PROVN OF BACK FEED FOR POWER RING AND SPECIAL REPAIR/REPLACEMENT OF HT CABLE AND CONNECTING ACCESSORIES OF HT POWER RING AT AF STN TEZPUR

Carry out Site inspection and Survey to MAFI- PS-I and MAFI- PS-II including to and from and loading boarding of equipment required to carryout works of "back feed" system at AF Station Tezpur.

Provision of "back feed" with auto function & Integration of ACB 4 pole 1000 Amps-02 Nos in MAFI PS-I VCB 3 pole 630 Amps electrically and mechanically operated -12 Nos (MAFI PS-I- 06 Nos & MAFI PS-II- 06 Nos) to suit emergency power feed up to MAFI PS-2 including selection & supply of various control cable, laying, termination, testing in complete with conformance to interlock suitability for Normal & CATII modes of operation for specific direction of power feeds complete all as specified and directed by Engr-in-charge.

Provision of Interlocks (Only) to limit the auto ops in existing ACB4 pole 1000 Amps-02 Nos in MAFI PS-I VCB 3 pole 630 Amps electrically and mechanically operated -12 Nos (MAFI PS-I- 06 Nos & MAFI PS-II- 06 Nos) to suit emergency power feed up to MAFI PS-2 with selection of various control cable including laying, termination, testing for Normal & CATII modes of operation for specific direction of power feeds complete all as specified and directed by Engr-in-charge. Note: Interlocking system contain PLC controlled breakers of HT Incomer VCB and LT commercial ACB along with two numbers DG incomer ACBs will be interlocked electrically so that operations of these breakers will occur only one at a time. This interlocks will protect the supply collision in system failure/malfunctioning. 1. UV coils of ACB’s and trip circuit of VCB will be interlocked to avoid force full manual operation. 2. Breaker closing circuits will be interlocked electrically so that only one breaker will operate at a time.

Development/installation/testing of PLC software for monitoring & control of 7 VCB's,(06 Nos at PS-I and 01 Nos at MRS) ACB's, 750 KVA DG (02 Nos) operations at PS-1 to have emergency power feed up to MAFI PS-2 automatically by use of control over existing switchgear for Normal & CATII modes of operation for specific direction of power feeds complete all as specified and directed by Engr-in-charge. Note: Programming software details, make and validity 1. PLC Programming software : CX-Programmer 2. Make : Omron 3. Version : Version 9.7 or Higher 4. License Validity : Life time Validity 5. HMI Programming software : NB Designer 6. Make : Omron 7. Version : Version 1.7 or Higher 8. License Validity : Life time Validity

Testing, decommissioning & re-commissioning of existing MAFI-1 PS transformer- 02 Nos,(630 KVA -01 Nos in MAFI PS-I & 200 KVA-01 Nos in MAFI PS-II) VCB’s 14 Nos 630 Amps (total 12 Nos at PS-I & II and 02 Nos at MRS), ACB’s 1000 Amps 4 pole of both substations including rearrangement (if required) in terms of position / place to suit updated power flow arrangement complete all as specified and directed by Engr-in-charge.

Development of scheme wirings / scheme diagrams/cable schedule for each station to suit integration program and preparation / conduct of scheme test protocolscomplete all as specified and directed. Note: Contractor should submit Schematic diagram for this project in hard copy as well as in soft copy to authorized officials and one copy will be displayed at the project site.

Health Check & Repair functions for transformer- 02 Nos,(630 KVA -01 Nos in MAFI PS-I & 200 KVA-01 Nos in MAFI PS-II) 11 KV VCB's 14 Nos (total 12 Nos at PS-I & II and 02 at MRS) , Interconnection Cabling tests and termination, 1000 Amps ACB's, bus coupler's including addition of remote control facility, U/V facility, Enhancement of aux contacts (if required) with extension of control wiring within equipment in complete to suit Original MAFI Concept complete all as specified and directed. Note : Health check should be as follow A. Inspection for abnormal temperature variation and cooling system of T/F. B. Check against transformer oil level/ temperature. Top up with dry oil, if necessary. C. Check T/F for any oil leakage from bushings, breathers etc. D. Check for any abnormal sound or excessive chattering. If any investigate and repair. E. Examine relays and alarm contacts and their operation, fuses etc. Check for relays functioning clean or replace the contacts. F. Earth resistance measurement of the (a) T/F body, neutral and other body parts. G. Oil test for dielectric strength, Dehydrate or replace the oil, if necessary. H. In case of fan & pump cooled T/F, Lubricate all bearings, check gear box. Examine Contacts, Check Manual control and interlocks. Replace burnt or worn out contacts or other parts. J. Insulation resistance comparison in 70 degree temperature with the initial values available at commissioning time. K. Check and arrest leakage/seepage of oil from main tank to OLTC tank L. Check for proper earthing of transformer body top cover with main body to reduce eddy current loss. M. After completion of the project the contractor shall have to arrange training to the officials/ persons/operators available at site without any extra cost to the depot. A certificate in this respect shall be provided against the said training to 08 personals of MES/User rep.

Excavating in Trenches not exc. 1.50 mtr wide and not exc. 1.50 mtr in depth, Taking Out and Laying of Cables, etc. and getting out in Soft/ Loose Soil, complete all as specified and as directed.

Returning, Filling in, including Spreading, Levelling, Watering and Well Ramming in Layers not exc. 250mm in Soft/Loose Soil, complete all as specified and as directed.