SERVICE MANUAL
15
www.norcold.com
Controls, cont’d.
When the outside air temperature is below 50° F., the refrigerator
may have a tendency to freeze food. To reduce the tendency to
freeze food:
- Turn the gas control to LO position.
- Keep the refrigerator full.
- Put foods that are more likely to freeze on the lower shelf.
The gas control has a gas safety valve built into it. As long as a
fl
ame is present, the safety valve is open and allows propane gas
to
fl
ow to the burner. Any loss of
fl
ame (empty gas tank, blow out,
etc.) closes the safety valve and stops the
fl
ow of propane gas.
The piezo lighter [216] makes a spark which ignites the
fl
ame at
the burner.
The 3 Amp fuse [220] protects the AC wiring of the refrigerator.
The 20 Amp fuse [223] (model 323) protects the DC wiring of the
refrigerator.
Modes of Operation
The controls are designed so that each mode of operation is
independent of the others. The refrigerator will still operate in the
GAS mode without any electrical input.
Gas Mode
The GAS mode uses a thermocouple system to produce a self-
generating power (millivolts). The Thermocouple, when heated
by the burner
fl
ame, produces enough millivolts to hold the safety
valve open. A loss of
fl
ame de-energizes the safety valve and
shuts the propane gas down. An Interrupter device is coupled in
series with the thermocouple so that the milliamperes cannot
fl
ow
to the Safety Valve (part of the Control Valve) until the Interrupter
contacts are shunted (jumpered). The shunt is provided by the
Selector switch when it is switched to GAS mode. The Selector
switch not only serves as a mode selector but also as an interlock
between modes so that two sources of power cannot be energized
simultaneously.
The GAS mode utilizes an adjustable GAS control. The control can
be manually adjusted to meter the
fi
xed amount of propane gas
to the burner thereby acting as a temperature control to maintain
cabinet temperature.
Note:
This is not an automatic gas control. It does not change the
fl ame from high fi re to low fi re as other RV refrigerators. If the cooling load
changes, you must manually change the gas control to maintain the same
temperature inside the refrigerator.
The gas ignition method uses a piezo spark ignitor requiring a
manual ignition of the burner. See the Lighting Instructions.
To change the desired temperature setting, push and turn the
gas control to the HI, MED, or LO position. HI is the coldest
temperature setting.
Note!
The gas control changes the amount of propane gas that goes
to the burner. It is not an automatic gas control. It does not change the
fl ame from high fi re to low fi re. If the cooling load changes, you must
manually change the gas control to maintain the same temperature inside
the refrigerator.
When the outside air temperature is less than 50° F (10° C), the
refrigerator may have a tendency to freeze food at the colder
temperature settings. To reduce the tendency to freeze food:
■
Turn the gas control to the LO position.
■
Keep the refrigerator full.
■
Put foods that are more likely to freeze on the lower shelf.
AC and DC Modes
The AC mode is thermostatically controlled by an adjustable
thermostat. The thermostat has a capillary sensor attached to the
cooling
fi
n. The AC electric heater will cycle in response to the
fi
n
temperature to maintain the cabinet temperature. The DC mode is
not thermostatically controlled. When operating in DC Mode, the
DC heater is on continually.
DC Operation Precautions
The refrigerator is made to operate on DC power while the vehicle
is “in transit” and neither AC power nor propane gas sources are
available. Operate the refrigerator on DC power only while the
vehicle engine is running.
■
For the refrigerator to operate correctly on DC power, the bat-
tery must be in a fully charged condition.
■
For the battery to be fully charged at all times during refrigerator
operation, the vehicle engine must be running and the battery
charging system must be in good operating condition.
■
While the vehicle engine is running, make sure the voltage at
the DC power supply leads at the refrigerator is more than 11.5
VDC.
