Sub-Zero UC-24 series Service Manual page 13

Under Counter (UC-24) Series
Regulate Refrigerator Zone Temperature (UC-24C Only)
When the thermistor in refrigerator compartment reaches high off-set temperature, calling for cooling, the micro-
processor sends an 18 Volt pulse signal to the air baffle control to open, regardless of operational state of the com-
pressor. When calling for cooling, the microprocessor repeats sending a pulse signal every five (5) minutes to the
air baffle control to open. (See Figure 3-19)
When the refrigerator compartment thermistor detects low off-set temperature, the microprocessor sends an 18 Volt
pulse signal to the air baffle control to close. Whenever the refrigerator compartment is not calling for cooling, the
microprocessor repeats sending a pulse signal every five (5) minutes to the air baffle control to close.
NOTES:
• If compartment tem-
perature exceeds
either high or low
offset the tempera-
ture display will
change by one
degree (1°) per
minute.
• If refrigerator com-
partment thermistor
is faulty, air baffle
defaults to twenty
(20) minutes open,
forty (40) minutes
closed cycling; EE
appears in right of
LCD; SERVICE
flashes and Error
Code 05 is logged.
• When in Sabbath
Mode, refrigerator
compartment ther-
mistor still controls
baffle operation
except there is a
random fifteen (15)
to twenty-five (25)
second delay before
the baffle is ener-
gized.
LOW VOLTAGE SCHEMATIC
2. Pulse signal to air baffle
control every 5 minutes.
MEMBRANE KEYPAD
DISPLAY
PIN 1
DISPLAY BOARD
THERMISTOR CABINET/FREEZER
1. Refrigerator compartment
thermistor at high off-set
HIGH VOLTAGE SCHEMATIC
temp. calling for cooling.
ORANGE
GRAY/WHITE
J2
P4
PIN 1
P3
MAIN BOARD
P1
P2
PIN 1
J6
J4
PIN 1
PIN 1
PIN 1
J3
J5
ORANGE
Figure 3-19. UC-24C Signal Trace - Regulate Refrigerator Zone
REF AIR DUCT BAFFLE
YELLOW W/WHITE STRIPE
YELLOW W/BLACK STRIPE
YELLOW W/RED STRIPE
J2
PIN 1
J3
THERMISTOR
ORANGE W/RED STRIPE
EVAPORATOR
THERMISTOR CABINET/REF
115 VOLTS
60 CYCLES
L1 NEUTRAL
WHITE
WHITE
BLACK
PURPLE
BLUE
GRAY/WHITE
RED
ORANGE
REF LIGHT SWITCH
THERMAL
FUSE ICEMAKER
BLACK
3-13
Electronic Control System
J6
ORANGE
YELLOW
RED
WHITE
BLUE W/RED STRIPE
BLUE W/WHITE STRIPE
BLUE W/WHITE STRIPE
J5
BLUE W/BLACK STRIPE
BLUE W/BLACK STRIPE
OVERLOAD
PROTECTOR
COMPRESSOR
M
M
REF FAN MOTOR
CONDENSER FAN
M
DEFROST HEATER
R55 OHMS
REF (TOP) LIGHT
WHITE
ICEMAKER
VALVE
TAN
R160 OHMS
#7003933 - Revision B - November, 2007
J2
P4
PIN 1
P3
MAIN BOARD
P1
P2
PIN 1
J4
PIN 1
PIN 1
PIN 1
J3
WHITE
RUNNING
CAPACITOR
(WHEN
USED)
COMPRESSOR
STARTING
RELAY
WHITE
WHITE
WHITE
WHITE
WHITE
WHITE