Condenser Fan Cycling Control; Thermostatic Expansion Valves; Starving Txv - Product Symptoms; Flooding Txv - Product Symptoms - Cornelius XAC 1444 Service Training Manual

NOTE: The sensor controls the condenser fan cycling from 88/100 degree Fahrenheit. Thus any
defects in the condenser circuit will effect the fan cycling rate.

CONDENSER FAN CYCLING CONTROL

The condenser fan on air-cooled cubers is cycled by the circuit board. The condenser sensor signals the
circuit board when the condenser temperature reaches 100°F (38°C) the fan starts and continues to run
until the temperature is reduced to 88°F (31°C).
NOTE: There is no pressure control used to cycle the fan motor on integral condenser unit.

THERMOSTATIC EXPANSION VALVES

The following suggestions for diagnosis of automatic Thermostatic Expansion Valve (TXV) are given with
the understanding that the following have been checked and are correct and/or have been corrected prior
to proceeding.
1. The condenser and fan blade are clean and have proper operating conditions.
2. Water supply to the product is correct and flow over the evaporator is correct.
3. Cuber refrigerant charge is correct.
4. TXV sensing bulb is properly located and secured to the suction line and correctly insulated.
5. Hot gas valve(s) are not leaking and/or seeping through.

Starving TXV - Product Symptoms

1. Suction pressure lower than normal for the operating conditions.
2. Ice production lower than normal and/or none.
3. Ice pattern on evaporator (if any) thin at top and thick at bottom.

Flooding TXV - Product Symptoms

1. Suction pressure stabilizes at higher than normal pressure for operating conditions. Suction pressure
does not modulate and may start to slowly rise.
2. Ice pattern will be very heavy at the bottom and thin at the top of the evaporator. Product may not
enter harvest cycle because of higher than normal suction line temperature.
IMPORTANT: Frost on the suction line may be normal on medium temperature refrigeration
equipment. Frost should be considered a red flag, long run times will normally produce some
type of frost pattern. Before checking the sealed refrigeration system, the external conditions
that could lead to frost follow:
1. Dirty condenser
2. Dirty condenser fan blade
3. Improper air clearance around Cuber
4. Loose TXV bulb mount
5. Poor water flow over evaporator
6. Ventilation problems
The expansion valves used on Cornelius "X" series ice equipment have special super heat settings and
bulb charge designed for the product load and HP 62 refrigerant. Should the need arise to replace this or
any refrigerant components, be certain to use only components recommended by Cornelius for the model
of the Cuber being serviced. Use of non–approved components will compound system difficulties and
may void product warranty.
TP00952 30
Xtreme Ice Training Manual
October 17, 2005