Trane CVGF-SVU02B-E4 Operation And Maintenance Manual page 61

CVGF-SVU02B-E4
Control System
Components
If the chilled water temperature
drops below the chilled water set
point by an amount set as the
"differential to stop" setpoint, a
normal chiller stop sequence is
initiated as follows:
1. The inlet guide vanes are
driven closed for 50 seconds.
2. After the 50 seconds has
elapsed, the stop relay (2A1-
J10) and the condenser water
pump relays (1A5-J2) open to
turn off. The oil pump motor
(4B3) will continue to run for 1
minute post-lube while the
compressor coasts to a stop.
The chilled water pump will
continue to run while the
Main processor module
(1A22) monitors leaving
chilled water temperature
preparing for the next
compressor motor start based
on the "differential to start"
setpoint.
If the <STOP> key is pressed on
the operator interface, the chiller
will follow the same stop
sequence as above except the
chilled water pump relay (1A5-
J2) will also open and stop the
chilled water pump after the
chilled water pump delay timer
has timed out after compressor
shut down.
If the "Immediate Stop" is
initiated, a panic stop occurs
which follows the same stop
sequence as pressing the
<STOP> key once except the
inlet guide vanes are not
sequence closed and the
compressor motor is
immediately turned off.
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