Regulate Freezer Zone Temperature (Bc/Bf) - Sub-Zero 700-3 BASE Technical & Service Manual

Integrated
Regulate Freezer Zone Temperature (700BCI-3, 700BFI-3)
When the thermistor in the freezer compartment reaches high off-set temperature, calling for cooling, the compres-
sor and condenser fan are energized, but the evaporator fan is not allowed to run until the thermistor on the evapo-
rator reaches 35°F (2°C). (See Figure 3-19)
If either drawer is opened while the evaporator fan is operating, the microprocessor will detect the power signal to
the lights and cut power to the fan.
Though compartment air temperatures will fluctuate, LCD displays average temperature.
NOTE: If compartment temperature exceeds either high or low offset (Ex: drawer is left open), temperature display
will change by one
degree per minute.
NOTE: If freezer
compartment thermis-
tor is faulty, compres-
sor operation defaults
to 20 minutes ON, 20
minutes OFF cycling,
EE appears in left of
LCD, SERVICE will
flash and Error Code
07 will be logged.
NOTE: If evaporator
thermistor is faulty,
the compressor will
be energized after
the dwell time and
the evaporator fan
will be energized 3
minutes later. SER-
VICE will flash and
Error Code 08 will be
logged.
NOTE: When in
Sabbath Mode, the
freezer compartment
thermistor still con-
trols compressor
operation, except
there is a random 15
to 25 second delay
before the compres-
sor is energized.
3
(700- BASE)
LOW VOLTAGE SCHEMATIC
DISPLAY
4. Evap Thermistor
below 35°F (2°C).
1. Thermistor at high off-set
temp. calling for cooling.
HIGH VOLTAGE SCHEMATIC
ORANGE
J2
PIN 1
MAIN BOARD
PIN 1
J6
J4
PIN 1
PIN 1
PIN 1
J5
ORANGE W/BLACK STRIPE
ORANGE
Figure 3-19. 700BCI-3 Signal Trace - Regulate Freezer Zone
Series
MEMBRANE KEYPAD
J2
PIN 1
DISPLAY BOARD
PIN 1
J3
THERMISTOR
EVAPORATOR
THERMISTOR LOWER
DRAWER/FREEZER
115 VOLTS
60 CYCLES
L1
NEUTRAL
WHITE
3. Compressor and
condenser fan
WHITE
P4
energized.
BLACK
P3
PURPLE
P1
P2
RED
J3
ORANGE
REF LIGHT
SWITCH
FRZ LIGHT
SWITCH
3-11
Electronic Control System
J6
J4
ORANGE W/RED STRIPE
BLUE W/RED STRIPE
BLUE W/BLACK STRIPE
BLUE W/BLACK STRIPE
J5
M
OVERLOAD
PROTECTOR
COMPRESSOR
M
M
CONDENSER FAN
M
FRZ FAN MOTOR
5. Evap fan
energized.
REF (TOP)
DRAWER LIGHT
FRZ (BOTTOM)
2. No signal
DRAWER LIGHT
to lights.
#3758424 - Revision B - December, 2005
J2
P4
PIN 1
P3
MAIN BOARD
P1
P2
PIN 1
PIN 1
PIN 1
PIN 1
J3
WHITE
RUNNING
CAPACITOR
(WHEN
USED)
COMPRESSOR
STARTING
RELAY