Method Of Checking The Inverter's Power Transistors And Diode Modules; Diode Modules - Daikin RTSQ20PY1 Service Manual

Method of Checking the Inverter's Power Transistors and Diode Modules

8. Method of Checking the Inverter's Power
Transistors and Diode Modules
8.1 Method of Checking the Inverter's Power Transistors
and Diode Modules
Checking failures in power semiconductors mounted on inverter PCB
Check the power semiconductors mounted on the inverter PCB by the use of a multiple tester.
<Items to be prepared>
h
<Test points>
h
<Preparation>
h
Inverter PCB
Electronic circuit
h
h
h
h
In order to replace the faulty inverter, be sure to check for the points aforementioned.
411
Multiple tester : Prepare the analog type of multiple tester.
For the digital type of multiple tester, those with diode check function are
available for the checking.
Turn OFF the power supply. Then, after a lapse of 10 minutes or more, make measurement
of resistance.
To make measurement, disconnect all connectors and terminals.
J1
J2
J3
DM
X10A K2
J1
L1
J2
L2
L3
J3
According to the checking aforementioned, it is probed that the malfunction results from the
faulty inverter. The following section describes supposed causes of the faulty inverter.
Faulty compressor (ground leakage)
Faulty fan motor (ground leakage)
Entry of conductive foreign particles
Abnormal voltage (e.g. overvoltage, surge (thunder), or unbalanced voltage)
N3 U V
P1 P3
P1 P2 P3
N3
U
SiBE31-801_C
W
IGBT
V W
X11A
(V2895)
Appendix