Control Description; Lp Gas Mode - Norcold 8682 Repair Manual

Control Description

Models 865, 866 and 868 require
that 12 volt DC be connected to
terminals J-4 (-) and J-5 (+) of the
Power Supply board located at the
rear bottom left of the refrigerator.
The 12 volts DC is necessary for
the refrigerator to work on either
LP GAS or electric operation. The
12 volt power is then routed
through the 3 amp fuse, located
on the Power Supply board, then
to the interior light and HIGH HU-
MIDITY circuit. A resistor, R3, acts
to limit the maximum amount of
current through the cable and Eye-
brow circuit.
Note:
When defective, the temperature
control circuit (Thermistor) can cause
the food storage cabinet to over-
freeze. The same result will occur
when the Thermistor is disconnected
from the Eyebrow board.
When the wiring harness is plug-
ged in, the +12 volt DC is reduced
to 5.6 Volts DC by a zener diode
D12 or D13 located on the Eye-
brow board. This 5.6 Volts DC is
the control voltage for the tem-
perature control circuit.
Gas Mode
When the Mode Selector switch
is set to LP, the indicator lamp will
illuminate and 12 volts DC will be
sent to the Ignition Module. When
the Ignition Module receives 12
Volts DC, the Ignition Module will
open the gas solenoid valve, al-
lowing gas to flow to the Burner.
The Ignition Module will then send
energy to the Ignition electrode to
spark the Burner.
If the flame is established the Ig-
nition Module will sense the flame
through the Sense electrode, and
cease the sparking at the Burner.
Operation
If ignition did not occur after the trial for ignition, the Ignition Module will
stop sparking and automatically close the gas valve. The Ignition Module
will then send 12 Volt power to the Eyebrow board and illuminate the Red
(X) CHECK lamp indicating ignition failure.
AC Mode
120 Volts AC is supplied to the Power Supply on terminals J-9 and J-10 by
the AC power cord when it is plugged into an active AC receptacle.
The neutral side of the AC J-9 is tied directly to terminal J-8 of the Power
Supply and to the AC heater when connected.
The hot side is routed through a 5 amp fuse to the normally open contact
of relay (K-1). The relay is energized by the 12 volt control voltage from the
Temperature Control circuit.
When the Mode Selector switch is set to AC ELEC, the temperature con-
trol circuit will complete the circuit of relay (K-1) coil and the relay contacts
will close. The hot side of the 120 Volts AC will be applied through the relay
contacts to the AC heater terminal J-7.
DC Mode (Three Way Models Only)
When 12 Volts DC is supplied to terminals J-4 (ground) and J-5 (+ 12
Volts DC) of the Power Supply, the power is routed directly to the normally
open contact of relay (K-2) and through the 3 AMP fuse to the storage
switch for the interior light and HIGH HUMIDITY circuits, then to the coil of
relay (K-2). The 12 Volt power is routed through the wiring harness to the
Eyebrow board.
The zener diode (D-12) or (D-13) on the Eyebrow board reduces the 12
Volts DC to 5.6 Volts DC, which is the control voltage within temperature
control circuit.
When the Mode Selector switch is set to DC ELEC, it completes the circuit
to the coil of relay (K-2), the relay contact closes, and 12 Volts DC is ap-
plied to terminal J-6 of the Power Supply.
Current then flows through the 20 AMP fuse and on the DC heater.
Note:
DC operation will not initially cool down the refrigerator. The initial cooling
must be done in either the GAS or AC modes. Trying to cool down the re-
frigerator in the DC mode will result in no cooling and battery run down.
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