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START-UP/SHUTDOWN/
RECYCLE SEQUENCE
Local Start/Stop Control
Local start-up (or manual start-up) is initiated by pressing the
gray Start/Stop icon on the HMI interface. See Fig. 14. Note the
display may change based on product type and options selected.
Fig. 14 — Chiller Start/Stop Icon
This initiates the PIC6 starting sequence by displaying the list of
operating modes. Press Local On to initiate start-up. See Fig. 15.
Fig. 15 — Local On
NOTE: Prior to start-up, the start-to-start timer and the stop-to-
start timer must have elapsed and all alarms must be cleared (see
Troubleshooting Guide section on page 51).
When start-up is initiated, the status screen displays start-up prog-
ress and the Start/Stop icon
begins, the PIC6 control system performs a series of pre-start tests
to verify that all pre-start alerts and safeties are within acceptable
limits. Table 2 shows appropriate Prestart Alerts/Alarms condi-
tions. If a test is not successful, the start-up is delayed or aborted.
If the tests are successful, the start-up will be in progress and the
COMPRESSOR RUN STATUS shall be "Startup." The control
shall then energize the chilled water/brine pump relay.
blinks green. Once local start-up
Five seconds later, the condenser pump relay energizes. Thirty
seconds later the PIC6 control system monitors the chilled water
and condenser water flow devices and waits until the WATER
FLOW VERIFY TIME (operator-configured, default 5 minutes)
expires to confirm flow. After flow is verified, the chilled water
temperature is compared to CONTROL POINT plus 1/2
CHILLED WATER DEADBAND. If the temperature is less than
or equal to this value, the PIC6 control system turns off the con-
denser pump relay and goes into a Recycle mode.
If the water/brine temperature is high enough, the start-up se-
quence continues and checks the guide vane position. If the
guide vanes are more than 4% open, the start-up waits until the
PIC6 control system closes the vanes. If the vanes are closed and
the oil pump pressure is less than 6 psi (41.4 kPa), the oil pump
relay energizes. The PIC6 control system then waits until the oil
pressure (OIL PRESS VERIFY TIME, operator-configured, de-
fault of 40 seconds) reaches 18 psi (124 kPa) which indicates
satisfactorily oil pump pressure to continue start-up. After oil
pressure is verified, the PIC control system waits 40 seconds,
and the compressor start relay energizes to start the compressor.
Compressor ontime and service ontime timers start, and the
compressor STARTS IN 12 HOURS counter and the number of
starts over a 12-hour period counter advance by one.
Failure to verify any of the requirements up to this point will result
in the PIC6 control system aborting the start and displaying the ap-
plicable pre-start alert alarm state number near the bottom of the
home screen on the HMI panel. A prestart failure does not ad-
vance the STARTS IN 12 HOURS counter. Any failure after the
start command relay has energized results in a safety shutdown,
advances the starts in 12 hours counter by one, and displays the
applicable shutdown status on the display.
For normal start-up the minimum time to complete the entire pre-
start sequence is approximately 185 seconds. See Fig. 16 for nor-
mal start-up timing sequence. See Table 2 for a list of prestart
checks.
Table 2 — Prestart Checks
PRESTART CHECK CONDITION
STARTS IN 12 HOURS 8 (not counting recycle restarts or auto
restarts after power failure)
OIL SUMP TEMP 140°F (60°C) and
OIL SUMP TEMP EVAP_SAT + 50°F (27.8°C)
COND PRESSURE COND PRESS OVERRIDE – 20 psi
#RECYCLE RESTARTS LAST 4 HOURS > 5
COMP BEARING TEMPS COMP BEARING ALERT– 10°F (5.6°C) Alarm – 230
COMP MOTOR WINDING TEMP MOTOR TEMP OVERRIDE –
10°F (5.6°C)
COMP DISCHARGE TEMPERATURE COMP DISCHARGE
ALERT– 10°F (5.6°C)
EVAP REFRIG LIQUID TEMP OR EVAP_SAT
< EVAP REFRIG TRIPPOINT
AVERAGE LINE VOLTAGE UNDERVOLTAGE THRESHOLD
AVERAGE LINE VOLTAGE OVERVOLTAGE THRESHOLD
CHECK FOR GUIDE VANE CALIBRATION
NOTE(S):
a. If Prestart Check Condition is True, then resulting State is as indicated in the
State Number column.
b. See the Controls Operation and Troubleshooting guide for alarm and alert codes.
c. Refrig trip point = 33°F (0.6°C) (water) and configurable for brine application.
19
a
c
+ EVAP OVERRIDE DELTA T
STATE
NUMBER
b
Alert – 100
Alert – 101
Alert – 102
Alert – 103
Alarm – 231
Alarm – 232
Alarm – 233
Alarm – 234
Alarm – 235
Alarm – 236
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