Sub-Zero 235 User manual

Technical Data 28
subzero.com 800.222.7820
235
Service Manual

Page 2
Model 235
Model 235
Technical Data & Tech Tips
8-2
SERVICEABLE ELECTRICAL COMPONENTS
SERVICEABLE PARTS
COMPRESSOR
Run Winding
Start Winding
RELAY
OVERLOAD
WATER PUMP
WATER VALVE.(31 gpm)
SOLENOID COIL (HGV)
THERMISTOR (Bin)
THERMISTOR (Evap)
PC BOARD
TRANSFORMER
FAN MOTOR
DRAIN PUMP (optional)
Part No.
2176659
2183410
2183404
2185748
2185531
759112
2185679
2185680
2185621
2185657
2183437
2185528
Wattage
244
26 - 30
12 nom.
7 - 9
23
40
12 - 15
Resistance
1 - 5Ω
3 - 11Ω
15.95Ω
277.5Ω
376Ω
10K@ 77 F (25 C)
10K@77 F (25 C)
360
277 - 275Ω
6.9Ω
S
ERVICING INFORMATION
1. Refrigerant charge must be applied to the high side only.
2. This unit operates on 120 VAC except for the cutter grid, electronic control board and optional
light, which operate at 8.7 VAC.
3. The transformer, cutter grid and electronic control board remain energized in ON and CLEAN
modes.
THERMISTOR OPERATING PARAMETERS
EVAPORATOR THERMISTOR
ICE THICKNESS
NORMAL
THICK
THIN
CUT-IN CUT-OUT WATER VALVE OFF (during harvest)
Temperature
52.5 F – .3
52.5 F – .3
52.5 F – .3
Resistance
18.7kΩ– 1%
18.7kΩ– 1%
18.7kΩ– 1%
Temperature
6.5 F – .3
4.5 F – .3
8.5 F – .3
Resistance
69.3kΩ– 1%
73.5kΩ– 1%
65.3kΩ– 1%
Temperature
40 F – .3
40 F – .3
40 F – .3
Resistance
25.9kΩ– 1%
25.9kΩ– 1%
25.9kΩ– 1%
ICE BIN THERMISTOR
BIN SHUT-OFF Temperature 40 F – 1 Resistance 25.9kΩ– 3% Temperature 35 F – 1 Resistance 29.8kΩ– 3%
NOTE: If evaporator thermistor is not present or open, the electronic control will continue to make ice based
on time instead of temperature. (20 minutes for ice making and 3 minutes for harvest.)
QUICK TIP: To check the ohms of the evaporator or ice bin thermistor, stir the thermistor in a glass of ice
water for two minutes. This should create a ice bath of approximately 32 F. With the thermistor submersed in
the ice water check for 30000 to 33000 Ω. If the ohm readings fall between this range, the thermistor is good.
NOTE: The evaporator thermistor is clipped to the outlet tubing of the evaporator, between the two 90 bends
before the accumulator..

Page 3
Technical Data & Tech Tips
8-3
Model 235
Model 235
ON CYCLE
SECONDS
WATER VALVE
CONDENSER FAN
HOT GAS VALVE
WATER PUMP
COMPRESSOR
POWER ON START UP ONLY
120 12060 ICE MAKING HARVEST ICE BIN FULL *ICE BIN NOT FULL
OPERATION
>6.5 F <52 F <35 F >41 F
CLEAN CYCLE
SECONDS
WATER VALVE
CONDENSER FAN
HOT GAS VALVE
WATER PUMP
COMPRESSOR
LED
DIAGNOSTICS
5
CLEAN CYCLE
47 MINUTES
555 5
CYCLE CHARTS
* Return to Ice Making
Press CLEAN switch for diagnostic mode.
To exit Clean/Diagnostic Cycle press ON or OFF.
If a short or open thermistor is detected the LED will flash for 5 seconds before the Clean Cycle is
started.

Page 4
Model 235
Model 235
Technical Data & Tech Tips
8-4
PERFORMANCE DATA
Suction Pressure Head Pressure
at End of at End of
Temperature Freeze Cycle Freeze Cycle Cycle Time
Ambient 70°F (21°C)
Water 60°F (16°C) 1 - 4 psi 65 - 80 psi 18 - 22 Min.
Ambient 90°F (32°C)
Water 60°F (16°C) 2 - 5 psi 85 - 100 psi 21 - 27 Min.
Ambient 100°F (38°C)
Water 60°F (16°C) 2 - 6 psi 85 - 105 psi 28 - 35 Min
Ambient 70°F (21°C)
Water 80°F (27°C) 1 - 4 psi 65 - 80 psi 20 - 25 Min.
Ambient 90°F (32°C)
Water 80°F (27°C) 2 - 5 psi 85 - 100 psi 23 - 30 Min
Ambient 100°F (38°C)
Water 80°F (27°C) 2 - 6 psi 85 - 105 psi 30 - 38 Min
100°F (38°C) 37 36 35 34
90°F (32°C) 44 42 40 38
80°F (27°C) 42 40 38 36
70°F (21°C) 44 43 41 40
50°F (10°C) 60°F (16°C) 70°F (21°C) 80°F (27°C)
TYPICAL ICE PRODUCTION, LBS., 24 HOURS
Ambient Temperature
Water Temperature
PERFORMANCE AND PRODUCTION TABLES

Page 5
Technical Data & Tech Tips
8-5
Model 235
Model 235
CIRCUIT BOARD JUMPERS (To Adjust Ice Thickness)
NOTE: This information can also be found on the control board.
1
3
4
6
THIN
1
3
4
6
THICK
P1
CODE
1
3
4
6
NORMAL
P1
CODE P1 CODE
Cut-Out Values
6.5 F – .3
69.3k Ohms – 1%
Cut-Out Values
4.5F – .3
73.5k Ohms – 1%
Cut-Out Values
8.5F – .3
65.3k Ohms – 1%

Page 6
Model 235
Model 235
Technical Data & Tech Tips
8-6
Optional Drain Pump
The optional drain pump consists of a motor, a pump that is magnetically coupled to the motor, a water
reservoir with sensing devices, an electronic control board that controls the water level in the reservoir
using the sensing probes.
How It Works
1. Water enters the pump reservoir from the
ice machine bin.
2. The reservoir has three probes for sensing
water level:
High Water Cut-In
High Water Shut Off
Common
As the water level rises to contact the high water cut-in probe in the reservoir, a signal is sent
to the electronic control board. The control board performs a low voltage comparison by water
contact between the high water cut-in and common probes. If water is contacting both probes
the pump motor turns on and the pump runs.
Once the water level drops and breaks the contact between the high water cut-in and common
probes, the electronic control board will turn the pump motor off after a built-in 12 second
delay. This delay prevents the motor from short cycling and over heating.
3. If the the drain outlet becomes clogged to the point where water will not be allowed to be
pumped out or a large volume of water enters the reservoir quickly, the high water shut off
probe will come in contact with the water. If this occurs, the signal sent to the electronic control
board will trigger a complete shut down of the ice machine. The pump motor will continue to
function in this mode until the reservoir is empty or the motor cycles off from over heating.
(The motor is equipped with a resettable thermal fuse.)
Drain Pump Installation
1. Pull the ice machine from its installed position.
2. Disconnect the power supply cord from the wall outlet.
3. Remove the seven screws securing the rear component compartment cover to the cabinet.
4. Slide the drain pump into the back of the cabinet.
5. If the unit already has a drain tube connected
to the ice bin outlet, remove it and the clamp
attached to the bin. (Clamp will be used later.)
6. Install the new drain tube (Part No. 2185672)
provided in the drain pump kit. Use the clamp
removed earlier to secure the new drain tube
to the bin.
(Fig. 1) .
Drain Tube
(Bin to Pump)
Drain Pump
Reservoir Inlet
Fig. 1
Ice Bin
Condenser
Drain Pump

Page 7
Technical Data & Tech Tips
8-7
Model 235
Model 235
8. Attach the drain tube from the bin to the pump inlet. Install the vent tube and drain tube to the
household drain before securing the pump to the unit base. The vent tube and drain tube
should be threaded through the component compartment cover. (Fig. 3)
7. Install the drain pump. Carefully slide in, aligning
the tab on the pump base to the rectangular slot
in the unit base.
(Fig. 2)
Fig. 2
Pump Mounting
Tab
Vent Tube
Drain Tube
(Pump to
Household
Drain)
Drain Tube
(Pump to
Household
Drain)
Drain Pump
Fig. 3
Pump Mounting
Screws
9. Coil the power cord from the Ice Maker into a figure 8. Wrap electrical tape around the center
of the figure 8. Place the wrapped cord between the compressor and the drain pump. Install
the plug on the power cord to the electrical outlet of the drain pump.
9. Line up the two (2) holes at the rear of the pump with the two holes in the unit base and install
two (2) #8 x ‰hex-head screws.
(Fig. 3)
10. Secure the vent tube to the back of the ice maker
using three (3) clamps and three (3) #8 x ‰
hex-head screws supplied in the drain pump
kit.
(Fig. 4)
11. Check all connections for leaks.
12. Reinstall the component compartment cover.
13. Connect the power cord from the drain pump to
the house hold electrical supply in accordance
with National Electrical Code and local codes
and ordinances.
Vent
Tube
Vent Tube
Mounting
Clamp &
Screw
Fig. 4