5-4
5.5 The method to check Inverter, converter part
A test is possible to check quality.
(Preparation)
[1] Take out the power lines (R, S and T) connected to the inverter, the motor connection lines (U, V and
W) and the regenerative control resistance (P and RB).
[2] Prepare tester. (Using range of 1 ohm resistance measure range.)
(How to check)
It is possible to check the quality of the charging state of the terminals R, S, T, U, V, W, RB, P and N of
the inverter and the pole of the tester by measuring the charging state.
(Note 1) Before you measure the voltage between P and N with DC current range, confirm that the
smoothing capacitor is discharged fully, execute checks.
(Note 2) Almost infinite value is indicated on no conducting.
With the effect of the smoothing capacitor, the inverter conducts instantly and an infinite value isn’t
indicated. Ohm-number 10 ohms is indicated on conducting.
The values indicated will not be exactly the same for each terminal, however they will be very close
together. If there is a significant difference a problem may exist.
Pole of tester
(Red)
(Black)
Measure
value
R
PD
No-conduct
D1
PD
R
Conduct
S
PD
No-conduct
D2
PD
S
Conduct
T
PD
No-conduct
D3
PD
T
Conduct
R
N
Conduct
D4
N
R
No-conduct
S
N
Conduct
D5
N
S
No-conduct
T
N
Conduct
Convert
e
r
D6
N
T
No-conduct
U
P
No-conduct
TR1
P
U
Conduct
V
P
No-conduct
TR2
P
V
Conduct
W
P
No-conduct
TR3
P
W
Conduct
U
N
Conduct
TR4
N
U
No-conduct
V
N
Conduct
TR5
N
V
No-conduct
W
N
Conduct
In
ve
rt
e
r
TR6
N
W
No-conduct
RB
P
No-conduct
P
RB
Conduct
RB
N
No-conduct
BR
p
art
TR7
N
RB
No-conduct
Chapter 5 Maintenance, Inspection
Converter
Inverter
PD P
D1
D2
D3
C
+
RB
TR4
TR5
TR6
TR1
TR2
TR3
N
D4
D5
D6
U
V
W
R
S
T
TR7
