Electronic Control System
Integrated
Integrated
(700-
(700-
3
3
T
T
ALL)
ALL)
Series
Series
3-2
#3758412 - Revision B - December, 2006
ELECTRONIC CONTROL TERMINOLOGY & COMPONENT DESCRIPTIONS
The electronic control system monitors, regulates and controls a variety of functions. It also displays temperature
readings, ice maker system operational status, possible problems with the unit and door ajar alarm status. The table
below defines some basic electronic control system terminology and describes some of the electronic control system
components. An understanding of the following information is needed in order to comprehend the input operations
and functions of the electronic control system.
Term/Component
Definition / Description
Control Board ……………………..…….. The printed-circuit board (PC Board) contains the microprocessor, relays and
electrical connections which control and monitor all functions and operations of
the appliance.
Microprocessor ……………………..…... An electrical component on the control board which receives electrical signals
from other components, processes that information, then sends an electrical sig-
nal to the relays on the board to open or close, and other electronic components
in the unit to switch on or off.
Relay ………………………………..…… The electrical components on the control board which switch other components in
the unit ON and OFF when instructed to do so by the microprocessor.
LCD (Liquid Crystal Display) …..…...... That part of the control board seen at the control panel which displays zone tem-
peratures, service indicator, door ajar alarm bell & ice indicator.
Control Panel Assembly ……..………… The information input and read-out area of the electronic control system, located
at the top of the upper Compartment.
Membrane Switch …………..………….. An integral part of the control panel assembly, which consists of the function keys
used for all input operations to the electronic control system.
Keys (Function Keys) ………..………… The buttons on the Membrane switch used for input operations. (The keys are:
UNIT ON/OFF, ALARM ON/OFF, ICE ON/OFF, WARMER, COLDER)
Indicators .....…………………..………... The words and numbers that are displayed at the control panel assembly.
(Example: Temperature displays, alarm bell indicator, SERVICE indicator, and ICE
system indicator)
Error Codes .…………………..………... The code numbers accompanied by the letters “EC” that appear on the LCD dur-
ing diagnostic mode if the unit experienced specific problems related to electrical
signals supplied by electrical components.
Display Units of Measure…………..…... Temperatures displayed at the LCD may be in fahrenheit units of measure (°F) or
celsius units of measure (°C). A series of key strokes allows the temperature dis-
play units of measure to be switched to read as either °F or °C.
Set-Point …………………………..…….. The desired zone temperature, established by pressing the COLDER or
WARMER keys.
High Offset (Cut-in)……………..……..... As the zone air temperature cycles up and down, the high offset is the maximum
zone temperature that the electronic control system will allow before calling for
cooling.
Low Offset (Cut-out)……………..……... As the zone air temperature cycles up and down, the low offset is the minimum
zone air temperature that the electronic control system will allow before interrupt-
ing cooling.
Thermistor (Temperature Sensor) ..….. A resistor with which resistance changes as the temperature around it changes.
For electronic control system purposes, the microprocessor measures this resist-
ance and displays it as a temperature reading at the LCD.
Variable Speed Compressor ….............. A compressor that runs at varying speeds depending on the load detected by the
compressor’s inverter.
Summary of Contents for 700TC-3
Page 2: ......
