Shutdown sequence – Carrier 17/19EX User Manual
Page 120
Shutdown Sequence
Shutdown of the machine can occur if any of the following events happen:
•
the STOP button is pressed for at least one second (the alarm light will blink once to
confirm stop command)
•
recycle condition is present (see
section)
•
time schedule has gone into UNOCCUPIED mode
•
remote contact opens
•
the start/stop status is overridden to stop from the CCN network or the LID
When a stop signal occurs, the shutdown sequence first stops the compressor by
deactivating the start relay. A status message of ‘‘SHUTDOWN IN PROGRESS, COMPRES-
SOR DEENERGIZED’’ is displayed. The guide vanes are then brought to the closed position.
The oil pump relay and the chilled water/brine pump relay are shut down 60 seconds after the
compressor stops. The condenser water pump will be shut down when the
CONDENSER
REFRIGERANT TEMP
is less than the
CONDENSER PRESSURE OVERRIDE
minus 5 psi
(34 kPa) or is less than or equal to the
ENTERING CONDENSER WATER TEMP
plus 3° F
(2° C). The stop-to-start timer will now begin to count down. If the start-to-start timer is still
greater than the value of the start-to-stop timer, then this time is now displayed on the LID.