34
5)
Freeze Cycle
– LED 1 is on. The compressor, fan motors and pump motor remain
energized. The liquid line valves energize and the hot gas valves de-energize (also
de-energizing the X1 relay). The lower float switch activates (open) times during
the course of a freeze cycle; the first is for refill, the second is for freeze termination.
After the second lower float switch activation, the control board terminates freeze and
initiates harvest. Every 10th cycle, the control board initiates a 10 second pump-out
cycle between the freeze and harvest cycles. See "II.C.3.d) Pump-Out Frequency
Control."
a.
Lower Float Switch 1st Activation
:
Refill
– LEDs 1 and 4 are on. The refill can occur
at any time during the freeze cycle (1 refill per cycle). As ice builds the water level
drops in the reservoir and the lower float switch activates (opens). LED 4 comes on and
the control board energizes the fill water valve. The fill water valve remains energized
until the upper float switch closes or the 1 minute fill timer terminates, whichever comes
first.
b.
Lower Float Switch 2nd Activation:
LED 1 is on. The unit is held in freeze by a
5 minute short cycle protection timer. After the 1st lower float switch activation and
refill, ice continues to form and the water level drops in the reservoir. When the lower
float switch activates (opens) a second time, the freeze cycle terminates (freeze
can only be terminated on the second activation of the lower float switch and after
5 minutes of freeze).
Diagnosis:
Minimum freeze time is 5 minutes. During the first
5 minutes of freeze, confirm that the evaporator temperature drops, compressor, fan
motors, pump motor, and liquid line valves are energized and that the hot gas valves,
harvest water valve and fill water valve (except during refill) are de-energized and
not bypassing. Make sure the expansion valves are operating properly and, in cold
conditions, make sure the headmaster (C.P. Regulator) is operating correctly. Make
sure that the drain water valve is not leaking by (water flowing down the potable drain).
Check for proper unit pressures (see "III.C. Performance Data"), or an inoperative
compressor. Disconnect the black K5 float switch connector from the control board.
15 seconds after disconnecting the black K5 float switch connector, LED 4 comes
on and refill begins. Connect the black K5 float switch connector back on the control
board. When the refill is finished (LED 4 goes off), disconnect the black K5 float switch
connector again. If 5 or more minutes have elapsed in the freeze cycle, the unit should
switch out of the freeze cycle. After the unit switches out of freeze, reconnect the black
K5 float switch connector to the control board. If the unit remains in freeze with the float
switch disconnected, replace the board. To check the float switch, see "II.F.3. Float
Switch Check Procedure."
Note: Normal freeze cycle will last 30 to 35 minutes depending on model and
conditions. Cycle times and pressures should follow performance data provided
in this manual.
