bids are invited for supply, installation, testing and commissioning of vrv / vrf air-conditioning system comprising of modular type high efficiency dc scroll / twin rotary multiple compressor with dc inverter, high efficiency heat transfer cooling coil suitable for environment friendly hfc r410a / r407c refrigerant, air cooled propeller type condenser fan with dc motor drive, interconnecting piping, insulation etc., micro-processor control panel suitable for automatic operation, high speed calculation inverter control, active oil control mechanism incorporating all safety functions as per technical specifications & other points listed below. unit shall have a mimumum of 2 compressors. and each compressor shall run independently even though there is a failure in the other compressor.the unit mounted starter panel shall be complete with ip-55 protection consisting of power disconnecting switches with fuses, soft starters, for compressor motors, under / over voltage trip, single phase preventers, communication card which can accept 4-20 ma or 2-10 vdc analog signal.all components shall be mounted on welded steel base frame, structural steel profiles / panels made out of galvanized sheet steel, protected with primary coat & finished with epoxy paint.