Operating instructions
45
Be sure that the water system drains are closed. It is
recommended:
• to flush the water circuits to remove any soft rust
which may have formed
• to clean the tube vessel
• to inspect the probe pressure taps and change them, if
necessary.
Check the cooler pressure on the ICVC default screen, and
compare to the original holding charge that was left in the
chiller. If (after adjusting for ambient temperature changes)
any loss in pressure is indicated, check for refrigerant leaks.
See chapter 4.2.2 “Leak test chiller”.
Recharge the chiller by transferring refrigerant from the
pumpout storage tank (if supplied). Refer to transfer unit
installation manual, document order no. 19999 and sections
4.11 “Chiller equalization without pumpout unit” and 4.12
“Chiller equalization with pumpout unit”. Observe the
freeze-up precautions.
Carefully make all regular preliminary and running system
checks. Perform a Control Test before start-up. If the
compressor oil level appears abnormally high, the oil may
have absorbed refrigerant. Make sure that the oil tempera-
ture is above 60°C or cooler refrigerant temperature 27°C.
When the entering condenser water drops very low, the
operator should automatically cycle the cooling tower fans
off to keep the temperature up. The PIC controls have a
tower fan output (terminals 11 and 12 of the ISM).
Manual operation of the guide vanes in order to control
the guide vanes in an emergency operation is possible by
overriding the target guide vane position. Access the
‘COMPRESS’ screen on the interface, and select TARGET
GUIDE VANE POSITION. To control the position, enter
a percentage of guide vane opening that is desired. Zero
percent is fully closed, 100% is fully open. To release the
guide vanes to AUTOMATIC mode, press the RELEASE
softkey.
NOTE: Manual control will increase the guide vane
opening and override the pulldown rate during start-up.
Manual control of the guide vanes will not have override
status in the following cases:
• Limitation overrides are active
• The chilled water temperature is below the set point.
The PIC control will then close the guide vanes.
For a description of capacity overrides and set points, see
the Capacity Override section in the Installation, Operation
and Maintenance Manual for the control.
A refrigeration log, like the one shown in Fig. 33 provides a
convenient checklist for routine inspection and
maintenance and provides a continuous record of chiller
performance. It is an aid in scheduling routine maintenance
and in diagnosing chiller problems.
Keep a record of the chiller pressures, temperatures, and
liquid levels on a sheet similar to that shown. Automatic
recording of PIC data is possible through the use of devices
connected to the CCN such as the Data Collection module
and a Building Supervisor. Contact your Carrier represen-
tative for more information.