43
Fig. 40 — Guide Vane Actuator Detail
4. If required, rotate the guide vane sprocket fully clockwise
for first stage and counterclockwise for second stage and
spot-drill the guide vane actuator shaft. Spot-drilling is
necessary when the guide vane actuator sprocket set
screws on the guide vane actuator shaft need to be re-
seated. (Remember: Spot-drill and tighten the first set
screw before spot-drilling for the second set screw.)
Trim Refrigerant Charge — If to obtain optimal chiller
performance it becomes necessary to adjust the refrigerant
charge, operate the chiller at design load and then add or re-
move refrigerant slowly until the difference between the leav-
ing chilled water temperature and the cooler refrigerant tem-
perature reaches design conditions or becomes a minimum. Do
not overcharge. Use cooler sight glasses to visually determine
optimum charge. At steady state full load operation the cooler
tubes should be covered with liquid refrigerant — if tubes are
covered maximum efficiency is achieved and there is no bene-
fit of additional refrigerant.
Refrigerant may be added either through the storage tank or
directly into the chiller as described in the Charge Unit with
Refrigerant section.
To remove any excess refrigerant, follow the procedure in
Transfer Refrigerant from Chiller to Pumpout Storage Tank
section.
WEEKLY MAINTENANCE
Check the Refrigerant Lubrication System
1. Enter INPUT menu and verify that Liquid Level Switch
is closed (if compressor is on).
2. Check moisture indicating sight glass on bearing sup-
ply line (Fig. 41) as well as on the motor/VFD liquid
cooling line (located between vessels feeding of the
high side float chamber; sight glass is located down-
stream of filter drier).
3. Check that pressure Ref Pump Delta P (PRESSURE
Menu is above 13 psig [89.6 kPa]).
Check for Leaks — Frequent purge pumpout operation
is an indication of a leak. When the daily pumpout limit is ex-
ceed, the controls will show process Alert 148 — Purge Daily
Pumpout Limit Exceeded. If no alert, the purge run-time for the
past 24 hours as well as the past 7 days can be obtained from
RUNTIME menu.
SCHEDULED MAINTENANCE
Establish a regular maintenance schedule based on your actual
chiller requirements such as chiller load, run hours, and water
quality. The time intervals listed in this section are offered as
guides to service only.
Service Ontime — The HMI will display a resettable
“After Service Hrs”, “Total Pumpout Numbers”, and “Total
Pumpout Time” value on the MAIN MENU RUN TIMES
screen. These values should be reset to zero by the service per-
son or the operator each time major service work is completed
so that the time between service events can be viewed and
tracked. Previous values and associated dates should be logged
for future reference prior to resetting.
Inspect the Control Panel — Maintenance consists of
general cleaning and tightening of connections. Vacuum the
control cabinets to eliminate dust build-up. If the chiller control
malfunctions, refer to the Troubleshooting Guide section on
page 46 for control checks and adjustments.
NOTE: For first stage, rotate coupling clockwise to close
guide vanes; rotate coupling counterclockwise to open
guide vanes. For second stage, rotate coupling counter-
clockwise to close guide vanes; rotate coupling clockwise
to open guide vanes.
WARNING
Ensure power to the starter is isolated when cleaning and
tightening connections inside the starter enclosure. Failure
to disconnect power could result in electrocution.
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