NIT No 11 (2025-26)EE(EandM)TYRSV

11KV Compact Substation (CSS) shall be metal-enclosed prefabricated substation suitable for outdoor installation. It shall house an 11kV Ring Main Unit (RMU) ICOG type, distribution transformer, and Low Voltage (LV) switchboard in a compact, weatherproof, tamper-proof enclosure comply with standard or relevant IS of components Parameter Specification System Voltage (HV) 11kV, 3-Phase, 50Hz Transformer Rating [Specify: 999 KVA] HV Switchgear SF6 gas insulated RMU LV Voltage Output 433 V, 3-Phase, 4-wire Cooling Type ONAN (Oil Natural Air Natural) Degree of Protection IP54 for enclosure. Installation Location Outdoor (Pad-mounted / Plinth-mounted) 1. Major Components 1.1 High Voltage Compartment (RMU) • Type-tested RMU, SF6 gas insulated ring main unit. • Rated Voltage: 12kV • Rated Current: 630A • Short-time withstand: 20kA for 3 sec • Degree of Protection IP54 for enclosure. • Rated power frequenecy voltage - 28 KV & Rated lightening withstand voltage - 75 KV. • Dead short Circuit life of VI - 40 nos. • Rated internal arc rating - 21 KA for 1 sec for tank and cable box category IAC-AFLR. • Protection: Feeder protection relay with metering • Manual or motorized operation 1.2 Transformer Compartment • Type: Hermetically sealed or conservator-type • Core type: CRGO / Amorphous (as specified) • Insulating Medium: Mineral Oil • The Losses of Transformer should be as per IS 1180 part 1 Eff level 2 norms. • H.V. Power Frequency (KV rms): 28 kV. • H.V. Impulse withstand voltage (KV peak): 75 kVp. • Temp Rise: 50°C for Oil, 55°C for Winding as IS 1180 part 1 Eff level 2 norms. • Degree of Protection IP34 for enclosure. • HV & LV bushings: Cable box or plug-in type • Transformers shall be designed for 110% continuous overfluxing withstand capability. • OTI & WTI,Pressure relief valve (without auxiliary contacts),Skids,Earthing terminal,Lifting lugs,Rating plate,Dehydrating breather. 1.3 Low Voltage Compartment • Incomer: 1 no 4 Pole, 1600A, Microporcessor based ACB, rated operational voltage of 415V AC, rated insulation voltage of 1000 volts AC, rated impulse voltage of 12kV, 50 KA Icu=Ics=Icw for 1 sec @440V with LSIG Protection, % load indication of each phase display on the release, No-derating upto 50 Degree Celsius and with Inbuilt ZSI feature. (Schneider,Siemens, L&T/DJB approved make ) • Outgoing feeders: 4 no - 3P,400A,25kA, 3 nos-3P,160A,25kA and 1 no-3P,100A,25kA, Thermal Magnetic MCCB and all MCCB are Double make & Double break technique, Class 2 front facia, Locking in off position, Suitable for Isolation (Schneider , Siemens, ABB/DJB approved make) • Metering: Digital multi-function meter • Cable entry: Bottom / Top (as specified) • Degree of Protection IP54 for enclosure. • Busbar: Aluminum Rated for transformer capacity, 50kA for 1 sec 2. Enclosure • Material: Galvanized Steel Sheet (minimum 2 mm thick) • The enclouser shall have IP54 degree of protection for HT & LT switchgear compatment IP34 degree of protection for Transformer compartment. • The Enclosure to be tested for Internal Arc fault test to the tune of atleast 21 KA for 1 second for class A&B both, adhering to as per latest IEC 62271-202. • The temperature rise test on enclosure for K10class. • The encloser, RMU and LV Breaker should be of same make for better co-ordination and services. • Finish: Powder-coated with anti-corrosive treatment • Roof: Sloped with rainwater drainage • Doors: Lockable with anti-vandal features • Lighting and ventilation: Internal light and louvers. 3. Protection and Safety • Overcurrent and earth fault protection for HV and LV sides • Surge arresters on HV side • Neutral grounding on transformer LV side (solid/through resistor) • Earthing terminals for all compartments • Danger signage and mimic diagram 4. Accessories • Cable glands and lugs • Lifting hooks and skid base • Fire extinguisher bracket • Earthing rods and cables Make: ABB/Schneider/Siemens/L&T/DJB Approved Make.

S/O XLPE insulated 11KV 185 sq mm 3 core cable Make: Gloster/Havells/Polycab/Grandlay/DJB Approved Make.

11KV 3 core indooe type cable jointing kit

S/O PVC insulated 400sq mm 3.5 core aluminum armored Make: Gloster/Havells/Polycab/Grandlay/DJB Approved Make.

Installation of CSS unit ,making foundation/base frame as per relevant IS for fixing the CSS unit

Laying of HT cable & making connection as per site requirement & making connection of termination kit both side

Laying of LT cable & making connection as per site requirement in CSS unit

Testing & commissioning of CSS unit as per required parameters with relevant IS. testing of the System prior to switching on as Continuity and earth testing, Meggaring of all equipment’s for phase to phase, neutral to body, neutral to earth and phase to earth.

Premier Engineering Company (BID ID -1621750)