Amana Bottom Mount Refrigerator service manual April RS1200001 Rev.1

Component Function and Testing

Condenser	Condenser is a tube and w ire construction located in	•		Leaks in condenser can usually be detected by using an electronic
	compressor compartment. Condenser is on high			leak detector or soap solution. Look for signs of compressor oil w hen
	pressure discharge side of compressor.			checking for leaks. A certain amount of compressor oil is circulated
	Refrigerant flow s from compressor into a pre-			w ith refrigerant.
		•		Leaks in post condenser loop are rare as loop is a 1 piece copper
	condenser serpentine below drain pan to evaporate			tube.
	defrost w ater. From serpentine, refrigerant flow s into	•		In cases of minute leaks it may be necessary to separate condenser
	pre-condenser loop (Yoder loop) foamed around			from rest of refrigeration system and pressurize condenser up to a
	freezer door opening to help control external			maximum of 235 PSI w ith a refrigerant and dry nitrogen combination.
	condensation around freezer door and on flange.
	Higher pressure refrigerant gas is routed to condenser			WARNING
	w here as gas temperature is reduced, gas condenses			To avoid severe personal injury or death observe the follow ing:
	into high pressure liquid state. Heat transfer takes place			•	Protect against a sudden eruption if high pressures are
	because discharged gas is at higher temperature than				required for leak checking.
	air that is passing over condenser.			•	High pressure compressed cases should never be used in
	Condenser is air cooled by fan motor. It is very				refrigeration systems w ithout a reliable pressure regulator and
					pressure relief valve in the lines.
	important that adequate air flow over condenser is
	maintained. If efficiency of heat transfer from
	condenser to surrounding air is impaired, condensing
	temperature becomes higher. Higher temperature liquid
	means less heat w ill be removed during boiling in
	evaporation. This is indicated by higher that normal
	head pressures, long run time, and high w attage.
	Remove any lint, dust accumulation, etc. that w ould
	restrict normal air movement throughout the condenser.
Drier	Desiccant		Drier is placed at P.C. loop outlet and passes liquified refrigerant to
	(20) 8 X 12 4AXH - 7 M.S. - Grams		capillary.
			Drier must be changed w henever sealed refrigeration system is opened.
			Drier used in R12 sealed system is not interchangeable w ith drier used in
			R134a sealed system. Replace drier w ith part #B2150504.
Evaporator	Inner volume of evaporator allow s liquified refrigerant	Leaks in evaporator can usually be detected by the use of electronic leak
	discharged from capillary to expand into refrigerant	detector or soap solution. Compressor oil is circulated w ith refrigerant so
	gas.	look for oil w hen checking for leaks.
	Act of expansion cools evaporate tube and fin	For minute leaks separate condenser from rest of refrigeration system
	temperature to approximately -20°F, transfering heat	and pressurize condenser up to a maximum of 140 PSI w ith a refrigerant
	from freezer section to refrigerant.	and dry nitrogen combination. Recheck for leaks.
	Passing through suction line to compressor, the
	refrigerant picks up superheat (a relationship betw een
	pressure and temperature that assures complete
	vaporization of liquid refrigerant) as result of capillary
	being soldered to suction line.
	Refrigerant gas is pulled through suction line by
	compressor to complete refrigerant cycle.
Heater,	See "Electronic Functional Description, Adaptive		Check resistance across heater.
evaporator	Defrost Circuitry"
(defrost)			Check defrost system by thermocoupling defrost thermostat and plugging
			refrigerator in w attmeter. Force into defrost mode. Wattmeter should read
			specified w atts (according to tech sheet) ± 20 w atts. When defrost
			thermostat reaches specified temperature (according to tech sheet) ±
			5°F., thermostat should interrupt pow er to heater.
Ice Maker	See “Ice Maker” section for service information.

April 1998 21 RS1200001 Rev.1