Specifications

48
Table 6 — Protective Safety Limits and Control Settings (cont)
Default Screen Freeze — When the chiller is in an
alarm state, the default ICVC display “freezes,” that is, it stops
updating. The first line of the ICVC default screen displays a
primary alarm message; the second line displays a secondary
alarm message.
The ICVC default screen freezes to enable the operator to
see the conditions of the chiller at the time of the alarm. If the
value in alarm is one normally displayed on the default screen,
it flashes between normal and reverse contrast. The ICVC de-
fault screen remains frozen until the condition that caused the
alarm is remedied by the operator. Use ICVC display and
alarm shutdown record sheet (CL-15) to record all values from
default screen freeze.
Knowledge of the operating state of the chiller at the time an
alarm occurs is useful when troubleshooting. Additional chiller
information can be viewed on the status screens and the
ISM_HIST screen. Troubleshooting information is recorded in
the ALARM HISTORY table, which can be accessed from the
SERVICE menu.
To determine what caused the alarm, the operator should
read both the primary and secondary default screen messages,
as well as the alarm history. The primary message indicates the
most recent alarm condition. The secondary message gives
more detail on the alarm condition. Since there may be more
than one alarm condition, another alarm message may appear
after the first condition is cleared. Check the ALARM HISTO-
RY screen for additional help in determining the reasons for the
alarms. Once all existing alarms are cleared (by pressing
the softkey), the default ICVC display returns to nor-
mal operation.
MONITORED PARAMETER STATE LIMIT COMMENTS
Overload Trip 217
Any LOAD CURRENT PHASE > 108% for Exces-
sive Time Period
Preset Alarm, Force ACTIVE DEMAND
LIMIT in MAINSTAT screen
Locked Rotor Trip 218 Motor Locked Rotor Amps exceeded Preset Alarm
Excessive Amps 208 PERCENT LOAD CURRENT > 110% for 30 sec. Preset Alarm
Acceleration Fault (full voltage) 203
PERCENT LOAD CURRENT >100% at 10 sec
after 1CR closes (across the line)
Preset Alarm, PERCENT LOAD CUR-
RENT = AVERAGE LOAD CURRENT/
MOTOR RATED LOAD AMPS
Acceleration Fault (reduced
voltage)
203
PERCENT LOAD CURRENT >150% at 20 sec
after 1CR closes (reduced voltage)
Preset Alarm, PERCENT LOAD CUR-
RENT = AVERAGE LOAD CURRENT/
MOTOR RATED LOAD AMPS
Acceleration Fault (reduced
voltage)
203
PERCENT LOAD CURRENT >100% at 45 sec
after 1CR closes (reduced voltage)
Preset Alarm, PERCENT LOAD CUR-
RENT = AVERAGE LOAD CURRENT/
MOTOR RATED LOAD AMPS
Amps not Sensed 202
PERCENT LOAD CURRENT < 15% w/1M/2M
closed
Preset Alarm, PERCENT LOAD CUR-
RENT = AVERAGE LOAD CURRENT/
MOTOR RATED LOAD AMPS
Amps when Stopped 205 Amp signal > 10% w/1M/2M open preset alarm
Failure to Stop 204 1M/2M contacts fail to open Shunt trip, if equipped
Failure to Stop 205
MOTOR AMPS WHEN STOPPED ( Amps > 10%
w/ 1CR OFF )
Shunt trip, if equipped
Starts Limit Exceeded 100 More than 8 starts in 12 hours Preset Prestart Alert
Low Chilled Water Flow 229
CHILLED LIQUID DELTA P < EVAP FLOW DELTA
P CUTOUT OR EVAPORATOR APPROACH >
EVAP APPROACH ALERT AND EVAP REFRIG
LIQUID TEMP < EVAP REFRIG TRIPPOINT + 1
OR CALC EVAP SAT TEMP < EVAP REFRIG
TRIPPOINT
Optional Alarm With ICVC DSABLE
FLOW DELTA P DISPLAY in SETUP1
screen Optional Alarm, All limits configu-
rable in SETUP1 screen
Low Cond Water Flow 230
CONDENSER LIQUID DELTA P < COND FLOW
DELTA P CUTOUT OR CONDENSER APPROACH
> CONDENSER APPROACH ALERT OR CON-
DENSER PRESSURE > COND PRESS OVER-
RIDE + 5
Optional Alarm With ICVC DSABLE
FLOW DELTA P DISPLAY in SETUP1
screen
High Approach - Evaporator 162
EVAPORATOR APPROACH > EVAP APPROACH
ALERT and startup complete
Configure EVAP APPROACH ALERT in
SETUP1 screen
Condenser 163
CONDENSER APPROACH > COND APPROACH
ALERT and startup complete
Configure COND APPROACH ALERT in
SETUP1 screen
VFD - High VFD Speed 245
ACTUAL VFD SPEED > VFD SPEED OUTPUT +
10%
Preset Alarm, Must be outside +10%
threshold for 30 sec.
Starter Transition - 2M Start/Run
Fault
201
ISM 2M aux contact not closed after 20 sec from
start
Reduced voltage starters only
Ground Fault 220
GROUND FAULT CURRENT > GROUND FAULT
AMPS
Configure GROUND FAULT AMPS in
ISM_CONF screen
Optional Limits - Spare
Temperature
158/159
SPARE TEMPERATURE > or < SPARE TEMP
LIMIT
Optional Alarm/Alert, Confirure SPARE
TEMP ENABLE and SPARE TEMP LIMIT
in SETUP1 screen
Guide Vane Position 253
During startup: ACTUAL GUIDE VANE POSITION
value> 4% after 4 minutes of closing; After startup
complete and running: (AGV) POSITION value >
103% or < -1%; (AGV) POS voltage input < 0.045
volts or > 3.25 volts
Preset Alarm
High Condenser Water Flow 254
CONDENSER WATER DELTA P > CONDENSER
HIGH FLOW DELTA P LIMIT for more than
2 minutes.
Optional Alarm. Configure COND HI
FLOW DEL P LIMIT in SETUP1 screen
Variable Diffuser Operation 247
Detects discharge pulses caused by incorrect dif-
fuser position.
Preset Alarm. Transducer measures
pulses, no on-screen pressure reading. No
calibration needed.
RESET