Thermistors; Viewing Temperature; Thermistor Calibration - U-Line U-3018RFOL-00 Service Manual

General Information

Thermistors

There are 3 thermistors used with the 3018 models.
• Zone Thermistor - Located on the right hand wall and is used to
maintain temperature.
• Evaporator Thermistor - Located on the back of the evaporator
plate and is used during defrost.
• Ambient Thermistor - Located in the base of the unit on the
condenser and is used to monitor ambient air temperatures.

Viewing Temperature

Note: The display shows set point NOT the actual temperature.
The 3000 series is equipped with an advanced electronic display and
control. Thermistor readings can be obtained through both the
customer and service menu. The customer menu will display readings
while using offset calculations. It is important to note that the system
will use these adjusted readings when determining cooling and
defrost cycles. The service menu will display the actual thermistor
reading while disregarding offsets.
Customer Menu:
To view the adjusted temperature of each available thermistor, follow
the steps below.
1. Initiate the customer menu by holding Select
2. Use Down to scroll to "Actual Temperatures".
3. Press select .
4. Use Up or Down to scroll through available information.
Service Menu
To view the actual temperature without having the offsets taken into
consideration, follow the steps below.
1. Initiate the service menu by holding both up
for 5 seconds.
2. Use Up or Down to scroll to "Actual Temperatures".
3. Press select .
Use Up or Down to scroll through available information.
6

Thermistor Calibration

While thermistors generally do not require calibration, over time
contact corrosion and or element wear may make calibration
necessary.
Calibration
To calibrate a thermistor one must first prepare an ice-bath of
crushed ice and water in a suitable container. Allow the ice bath
temperature to stabilize for at least 5 minutes before beginning.
Offsets are preset at the factory to efficiently maintain
product temperature. If modifying offset, existing values
Customer Care must be notified before any changes are
made to factory set offsets. Failure to notify Customer
1. Enter the service menu and record existing offset values for each
thermistor to be calibrated. See page 13. Some models have a
factory offset setting of 0.
for 5 seconds.
2. Change offset of each thermistor to be calibrated to 0.
3. Enter "Actual Temps" through the Customer Menu. See
"Viewing Temperature".
4. Submerge the thermistor in the ice bath. The temperature read
out through the menu should be 32°F. If different, record
difference.
5. Enter "Offsets" through the service menu and set the value
recorded in step 4 to the thermistor to be calibrated.
and Zone Toggle
6. Enter "Actual Temps" through the Customer Menu, the
temperature readout should now be 32°F. If the readout is still
incorrect reset the offset to 0 and preform steps 4 & 5 again.
7. Enter the "Offsets" menu and add the value recorded in step 1 to
the new offset setting. For example, if after the ice bath an offset of
1 was needed and the existing offset value recorded in step 1 was
-2 the new offset value would be -1. If the calculated value is
outside the maximum range capable in the offset menu the
thermistor must be replaced. The offset menu has a maximum
range of -10 through 10.
Note: If a mistake is made in the calibration process a "Factory Reset"
will restore offsets to their factory pre-set values. See page 14.
U-Line Service
IMPORTANT IMPORTANT
must be taken into consideration.
WARNING
Care will void the warranty.