Rakesh Nath - CEA

1 Rakesh NathChairperson, Central ElectricityAuthority & Ex officio SecretaryGovernment of IndiaForewordThe objective of National Electricity Policy is Power to all by 2012 . To achive this, about78500 MW of generation capacity and matching Transmission and distribution systems are to beadded during 11th Plan. This would entail addition of about lakh MVA of DistributionTransformer capacity during the Plan. Stringent quality control has to be ensured right from selectionof raw materials, manufacturing to procurement and installation of these transformers .

2 The distribution utilities have generally been procuring transformers with maximum allowablelosses as per IS1180. With the advent of more efficient materials and improvement in technology,it is now possible to have much more efficient and better quality transformers at reasonable specifications for single phase and three phase outdoor oil filled distribution Transformershave been prepared by the Central Electricity Authority to act as Guidelines for the utilities forselection and procurement of energy efficient transformers . The specifications have been finalizedafter detailed discussions with the distribution utilities and the manufacturers of DistributionTransformers.

3 This has been possible through the concerted efforts of engineers in the distribution Planning& Development Division of Central Electricity Authority. I hope the Guidelines will be of immenseuse for the engineers in the Power distribution utilities. ( Rakesh Nath)Member GO&DCentral Electricity AuthorityEx-officio Additional SecretaryGovt. of IndiaPrefaceReforms in the distribution sector have got a big boost with the implementation of theAccelerated Power Development and Reform programme of Govt. of India. Distributiontransformers form a very vital and substantial part in the delivery supply chain and large number oftransformers are being procured by the utilities under this programme as well as with their ownresources to meet the GOI mission of Power for all by 2012.

4 Recognising the importance ofstandardization of specifications of the distribution transformer for procurement of qualitytransformers, the Central Electricity Authority has formulated technical Specifications for Threephase and single phase oil filled outdoor type distribution transformers . The document has been prepared after discussions and considering inputs from the variousstakeholders of the Power distribution industry viz power utilities, manufacturers and Bureau ofEnergy Efficiency. The document is intended to provide Guidance for preparing technical part ofthe tender document for procurement of distribution specifications are the result of the concerted efforts of Sh.

5 Alok Gupta Chief EngineerDP&D and Smt. Anjuli Chandra Director ( distribution ) and other officers of distribution Planning& Development Division. ( Dhiman)Sl. FOR OUTDOORS TYPETHREE PHASE OIL immersed (INCLUDINGCOMPLETELY SELF PROTECTED) 01 distribution transformers 11 kV/433 250V and 33 kV FOR OUTDOOR TYPESINGLE PHASE OIL immersed (INCLUDING 55 COMPLETELY SELF PROTECTED) DISTRIBUTIONTRANSFORMERS 11 kV/230 V and 11/ 3 kV/230 FOR OUTDOOR TYPE THREE PHASE OIL immersed (INCLUDING COMPLETELYSELF PROTECTED) distribution transformers OF 11 kV/433 250V and 33 kV for non preparation and self protected (CSP)

6 Management signal tests to be conducted on one at and testing of transformer assurance and -IMethodology for computing total owning cost29 Annexure -IIProforma for stage inspection of distribution30transformersAnnexure -IIIP roforma for pre-delivery inspection of41distribution transformersAnnexure -IVSource of meterial / places of manufacture,47testing and inspectionSchedule-IAGuaranteed and other particulars for distribution48transformersSchedule-IBAdd itional details52 CONTENTSSPECIFICATION FOR OUTDOOR TYPE SINGLE PHASE OIL immersed (INCLUDINGCOMPLETELY SELF PROTECTED) distribution transformers 11 kV/230 V and 11/ 3 kV/230 V.

7 Clause for non preparation and and terminal release kv lightning load capacity6821 Protection : (for CSP transformers ) tests to be conducted on one at assurance and for computing total owning cost76 Schedule IAGuaranteed technical particulars for completely77self protected distribution transformersSchedule IBAdditional details79 Schedule IIBS ource of materials/places of manufacture,80testing and inspectionSTANDARD TECHNICAL SPECIFICATIONFOROUTDOOR TYPE THREE PHASE OIL immersed (INCLUDING COMPLETELY SELF PROTECTED)

8 distribution TRANSFORMERS11 kV/433-250 VAND33 kV/433-250 V11/ 3 kV/230 V1 TECHNICAL SPECIFICATION FOR OUTDOOR TYPEDISTRIBUTION transformers 11 kV/433 250 Vand 33 kV / 433-250V1 specification covers design, engineering, manufacture, assembly, stagetesting, inspection and testing before supply and delivery at site of oil immersed ,naturally cooled 3 phase 11 kV/433 - 250 V and 33 kV/433-250 V distributiontransformers for outdoor is not the intent to specify completely herein all the details of the design andconstruction of equipment.

9 However the equipment shall conform in all respectsto high standards of engineering, design and workmanship and shall be capableof performing in continuous commercial operation, in a manner acceptable tothe purchaser, who will interpret the meanings of drawings and specificationand shall have the power to reject any work or material which, in his judgment isnot in accordance therewith. The offered equipment shall be complete with allcomponents necessary for their effective and trouble free operation. Suchcomponents shall be deemed to be within the scope of bidder s supplyirrespective of whether those are specifically brought out in this specificationand / or the commercial order or transformer and accessories shall be designed to facilitate operation,inspection, maintenance and repairs.

10 The design shall incorporate everyprecaution and provision for the safety of equipment as well as staff engagedin operation and maintenance of outdoor apparatus, including bushing insulators with their mountings, shallbe designed so as to avoid any accumulation of standard ratings shall be 10, 16, 25, 63, 100, 160, 200, 250, 315, 400,500, 630, 1000, 1250, 1600, 2000 and 2500 kVA for 11 kV distributiontransformers and 100, 160, 200, 315, 400, 500, 630, 1000, 1250, 1600, 2000,2500 kVA for 33 kV distribution materials shall conform in all respects to the relevant Indian/InternationalStandards, with latest amendments thereof unless otherwise specified of them are listed below.