Trane CXAU - User Manual

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Overview

Function Description
Important Technical Specifications
Usage Features
Maintenance Features

The Trane CXAU Air-Cooled Modular Chiller/Heat Pump (R410A, models CXAU065/130) is a versatile HVAC unit designed for commercial and residential applications, offering both cooling and heating functionalities. It is a modular system, allowing for flexible installation and scalability.

Function Description:

The CXAU unit operates as an air-cooled chiller or heat pump, providing conditioned water for various applications. It can be used in single or multi-unit configurations, with a centralized controller capable of managing up to 16 units. The unit's operation is governed by a sophisticated control system that includes features like temperature control, defrosting, and various protection mechanisms to ensure reliable and efficient performance. It is designed for closed-loop water systems, emphasizing the importance of proper water quality and flow management.

Important Technical Specifications:

Models: CXAU065 (65 kW nominal cooling/heating capacity) and CXAU130 (130 kW nominal cooling/heating capacity).
Refrigerant: R410A.
Voltage: Available in 380V/50Hz/3Ph, 380V/60Hz/3Ph, and 460V/60Hz/3Ph configurations.
Efficiency: Super-efficiency (indicated by 'S' in model number).
Controller: Can be ordered with or without a controller (380V or 460V options).
Operating Map:
- Cooling Ambient Temperature Range: -20°C to 48°C.
- Heating Ambient Temperature Range: -30°C to 48°C.
- Cooling Outlet Water Temperature Range: 5°C to 20°C.
- Heating Outlet Water Temperature Range: 30°C to 55°C.
- Controller Operating Temperature Range: -10°C to 60°C.
- Controller Relative Humidity Range: <90%.
Water Flow Rate:
- CXAU065: 9.7 m³/h (rated).
- CXAU130: 19.4 m³/h (rated).
Water Pressure Drop (with filter):
- CXAU065: 55 kPa.
- CXAU130: 39 kPa.
Water Pipe Connections:
- CXAU065: Rc 2".
- CXAU130: Rc 2-1/2".
Electrical Wiring: Requires independent power supply with a circuit breaker matching the unit's voltage. All field-installation wiring and grounding must conform to local electrical codes. Minimum copper core wiring sizes are specified based on model and voltage (e.g., 4 AWG for CXAU0655BVS, 1 AWG for CXAU1305BVS).
Controller Dimensions: 250 x 220 x 90 mm (W x H x D).

Usage Features:

Modular Design: Allows for flexible installation and expansion, with the ability to connect up to 16 units to a single centralized controller.
Centralized Control: The touch-screen centralized controller provides comprehensive management of all connected units, including mode selection (cooling/heating), temperature setpoint adjustment, noise reduction settings, and manual defrosting.
Language Selection: The controller interface supports multiple languages (Chinese, English).
Power-off Memory: Allows setting fixed ON/OFF times for each day of the week, with a timer icon appearing on the header when enabled.
Remote Control: Supports remote switch/terminal interlock and remote mode switching (cooling/heating).
System Protection: Includes various automatic protection functions:
- High Pressure Protection (HP1, HP2): Alarms and stops the unit if pressure setpoint is reached.
- Low Pressure Protection (LP1, LP2): Stops the compressor if operating pressure is too low, requiring manual reset.
- Winter Anti-Frost Protection: For heat pump units, automatically switches to anti-freeze operation when water temperature is low. For chiller units, requires draining water or adding antifreeze.
- Heat Exchanger Anti-freeze Protection: Shuts down the unit if leaving water temperature is below the anti-freeze setpoint.
- Motor Overload Protection: Protects compressor, water pump, and fan motors from overload.
- Temperature Sensor Protection: Alarms and shuts down if a temperature sensor fails, requiring manual reset.
- Low Refrigerant Suction Pressure Protection: Shuts down and alarms in cooling mode if suction pressure falls below setpoint.
- Water Pump Overload Detection: Shuts down and alarms if the water pump is overloaded.
- Abnormal Temperature of Entering and Leaving Water: Shuts down and alarms if pipes are connected reversely.
- Compressor Overload Detection: Alarms and shuts down if any compressor is overloaded.
- High Discharge Temperature Protection: Alarms and shuts down if discharge temperature is too high.
- Ambient Temperature Lockout Protection: Prevents startup or shuts down if ambient temperature is out of range.
- Cooling and Heating Temperature Setpoint Automatic Adjustment Protection: Adjusts operation within allowable temperature ranges.
- Low Water Flowrate Protection: Shuts down and alarms to prevent evaporator freezing due to low water flow.
Water System Requirements: Emphasizes professional design for water flowrate, proper piping size, installation of anti-vibration hoses, pressure gauges, water filters (20-40 mesh), automatic exhaust valves, and expansion tanks. Closed-loop water systems are required.
Antifreeze: Ethylene glycol antifreeze is recommended for low ambient temperatures, with specific concentration guidelines (above 20%) and regular testing.

Maintenance Features:

Regular Checks: Daily checks include condenser cleanliness, fan blade cleanliness, compressor noise/vibration, unit integrity (loose electric control box, pipeline leakages), air in water pipe system, water filter cleanliness, and water quality.
Water Quality Monitoring: Regular testing of water quality (pH, conductivity, chloride, sulfate, acid consumption, hardness, iron, ammonium, silicon oxide, residual chlorine) is crucial to prevent corrosion, scaling, and performance degradation. Exceeding allowable ranges can lead to unit damage and paid services.
Antifreeze Concentration Check: For units using ethylene glycol, regular checks of its concentration are necessary to maintain antifreeze ability.
Condenser Cleaning: Regular cleaning of the condenser (fins, fan blades) is essential to prevent high operating pressure, increased power consumption, and unit failure. Compressed air, brushes, or water columns can be used, with specific instructions to avoid damage.
Water Flow Switch Check: The built-in flow switch (if present) or temperature difference between inlet and outlet water can be used to verify adequate water flow.
Professional Maintenance: All maintenance and servicing work should be carried out by qualified professionals at least every six months or 1000 operating hours.
Safety Precautions: Emphasizes cutting off the main power supply before any contact with the unit during maintenance to prevent casualties and damage.
Hazardous Substances: The manual includes a table detailing hazardous substances in various components (Pb, Hg, Cd, Cr(VI), PBB, PBDE), indicating compliance with SJ/T 11364 standards, with some exceptions where technical conditions temporarily prevent complete elimination.