Service manual

42TD 204
10. Should sensor (thermistor) pass the voltage test pro-
ceed to the control board diagnosis for LED sequence
(see page 39).
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.
Evaporator Switches
Proximity Switches are half mounted to the water curtain, and the
other half mounted to the evaporator side rail. They provide signals
to the control board to allow the board to change cycles from harves
to freeze as well as shut down of the unit in a full bin condition.
Switch Notes
1. Manually holding the curtain open during freeze
mode, will shut the Cuber down in 5 seconds.
2. During harvest cycle, if curtain is open for 10 seconds,
the water pump will stop. The compressor will operate
for 20 additional seconds before Cuber shut down
takes place. When the water curtain closed, the Cuber
will begin the normal start-up process.
3. In single evaporator machines, the proximity switch
connection must be on the top (RH) connection on the
circuit board.
4. In dual evaporator machines, both RH and LH
switches must open and reset to start the next freeze
mode.
Voltage Checks
Turn Cuber power switch Off. Disconnect proximity switch plug(s)
from the circuit board. Use a digital multimeter set for D.C. Voltage;
turn power switch ON, connect leads of meter across the top two ter-
minal pins on the board, (for the switch being tested), meter should
read 5 VDC ± 0.2 output voltage. If not, replace the circuit board.
Water Regulating Valve
The water regulating valve is used on water–cooled cubers only. The
valve is installed in the condenser outlet water line. It’s function is
to control the proper operating head pressure by regulating the
amount of water flowing through the condenser. The valve is adjust-
able and factory set to maintain condenser discharge water tempera-
ture @ 108/112_F (42-44_C). Setting the water regulating valve to
Continued on page 42
maintain discharge water temperature eliminates the need to enter
the sealed refrigeration system. When checking the valve, the water
temperature should be taken as close to the condenser discharged as
possible. The water temperature will equate to operating head pres-
sure of approximately 310 PSI (21.1 BAR).