Replacement of obsolete VCBs with latest technology VCBs at main power house at Mil Stn Suranussi under AGE I Suranussi

Amount

M&L for Disconnection,dismentling and shifting of existing VCB 01 No incomer 02 Nos outgoing to MES Store yard after taking proper shut down and disconnecting with the help of cranes and reqd manpower carefully complete all as specified and directed.

Supply, install, test & commissioning indoor type HT 11 KV 800 Amps, 26.3KA for 3 sec, 3 phase, 50Hz, AC supply Vacumm Circuit Breaker (VCB) 01 No incomer 02 Nos outgoing totally enclosed, free standing floor mounted type with truck mounted, horizontal isolation and horizontal drawout cubicle type having IP 4X class degree of protection, proper ventilation and control voltage 240 Volts AC and 110 Volts DC complete with CT, PT, indication lamps, meters, relays, copper bus bar 800 Amps, switches and other accessories, 8 window annunciator on each VCB complete all as specified and directed.

1. TECHNICAL SPECIFICATION CIRCUIT BREAKER (VCB) (a). The circuit breaker shall be mounted on a withdrawable truck which shall roll out horizontally from service position to isolated position with ease and it shall also be possible to take out the breaker truck from cubicle smoothly on to the floor without use of any separate handling equipment. It is preferable to provide three-point guide for withdrawal and insertion of truck into the cubicle with ball bearing arrangement on the top of the truck. Circuit breaker shall be of vacuum only and the truck shall have distinct ‘SERVICE’ & ‘TEST’ position. Isolated position by defeating the interlock shall also be inside the cubicle so that the front door of breaker compartment can be closed even in breaker isolated position. Special more than three point hinged locking arrangement shall be provided to prevent opening of door in the event of internal arc in breaker compartment. Isolation shall be horizontal. (b) All the three interrupters of individual phases shall be mounted Vertically on a common phase segregated epoxy body mounted on a truck for better insulation and avoidance of non-simultaneity of poles. Circuit breaker shall be vacuum type only. Interrupter mounted on the conventional individual insulators will not be accepted. No separate fiberglass sheet barrier to be used. Interrupter position on VCB should be Vertical. Horizontal Position mounting of Vacuum interrupter is not acceptable. (c). It shall be operated through a common motor wound spring charged mechanism with electrical release coil for closing and shunt trip coil for tripping. Operating mechanism must have manual charging, closing and tripping facility with the provision locking facility in push to close & push to trip mechanical push button. (d). The mechanism shall be such that motor will automatically recharge the mechanism springs after a closing operation enabling breaker to perform OCO operation. The charging time of motor shall be less than 15 secs making it suitable for rapid auto reclosing duty. Emergency mechanical push to trip button shall be provided for emergency manual tripping with front door closed. All the ‘MS’ components of circuit breaker mechanism shall be treated with zinc platting with olive green passivation for longer life even in adverse climatic condition. Yellow passivation shall not be acceptable. All mechanism springs shall be powder coated. Plating on mechanism spring is not acceptable. The normal current rating of circuit breaker shall be in panel rating without fan. (e). There shall be minimum 4NOand 4NC contacts in breaker auxiliary switch. In case of Additional contacts, the same can be multiplied through latched type contactors. Auxiliary plug and socket shall be of minimum 24 pin plug type and shall have scrapping earth feature. Auxiliary contacts shall be suitable for continuous thermal current rating of 10A.

2. INTERLOCKS (a). Circuit breaker can be inserted only in open position. Likewise, circuit breaker in closed position cannot be withdrawn. Attempt to draw out closed breaker shall not trip the breaker.(b) The circuit breaker shall operate only in one of the two defined positions i.e. service and test. For isolation Auxiliary terminal Plug to be removed manually. (c) The circuit breaker cannot be inserted into service position till auxiliary contacts are made. Similarly interlock prevent auxiliary contacts from being disconnected, if circuit breaker is in service position. (d) It will not be possible to rack out the withdrawable part from Service to Test position when the switching device is switched ON. Similarly, it will not be possible to rack in the withdrawable part from Test to Service position, if the switching device is switched ON. (e) Any attempt to rack out withdrawable part from Service to Test position will not result in switching OFF the Circuit Breaker instead the Service position will be locked till switching device is ‘ON’. (f) It will not be possible to rack in or rack out withdrawable truck when the front high voltage door is open. However, a suitable defeat interlock mechanism is provided for emergency purpose. (g) It will not be possible to rack in the withdrawable truck from test to service position when the low voltage control plug is not in position and locked on the truck itself.(h) It will not be possible to close the door if the low voltage control plug is not engaged.

3. BUS BAR (a). Bus bar material shall be Electrolytic Copper 800 Amps with PVC sleeves. (b) All bus bars shall be insulated with heat shrinkable PVC sleeves. Joints shall be insulated with shrouds in busbar chamber and interphase barrier shall be provided in cable chamber. (c) Phase identification shall be made at the end by colored tape. (d) Bus bars shall be mounted on integral seal off bushings while passing from one compartment to another except busbar compartment (e) Bus bar shall run throughout the switchgear without interruption so incase of any arc, arc shall travel and cause minimum damage to the switchgear.(f) Temperature Rise of busbar along with other parts of switchgear shall be governed by IEC 60694, Table I.

4. CUBICLE CONSTRUCTION (a). The switchgear panel shall be of sheet steel construction with ALUZINC except doors and covers, not less than 2.5mm thickness for load bearing section and not less than 2 mm thickness for non-load bearing and shall totally dust and vermin proof. The panels shall be rigid without using any external bracings. The switchboard panels should comply with relevant IS/IEC and revision thereof and shall be designed for easy operation maintenance and further extension. Bus bar, metering circuit breaker chamber, cables and cable box chamber should have proper access for maintenance, proper interlocks should be provided. All instruments shall be non-draw out type and safe guard in every respect from damages and provided with mechanical indicator of connection and disconnection position. The switchgear shall be completed with all necessary wiring fuses, auxiliary contacts terminal boards etc. (b) Width of cubicle is 600mm up to 1250A and 800 mm above 1250A. (c) All the high voltage compartments must have pressure discharge flap for the exit of gas due to internal arc to insure operator safety. All the HV compartment design i.e. Busbar compartment, VCB compartment & cable compartment should ensure conformity to IEC 62271-200 and must be type tested individually for Internal Arc Test for AFLR 26.3kA for 100ms. The switch gear panels shall be suitable for loss of service continuity LSC 2B. Safety shutters complying with IEC-62271-200 shall be provided to cover up the fixed high voltage contacts on busbar and cable sides when the truck is moved to ISOLATED position.(d) Safety shutters shall be metallic and shall be provided to cover up the fixed High voltage contacts on bus bar and cable sides when the truck is moved to Test / isolated position. The shutters shall move automatically, through a Linkage with the movement of the truck and shall be of gravity fall type only. It shall be possible to padlock shutters individually. (e) Switch gear cubicle shall have seal off bushing arrangement between the circuit breaker compartment and bus bar / C.T. cum cable compartment, i.e. the fixed isolating contacts shall be embedded in epoxy cast bushing so these act as seal off bushing to prevent transfer of arc from one compartment to the other in the event of internal arc within the cubicle & must be tested for internal arc in all three HV compartments as per new IEC 62271-200. (f) Louvers can be provided for higher normal current rating however, same shall be backed up by fine wire mesh. (g) Joints for All front door shall be provided with neoprene or cross-linked poly ethylene gaskets self adhesive type. For compressibility step type channel base shall be provided for easy compressibility. It shall be preferable to provide cross linked poly ethylene type. It shall be preferable to supply cubicle with gaskets between all metal to metal proper vermin proof. Minimum degree of protection shall be IP4X.

5. LOW VOLTAGE COMPARTMENT (a). Low voltage compartment shall be mounted at the front on the top of breaker compartment and shall also have hinged type of door. (b) All wiring shall be routed through PVC ducts and shall be terminated on to stud type terminal with plastic cover. (c) For current transformer terminal shall be disconnecting link type only. (d) The wire shall be of 1.1KV grade and suitable for 2KVrms for I minute power frequency high voltage.

6. CABLE COMPARTMENT (a) It shall be at the rear side with rear bolted box type back covers. There shall be an inspection window at the rear back cover enabling operator to have visual inspection without opening back cover in live condition. Viewing window at the rear side shall be of poly carbonate only and shall be tested for internal arc. (b) The gland plate of cable chamber shall be of minimum 3mm thickness MS sheet in two halves section with built in adjustable cable holding clamp. In case of single core cable, it shall be supplied with non- magnetic gland plate. Cable box shall accommodate 2-3Core 630 sq. mm. Cables or 6-1C cables. Addition rear extension box of minimum 500 mm depth shall be provided for cables more than the quantity mentioned above. (c) Sufficient headroom shall be provided for cable termination. The distance between gland plate and terminal shall be minimum 600mm. (d) Phase barrier should be provided in all three phases of cable. (e) Control cable entry shall be from front and there should be a possibility of terminating to LV chamber from both right hand and left-hand side. Power cable entry shall be from rear bottom. Provision shall be available for entry of power cable or bus duct from rear bottom or rear top.

7. EARTHING (a) There shall be a continuous copper earth bus of size 30 x 6 sq. mm running at the bottom of the panel. Earth bus shall be robust and shall can carry full short circuit current for 1 second. Doors, covers and all non-current carrying metallic parts shall be earthed through flexible copper wires. This also includes instrument casing and cable armour which are also connected to the earth bus. Earth bus must be tested for 26.3KA for 1 sec (b). Separate earthing truck shall be provided for bus earthing and cable earthing. The earthing truck shall be so designed that it is impossible to earth a live. It shall be provided with capacitive voltage divider and complete with audio visual annunciation.

8. CURRENT TRANSFORMER AND POTENTIAL TRANSFORMER Current transformer for all feeders as per requirement all as specified and directed by Engr-in-Charge. Core 1 : 630/1A : Cl-0.5, Burden 25 VA Core 2 : 630/1A : Cl-5P20, Burden 25 VA Core 3 : 800-1200Amps/1Amps (a) Current transformers shall be triple core window / bar primary for higher rating or wound primary for lower rating. Maximum VA burden shall be of 25 VA and shall be rated for full short circuit current for 1 second. Differential / REF CTs can be in one mould. Incase of numerical relays 10VA burden shall be sufficient. CT shall be of a minimum accuracy of class 0.5/5P20 and CT Secondary rating shall be 1A unless otherwise specified. (b) Potential transformer for incomer feeder shall be 3phase with ratio 11KV/110Volts 3 limb type with 25VA of class 0.5/3P accuracy and shall be mounted on incomer breaker truck. For bus connected P.T the same shall be mounted in a separate with drawable truck in a separate vertical panel. (c) In addition to scrapping earth in auxiliary plug and socket proper arrangement should be made so that during engagement of the breaker in service condition earthing contacts is made first before isolating power contacts are engaged

(a) 1 No of SCADA Compatible Feeder Protection Relay 50/51(3 phase overcurrent), 50/51N (Earth overcurrent), 67P (3 phase directional overcurrent), 67N (Earth fault directional overcurrent) , 51V (Voltage controlled overcurrent), 37 (3 phase undercurrent), 46 (Negative phase sequence overcurrent), 59N (Residual over voltage), 32 (Directional Power protection (Under / Over active / reactive power), 81U/O (Under/over frequency), 49 (Thermal overload), 79 (Autoreclose), 50BF (Circuit breaker failure detection), Cold load pick up, Inrush blocking. Relay will be on Modbus Protocol.

(b) Master Trip Relay

iv. Outgoing Feeder

(a) 1 No of SCADA Compatible Feeder Protection Relay 50/51 (3 phase overcurrent), 50/51N (Earth overcurrent), 67P (3 phase directional overcurrent), 67N (Earth fault directional overcurrent), 51V (Voltage controlled overcurrent), 37 (3 phase undercurrent), 46 (Negative phase sequence overcurrent), 59N (Residual over voltage), 32 (Directional Power protection (Under / Over active / reactive power), 81U/O (Under/over frequency) , 49 (Thermal overload), 79 (Autoreclose), 50BF (Circuit breaker failure detection), Cold load pick up, Inrush blocking. Relay will be on Modbus Protocol. Make: Schneider (Easergy P3U20) / ABB (REF630) / Siemens (7SJ65)

(b) Outgoing feeder should have auxiliary relay for transformer OTI, WTI and Buchholz protection (i.e. Alarm and Tripping)

(c) Master Trip Relay

• The Protection and Control device shall be of numerical type and designed to meet a high degree of dependability and security.

• The local human machine interface (HMI) shall be based on a user-friendly and menu-structured program. The device shall include a 64x128 LCD matrix display which supports mimic (e.g. single line diagram can be drawn) and freely assignable analogue values.

• One common relay’s management software (based on standard Windows operating systems) shall provide all necessary tools and functions to operate the devices. Via the management software relay parameters, configurations and recorded data can be exchanged between PC and the device. Supporting the comtrade format, the management software also incorporates tools for analyzing relay events, waveforms and trends from data recorded but the device.

• The device shall support webserver/web HMI through which we can monitor and control the relays over a ethernet Lan network.

• The device shall support virtual simulation through which protection functions and logic testing can be achieved without any separate software.

• The device shall have USB communication port in the front for the setting software use and at the back the communication ports shall be either 2xRJ-45 Ethernet port. The device shall support Native IEC61850 Communication protocol.

12. Thermal & Humidity Monitoring System

MV Switchboard shall also be provided with Condition Based Monitoring System through wireless sensor’s for Thermal & Humidity monitoring.

Self power, Battery less wireless Thermal monitoring sensors shall be provided to detect abnormal temperatures due to faulty connections at Hot point of cable termination

- Ambient monitoring sensors shall be provided at a) substation room (relative humidity & ambient temperature) and Cable Compartment of each switch gear (dew point and relative humidity)

- All Sensors and Receivers shall be comply with UL 61010-1 requirements and will be UL and IEC Approved.

All sensors should be direct measurement type for temperature, and no algorithm or indirect calculation based measurement should be used

- The temperature sensors installed shall be suitable for wireless, with direct contact to hot point, operating range from -25°C to 125 °C with ± 2°C accuracy, relative humidity.

The system shall be online and have integrated algorithms enabling to anticipate very early abnormal condition, before damage occur (strong predictive capacity) and allow 2 configurable threshold (pre-alarm & alarm). A graphic switch board mounted HMI shall provide identification / location of the abnormal temperature for local monitoring and investigation. The system shall also be able to communicate these data in open protocol for future remote monitoring options

10. AUXILIARY/CONTROL WIRING (a) Control supply for closing and tripping shall be 220 or 110Volts D.C. through external battery source. 230 Volts single phase A.C. supply shall also be available for the operation of spring charging motor and cubicle space heater. Wattage of closing and tripping coils shall be within 250 watts. Aux supply shall be suitably distributed along with switchgear in loop in loop out fashion. (b) All Switchgear panels shall be supplied completely wired internally up to the terminal block ready to receive external cabling. (c). All the secondary wiring in the panel shall have high quality PVC insulation and the same shall have conductor size of not less than 1.5 mm2 of copper. (d) Colors of the secondary / auxiliary wiring should confirm to IS 375/1963 and latest amendment thereof if any. All wiring shall be neatly run and group of wiring shall be securely fixed by clips so that wiring can be checked without necessity of removing the clamps. Wiring between fixed and moving portion of the panel shall be run in flexible tubes and the same shall be so mounted to avoid any damage to them due to mechanical movements. Ferrules with number shall be provided on both end of the wiring. (e) All wires directly connected to trip the circuit breaker shall be distinguished by the addition of a red coloured unlettered ferrule.

11. PRE TREATMENT AND PAINTING (a) Switch gear front and rear covers shall be painted for aesthetic purposes and paint shade shall be RAL 7032.

Supply, laying, jointing and testing XLPE insulated, screened, PVC bedded, galvanized steel strip or wire armoured electric power cable (heavy duty) with stranded aluminium conductor, 11000 volts grade earthed system of size 120 Sqmm 3 core conforming to IS-7098 (Part-II) 1985 laid in trenches, in floor, in duct, through pipes or along the pole including taking out unserviceable HT overhead conductor/cable complete all as specified and directed

Supply and fixing Cable Jointing Kit for 11 KV grade earthed cable for outdoor type end termination heat shrinkable joint complete with jointing material and accessories suitable for XLPE insulated, screened, armoured aluminum conductor cable of size 120 Sqmm 3 core incl opening cable connections/ taking down, taking old unserviceable joint kit and re-fixing cable complete.

Supply and Fixing Cable Jointing Kit for 11 KV grade earthed cable for indoor type termination heat shrinkable joint complete with jointing material, thimble and accessories suitable for XLPE insulated, screened, armoured aluminum conductor cable of size 95 sqm to 120 sqmm 3 core incl opening cable connections/ taking down, taking old unserviceable joint kit and re-fixing cable complete.

Earthing complete with galvanised copper earth plate electrode 60 x 60 cm x 3.15 mm thick, buried directly in ground (earth pit not less than 2.25 metres deep below ground level) with top edge of the plate not less than 1.5 metres below normal ground level, connected to copper earth lead strip 20 x 3 mm fixed by means of bolts, nuts, check nuts and washers of galvanised iron or steel all as shown in electrical plate no. 3 connected to earthing test point all as specified or indicated including testing on complection., earth plate surrounded by packed layers of charcoal dust and common salt each 15cm thick, all around including top and bottom and watering pipe 20mm bore of GI pipe light grade with funnel and wire mesh, PCC chamber of size 300x300x300mm (top of chamber minimum 15 cm above the normal ground level (1:3:6) using 20mm graded stone aggregate and RCC cover (1:2:4) type B-I using 20mm graded crushed stone aggregate with 1 nos mild steel handles made out of 8mm dia mild steel bar including necessary excavation/ earth work in any type of soil/rock and as shown in Electrical plate No. 3 of SSR Part-I (2020) testing on completion complete all as specified.

Excavation in trenches in soft/loose soil not exceeding 1.50 mtr wide and not exceeding 1.50 mtr in depth for laying of cables incl taking out old PCC cover and stacking for re-use and getting out soil complete all as specified and directed by Engineer-in-Charge.

Returing, filling in, including spreading, leveling watering and well ramming in layers not exceeding 25 cms thick each layer compete all as specified and directed by Engineer-in-Charge.

Removal of surplus soil to a distance not exceeding 50 mtr and depositing where directed at a level not exceeding 1.5 mtr above the starting point complete all as specified and directed by Engr-in-charge.

Material and labour for sand cushioning with a layer of sand 8cm thick before laying of cable and 15 cm thick after laying of cable in trenches and punned down to thickness of 18cm complete all as specified. Note: The punned down thickness of 18 cm will be measured.

Supply and fix common burnt clay building brick Sub class B designation 75 all as specified and directed.

UNITED ENGINEERING CORPORATION (BID ID -3194957)

SATISH AND CO (BID ID -3195197)

Northern cable fault locatoers (BID ID -3200613)