Case Study - Poor Cooling Caused By Ipm Overheated - Samsung AM072BXV Series Service Manual

Troubleshooting
4-4 Case study for trouble shoots (cont.)
4-4-13 Case study – Poor cooling caused by IPM overheated
- Problem : Poor cooling
- Condition : Compressor frequency doesn't increase, IPM temperature is too high, Low pressure is high
- History
: 13.05.07 Trial operation
: 13.05.27 Inverter PBA, EMI PBA, Reactor replacement
: 13.05.27 IPM temperature ↑ → comp Hz ↓ → cooling capacity ↓
Test
Upper PBA
(inv 2)
Lower PBA
(inv 1)
- Root cause : Bad contact of IPM cause by faulty bolt.
IPM
Heat sink
- Conclusion : Change bolt to new one, reattach the IPM → Problem solved
Date
OD Temp
High pressure
Low pressure
Comp1
Comp2
Current1
Current2
IPM1
IPM2
※ IPM Temp Protection
- Hz Hold : 90℃
- Hz Down : 93℃
Samsung Electronics
5/27 case 1
upper PBA change
PBA_A PBA C
freq. 55hz freq. 54hz
IPM 89℃ IPM 82℃
PBA B PBA B
freq. 52hz freq.51hz
IPM 86℃ IPM 92℃
IPM1
5/28 5/29
38 38
30.5 30.4
10.9 11.4
52 52
55 55
12.3 15.3
10.3 14.2
86 89
89 81
Basic Reattach #1
5/28
case 2
lower PBA change
PBA C
freq. 55hz
IPM 79℃
CB D
freq. 52hz
IPM 91℃
IPM2
There is no thermal grease.
Date 6/5
OD Temp 41.6
High pressure 34.7
Low pressure 10.5
Comp1 61
Comp2 64
Current1 14.9
Current2 14.2
IPM1 88
IPM2 90
Reattach #2
※ HP Protection
- Hz Hold : 36 kgf/㎠
- Hz Down : 37 kgf/㎠
case 3
exchange PBA position each other
PBA D
freq. 55hz
IPM 81℃
PBA C
freq. 52hz
IPM 89℃
IPM 2- Reattach
6/5
40.8
36.4
9.9
82
85
20.2
19.3
85
86
Solved
170