Sub-Zero 700-2 Series

Page 48
Electronic Control
Integrated (
Integrated (
700-
700-
2) Series
2) Series
3-38
#3756780 - Revision D - July, 2005
Monitor and Control Refrigerator Off-Cycle Defrost in the 700BR-2
If the the upper drawer compartment in a 700BR-2 calls for cooling (upper compartment at high offset temperature),
but the temperature sensed by the evaporator thermistor has not reached 38°F (3°C), the evaporator fan will be
energized, but power to the compressor and condenser fan will wait. This allows the refrigerator evaporator to fully
defrost before the compressor and condenser fan are energized. (See Figure 3-81)
Figure 3-81. Signal Trace Schematic (High & Low Voltage) of Model 700BR-2 Refrigerator Off-Cycle Defrost
L1
RED
WHITE
BLACK
LOW VOLTAGE
BLUE W/BLACK
BLUE W/BLACK
BLUE W/YELLOW
BLUE W/YELLOW
BLUE W/RED
BLUE W/RED
THERMISTOR
EVAPORATOR
THERMISTOR
LOWER DRAWER
NEUTRAL
RELAY
M
COMPRESSOR
OVERLOAD
EVAPORATOR FAN MOTOR
PROTECTOR
COMPRESSOR
STARTING
MAIN BOARD
60 CYCLES
115 VOLTS
M
CONDENSER FAN
M
HIGH VOLTAGE
TOP DRAWER
THERMISTOR
MAIN BOARD
DISPLAY BOARD
WHITE
1. High offset
temperature
detected
2. Evaporator temp
below 38°F (3°C)
3. Evap fan
energized
4. Compressor &
Condenser
fan wait until
evap rises to
38°F (3°C)