55
3. IPM continuity check
Turn off the power, let the large capacity electrolytic capacitors discharge completely, and dismount the IPM. Use a digital
tester to measure the resistance between P and UVWN; UVW and N.
Digital tester
Normal resistance value
Digital tester
Normal resistance value
(+)Red
(-)Black
∞
(Several MΩ)
(+)Red
(-)Black
∞
(Several MΩ)
P
N
U
N
U
V
V
W
W
(+)Red
4.4-way valve
1. Power on, use a digital tester to measure the voltage, when the unit operates in cooling, it is 0V. When the
unit operates in heating, it is about 230VAC.
If the value of the voltage is not in the range, the PCB must have problems and need to be replaced.
2 Turn off the power, use a digital tester to measure the resistance. The value should be 1.8~2.5 KΩ.
