5
1.3
Condenser Layout
The new compressors have no oil cooler lines, therefore the re-routing of the
condenser is as follows:
Discharge line from the compressors runs directly to the condenser on the back
panel. From the back panel it enters the LH side condenser, through the cross rail
heater (if applicable) then into the RH condenser, then into the filter dryer. The
remaining layout remains unchanged.
2
ELECTRONICS
2.1
Control Module
The electronic control module is situated in the unit compartment. It is connected to
220-240 volt supply for switching of the compressor, defrost heaters and FC fan.
The compressor is switched through a solid state Triac and relay, and the defrost
heater through a relay. The compressor has an external overload. Sensors are
located in the PC and FC and, along with a variable resistor, which replaces the
thermostat, are used to cycle the refrigerator. The defrost timer has also been
replaced by the control module.
2.2
Light Operation
The light globe remains at 230V 15 watt and is switched using the same light switch
mechanism as for compacts. The light switch is operated by the plunger being
depressed by the dairy cover to turn the light on and off. If the P.C. door is left open
longer than 90 seconds, the alarm will sound. This will repeat every 30 seconds until
the door is closed, and will sound continuously after the door has been left open for 5
minutes. The control module measures the current drawn by the P.C. light to
determine whether the door is open or closed. If the P.C. lamp circuit is open circuit
(e.g. lamp is blown or missing) the door open alarm will not operate.
2.3
Beeper
This is a piezo electric device located in the control module to provide the user with
feedback on fault alarms. If a fault occurs, the alarm only sounds when the PC door
is opened. It turns off when the door is closed.
2.4
Temperature Sensors
These are temperature sensing devices, the resistance of which change with respect
to temperature. They have a single connector on the printed circuit board to ensure
the integrity of the resistance of the sensor is measured. Two sensors are located in
the product. The PC sensor is located in a pocket attached to the left-hand side of
the PC evaporator and senses the temperature for switching on and off the
compressor. The FC sensor, which is the defrost sensor, is located immediately
above the FC evaporator for defrost termination temperature sensing.
