Electronic Control System
Integrated
(700-
3
BASE)
Series
3-14
#3758424 - Revision B - December, 2005
Monitor and Control “Adaptive Defrost” (700BCI-3, 700BFI-3)
Initially, the compressor will cycle-run for 12 hours, after which the microprocessor sends a signal to the defrost relay
on the control board to close. This supplies power to the defrost heater, drain tube heater and fill tube heater. At
the same time the compressor, condenser fan and evaporator fan are switched off.
With the “Adaptive Defrost” technique, the length of time that the defrost heater stays on to open the defrost termina-
tor bimetal (70°F/21°C), is observed by the microprocessor via the grey w/white stripe wire to J2.
The microprocessor then determines the number of hours before the next defrost. If the heater stays on for a short-
er time than specified, the microprocessor increases the next defrost interval. If the heater stays on longer than
specified, the electronic control decreases the next defrost interval. (See Figure 3-13) This is an ongoing process
whereby the defrost time and the defrost interval will vary by unit use.
NOTE:
A 5 minute time delay/dwell follows all defrosts, during which the drain tube heater and fill tube heater
remain energized. At the end of the 5 minute dwell, the drain tube heater and fill tube heater are switched off, then
the compressor and condenser fan are energized, but the evaporator fan will not be energized until the evaporator
temperature falls below 35°F (2°C).
NOTE:
The minimum defrost interval is 6 hours of compressor run time; the maximum defrost interval is 42 hours of
compressor run time; the maximum defrost duration is 25 minutes plus 5 minute dwell.
NOTE:
If the grey w/white wire defrost sensing line is open, defrost operation defaults to 25 minute defrost time and
6 hour build time, and Error Code 22 is logged. If the evaporator thermistor detects an underheat or overheat situa-
tion at the same time, Error Codes 20 or 23 will be registered, respectively.
NOTE:
During defrost, the display temperature is locked.
Figure 3-22. 700BCI-3 Signal Trace Schematic - Adaptive Defrost
BLUE
60 CYCLES
BLACK
L1
NEUTRAL
WHITE
FILL TUBE HEATER
2300 -2900 OHMS
FRZ FAN MOTOR
TERMINATOR
DEFROST
CONDENSER FAN
DEFROST HEATER
1700 - 2100 OHMS
25 - 29 OHMS
DRAIN HEATER
COMPRESSOR
WHITE
HIGH VOLTAGE SCHEMATIC
115 VOLTS
GRAY W/WHITE STRIPE
MAIN BOARD
PIN 1
PIN 1
PIN 1
PIN 1
PIN 1
WHITE
BLUE
GRAY W/WHITE STRIPE
GRAY W/WHITE STRIPE
J5
J3
J4
J6
P2
J2
P1
P3
P4
M
M
M
M
5. Drain and fill tube
heaters remain
on during dwell.
2. Defrost circuit
energized.
3. Terminator
opens at
70°F (21°C)
1. Compressor runs 12
hours, then switched off.
4. Defrost duration
observed, interval
between next
defrost adjusted
Summary of Contents for 700-3 BASE
Page 2: ......
Page 12: ...Installation Information Integrated 700 3 BASE Series 2 4 3758424 Revision B December 2005 ...
Page 40: ...Electronic Control System Integrated 700 3 BASE Series 3 28 3758424 Revision B December 2005 ...
Page 48: ...Sealed System Information Integrated 700 3 BASE Series 4 8 3758424 Revision B December 2005 ...
Page 52: ...Airflow Fan Blade Spacing Integrated 700 3 BASE Series 5 4 3758424 Revision B December 2005 ...
Page 58: ...Icemaker Information Integrated 700 3 BASE Series 6 6 3758424 Revision B December 2005 ...
Page 114: ...Wire Diagrams Schematics Integrated 700 3 BASE Series 10 10 3758424 Revision B December 2005 ...
