Trane CGWF, CCAF manual Mechanical Specifications

Mechanical Specifications

General

All scroll chillers are factory tested and monitored for power and control operation (CGWF only). CGWF units ship with a full operating charge of refrigerant and oil. CCAF units ship with a full operating charge of oil. Exposed surfaces are painted with an air-dry beige primer-finisher prior to shipment.

Compressor-Motor

Direct-drive, hermetic, 3600 rpm, 60 Hz [3000 rpm, 50 Hz] fixed compression, scroll compressors (20 to 30 tons - two compressors; 40 to 60 tons - four compressors). Each compressor has: centrifugal oil pump, oil level sightglass, oil charging valve, two point lubrication for each motor bearing, flooded lubrication for the journal and thrust bearings, and a check valve on the scroll discharge port.

Motor is suction gas-cooled, hermetically sealed, two-pole, squirrel cage induction type.

Evaporator

Shell and tube design with seamless copper tubes roller expanded into tube sheets. Designed, tested and stamped in accordance with ASME Code for refrigerant side working pressure of 300 psig. Water side working pressure is 300 psig for CGWF 20-50 and CCAF 20-60, 215 psig for CGWF 60. One water pass with a series of internal baffles. Each shell includes drain connections, entering and leaving temperature sensors, and ¾ inch Armaflex II (or equal) insulation (K= 0.26).

Condenser (CGWF only)

Shell and tube design with seamless internally enhanced copper tubes. Designed, tested and stamped in accordance with ASME Code (CGWF 60 only) the refrigerant side working pressure of 450 psig. Water side working pressure is 300 psig for CGWF 20-50, 150 psig for CGWF 60. Two pass construction with six-inch diameter shell (20 to 30 tons). One pass construction with two separate condensers connected in series (40 to 60 tons). Each condenser includes a subcooler circuit. Tubes are cleanable and replaceable.

Refrigerant Circuit

Each refrigeration circuit shall be completely independent and shall include liquid line and discharge line service valves, filter dryer, combination moisture indicator-sightglass, charging port, insulated suction line, liquid line solenoid valve and thermal expansion valve.

Isolation valves provide means of isolating refrigerant charge in either the high or low pressure side while servicing. One refrigerant circuit on

20 to 30 tons; two refrigerant circuits on

40 to 60 tons.

Condenserless units (CCAF) shall be equipped with discharge check valve and moisture indicator sightglass.

Unit Controls (CH530)

The microprocessor-based control panel is factory-installed and factory-tested. Chilled water reset based on return water is standard.

The CH530 microprocessor automatically acts to prevent unit shutdown due to abnormal operating conditions associated with low evaporator refrigerant temperature, high condensing temperature, and/or motor current overload. If an abnormal operating condition continues and the protective limit is reached, the machine should shut down.

The panel includes machine protection shutdown requiring manual reset for the following conditions:

•low evaporator refrigerant temperature and pressure

•high condenser refrigerant pressure

•critical sensor or detection circuit faults

•motor current overload

•high compressor discharge temperature

•lost communication between main processor and LLID

•electrical distribution faults: current loss or phase reversal

•external and local emergency stop

•starter contactor interrupt failure

The panel also includes machine protection shutdown with automatic reset for the following correctable conditions:

•power loss

•loss of evaporator or condenser water flow

When a fault is detected, the control system conducts more than 60 diagnostic checks and displays results. The display will identify the fault, indicate date, time, and operating mode at time of occurrence, and provide type of reset required and a help message. The diagnostic history will display the last ten diagnostics with their times and dates of occurrence.

38 CG-PRC012-EN