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

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Electronic Control System
Integrated
(700-
3
BASE)
Series
3-2
#3758424 - Revision B - December, 2005
ELECTRONIC CONTROL TERMINOLOGY & COMPONENT DESCRIPTIONS
All 700-3 Series units utilize an electronic control system which monitors, regulates, controls and displays a variety
of functions and operations in the appliance.
The table below defines some of the basic electronic control system terminology.
Term/Component Definition / Description
Main Control Board ..……....…… The printed-circuit board (PC Board) which contains a microprocessor, relays, triacs and
electrical connections that monitor and control all functions of the appliance.
Microprocessor ……….…....…... An electrical component on the control board which receives electrical signals from
other components, processes the information, then sends electrical signals to relays and
triacs on the board to open or close, switching components in the appliance ON or OFF.
Relay …………………….....……. An electrical component on the control board which switches other components in the
appliance ON or OFF when instructed to do so by the microprocessor.
Triac …………………….......…… Similar in function to the relay, the triac is a three terminal semiconductor for controlling
current in either direction.
Control Panel Assembly ….....… (Also referred to as the Control Keypad Interface), is that part of the electronic control
system where all input operations are performed.
Membrane Switch ……….……... Part of the control panel assembly, which consists of the function keys.
Keys (Function Keys) ……......... The “buttons” on the Membrane Switch used for input operations: “POWER”, “ALARM”,
“ICE MAKER”, “WARMER” and “COLDER”
LCD (Liquid Crystal Display) ..... A semi-liquid substance sandwiched between glass in the display of the control panel
assembly. The molecules of this semi-liquid substance have no specific orientation.
However, when electricity is applied to them, they react predictably, aligning and
straightening in such a way as to control light passage.
Indicators .....……..………….…... The words, numbers and icons that appear on the display of the control panel assembly
through the use of LCD’s.
Error Codes .………...…………... The code numbers that may appear on the display of the control panel assembly when
accessing Error Code History. Error Codes are logged if the unit experienced specific
problems related to electrical signals supplied by electrical components.
Temperature Units of Measure.... Temperature observed on the display of the control panel assembly may be in
Fahrenheit units of measure (°F) or Celsius units of measure (°C). A series of key
strokes allows the temperature units of measure to be switched to display 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 interrupting cooling.
Thermistor ……………..………. (Also Referred to as a Temperature Sensor), is a resistor with which resistance changes
as the temperature around it changes. For electronic control system purposes, the
microprocessor measures the resistance, then displays it as a temperature reading.
Variable Speed Compressor …... A compressor that runs at varying speeds depending on the temperature detected in the
corresponding zone(s) of the appliance.