Schreiber Chillers Modular Chillers - Manual (Page 7)

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CHILLER SYSTEM MANUAL
System Overview:
The Schreiber Modular Chiller System is designed to provide a reliable supply of chilled water
to a cooling process load and ability to add-on cooling capacity at a minimum investment
cost. The modular design allows for accurate temperature control and reliability by using
multiple refrigeration circuits.
The modular system is made up of two types of modules:
PUMP STATION MODULE
CHILLER MODULES – REFRIGERATION SYSTEM
Pump modules contain a chilled water reservoir, a chilled water pump, and a process pump.
In the control architecture, the pump module serves as the “master” controller. The control
enclosure centralized the module fuses, disconnect, the power connection to the chiller, and
pump-chiller communication cable. The pump module contains and monitor supply
temperature (tank temperature) and process return temperature.
Each Chiller module comes with water flange connection for inlet and outlet. The chiller
module contains its own controller that will communicate with the master controller at the
pump station. The chiller control manages the chiller functionality which includes
compressors and fans operations, and alarms.
The distributed control architecture and the chiller module construction allows for maximum
flexibility by allowing two chiller modules to be added, without reconfiguring the rest of the
system.
Control System Architecture
THE PUMP MODULE NEEDS TO BE CONFIGURED FOR NUMBER OF MODULE IN THE
SYSTEM INCLUDING THE PUMP MODULE. For example, if there are two chiller and a
pump station, the number of module will be configured to three (3). During normal operation,
both the chiller pump and process pump will be operating. The pump module controller reads
the supply and returns temperature of the process and determines the numbers of
compressors need to activate to react to the load and maintain set point within a specified
degree of accuracy. If the master control is configured to be three (3) modules, the master
controller “broadcasts” its requirement to compressors across the p-LAN network. The
assigned compressor will then start according to the signal.
Each chiller contains refrigeration system, fans system and water connection for heat
exchanger. Each chiller also includes its own control circuit the monitor the following devices:
High Refrigerant Pressures
Low Refrigerant Pressures
Loss of Water Flow
Inlet Temperature Sensor