Refrigerator Off-Cycle Defrost - Sub-Zero 601R-2 Technical & Service Manual

Electronic Control System
Monitor and Control Refrigerator Off-Cycle Defrost
Temperature signals from the refrigerator compartment evaporator thermistors are monitored by the microprocessor.
During off cycle defrost, if the compartment temperature reaches high offset before the evaporator rises to 38°F
(3°C), the signal to run the compressor and evaporator fan will wait, allowing the refrigerator evaporator to fully
defrost before the compressor is energized (See Figure 3-15).
NOTE: If a refrigerator compartment thermistor is faulty, the refrigerator compressor defaults to 20 minutes on, 40
minutes off cycling, EE appears at right in LCD, SERVICE flashes and Error Code 05 is logged.
NOTE: If a refrigerator evaporator thermistor is faulty, the refrigerator compressor is not energized until compart-
ment air temperature exceeds high offset by 5°F (3°C). SERVICE flashes and Error Code 06 is logged.
J5
J7
E2 E7 E10 E6
J3
J4
J2 J1
Figure 3-15. Signal Trace Schematic (High Voltage only) of Refrigerator Off-Cycle Defrost
#3758407 - Revision B - August, 2006
L1 NEUT
115 VOLTS
60 CYCLES
BLACK
WHITE
GRAY
CONTROL
BOARD
J6
Signal from refrigerator compartment
and evaporator thermistors, compartment
calling for cooling, but evaporator below 38°F.
Built-In
Built-In
(600-
(600-
WHITE
REFRIGERATOR
FAN SWITCH
REFRIGERATOR
COMPRESSOR
M
REFRIGERATOR
OVERLOAD
PROTECTOR
No power supplied
to refrigerator compressor
M
M
3-12
Series
Series
2
2
)
)
REFRIGERATOR
FAN MOTOR
RED
M
REFRIGERATOR
COMPRESSOR
STARTING
RELAY
M
160 OHMS