Calibrate Temperature Control - True GDM Series Technical & Service Manual

INSTALLATION INSTRUCTION

CALIBRATE TEMPERATURE CONTROL

REQUIRED TOOLS
• Accurate Remote Reading
Thermometer
• 1/4" Nutdriver
• Jeweler Screwdriver
Refrigerator Instructions
___
For cooler calibration install ther-
mometer in evaporator coil. Shut door
and get true reading of where control is
opening and closing. Watch to see at
what temperatures compressor cycles
on and off. Compare these to design
temperature of the control and adjust
accordingly.
Freezer Instructions
____
For freezer calibration install ther-
mometer next to temperature control
bulb (this is an air sensing control).
Shut door and get a true reading of
where control is opening and closing.
Watch to see at what temperature the
compressor cycles on and off. Compare
these to the design temperature of the
control and adjust accordingly.
Calibration
_________
___________ STEP 1 ___________
Unplug the cabinet.
___________ STEP 2 ___________
Set control to setting #9.
___________ STEP 3 ___________
Remove control from evaporator hous-
ing and locate cut in and cut out
screws. Refer to Temperature Control
Change-Out Instructions, page 39-41.
___
Temp. Control
Part Number
800303
800306
800312
800313
800320
800325
800335
800340
800395
_____
___________ STEP 4 ___________
Use jeweler screwdriver and adjust
control accordingly:
a. Adjust screws clockwise for colder.
b. Adjust screws counter- c l o c k w i s e
for warmer.
Note: 1/4 turn is equal approximately
_________
4 degrees.
___________ STEP 6 ___________
Re-install control into housing. Refer
to Temperature Control Change-Out
Instructions, page 39-41.
When reinstalling freezer control make
sure temperature control wires are
being held up so they do not make con-
tact with evaporator heater.
___________ STEP 7 ___________
Reset control to setting #5.
˚F ˚F
Cut In Cut Out
35 14.5
40 18
-8.5 -14.5
___________ STEP 8 ___________
36.5 16
32.5 26.5
Check control operation with ther-
62 55
mometer as done prior to adjustment to
38 20
make sure control is functional as
26 10
desired.
40 22.8
97
Calibration Instructions For 20DT
Digital Thermometer
__________ STEP 1 _________
Note that each unit is factory calibrat-
ed and a glyptol color coded seal is
placed on the calibration potentiome-
ter to prevent calibration shift. T h e
color represents date of manufacturer.
__________ STEP 2 _________
Immerse the sensor in a known tem-
perature circulated liquid bath, using a
mercury glass thermometer to obtain
the right temperature, or have a mix-
ture of water and crushed ice (slush) to
obtain 32°F (0°C).
__________ STEP 3 _________
To recalibrate the thermometer use a
small phillips head screwdriver to
adjust the potentiometer on the back of
the 20DT. Turn clockwise to adjust
down and counter-clockwise to adjust
up. To re-seal the potentiometer you
can use clear nail polish.