Installation, Operation and Maintenance 7 - 1
8QLW6KXWGRZQ
Daily Unit Shutdown
The unit will shut down
normally
in either of two
ways: when the cooling requirement is satisfied and
when the <Stop> key is pressed.
NOTE: The normal shutdown sequence in the
following paragraphs is discussed in terms of Clear
Language Displays that will appear, events that are
initiated by the operator, and machine actions that
occur.
The shutdown sequence begins when either the
cooling requirement is satisfied in Auto mode or
when the <Stop> key is pressed. In either case, the
slide valve unload solenoid is energized for 20
seconds and the electronic expansion valve is
opened at the full rate. During this period the
following operating mode display appears:
After the 20 seconds required to close the slide
valve, the expansion valve remains open and the
compressor stops. Both the master oil line solenoid
and the condenser water pump are de-energized and
both the unload solenoid and oil heater are
energized. The unload solenoid remains energized
for 60 minutes. These actions mark the beginning of
a time-out sequence (restart inhibit timer at a
reduced rate if in Auto mode) and the chilled water
pump off delay timer for up to 30 minutes (adjustable)
if manual stop occurred.
If the unit was in Auto mode
when the stop sequence
began, the following:
is displayed and remains until the unit starts with a
need to cool.
If the unit was manually stopped by the operator
when the stop sequence began, the following:
or:
is displayed and remains until the end of the
sequence when the chilled water pump relay is de-
energized.
Seasonal Unit Shutdown
1 Perform the normal unit stop sequence using the
<Stop> key.
NOTE: Do not open the starter disconnect switch.
This must remain closed to provide control power
from the control power transformer to the oil sump
heater.
2 Verify that the chilled water and condenser water
pumps are cycled off. If desired, open the
disconnect switches to the pumps.
3 Drain the condenser piping and cooling tower, if
desired.
4 Remove the drain and vent plugs from the
condenser headers to drain the condenser.
5 Once the unit is secured, perform the
maintenance identified in Section 9.
Unit is Preparing to Shutdown
Auto
Waiting For Need To Cool
Local Stop: Cannot Be Overridden By
Any External Or Remote Device
Remote Run Inhibit
From <type> Source
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