MGI M4000E series, Instruction Manual

Page: 193 / 215

182
MAINTENANCE/INSPECTION
Checking the inverter and converter modules
<Preparation>
(1) Disconnect the external power supply cables (R, S, T (L
1
, L
2
, L
3
)) and motor cables
(U, V, W).
(2) Prepare a meter. (Use 100
Ω
range.)
<Checking method>
Change the polarity of the meter alternately at the inverter terminals R (L
1
), S (L
2
),
T (L
3
), U, V, W, P (+) and N (–), and check for continuity.
<Module device numbers and terminals to be checked>
(Assumes the use of an analog meter.)
Note:1. Before measurement, check that the smoothing capacitor is discharged
.
2. At the time of discontinuity, the measured value is almost
∞
. When there is
an instantaneous continuity, due to the smoothing capacitor the tester may
not indicate
∞
. At the time of continuity, the measured value is several to
several ten's-of ohms depending on the number of modules, number of
parallel modules, circuit tester type, etc. If all measured values are almost
the same, the modules are without fault.
Tester Polarity
Measured
Value
Tester Polarity
Measured
Value
Co
nv
e
rte
r
mod
u
le
D1
R (L
1
) P (+) Discontinuity
D4
R (L
1
) N (–) Continuity
P (+) R (L
1
) Continuity N (–) R (L
1
) Discontinuity
D2
S (L
2
) P (+) Discontinuity
D5
S (L
2
) N (–) Continuity
P (+) S (L
2
) Continuity N (–) S (L
2
) Discontinuity
D3
T (L
3
) P (+) Discontinuity
D6
T (L
3
) N (–) Continuity
P (+) T (L
3
) Continuity N (–) T (L
3
) Discontinuity
In
ve
rt
er
m
o
du
le
TR1
U P (+) Discontinuity
TR4
U N (–) Continuity
P (+) U Continuity N (–) U Discontinuity
TR3
V P (+) Discontinuity
TR6
V N (–) Continuity
P (+) V Continuity N (–) V Discontinuity
TR5
W P (+) Discontinuity
TR2
W N (–) Continuity
P (+) W Continuity N (–) W Discontinuity
Converter module
Inverter module
D1 D2 D3
D4 D5 D6
TR1 TR3 TR5
TR4 TR6 TR2
U
V
W
C
R (L
1
)
S (L
2
)
T (L
3
)
P (+)
N (-)
M4500E.book 182 ページ ２００５年２月２２日 火曜日 午後５時７分