Compressor Operating Characteristics; Compressor Electrical Check; Control Thermostat; Automatic Defrost Models - Electrolux BEVERAGE CENTER II Service Manual

COMPRESSOR OPERATING CHARACTERISTICS

• When the compressor electrical circuit is energized,
the start winding current causes the relay to heat
and switch off the start winding circuit.
NOTE: The relay will switch off the start winding
circuit even though the compressor has not started
(as when attempting to restart after momentary
power interruption).
• The overload protector is designed and calibrated
to open the compressor electrical circuit with locked
rotor run winding current only.
• With an open relay, the compressor will not start
since there is little or no current to the start windings.
The overload protector will open due to high locked
rotor run winding current.
• With a shorted relay or capacitor, the compressor
will start, and the overload protector will open.
• With an open or weak capacitor, the compressor will
start and run. However, the compressor will be
operating at reduced efficiency of energy usage.
• If the compressor casing gets too hot, it will shut
down on the overload. After the compressor has
cooled down, the overload will reset and the
compressor will restart.
• In rear mounted condensers, the overload will cycle
the compressor on and off if the refrigerator is set in
so tight that the air can't circulate around the
condenser. In air cooled condensers, the overload will
cut the unit off if the condenser becomes blocked or
the fan motor stops running.

COMPRESSOR ELECTRICAL CHECK

If the compressor will not run, make a voltage check
across the power lead terminals on the PTC Relay and
the Overload Protector. (See Figure C5.)
The voltmeter should show line voltage if the thermostat
knob is in normal operating position and not in the OFF
position. If this check does not show a live circuit, the
control thermostat and defrost timer wiring should be
checked for loose and/or broken connections.
A control thermostat check can be made by using a piece
of wire as a temporary bridge across two thermostat
terminals. If the compressor starts and runs with the
bridge, the control thermostat is at fault and should be
replaced.
If the voltage check shows power supply at the PTC Relay
terminals, use a test cord to check the compressor.
If the compressor does not start and run with the test
cord, check the line voltage to see if there is more than
10% variation from the rated voltage. If voltage is
correct and the compressor will not start and run,
replace the compressor.
If the compressor starts and runs with the test cord,
replace the PTC Relay.

CONTROL THERMOSTAT

Automatic Defrost Models

The control thermostat is a variable cut-in type. When
the thermostat knob is changed from one setting to
another, both cut-in and cut-out temperature change.
The degrees of temperature change are determined by
the knob setting.

Temperature Control Mounting

The temperature control is mounted in a one-piece
plastic control housing. The sensing element is attached
to the projection on the bottom of the housing, with a
single bend (See Figure C6).

To Remove Temperature Control

1. Disconnect electrical supply to refrigerator.
2. Remove four screws securing housing to top of
refrigerator compartment.
3. Unplug molex connector.
4. Remove Temperature Control knob.
5. To remove Temperature Control from housing, pull
back on two tabs and lift Temperature Control out.
(See figure C7.)
Figure C7
6. Disconnect three terminal lugs connected to control.
They may be tight so use needle nose pliers to loosen
them from terminals to prevent damanging terminals
and lugs.
7. Remove top of Air Diffuser. (It is in there kind of snug,
so be careful not to damage it while removing it.)
6. Remove control bulb from housing.
7. Reverse this procedure to complete repairs.
26
Figure C6