System Diagnosis - Maytag ACD2234HR*ACD2238HT Series Service

System Diagnosis

SUCTION
PRESSURE
CONDITION VARIATION
FROM
NORMAL
Refrigerant
Increase
Overcharge
Shortage of
Decrease
Refrigerant
Partial
Decrease
Restriction
Air in
Near Normal
System
Low Ambient
Installations
(High Decrease
Ambients the
Reverse)
Additional
Increase
Heat Load
Inefficient
Increase
Compressor
Symptoms of an Overcharge
• Above normal freezer temperatures.
• Longer than normal or continuous run.
• Freezing in refrigerator, especially on forced air
meatkeeper models.
• Higher than normal suction and head pressure.
• Higher than normal wattage.
• Evaporator inlet and outlet temperatures warmer than
normal.
• Suction tube temperature below ambient. Always
check for separated heat exchanger when suction
temperature is colder than ambient.
Various conditons could indicate an overcharge. For
example, if the cooling coil is not defrosted at regular
intervals, due to a failure of the defrost system, the
refrigerant will "flood out" and cause the suction line to
frost or sweat. The cause of this problem should be
corrected rather than to purge refrigerant from the
sytem. Running the freezer section colder than
necessary (-2 to -1 F. is considered normal package
temperatures) or continuous running of the compressor
for a variety of reasons, or the freezer fan motor not
running, may give the indication of an overcharge.
©2005 Maytag Services
HEAD
T1 INLET
PRESSURE
TEMPERATURE
VARIATION
VARIATION
FROM
FROM NORMAL
NORMAL
Increase Warmer
Decrease or
Increase Colder
See Text
Decrease or
Increase
Colder
See Text
Note 2
Increase Warmer
Decrease Colder
Increase Warmer
Normal or Warmer or
Decrease Colder
16025628
T2 OUTLET
TEMPERATURE
VARIATION
FROM NORMAL
Warmer
Warmer
Warmer
Warmer
Warmer
Warmer
Warmer
Symptoms of Refrigeration Shortage
• Rise in food product temperature in both
compartments. (See Note 1 below.)
• Long or continuous run time.
• Look for obvious traces of oil that would occur due to a
leak or cracked refrigerant line.
• Lower than normal wattage.
• Compressor will be hot to touch because of the heat
generated by the motor windings from long continuous
running. It will not be as hot as it would be with a full
charge and long run times for some other reason such
as a dirty condenser.
• Depending on the amount of the shortage, the
condenser will not be hot, but closer to room
temperature. The capillary tube will be warmer than
normal from a slight shortage.
• If the leak is on the high side of the system, both
gauges will show lower than normal readings and will
show progressively lower readings as this charge
becomes less. The suction pressure guage will
probably indicate a vacuum.
• If the leak is on the low side of the system the suction
pressure guage will be lower than normal - probably in
a vacuum - and the head pressure gauge will be
higher than normal. It will probably continue to
become higher because air drawn in through the leak
is compressed by the compressor and accumulates in
T3 SUCTION WATTAGE
TEMPERATURE VARIATION
VARIATION FROM
FROM NORMAL NORMAL
Colder Increase
Warmer Decrease
Warmer Decrease
Warmer Increase
Warmer Decrease
Warmer Increase
Warmer Decrease
27