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CHAPTER 6.
SJPT55RHS
FAILURE DIAGNOSIS
[1] OUTLINE OF CONTROL
1. ON/OFF Control of Compressor
•
ON/OFF of the compressor will be controlled depend on the temperature detected by
the R-thermistor and F-thermistor. (Normal cooling control)
•
In case the surrounding temperature is high at the power supply input, the compressor will be ON at once and the normal cooling control will start
after several hours.
•
During 5 minutes after the compressor stops, it will not start regardless of the detected temperature by R-thermistor and F-thermistor.
2. Defrosting
Microcomputer calculates the appropriate timing of defrosting and defrosting is made automatically. Therefore no manual operation by user is
required. The cycle of defrosting varies depend on the usage condition of the refrigerator. (Maximum time 50 hours, minimum time 40 minutes)
3. Thermistor
Thermistors are installed in 4 places; in the refrigerator and freezer compartment, and on the Main PWB and close to Evaporator. (R-thermistor, F-
thermistor, Outside temp-thermistor, Def-thermistor)
R-thermistor and F-thermistor reads the temperature in the refrigerator and freezer compartment respectively and controls ON/OFF of the compres-
sor and OPEN/CLOSE of the electrical damper.
Def-thermistor detects the temperature around the evaporator and shows the progress of defrosting.
Outside temp-thermistor reads the surrounding temperature of refrigerator. It changes the operation mode when the outside temperature is high.
[2] WHEN THE DEFROSTING FAILURE IS DOUBTFUL(Only for SJ-PT51R/PT55R)
Execute the Self-Diagnosis Mode. (Refer to the Chapter "SELF-DIAGNOSIS MODE")
•
In case the diagnosis result is "
mistor, defrosting will not be made for safety reasons.)
•
In case the diagnosis result is "
(This diagnosis result will be displayed when defrosting is made for 120 minutes, the maximum time length. In this case, the defect of PWB itself
and also the breakage of heater and heater circuit (melt down of current fuse and temperature fuse) are considerable.)
[3] RE-SETTING OF MICROCOMPUTER AT POWER FAILURE
•
At the power failure for over 0.2 second, the control of the microcomputer will be reset.
(Microcomputer might continue to operate for approximately 10 seconds maximum at power failure depending on the load at the operation. When
you need the difinite power off condition ,approximately 30 seconds is necessary.)
•
When the power is re-supplied, the normal cooling will be resumed.
•
The temperature set by user is not maintained if a power failure occurred.(Only for SJ-PT51R, PT55R)
(Defrosting also is not maintained.)
•
When the self diagnosis is made, each mode and setting are resumed to the initial condition.(Only for SJ-PT51R, PT55R)
03" (Def-thermistor system defect), follow up the flowchart of
07" (Defrost defect), follow up the flowchart of
Service Manual
07.
6 – 1
SJPT55RHS
03. (In case of any abnormity in the Def-ther-
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