Specifications

66
OPERATING INSTRUCTIONS
Operator Duties
1. Become familiar with the chiller and related equipment
before operating the chiller.
2. Prepare the system for start-up, start and stop the chiller,
and place the system in a shutdown condition.
3. Maintain a log of operating conditions and document any
abnormal readings.
4. Inspect the equipment, make routine adjustments, and
perform a Control Test. Maintain the proper oil and
refrigerant levels.
5. Protect the system from damage during shutdown
periods.
6. Maintain the set point, time schedules, and other PIC III
functions.
Prepare the Chiller for Start-Up — Follow the steps
described in the Initial Start-Up section, page 64.
To Start the Chiller
1. Start the liquid pumps, if they are not automatic.
2. On the ICVC default screen, press the or
softkey to start the system. If the chiller is in the
OCCUPIED mode and the start timers have expired, the
start sequence will start. Follow the procedure described
in the Start-Up/Shutdown/Recycle Sequence section,
page 46.
Check the Running System — After the compres-
sor starts, the operator should monitor the ICVC display and
observe the parameters for normal operating conditions:
1. The oil sump temperature will vary from 50 deg F to
140 deg F (10 deg C to 60 deg C) depending on the oper-
ating conditions. If the chiller has not been running for a
few hours the OIL SUMP TEMP will be warmer than the
CALC EVAP SAT TEMP. When the chiller is not run-
ning, the oil heater is energized whenever the OIL SUMP
TEMP is less than the smaller of 140 (60 deg C) or
53 deg F (29.4 deg C) greater than the CALC EVAP SAT
TEMP. The OIL SUMP TEMP generally decreases slow-
ly following start-up and eventually stabilizes at a point
lower than the temperature maintained during shut down.
The OIL PRESS DELTA P increases above 18 psid
(124 kPad) during start-up and generally does not vary by
more than ± 2 psid (14 kPad). The level in the oil sump is
generally very stable. Changes in the oil level occur very
slowly.
2. When the compressor is running, the liquid level should
be visible in the oil sump or the strainer housing sight
glass. Low oil pressure alarms are imminent if the oil lev-
el drops below the bottom of the oil strainer housing sight
glass.
3. The OIL PRESSURE DELTA P displayed on the ICVC
default screen is equal to the difference between the oil
pressure leaving the oil filter and the oil sump pressure
transducer readings. Typically the reading will be
between 20 and 28 psid (138 to 193 kPad) after the oil
pressure ramp up is complete.
4. The moisture indicator (dry-eye) sight glass on the refrig-
erant motor cooling line should indicate refrigerant flow
and a dry condition.
5. The condenser pressure and temperature varies with the
chiller design conditions. Typically the pressure will
range between 60 to 135 psig (329 to 780 kPa) with a cor-
responding temperature range of 60 to 105 F (15 to 41 C).
The condenser entering liquid temperature may be
controlled below the specified design entering liquid
temperature to save on compressor kilowatt requirements
but, not be below 55 F (12.8 C).
6. Cooler pressure and temperature also will vary with the
design conditions. Typical pressure range will be between
30 to 40 psig (204 to 260 kPa) with temperature ranging
between 34 and 45 F (1 and 8 C).
7. The compressor may operate at full capacity for a short
time after the pulldown ramping has ended, even though
the building load is small. The active electrical demand
setting can be overridden to limit the compressor kW, or
the pulldown rate can be decreased to avoid a high
demand charge for the short period of high demand opera-
tion. Pulldown rate can be based on load rate or tempera-
ture rate by PULLDOWN RAMP TYPE in the
RAMP_DEM screen. AMPS or KW RAMP%/MIN is ac-
cessed on the Equipment SERVICE screen, RAMP_DEM
table (Table 3, Example 22). TEMP PULLDOWN
RAMP/MIN is accessed on the TEMP_CTL screen.
To Stop the Chiller
1. The occupancy schedule starts and stops the chiller auto-
matically once the time schedule is configured.
2. The STOP button must be pressed for one second before
the alarm light blinks once to confirm the button has been
pressed. The compressor will then follow the normal
shutdown sequence as described in the Controls section.
The chiller will not restart until the or
softkey is pressed. The chiller is now in the OFF control
mode.
FAILURE TO STOP — If the alarm light does not blink after
pressing and holding the stop button for at least one second and
the chiller fails to stop, the operator should open the main
circuit breaker on the front of the control panel.
Do not restart the chiller until the problem is diagnosed and
corrected.
After Limited Shutdown — No special preparations
should be necessary. Follow the regular preliminary checks and
starting procedures.
Preparation for Extended Shutdown — The refrig-
erant should be transferred into the pumpout storage tank (if
supplied; see Pumpout and Refrigerant Transfer Procedures) to
reduce chiller pressure and the possibility of leaks. Maintain a
holding charge of 5 to 10 psi (34 to 69 kPa) of refrigerant or
nitrogen to prevent air from leaking into the chiller.
If freezing temperatures are likely to occur in the chiller
area, drain the chilled liquid, condenser liquid, and the
pumpout condenser liquid circuits to avoid freeze-up. Keep the
waterbox drains open.
Leave the oil charge in the chiller with the oil heater and
controls energized to maintain the minimum oil reservoir
temperature.
LOCAL
CCN
IMPORTANT: Do not attempt to stop the chiller by
opening an isolating knife switch. High intensity arcing
may occur.
CCN
LOCAL