TAMIL NADU ELECTRICITY BOARD

TENDER SPECIFICATION

FOR SUPPLY OF

Control and Relay Panels

For various Substations

TNEB SPECIFICATION NO.P&C-782

Office of the Superintending Engineer/Design,Protection & Communication,

MLDC Block, 2nd Floor,802, Anna Salai,

Chennai-600 002.TAMIL NADU.

TECHNICAL

DETAILED TECHNICAL SPECIFICATION :

TECHNICAL SPECIFICATION FOR CONTROL & RELAY PANELS:

This  specification   provides   for   the    design, fabrication, manufacturing of panels with  relays,  meters and other associated equipments with provision for wiring of all equipments. The equipments shall be capable of working satisfactorily in the environmental conditions:

1. GENERAL:

The manufacturer, whose C&R panels and protective relays are offered, should have a minimum of three years  experience for having designed, manufactured,  tested,  supplied  and commissioned C&R panels and protective relays upto 230 KV Feeders and 230KV Autotransformers. The panels are to be of simplex type; shall be  independent and  totally  closed having wiring  access  from rear for control  panels and either front or rear for relay  panels. The equipments are to be mounted on the front side of the panel. The control panels shall be provided with rear doors and  doors shall have handles with built-in  facility. The relay panel shall be provided with swing door on front  side and  transparent protective door covering the  front  swing door on which the relays and associate equipments shall be mounted. The panels shall be completely metal enclosed and shall be dust, moisture and vermin proof. The  enclosure shall provide  a degree of protection not less  than  IP-31  in accordance with IS:2147.Panels  shall have base-frame  with  smooth   bearing surface, antivibration strips / pad made of shock  absorbing materials shall be placed between panel and base frame. All doors, removable covers and panels shall be gasketted all around with neoprene gaskets. Ventilating louvre shall have screens and filters. Cable entries to the panels shall be from the bottom. Necessary cable gland should fitted. Cable  gland plates fitted  on  the bottom shall be connected  to  earthing  of panel/station  through a flexible braided copper  conductor rigidly. Each  panel shall be provided with space heater rated for 240V single phase AC supply with controlling thermostat. All equipments on and in panels shall be  mounted  and completely wired to the terminal blocks ready  for external connections. The spare contacts shall also be  wired  upto the terminal box. Each  panel shall be provided with the interior  lights (40W, fluorescent) controlled by door switch. A 230V single-phase, 3-pin AC socket 15/5A with  switch shall  be  provided in each panel for connection of  hand lamps. Accessories  required  for fixing the panel  such  as foundation  bolts and nuts shall be provided along with the panel.

1. DIMENSION: Height:- 2312 mm (The Height includes 10mm base frame

and 12mm vibration pad), Depth: 600 mm.

Width:- 720mm

Thickness of sheet: Front and near side not less than 10 SWG and top not less than 14 SWG.

For Vembadithalam SS Size of control panel :-720x650x2250 mmSize of relay panel :-720x650x2312 mm

3. NAME PLATE & MARKINGS:

All equipment mounted on front and rear side as well as equipment mounted inside the panels shall be provided  with individual nameplates with equipment designation  engraved. Also on the top of each panel on front as well as rear side, large and   bold  name plates  shall  be provided for circuit/feeder designation. Name plate shall be made of non-rusting metal or 3 ply lamicoid. Nameplates shall be black  with  white engraving lettering. Each instrument and meter shall be prominently marked with quantity measured e.g. KVA, MW etc., All  relays and other devices shall be clearly marked. Each  switch shall bear clear  inscription  identifying its function. Coloured  mimic diagram and symbols showing  the exact representation of the system shall be provided in the  front of control panel. Mimic diagram  shall be made  preferably  of anodized aluminium or plastic material, which shall be screwed on to panel and can be easily cleaned. Painted overlaid mimic is also accepted. The mimic bus shall be 2  mm  thick.  The width  of mimic bus shall be 10mm for busbars and 7  mm  for other connections. The colour of the mimic may be as follows: 230 KV Signal red.110 KV Brilliant green.

3. PAINTING:

i) All sheet steel work shall be phosphated in  accordance with IS:6005.

ii) Oil, grease, dirt, swart, rust and scale etc., shall be removed by adapting to proper cleansing procedure.

iii) After  phosphating and thorough rinsing, the  phosphate coating shall be sealed with application of two coats of ready mixed  stoved type zinc  chromate  primer.  The first coat may be `flash dried' while the second  coat shall be stoved.

iv) After application of the primer, two coats of  finishing synthetic enamel  paint shall be  applied,  each  coat followed by stoving.

v) The colour of the panel shall match the existing  panel colour of  the subject station and  normally  of  the following choice for new stations.

Exterior : stoved enamel greyInterior : stoved enamel whiteBus frame : stoved enamel blackFinish : glossy  surface treatment shall  be done as per

ISS.

5. INDICATING INSTRUMENTS AND METERS:

shall be of Size : 144 Sq.mm outer size with circular dials.Scale : 90 degrees.Accuracy : +/-1.0% uniform deflection.

Wattmeter  /  VAR  meter shall be of  three  phase  two element type suitable for measurement of unbalanced load  in 3 phase 3 wire circuit and shall be flush mounting type. The  instrument dial shall be parallax free with  white scale  and black knife-edge pointer and with black  numerals and lettering. Import (+) and Export (-) in MW / MVAR meters shall  be marked  to  indicate the direction of  active and  reactive power flow towards and away from the substation bus bar. Digital  bus voltage and frequency meters shall  be  of class: 0.5 and shall have digital display of five  (5)  and four  (4)  digits respectively with display size,  not less than 50 mm (height). All indicating  instruments,  meters, recorders  etc., shall be enclosed in dust proof moisture restraint cases and shall be suitable for tropical use. Electronic Trivector Meters  shall be with facility  for  separate registering  of  KWH, KVAH  and KVARH consumption and also to record export/import and demands and their input quantities. The accuracy of meters shall be 0.5 clause. The meter shall have communication facility with open protocol. It  shall record and indicate the  measured parameters for  frequency  variations  of  ±15%  and  for  AC auxiliary variation from -40% to +10% and shall have facility to communicate on line parameters as well as down load stored data. The connectivity  to  the  computer shall  be  of  RS485 and necessary  connectors  shall   be supplied.  

6. INDICATING LAMPS:i) Indicating  lamps  shall be panel  mounting  with  rear

terminal connections.  Lamps shall be  provided  with series connected resistors preferably built in the lamp assembly.

ii) Lamps shall have translucent covers to diffuse  lights. The lamp cover shall be preferably of  screwed  type, unbreakable and moulded from heat resisting material.

iii) The  wattage  and resistance of the lamps shall  be  as follows:

a) 220/250V DC : 5 to 10 Watts; 4 to 8 Kilo ohms.b) 110V DC : 5 to 10 Watts; 1 to 2 Kilo ohms.

iv) Bulbs/LEDs  etc., shall be interchangeable and  easily replaceable from  the front of the  panel.  Tools  if required for replacing the bulbs and LEDs  shall  be included in the scope of supply.

v) The  indicating  lamps shall withstand  120%  of  rated voltage on a continuous basis.

vi) Colour of the indicating lamps may be as follows:

a) P.T. Supply : Red, yellow and Blue for the three phases.

b) Breaker position : ON-Red. OFF-Green.c) Air pressure : White. normald) Gas pressure : White. normale) Line P.T. Supply : Yellow / Amberf) Isolator Position : ON-Red. OFF-Green.

7. SWITCHES:

Control   and  instrument  switches  shall  be   rotary operated type with escutcheon plates clearly marked to  show operating position and  circuit designation  plates   and suitable to flush mounting with only switch front plate  and operating handle projecting out.

a) Control switches for Breakers/Isolators shall  be of two position spring return  to  neutral type with pistol grip black handle. The control springs shall be strong and robust enough to prevent inadvertent operation due to light touch.

b) Instrument selection switches shall be of maintained contact (stay put) type. Ammeter selector switch shall have six position stayput type and shall  have make-before-break type contacts so as to prevent  open circuiting of CT secondaries when changing position of the switch. Voltmeter transfer switches  for AC shall   be suitable for reading all line-to-line voltages.

c) Synchronising switches shall  be  of  stay  put  type  having a common removable  key for a group of switches.  The key shall be removable only in OFF position.

d) Push Buttons shall  be  of  momentary contact  type  with rear terminal connections. They shall be provided with

functional indication engraved in an  inscription plate.  The contacts of the push  button  switch shall be capable of carrying 5 Amps. at 250V DC and shall be cable of breaking lamp inductive load at 250V DC.

e) General: Lockable  type of switches which can be locked in particular   position  shall  be  provided   when specified. The contacts  of the switches shall be  open  and close with snap action

to minimise arcing. Contacts of switches shall be spring assisted  and contact faces shall be with rivets of pure silver or sliver alloy. The springs shall not be used  as current carrying parts. The  contacts shall be of the rating of  not less than 10 amps. for make and carry continuously and 30  amps for short time rated for 0.5 sec.   And   3 amps for breaking resistive loads and 0.2 amps for breaking inductive load with L/R = 40 m sec.

8. PANEL WIRING:

i) All  wiring shall be provided with  minimum  650V Grade single core multistrand  copper  conductor wires  with  PVC insulation and shall  be  flame, vermin and rodent proof. The minimum size of  the stranded copper wire shall be:

a) for all circuits except C.T. circuits. 1.5 sq.mm.b) for C.T. circuits 2.5 sq.mm.  

All wiring shall be in accordance with the wiring diagram  for functioning  of connected equipment.

ii) Flexible wires shall be used for wiring of devices on moving parts such as swinging panels or  panel door.

iii) Panel  wiring shall be securely supported,  neatly arranged, readily  accessible  and  connected  to equipment terminals and terminal blocks. Wiring gutters  and troughs  shall be  used  for  this purpose.

(iv) Cables/wires shall be uniformly bunched and  tied by means of PVC belts and carried in PVC  carrying troughs. The position of PVC carrying troughs  and hanging bunch of wires shall not give any hindrance for fixing or removing relay casing, switches etc.,

v) Wire  termination  shall be made  with  solderless crimping type and tinned copper lugs, which firmly grip  the conductor. Insulated sleeves  shall  be provided at all the wire terminations.

vi) Engraved  core  identification  plastic   ferrules marked  to correspond with panel  wiring  diagram shall be fitted at both ends of each wire.

vii) The  wire number shown on the wiring shall  be  in accordance with the I.S. 375.

viii) All  wires  directly  connected  to  trip  circuit breaker  or device shall be  distinguished  by addition of red colour unlettered ferrule.

ix) Inter  connections  to adjacent  panels  shall  be brought out to a separate set of terminal  blocks located near the slots or holes to be provided  at the  top portion of the panel. Arrangements shall be made for easy connections to adjacent panels at site and wires for this purpose shall be  provided and bunched inside the panel.

x) Bus wire shall run at the top of the panel.  The terminal block for bus  wire  shall  be   with isolating links.

xi) The  terminal block used shall be  minimum  650V grade and have 10 amps continuous rating, moulded piece, complete with insulated barriers, stud type terminals, washers, nuts and locknuts  suitable for  operation  with a tubular  box spanner  or screw driver.

xii) Terminal  block  shall be  arranged  in  vertical formation at an inclined angle  with  sufficient space  between terminal blocks with a minimum  of150 mm for easy wiring.

xiii) Terminal  block  shall  include  a  white  fibre marking strip with clear plastic, slip on/clip on terminal  covers. Markings on the terminal strips shall  correspond  to  wire number  and terminal number on the wiring diagrams.

xiv) There  shall  be a minimum clearance  of  250  mm between the first row of terminal blocks and  the associated cable and plate or panel sidewall.

xv) At least 20% of total terminals shall be  provided as spare for further connections and these spare terminals  shall be uniformly distributed on  all terminal blocks.

xvi) Wiring is preferable with the following colour code.

PT supply : Red, Yellow, Blue for phase and Black for neutral.

CT circuits : Similar to the above.DC circuit : Gray for both Positive and Negative. 230V AC circuits: Black for both Phase and Neutral.Earthing : Green.

9. EARTHING:

i) All  panels  shall be equipped with an  earth  bus securely fixed along the inside  base  of  the panels. When several panels are mounted adjoining to  each  other,  the earth bus shall  be  made continuous and necessary connectors and clamps for this  purpose shall be included in the  scope of supply.

ii) The size of the earth bus shall be made of 25mm  x 6mm tinned copper flat.

iii) The earth of the substation will be 40mm  diameter M.S. rods, Provision shall be made on  the  earth bus  bars of the end panels for connecting to  the earth   grid. Necessary terminal clamps   and connectors shall be included in the scope of supply.

iv) All metallic cases of the relays, instruments  and other panel mounted equipments shall be connected to  the earth bus by independent copper  wires  of size not less than 2.5 sq.mm. The colour code of earthing  wire shall be green.  Earthing wires shall be connected on the terminals with  suitable clamp connectors  and soldering shall  not  be permitted.

10. CIRCUIT DISTRIBUTION AND ISOLATION:

i) Each control and relay panel shall be  provided with necessary arrangements   for   receiving, isolating  and fusing of AC and DC supplies  for various control of signaling, lighting and  space heaters.

ii) The incoming and sub-circuits shall be  separately provided with switch fuse units, selection of  the main and sub-circuit fuse rating shall be such as to  ensure  selective clearance of sub-circuit faults.

iii) Potential circuits for relaying and metering shall be protected by fuses.

iv) All  fuses  shall  be  of  HRC  cartridge   type conforming to IS 2203 mounted on plug-in  type fuse  bases. All accessible live connection  of fuse bases shall be adequately shrouded.

v) Fuses   shall  have  operation   indicators   for indicating `blown-fuse' condition.

vi) Fuses  carrier  base shall have imprints  of  fuse rating and voltage.

vii) Removable links should be provided at the  output of each relay for trip output and reclose output. Adequate space shall be left between fuse units when arranged adjacently.

11. LABELS:

All  front  mounted  equipment as  well  as  equipment mounted inside the panel shall be  provided  with  individual labels  with equipment designation engraved. Labels  shall  be made  of  non rusting metals or 3 ply lanced. Label  shall  have white  letters on black or dark back-ground. The size  of  the label  shall  be  ; width-1.5  cms;  length-as  per  length of inscription; the letter size-0.75cm.

12. SYNCHRONISING EQUIPMENT:i) The  synchronizing  panel shall  be  mounted  with double

voltmeter, double   frequency    meter, synchroscope and lamps fully wired.

ii) Suitable auxiliary voltage transformers  wherever necessary   shall  be provided  for  synchronizing condition.

13. ANNUNCIATORS:i) The  annunciations fascia shall be  provided  with flasher,

hooters and  bell  for separate  indication of tripping alarm/non-tripping alarms.  All  the  panels shall  have  the inter connection  for accepting the alarm but the  reset shall be from the individual panel.

ii) Each annunciations fascia/window  shall be provided  with LED.

iii) Trip  and  non-trip  discrimination shall be made  in  the fascia. For example all trip fascia shall have  red colour and non trip fascia white colour.

14. RELAYS:

i) All relays shall confirm to IS: 3231 and IS:  8686 and or other relevant standards in vogue.

ii) Descriptive  details of the relays  are  furnished and specified in separate heads.

iii) Testing  facility provided on the relay  shall  be detailed.

iv) Necessary  test  plugs, test blocks  and  switches shall be provided.

v) Unless  otherwise specified all  auxiliary  relays and timers shall be supplied in non-drawout  cases / plug in type modular cases.

vi) Relays   shall  have  the  rating  for   110V   VT secondaries and 1 amp CT s secondaries.  D.C.Auxiliaries  and timers shall be designed for  the DC Voltage specified.

vii) Provision  shall  be made for  isolation  of  trip circuits of each relay for the purpose of  testing and maintenance.

viii) All relays / wiring shall withstand a test voltage of 2.5 KV, 50 Hz r.m.s. voltage for 1 minute.

ix) The relays shall be able to be tested with universally acceptable testing kit.

x) All the relays offered shall have to be type tested. Necessary  bill of materials in each case has been enclosed in the appendix.

15. GENERAL:-For each type of Numerical relay offered in the tender,

necessary software capable of interacting with the realy for performing following complete functions:

i) Input/Output relay assignmentii) LED configurationiii) Setting & Modification of relay parametersiv) Analysis of disturbance recording v) Tools to download details of relay shall be supplied .

No Laptop/Desktop computer is required.

16. RELEVANT REFERENCE STANDARDS:

IS - 3231 Electrical relays for power system protection.IS - 8686 Static protective relays.IS - 2147 Degree of protection of cubicles.IS - 1248 and IS - 2419 indicating instruments.IS - 6236 Recorders.IS - 2705 Current Transformers.IS - 3156 Voltage Transformers.IS - 4237 General requirements for switches and control gear for

voltages not exceeding 1 KV.

IS - 0722 Energy meters, control  switches  (LV  switching devices

for control and auxiliary circuits).IS - 0337, 0337-1 -do-IS - 0297 (Part 1-3) Dimensions for mechanical structures of

the 482.6 mm (19") Series.

IS - 0375 Marketing and arrangement for switch  gear,  busbars main connection and auxiliary wiring.

IS - 6875 Control Switches  (CLV  switching  devices  for control and aux. circuits)

IS - 0005 Colour for ready mix paints.IS - 1554 (Part-I) PVC insulated cables upto and including

1000 Volts.IS - 3842 (Part I - VII) Application guide for protection.IS - 9224 (Part-II) HRC cartridge fuse links.IS - 6005 Code of practice for phosphating iron and steel.IES- 2555-1-0 Electrical relays -All-or-nothing elec. relays.ICE- 255-3,5,6,7,8,10,11,12,13,16 Electrical relays for various specifications.ICE- 255-21-2,3ICE- 255-22-1,2,3,4 Electrical relays - vibration & disturbance

etc., test.

ICE- 255-23 Electrical relays - contact performance.

TRANSFORMER PROTECTION:A. Biased Differential Protection Relay for Two Winding

Transformers. 1. Shall be Numerical Type.

2. Three phase with faulty phase identification.

3. Shall have continuous self monitoring and Diagnostic features.

4. Shall have instantaneous High set feature with facility to adjust 5 to 20 times normal current.

5. Shall have second harmonic restraint feature with second harmonic content in the range of 15 to 25 %.

6. The disturbance recording functions should be Integrated in the relay module. The disturbance recorder shall have facility to record at least 4 Nos. external digital signals apart from digital signals from relay and currents in HV & LV windings.

7. Facility to set transformer Vector group and CT ratio selection/correction through software.

8. Rated current 1 amp.

9. Thermal withstand current. Continuous 2 amps and for 1 sec-70Amps

10. Rated Voltage : 110/220 V DC

11. Basic bias setting 20 to 40% in steps of 10%or15% to 45% in steps of 15%.

12. Operating current setting range 15 to 30%

13. Have an operating time not greater than 35 ms at 3 times normal current.

14. maximum operating time for instantaneous operation:25 ms +/-4% of set value

15. Recording memory capacity : 5 Sec.

16. Shall have restricted earth fault protection.

17. Have front or back RS232 port for connecting Lap Top (Suitable connecting cards/converter to be supplied) and rear RS485 or Fibre optic port for local and remote communications. However for uniformity all the relays shall be provided either with RS 485 port or Fibre optic port at the rear. The communication shall be through IEC-60870-5-103 or DNP3.0. or IEC 61850 protocols.

18. Have time synchronisation facility.

B. Back up non-directional overcurrent protection with high set instantaneous for HV.

1. Shall be of Numerical Type.

2. IDMT Characteristic with a definite minimum time of 3.0 sec. at 10 times current and with a variable setting range of 50 to 200% of rated current of one ampere in steps of 10%. Time multiplier range 0.05 - 1.0 in steps of 0.05.

3. Provided with Hand reset flags/LED Indicators.

4. High set feature 500 - 2000% of rated current.

5. Have front or back RS232 port for connecting Lap Top ( Suitable connecting cards/converter to be supplied) and rear RS485 or Fibre optic port for local and remote communications. However for uniformity all the relays shall be provided either with RS 485 port or Fibre optic port at the rear. The communication shall be through IEC-60870-5-103 or DNP3.0. or IEC 61850 protocols.

C. Back up Non Directional Over Current Relay for LV side.

1. Shall be of Numerical Type.

2. IDMT Characteristic with a definite minimum time of 3.0 sec. at 10 times current and with a variable setting range of 50 to 200% of rated current of one ampere in steps of 10% Time multiplier range 0.05 - 1.0 in steps of 0.05

3. Provided with Hand reset flags/LED Indicators.

4. Have front or back RS232 port for connecting Lap Top ( Suitable connecting cards/converter to be supplied) and rear RS485 or Fibre optic port for local and remote communications. However for uniformity all the relays shall be provided either with RS 485 port or Fibre optic port at the rear. The communication shall be through IEC-60870-5-103 or DNP3.0. or IEC 61850 protocols.

V. MISCELLANEOUS PROTECTIONS:

1. Breaker Failure Relay (Stuck Breaker Protection Relay) LBB:-

The relay shall be triple pole type, be suitable for station DC supply.- have an operating time of less than 15 millisecs.- have a resetting time of less than 15 millisecs.- have  three  over current elements,  each  element, shall  be

arranged to get  individual  initiation from the corresponding phase of line protection.

- be of solid-state type.- have a setting range of 10 - 80% of rated current of one ampere.- have  a continuous thermal withstand of two times rated current

irrespective of the setting.- have  timer with continuously  adjustable  setting range of 0.1 - 1 Sec.- suitable  for  110/220V DC  operation.

No separate LBB is required under the following condition:For Transformers:

If biased differential and back up over current relays for HV and LV do have in built feature.

2. DC Supervision Relay: The  relay  shall  monitor continuously  DC  supply  to protection system. The de-energisation of this relay  will indicate the DC supply failure. Auxiliary supply for the relay is 110/220V DC. The relay shall have a time delay on drop-off' of not less than 100 millisec. The   relay  shall  be provided  with   operation indicators (reverse flag) - self reset. Sufficient number of contacts, potential free,  may be provided. Separate relays for dual source are to be provided.

3. Trip Circuit Supervision Relays: The relay shall supervise the healthiness of trip circuit continuously (both pre-closing and  post closing  conditions of the  circuit  breakers).The  relay shall  be  capable  of  monitoring the healthiness   of   each  `phase'   trip-coil   and associated circuit of the circuit breaker  during "ON" and "OFF" conditions. The  relay shall work on 110V or 220V  DC  with allowable margin

as the case may be. The   relay  shall  have  adequate  contacts for providing connection to alarm and  event  logger, self-reset. The relay shall have a `time delay on drop-off  of not  less than 200 millisecs., and provided  with operation indicators. The short  circuiting of  any series resistance provided  in  this relay or short  circuiting  the coil of the relay should not energize  the trip coil of the breaker.

4. Tripping (Master) Relay:- For  tripping  of feeder / transformer  breakers  in  a station on

operation of protective relays and for  interlock purposes. The relay shall be voltage rated  for  110V  or  220V  DC   with allowable margin of variation, be instantaneous (operating time not to exceed  10 milliseconds).

- Reset within 20 milliseconds.

- have adequate contacts to meet the requirement  of scheme, other functions like  auto-reclose  relay, LBB  relay  as  well as  to cater  to associated equipments like SER, DR, etc., be  provided with operation element / coil.

BILL OF MATERIALS

3. 132/11 KV TRANSFORMER CONTROL PANEL:

1. Circuit label in front and rear 2 Nos. 2. Mimic diagram

3. Ammeter - 144 sqmm, 90 degree scale (0.300A)CTR 300/12 Nos.

4. MW meter - 144 sqmm, 90 degree scale (100-0-100MW, 110V,1A) 1 No. 5. MVAR meter-144 sqmm, 90degree scale(60-0-60MVAR),110V,1A.

1 No.

6. Electronic Trivector meter for import and export with RS485 port for communication alongwith necessary software (110 V, 1A, 0.5 class). 1 No.

7. 6 position Ammeter selector switch    

2 Nos.

8. Control switch for HV/LV Breakers and HV Isolators. 5 Nos.

9. Trip Transfer Switch. 1 No. 10. Synchronizing switch lockable type for 230 KV side

1 No.

11. Indication lamps for ON-OFF position for breaker & isolators 10 Nos.

12.  Indication lamps for HV/LV breaker air/gas pressure indication

4 Nos.

13. Indication lamp for 132 KV Bus PT supply and DC fail

5 Nos.

14. Micro processor based Annunciation system suitable for 20 windows.

1 set

15. Test/Accept/Reset Push button for annunciation 3 Nos.

16. Test/Accept Push button for DC fail test for source 1 & 2.3 Nos.

17. Test terminal block1 No.

BILL OF MATERIALS

4. 132/ 11 KV TRANSFORMER RELAY PANEL:

1. Circuit label 1 No.

2. Numerical, biased Differential protection relay for 2 winding Transformer with REF features.

1 No.

3. Numerical, non-directional Over Current protection relay with High set for HV side. 1 No.

4. Numerical, non-directional Over Current protection relay without High set for LV side. 1 No.

5. Local Breaker Back up Relay with Timer for HV & LV side. 2 Nos.

6. Trip circuit supervision relay for HV & LV 8 Nos. 7. DC supply supervision relay for HV & LV 3 Nos.

8. 5 element High burden Hand Reset with Flag Indication Relay for HV/LV breaker annunciation and transformer function annunciation

with a minimum of 3 sets of N/O contacts and 1 set of N/O contact. 4

Nos.

9. Three phase Master Trip relay (Hand reset relay and Flag).2 Nos.

10. DC fail alarm accept Relay 1 No.

11. 4 position PT selector switch lockable type (for HV side)1 No.

GUARANTEED TECHNICAL PARTICULARS

1. Transformer Biased Differential Relay:

Make & Type :Numerical :Rated DC Voltage :Current Rated :Continuous :For 1 Sec. :Two Winding Relay :Operating time at 3 times normal current:Operating time for instantaneous operation:Bias setting range with steps :Availability of faulty phase identification :Availability of instantaneous High setfeature with current setting range :

Range of second harmonic restrain feature available. :

Availability of continuous self monitoring and diagnostic features. :

Transformer vector group and CT ratioselection/corrections through software.

Disturbance recorder:

a) No. of external digital signal that can be recorded. :

b) Facility to record currents in HV & LV Winding. :

Memory Capacity of D.R:

Fault records :No. of fault records that can be stored :

Details of ports available with protocol :

GUARANTEED TECHNICAL PARTICUALRS FOR DIRECTIONAL AND NON DIRECTIONAL OVER

CURRENT AND EARTH FAULT RELAYS:

1. Description : Model No. & Make :2. DC Operating Voltage & its Range :3. Selectability between definite : time & IDMT O/C function.4. Over current setting range :

Phase fault :Earth fault :Time setting range and steps :

5. High set Over current setting range : (Not applicable for non Phase fault. : directional over current

relays Earth fault : for LV side of transformer)Time setting range and steps :

6. IDMT characteristics :7. P.T. Voltage :8. Relay characteristic angle : settable for Phase fault and Earth fault. 9. Operating time for instantaneous : element.10. Indications provided :11. Communication ports provided :12. Protocols supported :13. Disturbance Recorder Details : a. No. of analog input. b. No. of digital input. c. Sampling rate. d. Maximum storage capacity 14. Event Recorder Details :

a. Maximum no. of events. b. Resolution. 15. Sampling rate & frequency :16. Self diagnostic feature provided :17. Availability of Time Synchronisation

facility :18. Reset ratio :19. Resetting time :20. Other features available :

: