Sub-Zero 700-3 BASE, Technical & Service Manual

Page: 22 / 114

Electronic Control System
Integrated
(700-
3
BASE)
Series
3-10
#3758424 - Revision B - December, 2005
FUNCTIONS OF ELECTRONIC CONTROL SYSTEM
The following few pages explain monitoring, regulating and controlling functions of the electronic control system.
Display Zone Temperatures
The temperature signals from the thermistors in the refrigerator and freezer compartments are monitored by the
microprocessor and then displayed on the LCD. Though the compartment air temperature does fluctuate, the LCD
displays the average temperature (See Figure 3-17).
NOTE: If zone temperature changes, temperature display will change by one degree per minute.
Figure 3-17. Display Zone Temperatures
UNIT ICE
REFRIGERATOR
ON/OFF
ON/OFF
ON/OFF
WARMER COLDER
FREEZER
WARMER COLDER
Average temperature displayed
Figure 3-18. 700BCI-3 Signal Trace Schematic (High Voltage) of Lighting System
REF (TOP)
DRAWER LIGHT
YELLOW
REF LIGHT
SWITCH
ORANGE W/BLACK STRIPE
FRZ LIGHT
SWITCH
ORANGE
60 CYCLES
BLACK
L1
NEUTRAL
WHITE
FRZ (BOTTOM)
DRAWER LIGHT
WHITE
HIGH VOLTAGE SCHEMATIC
115 VOLTS
MAIN BOARD
PIN 1
PIN 1
PIN 1
PIN 1
PIN 1
WHITE
ORANGE
ORANGE W/BLACK STRIPE
ORANGE
J5
J3
J4
J6
P2
J2
P1
P3
P4
M
M
M
M
1. 115 Volts are supplied to
lighting system unless
unit is switched OFF, or
in Sabbath Mode.
2. Light switch position monitored
for alarm and fan operation.
Supply Power to the Lighting System
Power is supplied to the lighting system through the control board when the unit is switched ON by pressing UNIT
ON/OFF key. With a drawer open, the light switch allows power to the light. (See Figure 3-18).
NOTE: Power to the lights is monitored by the microprocessor to control the door ajar alarm feature and to help
control the operation of the evaporator fan and/or refrigerator compartment fan.
NOTE: When in Sabbath Mode, lighting system is disabled. Sabbath Mode will be covered later.