Description of system and fundamentals of
operation
System operation description
The YORK Model YK Chiller is commonly applied to large air conditioning systems, but may be
used on other applications. The chiller consists of an open motor mounted to a compressor (with
integral speed increasing gears), condenser, evaporator and variable flow control.
The chiller is controlled by a modern state of the art Microcomputer Control Center that monitors
its operation. The Control Center is programmed by the operator to suit job specifications.
Automatic timed start-ups and shutdowns are also programmable to suit nighttime, weekends,
and holidays. The operating status, temperatures, pressures, and other information pertinent
to operation of the chiller are automatically displayed and read on a graphic display. Other
displays can be observed by pressing the keys as labeled on the Control Center. The chiller with
the OptiView Control Center is applied with an Electromechanical Starter, YORK Solid State Starter
(optional), or Variable Speed Drive (optional).
When the compressor motor is driven by a YORK Solid State Starter, one of two different starters
could be applied. Later production chillers are equipped with either the Style B Liquid Cooled Solid
State Starter (LCSSS) or the Medium Voltage Solid State Starter (MVSSS).
Figure 2: Model YK chiller
Callout
Description
Callout
Description
1
Condenser
2
Control center
3
Compressor
4
Motor
5
VSD
6
Evaporator
When the compressor motor is driven by a YORK Variable Speed Drive, there could be a Variable
Speed Drive (VSD) or a Medium Voltage Variable Speed Drive (MV VSD) applied.
In operation, a liquid (water or brine to be chilled) flows through the cooler, where boiling
refrigerant absorbs heat from the liquid. The chilled liquid is then piped to fan coil units or other air
Model YK Style H Centrifugal Liquid Chillers with OptiView Control Center
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