16 of 124  Construction of Giresun Wastewater Treatment Plant  Tender Dossier Volume 3 Employer’s Requirements  Section 08: Electrical Works  Cooling will be made by forced blower, which is coupled to transformer in transformers of which power is  greater than 800 kVA. (AF type). MV winding will be coated with epoxy resin under vacuum and LV winding  will be coated with cast resin. Transformer shall provide as followed regulations and standards;  Standards;  Acc to EC 60076-11 Climatic C2, Enviroment E2, Fire BehaviourF1  • HD 464 S1  • HD 538.1 S1  • EN 60726  • VDE 0532  • ANSI C57.12.01  Temperature control will be made in low voltage winding by PT100/PTC and will put forced fan into operation  at set value and will be able to switch off transformer if temperature continues.  Oil-immersed type transformers (Hermetically): Transformers shall be constructed in accordance with IEC 60076 and be of the naturally air-cooled (ONAN) oil  filled type and meet or exceed the requirements of IEC 60076. They shall be suitable for outdoor installation  (hermetically) and provided with a first filling of mineral oil to comply with BS 148 Grade B30 or similar  (VDE 0370, ANSI C59-2 and TS-623). The transformer shall be mounted over an oil pit. The pit shall have  capacity to consume the entire amount of oil in the transformer. The pit shall be filled with stones that in shape  and size are suitable for the purpose of preventing fire in the spilled oil.  All terminals shall be brought out through oil tight insulating bushings to facilitate cable testing without the  necessity to disconnect the cables. Bushings shall be made of porcelain.  All joints shall be arranged so that they may be tightened externally.  All windings, winding terminals and connections shall be fully immersed in oil under all operating conditions.  All materials shall be suitable for this duty and not subject to deterioration.  All transformer tanks, tubes and all steelwork shall be shot blasted internally and externally before painting and  a rust inhibiting paint shall be applied to both external and internal surfaces before applying a final finish. The  exterior shall be given an additional coat on site of a durable oil and weather resisting paint to BS 4800 to the  shade to be specified by the Engineer. Each transformer shall be provided with the following facilities:   Thermometer for oil temperature with alarm and trip function,   Buchholz relay with trip function,   Oil level gauge, clearly visible from ground level,   Large identity labels shall be affixed to each transformer identifying their high voltage circuit feeder  switchgear,   High voltage and low voltage power circuit cable termination to suit the specified power circuit cables,   Drain valve.  8_Vol3_d4 3_Section 8 electrical works_en_GIR rev6.doc 