Low Voltage Monitor - Dometic RM3604 Service Manual

®
Dometic MANUAL
Refrigerators
FLAME FAILURE DURING LP GAS
OPERATION
If the LP gas flame fails during the burner cycle, the high
voltage spark will continue arcing for up to three min-
utes.
At the end of three minutes the gas control will stop the
flow of LP gas to the burner, the sparking will stop and
the red indicator lamp "H" will light up. LP gas operation
will not be possible as long as this indicator is ON.
To restart LP gas operation, turn the main system switch
"C" to "OFF" for five seconds and then back ON. This
will reset the AES controls and turn off the flame failure
indicator "H". The system will start another cycle for gas
ignition.
If the refrigerator has not been used for a long time or
the LP tanks have just been refilled, air may be trapped
in the supply lines. To purge the air from the lines may
require resetting (turning OFF and ON) the On/Off
switch "C" three or four times.
If repeated attempts fail to start the LP gas operation,
check to make sure that the LP gas supply tanks are not
empty and all manual Shutoff valves in the lines are
open.
NOTE: If you are in the AES mode when the flame
failure light "H" comes on, the mode indicator lamp "A"
(green light) will go out. If 120 volt AC power becomes
available during this period, the mode indication lamp will
come on showing that the refrigerator is operating on
another energy source. The red lamp "H" will remain on
until the AES system is reset with an OFF/ON operation
of the main switch "C". If you have selected the LP gas
only mode (control button "B"), the 120 volt function has
been locked out. If the burner fails to light, the green
lamp over button "B" will go out and the red lamp "H" will
glow indicating flame failure. Even if 120 volts is avail-
able, the refrigerator cannot switch to electric operation
and all cooling will stop. This fact must be considered
when selecting "gas only" operation.
120 VOLTS AC OPERATION
Since 120 volt AC is usually the most economical source
for operation of the refrigerator, the AES control system
is designed to select this mode whenever it is available.
The only exception to this is when push-button "B" (LP
gas only mode) is selected. The 120 volt heating ele-
ments attached to the boiler provide the heat necessary
to operate the cooling system. The thermostat controls
the power ON and OFF to the elements and maintains
the desired temperature.

LOW VOLTAGE MONITOR

The AES system requires 12 volts DC power at all times
to operate properly. The DC power must be 9.5 volts DC
or higher. If the DC voltage drops below 9.5 volts DC,
the AES system will switch to an emergency cooling
mode.
1. The mode indicator lamp will go off (green light);
2. The system will revert to continuous LP gas
operation, with no thermostat control.
The refrigerator will continue to operate in the emer-
gency mode until the DC power supply is increased to
10.5 volts DC. When 10.5 volts is reached, the mode
indicator light (green) will come back on and normal
operation will resume.
During the low voltage condition, the interior light will
operate normally.
THERMOSTAT
The refrigerator is equipped with a thermostat that can
be adjusted to maintain various temperatures. Turn the
knob clockwise toward "MAX" for a lower temperature
and for a warmer temperature – turn the knob counter-
clockwise toward "MIN". Set the thermostat approxi-
mately mid-range and adjust it toward "MIN" or MAX" to
obtain the desired cabinet temperatures. Remember, at
the "MAX" setting, the heating element/burner is running
continuously and the lower cabinet temperatures are
obtained.
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