Section 1- Description Of System And Fundamentals Of Operation; General System Description; Refrigeration System Operation; Figure 1 - Model Yst Chiller - York YST Operation Manual

FORM 160.67-O1
ISSUE DATE: 4/1/2015
SeCTion 1- deSCripTion of SYSTeM and

general SYSTeM deSCripTion

The YORK Model YST Chiller is commonly applied
to large air conditioning systems, but may be used on
other applications. The Chiller is completely factory-
packaged including; the evaporator, refrigerant con-
denser, compressor, steam turbine, lubrication systems,
power panel, control center, and all interconnecting
unit piping and wiring. The steam condenser package
is shipped separately and suitable for direct mounting
onto the chiller or mounting along side the chiller.
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.
The chiller control panel provides control of entire sys-
tem, including turbine and steam condenser operation
and monitoring.
ATMOSPHERIC RELIEF
STEAM CONDENSER
PACKAGE
VACUUM PUMPS
CONDENSER
HOT GAS BYPASS
VALVE

figure 1 - MODEL YST CHILLER

JOHNSON CONTROLS
fundaMenTalS of operaTion
VALVE
The control panel includes a color liquid crystal display
(LCD) surrounded by "soft" keys which are redefined
based on the screen displayed at that time, mounted
in the middle of a keypad interface and installed in a
locked enclosure. The screen details all operations
and parameters, using a graphical representation of the
chiller and its major components. Panel text is in Eng-
lish only. Data can be displayed in either English or
Metric units.

refrigeraTion SYSTeM operaTion

(See Figure 3 on page 11)
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 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.
HOTWELL PUMPS
CONTROL CENTER
POWER PANEL
EVAPORATOR
STEAM TURBINE
COMPRESSOR
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