Dometic RM7732, RM7030 service manual Other

DIAGNOSTIC SERVICE MANUAL

DOMETIC® RM7030/RM7732 Refrigerators

SECTION 9

OTHER

9.1LEVELING

In an absorption refrigerator system, ammonia is liquefied in the finned condenser coil at the top of the refrigerator. The liquid ammonia then flows into the evaporator (inside the freezer section) and is exposed to a circulating flow of hydrogen gas, which causes the ammonia to evaporate, creating a cold condition in the freezer.

The tubing in the evaporator section is specifically sloped to provide a continuous movement of liquid ammonia downward by gravity through this section. If the refrigerator is operated when it is not level and the vehicle is not moving, liquid ammonia will accumulate in sections of the evaporator tubing. This will slow the circulation of hydrogen and ammonia gas, or in severe cases, completely block it, resulting in a loss of cooling.

Any time the vehicle is parked for several hours with the refrigerator operating, the vehicle should be level to prevent this loss of cooling. The vehicle needs to be leveled only so it is comfortable to live in (no notice- able sloping of floors or walls).

When the vehicle is moving, the leveling is not critical as the rolling and pitching motion of the vehicle will pass to either side of level, keeping the liquid ammonia from accumulating in the evaporator tubing.

9.2VENTILATION

Ventilation is one of the requirements for proper cooling unit operation. The coach vent system must be able to provide a way to direct the hot air produced by the action of the cooling unit, out away from the installation of the refrigerator.

0" CLEARANCE FROM SIDE OF CABINET

CLEARANCE

FROM

COMBUSTIBLE

MATERIALS

PATH OF

AIR FLOW

The refrigerator extracts heat from the interior of the refrigerator cabinet and dissipates the heat out through the vent system. In a proper installation there should be

as little open space as possible surrounding the sides and top of the refrigerator to achieve proper air flow. All potential dead air pockets should be blocked or baffled to ensure that heat won't be trapped in these spaces and reduce efficiency.

NOTE: Refrigerators should be installed in accordance with appropriate installation instructions received with the refrigerator.

9.3AIR LEAKS

Check the gasket on the doors to be sure of a positive air seal. A simple method to check gaskets is to close the door on a dollar bill, then pull the dollar bill out. If no resistance is felt, the gasket is not sealing properly. This should be done on all four sides of the door. If a gasket is not sealing properly, first warm the gasket material with a hair drier.

DO NOT OVERHEAT AS YOU CAN MELT THE MATERIAL.

Then close the door and the magnetic strip should pull the gasket to the metal frame. Leave door closed until the material has cooled. Then recheck for a positive seal. If a positive seal cannot be achieved, replace the gasket. Also check that the cooling unit is installed properly. The cooling unit's foam block, the portion that surrounds the evaporator coils, must be flush to the cabinet at the back of the refrigerator and have a positive seal. If the cooling unit is not installed properly, remove and install properly.

RM7030:

The refrigerator is secured in the enclosure with six screws and they must be installed in the following order:

First Two Screws installed on front base; Second Two Screws installed in the top frame; Third Two Screws installed in the rear base.

Failure to follow the sequence in securing refrigerator in

enclosure can
cause leakage
between the
frame and	2ND
cabinet.
NOTE: Air
leaks will
cause insuffi-	3RD
cient cooling
as well as
rapid forma-
tion of frost.
	1ST

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