JOHNSON CONTROLS
7
FORM 160.75-O1 (211)
nent to operation of the chiller are automatically dis-
played 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 compatible with an electro-mechanical start-
er, YORK Solid State Starter (optional), or Variable
Speed Drive (optional).
In operation, a liquid (water or brine to be chilled)
flows through the evaporator, where boiling refrigerant
absorbs heat from the liquid. The chilled liquid is then
piped to fan coil units or other air conditioning terminal
units, where it flows through finned coils, absorbing
heat from the air. The warmed liquid is then returned to
the chiller to complete the chilled liquid circuit.
SECTION 1 - 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 opera-
tion. The Control Center is programmed by the opera-
tor to suit job specifications. Automatic timed start-ups
and shutdowns are also programmable to suit night-
time, weekends, and holidays. The operating status,
temperatures, pressures, and other information perti-
1
LD15222
CONDENSER
CONTROL
CENTER
COMPRESSOR
MOTOR
EVAPORATOR
FIGURE 1 - MODEL YK CHILLER