Daikin VRV III REYQ10PY1B, Service Manual

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Method of Checking the Inverter’s Power Transistors and Diode Modules SiBE37-701
440 Appendix
9. Method of Checking the Inverter’s Power
Transistors and Diode Modules
9.1 Method of Checking the Inverter’s Power Transistors
and Diode Modules
Checking failures in power semiconductors mounted on inverter PC board
Check the power semiconductors mounted on the inverter PC board by the use of a multiple
tester.
<Items to be prepared>
h
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.
<Test points>
h
Turn OFF the power supply. Then, after a lapse of 10 minutes or more, make measurement
of resistance.
<Preparation>
h
To make measurement, disconnect all connectors and terminals.
Inverter PC board
Electronic circuit
„
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.
h
Faulty compressor (ground leakage)
h
Faulty fan motor (ground leakage)
h
Entry of conductive foreign particles
h
Abnormal voltage (e.g. overvoltage, surge (thunder), or unbalanced voltage)
In order to replace the faulty inverter, be sure to check for the points aforementioned.
P3
U V W N3
J1
J2
J3
P1
P1 P2
IGBT
X11A
U V W
L1
L2
L3
X10A
DM
K2
P3
N3
(V2895)
J1
J2
J3