transformer)

6. O/P power rating (Max.)

Page 30 of 39

7. Ripple at rated load

a. 8.5 V, 36 KA

b. 17 V, 36 KA

c. 25 V, 36 KA

8. Power factor @ rated load

9. Weight of major equipment:

Auto transformer

Transformer

Rectifier panel

10. Efficiency @ rated load

a. 8.5 V, 36 KA

b. 17 V, 36 KA

c. 25 V, 36 KA

11. Current density considered for bus bar design

12. Material of construction of AC & DC bus bar

13. Type of control

14. Ingress Protection class (IP) of rectifier panel

15. Ambient Temperature Considered for design purpose

16. Type of Cooling of thyristor panel

17. Type of DCCT

18. VCB rating

19. Transformer rating

20. Attached SLD

Page 31 of 39

21. Design fault current considered

b) General Data sheet:

S.No. Description Bidders Response

PART-1 (GENERAL & COMMERCIAL)

1 Name & Address of the firm Office & Works

2 Bidder is OEM or authorized Dealer, If Dealer then attached certificate

3 Detail of joint venture (if proposed is placed through Joint Venture)

4 Whether bidder has ISO9001 & 14001 certification

5 Details of ownership and contact persons with Telephone/Telex/Fax No/e-mail.

6 Details of registration if a Document attached (Yes / No) registered firm

7 Date of inception of company

8 Submission of balance Document attached (YES / NO) sheet for the last five years

2016-2017

2015-2016

Page 32 of 39

2014-2015

2013-2014

2012-2013

Part – 2: TECHNICAL

9 List of similar work executed

10 Documentary Previous Client Proof for work work experience to be experience Work / Purchase Order Ref.: submitted (36 KA and above in Performance certificate attached service more (Yes / No): than one year Job Description (Size & Qty) (P.W.E), Attached Order Value in Lakhs relevant Status document 11 Past performance Attached details (Separate relevant sheet may be document attached)

12 Past performance Attached details with DAE relevant (Separate sheet document may be attached)

13 Whether the (Yes/ No) bidder is agreeing for complete tender technical specifications.

14 Confirm whether (Yes/ No) the manufacturer has proper test set up for testing as

Page 33 of 39

specified.

15 Do you agree to (Yes/ No) conduct all the tests as per the specifications?

27. CONTRADICTIONS / DEVIATIONS / EXCLUSION STATEMENT: a) In case of conflict between the clauses of this tender specification, these shall be specifically brought out by the contractor as deviation to tender in his offer. Otherwise specifications as decided by purchaser will be final.

Sr. Tender Page Tender Tender Clause Page Tender Remark No. Clause No requirement having No requirement Contradiction

b) Each bid shall be deemed to be in full compliance with every clause of the specification unless exceptions are clearly indicated as a part of bid. Contractor shall indicate the reasons for departure from the specification. Deviations taken from the specifications shall be indicated in the following format.

Sr. Tender Page Tender Offered Reason for Remark No. Clause No requirement Specification deviation

c) Each bid shall be deemed to be in full compliance with every clause of the specification unless exceptions are clearly indicated as a part of bid. Contractor shall indicate the reasons for exclusions from the scope. Exclusions taken from the scope shall be indicated in the following format.

Page 34 of 39

Sr. Tender Page Tender Reason for Exclusion Remark No. Clause No requirement exclusion

28. SCHEDULE OF QUANTITY: (Rates shall be uploaded only in the online price bid)

Sr. no Item Description Unit Qty

1 Design, engineering, manufacture, Pre-dispatch Lot 1 inspection, packing, transportation, delivery and guarantee of one no. of DC power supply unit (Rectifier) 900 KW (25 V, 36 KA) along with accessories like VCB panel, Auto transformer, step- down transformer, ITP, harmonic filter, rectifier & control panel, AC & DC bus bar system, DCCT, DC isolator as per technical specification.

2 Design and supply of miscellaneous items (steel Lot 1 structural material, consumables, erection and commissioning material etc.) , which are not considered above and required for completion of this system in all respects as per technical specification.

3 Supply of spares as per technical specification Lot 1

4 Installation, commissioning, civil works, integration Lot 1 of system, testing, training, submission of drawing & documents as per tender specification.

29. PLACE OF DELIVERY:

The place of delivery shall be:

Page 35 of 39

Asst. Store Officer,

Heavy Water Plant (Baroda)

PO- Fertilizer Nagar

Baroda -391750

Page 36 of 39

30. APPENDIX

Appendix-I

Indicative area layout for transformer and Rectifier and other panel

Page 37 of 39

Appendix-II

Indicative diagram for termination arrangement at Anode (Electrolytic cell side)

Appendix-III

Page 38 of 39

Indicative diagram for termination arrangement at cathode (Electrolytic cell side)

Page 39 of 39