SERVICE MANUAL
3KVA/5KVA-230V
16
V201703A
3.2 Check the bus side components
Power devices
DC/DC IGBT: Q30/Q29/Q27/Q28
QB2 QD2 QA1 QC1 QD4 QD3 Q32 D13 Q30 Q29 Q27 Q28
Parts
Attribute
Reference values
Failure status
Q27/Q28/Q29/Q30
Resistor
1
GE: 47.8 ohm
GC: 178.5K
CE:35M
Short or explosion
Diode
EC: 0.37V
CE: OL
Note1:
When you use the multimeter to measure the resistor of the transistor, because of the capacitor in
the circuit, it will cause the changing of the values when you measure the CE and GE. So we recommend
you measure the diode forward voltage of EC, and the resistor of GE. These two values can reflect the
situation of the transistor more correctly.
Note:
If one or more of them were damaged, please replace all of them.
