Samsung AM072FXVAFH series Service Manual page 210

Troubleshooting
Inverter Overheat error
AM038/048/055KXWD
Outdoor unit
display
Judgment
∙ IGBT module internal temperature : 105°C more than (E500, E400)
Method
∙ Cooling pin and the IGBT junction part assembly defective.
Cause of
∙ Refrigerant cooling heat sink and refrigerant piping assembly
problem
defective.
∙ Assembled bolt defective.
1. How to check
Is the bolt of the heat sink fully tightened?
Did check the foreign objects between the heat
Did properly apply the heat sink grease?
(Between the heat sink and the IPM)
4-114
(cont.)
✳✳
(INVERTER1 PCB)
Power off
Yes
sink and IPM?
Yes
Yes
Complete
Both end resistance values of IGBT module pin(8, 9 pin)
Temperature [°C] NTC [ohm] AD [V]
10 9000 2.58
20 6000 2.33
30 4000 2.03
40 3000 1.80
50 2000 1.47
60 1600 1.29
70 1200 1.07
80 750 0.76
90 650 0.68
* Enforce the discharge mode before power off. (K2 : press the 6 times)
No
Tighten the Bolt (Screw)
No
Remove foreign objects and apply the heat sink
grease. And then reassembly.
No
Apply the heat sink grease and then reassembly.
Good
Temperature [°C] NTC [ohm] AD [V]
100 500 0.55
105 450 0.51
110 380 0.44
120 300 0.35
130 250 0.30
140 200 0.25
No Good
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