Dometic RM7732 - Manual (Page 23)

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DOMETIC® RM7030/RM7732
Refrigerators
DIAGNOSTIC SERVICE MANUAL
7.2 ORIFICE
The orifice is a small brass fitting that has a ruby
membrane that is laserbeam drilled and is mounted on
the gas line just prior to the burner. The orifice is
cleaned by using an alcohol based solvent and allowing
to air dry.
NEVER USE A DRILL BIT OR JET TIP CLEANER TO
CLEAN ANY ORIFICE AS THESE DEVICES WILL
DAMAGE THE FACTORY MACHINED PART AND
CREATE A POTENTIALLY DANGEROUS CONDI-
TION.
If there is lack of cooling on gas operation, verify the
orifice is the proper size (#73).
7.3 THERMOCOUPLE
A. RM7030 (Product No. 921890201 & 921890301)
The thermocouple is a component extending above the
burner assembly so the tip is in the path of the flame. It
will produce 14 to 30 millivolts DC in normal operation.
To check the thermocouple, use a known good safety
valve and attach to the thermocouple. Next, supply
flame to tip of the thermocouple for a few moments
while depressing the safety valve. Remove the flame
and release the safety valve.
The valve should hold for at least 30 seconds. If it does
not hold the safety valve open for 30 seconds, replace
the thermocouple. If it does hold for 30 seconds or
more, the thermocouple is good – do not replace it.
NOTE: Be sure the tip on the thermocouple is clean.
B. RM7030 (Product No. 921890401) & RM7732
The thermocouple is a component extending above the
burner assembly so the tip is in the path of the flame.
During normal gas operation, the thermocouple should
produce 25 to 35 millivolts when connected to the lower
circuit board. Any reading below 18 millivolts could
cause erratic gas operation. NOTE: A reading of 18 or
less could be caused by low gas pressure or improper
thermocouple location.
RM7030 (Product No. 921890401) and RM7732
PRESSURE TEST
PORT
ORIFICE
THERMOCOUPLE
ELECTRODE
BURNER TUBE
RM7030 (Product No. 921890201 & 921890301)