Haier HB21FWRSS Service Manual - page 43

certain phase is low, this means that short circuit does exist in the windings and/or between 

turns, and insulation layers have been burned or deteriorated. A megametre can be used in 

this inspection, too. If the insulation resistance is lower than 2 Mȍ, this means that the 

insulation layer is already breakdown. If the motor has been burned, repair it or replaced it 

with a new one. 

b) Fault of control relay 

Analysis of Trouble  

Overheat, burnout or wear of control relay contacts may occur generally. All these will cause 

poor contact in electricity. 

Remedy  

Dismantle it to repair, or replace it with a new one. 

c) Poor electric contractor in thermostat 

Analysis of Trouble  

Burnout of contractor and leakage of temperature sensing agent may occur generally. 

Remedy 

Replace the old with a new one. 

d) Check the terminals for loose connection and electric circuits for other abnormal 

phenomena.

5) Mechanical faults of compressor 

a) Seizing of shaft 

This phenomenon is caused mostly by poor lubrication, such as insufficient quantity of 

lubricant, clogging in the lubricant oil line, or intermittent lubricant oil supply. Dirt and other 

impurities in the lubricant oil will increase its viscosity and cause the shaft to be seized. 

Copper plating may also result in seizing of shaft. 

b) Seizing of piston 

This is caused by too small fit clearance between the piston and cylinder or expansion due to 

heat.

Judgement of seizing shaft and piston: After the refrigerator has been powered on, the 

compressor will not start and run, but a slight hum sound can be heard, and several seconds 

later, thermal protective relay will actuate and make the contacts open; this process will occur 

repeatedly, but the compressor cannot be started. 

E. Compressor won’t stop 

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