78
CVHE-SVX005C-EN
Figure 54. Sequence of operation: running
Starting
Compressor
Chiller
Is
Running
Starter
Status Is
“Running”
Limit Mode Exit
Limit Mode
Chiller Is Running Chiller Is RunningChiller Is Running—Limit
Modulate IGV/AFD*
for LWT Control
Modulate IGV/AFD*
for LWT Control
Modulate IGV/AFD*
for LWT Control
Enforce All Running Mode Diagnostics
*Note: AFD applies to CVH only.
Figure 55. Sequence of operation: satisfied setpoint
Satisfied Setpoint
Preparing Shutdown Shutting Down Shutting Down
Running Auto
Close IGV (0 to 50 seconds) Postlube
(CVH: 3 minutes)
(CVG: 1 minute)
De-Energize Oil Pump
Confirm No Oil Pressure*
5 minutes After Oil Pump is De-Energized
De-Energize
Compressor
Confirm No Compressor Currents
Within 0 to 30 seconds
De-Energize Condenser
Water Pump Relay
Command IGV Closed
Enforce All Running Mode Diagnostics
*Note: CVH: No oil pressure is less than 3 psid (20.7 kPaD)
CVG: No oil pressure is opened Oil Differential Pressure Switch
If the STOP key is pressed on the operator interface, the
chiller will follow the same stop sequence as described
earlier except the chilled water pump relay will also open
and stop the chilled water pump after the chilled water
pump delay timer has timed out after compressor shut
down (refer to the following figure [normal shutdown to
stopped and run inhibit]).
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.
Start-Up and Shutdown
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