Catalogue

52 RLC-PRC039B-EN
Mechanical Specifications
General
Units are leak and pressure tested at 390 psig high side, 250 psig low side, then evacuated and
charged. All Air-Cooled Series R Chillers are factory tested prior to shipment. Packaged units ship
with a full operating charge of oil and refrigerant. Unit panels, structural elements and control
boxes are constructed of galvanized steel and mounted on a welded structural steel base. Unit
panels and control boxes are finished with a baked on powder paint, and the structural base with
an air dry paint. All paint meets the requirement for outdoor equipment of the US Navy and other
federal government agencies.
Evaporator
The evaporator is a tube-in-shell heat exchanger design with internally and externally finned
copper tubes roller expanded into the tube sheet.The evaporator is designed, tested and stamped
in accordance with ASME for a refrigerant side working pressure of 200 psig.The evaporator is
designed for a water side working pressure of 150 psig.Water connections are grooved pipe. Each
shell includes a vent, a drain and fittings for temperature control sensors and is insulated with
3/4 inch equal insulation (K=0.28). Evaporator heaters with thermostat are provided to help protect
the evaporator from freezing at ambient temperatures down to -20°F (-29°C). Factory installed flow
switch is installed on a pipe stub in the evaporator inlet.
Condenser and Fans
Air-cooled condenser coils have aluminum fins mechanically bonded to internally finned seamless
copper tubing.The condenser coil has an integral subcooling circuit. Condensers are factory proof
and leak tested at 506 psig. Direct drive vertical discharge condenser fans are dynamically
balanced.Totally enclosed air over motors completely seal the motor windings to prevent
exposure to ambient conditions.Three-phase condenser fan motors with permanently lubricated
ball bearings and internal thermal overload protection are provided. Standard units will start and
operate between 25 to 115°F (-4 to 46°C) ambient.
Compressor and Lube Oil System
The rotary screw compressor is semi-hermetic, direct drive, 3000 rpm, 50 Hz, with capacity control
slide valve, a load/unload valve, rolling element bearings, differential refrigerant pressure oil pump
and oil heater. The motor is a suction gas cooled, hermetically sealed, two-pole squirrel cage
induction motor. Oil separator and filtration devices are provided separate from the compressor.
Check valves in the compressor discharge and lube oil system and a solenoid valve in the lube
system are also provided.
Refrigeration Circuits
Each unit has two refrigerant circuits, with one or two rotary screw compressors per circuit. Each
refrigerant circuit includes a compressor suction and discharge service valve, liquid line shutoff
valve, removable core filter, liquid line sight glass with moisture indicator, charging port and an
electronic expansion valve. Fully modulating compressors and electronic expansion valves
provide variable capacity modulation over the entire operating range.
Unit Controls
All unit controls are housed in an outdoor rated weather tight enclosure with removable plates to
allow for customer connection of power wiring and remote interlocks. All controls, including
sensors, are factory mounted and tested prior to shipment. Microcomputer controls provide all
control functions including startup and shut down, leaving chilled water temperature control,
evaporator flow proving, compressor and electronic expansion valve modulation, fan sequencing,
anti-recycle logic, automatic lead/lag compressor starting and load limiting.The unit control
module, utilizing Adaptive Control™ microprocessor, automatically takes action to avoid unit
shutdown due to abnormal operating conditions associated with low refrigerant pressure, high
condensing pressure and motor current overload. Should the abnormal operating condition
continue until a protective limit is violated, the unit will be shut down. Unit protective functions