Summary of Specifications:
Quotes are being solicited for maintenance and repairs on air conditioning systems of the fleet of eleven rail vehicles for the Detroit Transportation Corporation (the People Mover.) The air conditioning system comprises a 28-Kw (96,000 BTU, or 8-ton) system, including an underfloor compressor-condenser unit mounted in a steel frame secured to the underframe of the carbody and an evaporator coil and DC blower motor assembly mounted overhead in the center of the drop ceiling area within the passenger compartment. The compressor-condenser assembly includes a compressor, compressor motor, condenser coil, liquid receiver, a filter drier assembly, compressor start and run resistors, and a weatherproof refrigeration control box mounted on the support frame. The support frame is secured to the underframe of the carbody by four sets of resilient mounts. The compressor is a “Carrier”-manufactured 6-cylinder compressor unit, equipped with an unloading system to provide for capacity control of 100%, 66%, and 33%. The compressor motor operates on nominal 600-Vdc, is 16-HP, draws 25 Amps and has a rated speed of 1250 RPM. The overhead evaporator unit comprises a motor-blower assembly, an evaporator coil, two expansion valves, line and modulation control solenoid valves, a liquid line strainer and a drain pan for condensate. Two different, but similar, generations of evaporator and blower assemblies may be in service. Parts are generally interchangeable between the two systems. The refrigerant (R22) is circulated between the evaporator unit and the motor compressor unit by copper piping routed inside the vehicle walls. All repairs to the air conditioning unit are to be performed with personnel that are EPA-certified for the repair of air conditioning units.
