Specifications

12
General — The 19XR hermetic centrifugal liquid chiller
contains a microprocessor-based control center that monitors
and controls all operations of the chiller (see Fig. 10). The mi-
croprocessor control system matches the cooling capacity of
the chiller to the cooling load while providing state-of-the-art
chiller protection. The system controls cooling load within the
set point plus the deadband by sensing the leaving chilled water
or brine temperature and regulating the inlet guide vane via a
mechanically linked actuator motor. The guide vane is a vari-
able flow pre-whirl assembly that controls the refrigeration ef-
fect in the cooler by regulating the amount of refrigerant vapor
flow into the compressor. An increase in guide vane opening
increases capacity. A decrease in guide vane opening decreases
capacity. The microprocessor-based control center protects the
chiller by monitoring the digital and analog inputs and execut-
ing capacity overrides or safety shutdowns, if required.
MAIN CIRCUIT
BREAKER
TERMINAL
STRIP
MX
BOARD
METERS
SWITCHES
OPTIONAL
VOLT AND AMP
METERS AND
SELECTOR
SWITCHES
METERS
ME
S
WIT
C
HE
S
KEYPAD/
DISPLAY
Fig. 6 — Benshaw Solid-State Starter, Internal View
a19-1896
SIDE SERVICE
ACCESS PA N E L
AIR INTAKE
LOUVERS
OPTIONAL ANALOG 3-PHASE
VOLTMETER AND AMMETER
STARTER CONTROL
DISPLAY INTERFACE
VOLTMETER/
AMMETER
SELECTOR
SWITCHES
STARTER
ACCESS
DOOR
MOTOR
POWER
DISCONNECT
HANDLE
LOW VOLTAGE
ACCESS
DOOR
Fig. 7 — Typical Starter External View (Solid-State Starter Shown)
a19-1854