GE PSI21MGM, Technical Service Manual

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Fresh Food/Freezer Independent
Operation
In previous models, the fresh food and freezer
compartment components worked at the same
time. When the fresh food compartment called for
cold air, the freezer compartment components
would work with the fresh food compartment
components. This is called nonindependent
operation.
In this model, the fresh food compartment
components can operate without the freezer
compartment components operating. This is called
independent operation.
Normal Operating Characteristics that May
Occur, but Different from Previous Models
•
Icemaker auger rotates clockwise.
• Evaporator fan running, without compressor or
condenser fan. Fresh food fan is on.
• Post dwell (adaptive defrost), compressor and
condenser fan on with evaporator fan off after
defrost cycle.
• Liner Protection Mode, fans come on when the
doors are open for 3 minutes.
•
When the doors open, the fans shut off.
•
No airflow to the fresh food compartment when
the evaporator fan is on.
• Evaporator fan and compressor can run
continuously for 8 hours.
• Fans shift speeds, different sound levels can
be noticed when this happens.
•
Quick Ice mode, the evaporator fan runs for 48
hours non-stop.
•
Response time for drastic temperature change
is 2 to 10 minutes. The main control board will
only respond to 8 degrees of temperature
change per minute as determined by
resistance change of sensor.
Abnormal Operating Characteristics
(Incorrect Operation)
•
Fresh food fan on and evaporator fan off.
• Evaporator fan on, fresh food fan and
compressor off, and damper shut.
• Rapid fan speed changes, fan takes at least 1
minute to change speeds.
•
Compressor running without the condenser fan.
The compressor and condenser fan should
always run at the same time.
• Condenser fan running without the
compressor. The compressor and condenser
fan should always run at the same time.
Adaptive Defrost
Adaptive defrost can be described as a defrost
system that adapts to a refrigerator’s surrounding
environment and household usage.
Unlike conventional defrost systems that use
electromechanical timers with a fixed defrost cycle
time, adaptive defrost utilizes an intelligent,
electronic control to determine when the defrost
cycle is necessary. In order to accomplish the
correct defrost cycle time, the main control board
monitors the following refrigerator operations:
• Length of time the refrigerator doors were open
since the last defrost cycle.
•
Length of time the compressor has run since
the last defrost cycle.
•
Amount of time the defrost heaters were on in
the last defrost.
Adaptive defrost is divided into 5 separate cycles.
Those operations are:
• Cooling Operation
•
Pre-Chill Operation
• Defrost Heater Operation
•
Dwell Period
•
Post dwell
Refer to Pub # 31-9062 for more information about
Adaptive Defrost.