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PRECAUTIONS FOR MAINTENANCE AND INSPECTION
6
z
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z Checking the inverter and converter modules
<Preparation>
(1) Disconnect the external power supply cables (R, S, T) and motor cables (U, V, W).
(2) Prepare a tester. (Use 100Ω range.)
<Checking method>
Change the polarity of the tester alternately at the inverter terminals R, S, T, 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, due to the smothing 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
module type, 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
Converter module
D1
R P Discontinuity
D4
R N Continuity
P R Continuity N R Discontinuity
D2
S P Discontinuity
D5
S N Continuity
P S Continuity N S Discontinuity
D3
T P Discontinuity
D6
T N Continuity
P T Continuity N T Discontinuity
Inverter module
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
D1 D2 D3
D4 D5 D6
TR1 TR3 TR5
TR4 TR6 TR2
U
V
W
C
Inverter moduleConverter module
R
S
T
P
N
