Specifications

59
Table 9 — Prestart Checks
Chilled Water Recycle Mode — The chiller may
cycle off and wait until the load increases to restart when the
compressor is running in a lightly loaded condition. This
cycling is normal and is known as “recycle.” A recycle shut-
down is initiated when any of the following conditions are true:
• LEAVING CHILLED WATER temperature (or ENTERING
CHILLED WATER temperature, if the ECW CONTROL
OPTION is enabled) is more than 5 F (2.8 C) below the
CONTROL POINT.
• LEAVING CHILLED WATER temperature (or ENTERING
CHILLED WATER temperature, if the ECW CONTROL
OPTION is enabled) is below the CONTROL POINT, and
the chilled water temperature difference is less than the
(RECYCLE CONTROL) SHUTDOWN DELTA T (config-
ured in the EQUIPMENT SERVICE/SETUP1 table).
•the LEAVING CHILLED WATER temperature is within 3 F
(1.7 C) of the EVAP REFRIG TRIPPOINT.
NOTE: Recycle shutdown will not occur if the CONTROL
POINT has been modified (e.g., by a chilled water reset input)
within the previous 5 minutes of operation.
Also, chilled water recycle logic does not apply to Ice Build
operation (refer to page 54).
When the chiller is in RECYCLE mode, the chilled water
pump relay remains energized so the chilled water temperature
can be monitored for increasing load. The recycle control uses
RESTART DELTA T to check when the compressor should be
restarted. This is an operator-configured function which
defaults to 5 F (2.8 C). This value can be viewed or modified
on the SETUP1 table. The compressor will restart when the
chiller is:
• in LCW CONTROL and the LEAVING CHILLED WATER
temperature is greater than the CONTROL POINT plus the
(RECYCLE CONTROL) RESTART DELTA T.
•in ECW CONTROL and the ENTERING CHILLED WATER
temperature is greater than the CONTROL POINT plus the
(RECYCLE CONTROL) RESTART DELTA T.
Once these conditions are met, the compressor initiates a
start-up with a normal start-up sequence.
An alert condition may be generated if 5 or more recycle
start-ups occur in less than 4 hours. Excessive recycling can
reduce chiller life; therefore, compressor recycling due to
extremely low loads should be reduced.
To reduce compressor recycling, use the time schedule to
shut the chiller down during known low load operation period,
or increase the chiller load by running the fan systems. If the
hot gas bypass is installed, adjust the values to ensure that hot
gas is energized during light load conditions. Increase the
(RECYCLE CONTROL) RESTART DELTA T on the SETUP1
table to lengthen the time between restarts.
The chiller should not be operated below design minimum
load without a hot gas bypass installed.
Safety Shutdown — A safety shutdown is identical to
a manual shutdown with the exception that, during a safety
shutdown, the ICVC displays the reason for the shutdown, the
alarm light blinks continuously, and the spare alarm contacts
are energized.
After a safety shutdown, the softkey must be pressed
to clear the alarm. If the alarm condition is still present, the alarm
light continues to blink. Once the alarm is cleared, the operator
must press the or softkeys to restart the chiller.
BEFORE INITIAL START-UP
Job Data Required
• list of applicable design temperatures and pressures (prod-
uct data submittal)
• chiller certified prints
• starting equipment details and wiring diagrams
• diagrams and instructions for special controls or options
• pumpout unit instructions
Equipment Required
• mechanic’s tools (refrigeration) including T30 torx
• True RMS digital multimeter with clamp-on current probe
or True RMS digital clamp-on meter rated for at least 480
vac or 700 vdc
• electronic leak detector
• absolute pressure manometer or wet-bulb vacuum indicator
(Fig. 28)
• 500-v insulation tester (megohmmeter) for compressor
motors with nameplate voltage of 600 v or less, or a 5000-v
insulation tester for compressor motor rated above 600 v
Using the Optional Storage Tank and Pump-
out System —
Refer to Chillers with Storage Tanks sec-
tion, page 82 for pumpout system preparation, refrigerant
transfer, and chiller evacuation.
Remove Shipping Packaging — Remove any pack-
aging material from the control panel, power panel, guide vane
actuator, motor cooling and oil reclaim solenoids, motor and
bearing temperature sensor covers, and the VFD.
Open Oil Circuit Valves — Check to ensure the oil fil-
ter isolation valves (Fig. 4) are open by removing the valve cap
and checking the valve stem.
QUANTITY CHECKED REQUIREMENT ALERT STATE IF FALSE
STARTS IN 12 HOURS
< 8 (not counting recycle restarts or auto restarts after power failure)
ALERT is cleared once RESET is pressed.
100
COMP THRUST BRG TEMP < [COMP THRUST BRG ALERT] –10 F (5.6 C) 101
COMP MOTOR WINDING TEMP < [COMP MOTOR TEMP OVERRIDE] –10 F (5.6 C) 102
COMP DISCHARGE TEMP < [COMP DISCHARGE ALERT] –10 F (5.6 C) 103
EVAPORATOR REFRIG TEMP < [EVAP REFRIG TRIPPOINT] + [REFRIG OVERRIDE DELTA T] 104
OIL SUMP TEMP < 150 F (65.5 C) or <[EVAPORATOR REFRIG TEMP] + 50 F (27.8 C) 105
CONDENSER PRESSURE
< [COND PRESS OVERRIDE] –20 PSI (138 kPa) and
< 145 psi (1000 kPa)
106
PERCENT LINE VOLTAGE < [Undervoltage Threshold] 107
PERCENT LINE VOLTAGE > [Overvoltage Threshold] 108
ACTUAL GUIDE VANE POS Controls test guide vane calibration must be performed 109
RECTIFIER TEMPERATURE < RECTIFIER TEMP OVERRIDE – 20 F (11.1° C) 110
INVERTER TEMPERATURE < INVERTER TEMP OVERRIDE – 20 F (11.1° C) 111
RESET
CCN
LOCAL