Westric DW Series - User Manual

This document is an installation, operation, and maintenance manual for WESTRIC Precision Air Conditioners, DW series models DW-008, DW-010, and DW-012. These units are designed for critical environments such as telephone exchange centers, computer centers, laboratories, and other applications requiring a high degree of reliable air conditioning.

Function Description

The WESTRIC DW series are precision air conditioners designed to maintain stable temperature and humidity levels in sensitive environments. They are available in split configurations with either top or bottom air discharge and top or front return options. The units can be equipped with either indoor or outdoor compressors and are available with or without humidifiers. They utilize a sophisticated control system, often a Carel controller, to manage various operational parameters and ensure precise environmental control.

Key functions include:

• Cooling: Achieved through a refrigeration cycle, with options for air-cooled or water-cooled condensation.
• Heating: Provided by electrical resistors to maintain temperature when cooling is not required or when dehumidification is needed.
• Dehumidification: The system can dehumidify by slowing the evaporator blower speed, activating a solenoid valve, or by switching on electrical heating resistors if the unit is outside the refrigeration range.
• Humidification: For models equipped with a humidifier, the system can add moisture to the air when room humidity drops below the set point.
• Air Filtration: Equipped with medium-efficiency filters to ensure clean air circulation.
• Protection Circuits: Includes features like missing phase, under- and over-voltage sensors, low and high-pressure switches, and air-flow switches to protect the unit from abnormal operating conditions.

Important Technical Specifications

The DW series units come in various configurations regarding power supply, refrigerant type, and nominal capacity.

Power Supply Options:

• Single-phase: 220V - 50Hz - 1F, 220V - 60Hz - 1F
• Three-phase: 380V - 50Hz - 3F, 220V - 50Hz - 3F, 220V - 60Hz - 3F, 460V - 60Hz - 3F, 380V - 60Hz - 3F

Refrigerant Options:

• R-22
• R-407C
• R-410A (P)

Air Discharge Options (Indoor Units):

• For 3 to 5 TR units: Top front recycling ducts, Through plenum, To technical floor and front recycling ducts, To technical floor and top recycling ducts, Top rear recycling ducts.
• For 8 to 30 TR units: Top front recycling ducts, To technical floor and front recycling ducts, To technical floor and top recycling ducts, Top rear recycling ducts.
• Outdoor units typically have horizontal (H) or top (A) air discharge.

Controller Options:

• Slave Controller (E)
• Master Controller (M)
• Single unit controller (U)
• Unit without controller, for sequencer (S)

Unit Configurations:

• Self-contained units (from 3 to 12 TR only) (A)
• Built-in cabinet with compressor (C)
• Built-in cabinet without compressor (I)
• Detachable cabinet with compressor (D)
• Detachable cabinet without compressor (K)
• Outdoor unit without compressor (R)
• Outdoor unit with compressor (E)
• Outdoor unit without compressor horizontal coil (H)

Humidifier Specifications (Example for 3 Kg/h model):

• Water Production: 3 Kg/h
• Power Demand: 2.25 Kw
• Power Supply Voltage: 380VAC, 3 Ph
• Current: 3.2 Inom(A)
• Water flow requirement: 36 l/hour
• Pressure limits: 1-8 bar

Electrical Connections:

• Recommended wire sections are provided based on the installation method and number of poles.
• Standard cable colors are Brown (R phase), Black (S phase), Red (T phase), Light Blue (Neutral), and Yellow/Green (Ground).

Refrigerant Tubing:

• Specific diameters for suction and liquid lines are provided for different models (e.g., DW-008/010: Suction 1 1/8", Liquid 5/8"; DW-012: Suction 1 1/4", Liquid 3/4").
• Additional cooling gas is required for longer tubing runs (e.g., 8.5 g/meter for 1/4" liquid line).

Usage Features

General Features:

• Galvanized, pre-painted steel sheets: Ensure long service life.
• Electronically-controlled modulating condensation: Allows complete control of operating conditions.
• Evaporator section with large coil and high air flow: Ensures high performance and sensible heat.
• Heating batteries in evaporator section: Accelerate dehumidification.
• Stainless steel drip tray: Collects condensate.
• Scroll compressor: High-efficiency compressor with thermal relay protection.
• Electronic Condensation Control (CVTR): Regulates condenser gas pressure/temperature.
• Line Filter: Maintains constant filtration and dehydration of circulating coolant.
• Air Filters: Medium-efficiency filters ensuring clean air.
• Service Valves: Allow isolation of liquid and suction lines for maintenance.
• Electric Motors: Equipped with shielded ball-bearings for continuous, trouble-free operation.
• High-Pressure Switch: Stops evaporator when pressure reaches high values.
• Low-Pressure Switch: Stops evaporator when pressure falls below a certain value.
• Clogged-Filter Switch: Detects clogged filter and triggers an alarm.
• Air-Flow Switch: Monitors air flow and stops unit if flow is insufficient.
• Klixon Thermal Protections: Disconnects heating system in case of blower motor failure.
• Electric resistance for heating and/or dehumidification: Electrical output equivalent to the compressor's.
• Viewing Glass: Transparent tube to observe refrigerant presence.

Control Panel (Carel Controller):

• Four-line display with twenty characters, lit by LEDs.
• Six pushbuttons for navigation and parameter modification.
• Allows viewing and modifying parameters, faults, records, etc.
• Supports multiple units (Master/Slave configuration).

Communication Modes:

• RS485 Communication Card (Optional): Allows communication with a PC via RS485-USB or RS485-Ethernet ModBus.
• TCP/IP (WEBGATE) (Optional): Enables communication with a PC via a 10Mbps Ethernet network or directly to a PC, using standard SNMP protocol. The WebGate device has an integrated web server for remote monitoring and control via a web browser.

Automatic/Manual Start Up:

• Units can operate in automatic mode, controlled by the PLC, or in manual mode for basic operations and no time delays.

Maintenance Features

General Maintenance:

• Condenser Tray: Check and clean regularly. Fill with water to prevent odors.
• Gas Charge: Monitor pressure gauges, especially low pressure, which should be 65 to 75 psi. Recharge if necessary.
• Air Filters: Periodically check and clean. Disposable filters should be replaced when clogged.
  • Dimensions: 20 x 20 x 2" (Quantity 2), 20 x 24 x 2" (Quantity 2), 24 x 24 x 2" (Quantity 2) for top air inlet, front recycling.
  • Dimensions: 20 x 24 x 4" (Quantity 1), 24 x 24 x 4" (Quantity 1) for bottom air inlet, top recycling.
• Housing: Clean with detergent and sponge.
• Coil: Clean regularly to avoid performance loss. Use a brush or vacuum cleaner for dry dirt, and light detergent for oily residues.
• Condenser Coil: Clean regularly, especially if exposed to dust or other contaminants. Check for leaves, feathers, or pieces of paper.
• Power Board: Disconnect main switch before performing maintenance. Adjust screws of contactors and switch terminals. Clean contacts if dirty.

Humidifier Maintenance (if applicable):

• Cylinder Maintenance: Regular cleaning (scaling) of the cylinder every six months.
• Drainage: Manually drain the water by jumpering between GND Terminal and ON Terminal.
• Power Supply: Switch off power by means of the general thermo-magnetic circuit breaker.
• Steam Hose: Disconnect and clean the steam hose from the cylinder.
• Electrical Wiring: Disconnect electrical wiring from main electrodes and high-level electrodes.
• Cylinder Clamp: Remove and clean.
• Lift Cylinder: Remove and clean.
• Electrode Cleaning: Clean electrodes to prevent mineral deposits.
• Water Quality: Use demineralized water. Water parameters (conductivity, hardness, chlorides, etc.) must be within specified limits to ensure proper operation and longevity of the electrodes.

Troubleshooting Guide: The manual provides a comprehensive troubleshooting guide for common problems such as:

• Power supply issues
• Room temperature lower than set point
• Low pressure switch trip
• High pressure switch trip
• Electrical wiring error
• No supply voltage to controller
• Unit not enough to cool room
• Damaged component malfunction
• Gas leaks
• Defective compressor
• Clogged air filter
• Low performance (lack of air)
• Inappropriate wiring for power consumption
• Defective motors and/or compressors
• Low voltage
• Condensate tube clogged or overflowing
• Flow alarm
• Unit does not cool
• Unit does not heat
• Unit does not dehumidify
• LW alarm does not operate

Humidifier Failure Alarms and Troubleshooting: Specific alarms for humidifier failures are detailed, including:

• Electrode current over (High water conductivity, high water level, electrode malfunction)
• No voltage in electrodes (no steam produced)
• Internal Memory Error
• High Water Conductivity
• Saturated Cylinders
• Lack of input water
• Excessive Production Reduction
• Drain malfunction
• User Parameter Errors
• External Signal Command not properly Connected
• Cylinders full without Production
• Foam inside cylinder
• Cylinder Fully Saturated

Each alarm has a description, troubleshooting steps, type (Locked, Blocked, Warning), reset method (Manual, Automatic Reset), and alarm relay status (Enabled, Unaffected).

Blind Interconnection (if applicable):

• Instructions for connecting the blind motor with the terminal provided by the air conditioner.
• Details on adjusting the end switch of the blind motor for calibration.