Troubleshooting
62
9.2 Malfunction Checking and Elimination
14/18K:
24/28K:
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Communication failure with Unit A
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44
Communication failure with Unit B
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45
Communication failure with Unit C
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46
Communication failure with Unit D
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47
Unit A freeze protection
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48
Unit B freeze protection
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49
Unit C freeze protection
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50
Unit D freeze protection
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51
Unit A
overheating prevention protection
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52
Unit B
overheating prevention protection
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53
Unit C
overheating prevention protection
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54
Unit D
overheating prevention protection
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55
Unit A communication wire misconnection or expansion valve malfunction
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56
Unit B communication wire misconnection or expansion valve malfunction
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57
Unit C communication wire misconnection or expansion valve malfunction
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58
Unit D communication wire misconnection or expansion valve malfunction
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Note: discharge the position in below pictures with discharge resistance after open the top cover and
check if the voltage is below 20V with universal meter, then begin to check.
(1) IPM protection malfunction:
Main checking point:
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If the input voltage of the unit is within normal range?
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If the connection wire of compressor is connected well? Is it loose? If the connection sequence is correct?
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If the resistance of compressor coil is normal? If the isolation of compressor coil with copper pipe is good?
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If the unit is overloaded? If the heat radiation of the unit is good?
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If the refrigerant charge is suitable?
Flow chart:
