Service manual
Operation of the AES System (Automatic Energy Selector)
The control system on the AES selects the most suitable energy source. The selection
will be made with highest priority to 120 volt,
second priority to 12 volt from the
alternator (if 12V DC is provided to the ignition lock terminal from the vehicle ignition
switch) and lowest priority to gas operation.
There are only two customer controls to
operate the system; the thermostat and the on-off switch.
When the switch is turned
on, a green indicator light glows to show that the system has 12 volts supplied. This
indicator light will flash red on the gas mode, if the propane burner fails to light.
The AES has a built-in safety device that delays gas ignition and start up approximately
20 minutes from 12 volt operation. This enables the customer to stop and refuel the
vehicle without touching the refrigerator. If the delay is not desired after stopping, the
system may be re-set by switching the main switch off and then back on.
SAFETY DEVICE
The AES system also has a built-in safety device that will prevent operation, if one of
the following parts breaks down: A. the printed circuit board, B. the igniter or, C. there
is no control voltage to the terminal block. This feature ensures that the thermo-
electric solenoid valve will not open as the result of a part failure.
FIG.
1
A
-
Printed
Circuit Board
B
-
Igniter
C
-
Terminal Block
D
-
Electrode
E
-
Thermo-Electric Solenoid Valve
PART EXPLANATION AND TROUBLESHOOTING DIAGNOSIS
PRINTED CIRCUIT BOARD
The printed circuit board is the heart of the AES.
From this point, all the energy
sources are controlled, including the gas start-up delay from 12 volt operation.
The 120
volt operation is not affected by the 12 volt delay feature.
Anytime the system receives
120 volts, the refrigerator will switch over to the 120 volt electric mode. It should be
noted, however, if the 120 volt supply is disconnected within the 20 minute delay cycle,
a gas start-up will not occur until the end of the delay period.
As before, if a delay is
not desired, the refrigerator may be re-set by making an off-on procedure.
A normal
gas start-up will then occur.
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