Water Cooled Water Chillers

Water Cooled Water Chillers

Unit Description:
YONAN YWS series have been designed to be utilized in commercial and industrial air conditiong. Units are suitable for indoor installation. Where noise is concern, YONAN's water cooled water chillers provide the ideal solution for sound sensitive environment.

Compact design makes installation more flexible. Water cooled water chillers are designed with high efficiency scroll or semi-hermetic screw compressors, shell and tube heat exchangers and various safety devices. The units are incorporated with microprocessor control system allowing to monitor and manage all the functions and to communicate with external management system.

The units are completely assembled in the factory, supplied with full refrigerant charge and control equipments, to reduce time and costs. The installation normally requires just hydroid and electrical connections.

Construction Features:
Compressors
The unit adopts Scroll and Screw Compressors. Screw type compressor is direct male motor/female motor drive, with crankcase heater. Lubrication is ensured by discharge and suction pressure difference. Continuous cooling capacity control is available, enabling to maximize the energy efficiency of the unit in any operating condition; Integral electric motor protection and temperature sensors are inserted directly to the windings. Motor starters are delta-star type and are supplied with standard capacity step reduction.

Heat Exchangers
Shell and tube type, dry expansion evaporators are insulated with closed-cell foam material for reduced heat loss. All evaporators are incorporated with temperature probe for anti-freeze protection.

Refrigerant Circuit
Includes: Compressor discharge valves, liquid lines shut-off valve, charging connector, liquid line sight glass, filter drier, thermostatic expansion valve, low pressure control with automatic reset, high reassure control with manual rest, evaporator and condenser water temperature probes for readout by unit control system.

Electrical Control Panel
The electrical panel consists of
Main switch
Power and auxiliary circuit fused
Compressor contactors
Air pressure switch
Microprocessor for control of the following functions:

Water temperature control
Anti-freeze protection
Compressor operation timing
Compressor automatic start-up sequence
Alarm signals
Alarm reset
Digital display of:
Entering and leaving water temperature
Temperature and differential settings

Alarm description
Hour meters readout of operation and number of unit and compressor start-UPS
Electrical power-supply[V/f/Hz]: 380/3-/50+-10%
Control and Safety Devices
Manual reset high pressure switch
Automatic reset low pressure switch
Compressor over temperature protection
Test
Unit are factory tested and come with full oil and refrigerant charges.

Optional Accessories:
Compressor capacity continuous control
Compressor suction valve(only for water chiller)
Remote control terminal
Variable set point with remote signal
Leaving water temperature control