PROTECTIVE FUNCTIONS
37
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Checking the inverter and converter modules
<Preparation>
(1) Disconnect the external power supply cables (R, S, T) <L1, L2, L3> 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 <L1, L2, L3, U, V,
W, + and ->, and check for continuity.
Note: 1. Before measurement, check that the smoothing capacitor is discharged.
2. 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.
<Module device numbers and terminals to be checked>
Tester Polarity Tester Polarity
Measured
Value
Measured
Value
R<L1> P<+> Discontinuity R<L1> N<-> Continuity
D1 P<+> R<L1> Continuity D4 N<-> R<L1> Discontinuity
S<L2> P<+> Discontinuity S<L2> N<-> Continuity
D2 P<+> S<L2> Continuity D5 N<-> S<L2> Discontinuity
T<L3> P<+> Discontinuity T<L3> N<-> Continuity
Converter module
D3 P<+> T<L3> Continuity D6 N<-> T<L3> Disconti nuity
U P<+> Discontinuity U N<-> Continuity
TR1 P<+> U Continuity TR4 N<-> U Discontinuity
V P<+> Discontinuity V N<-> Continuity
TR2 P<+> V Continuity TR6 N<-> V Discontinuity
W P<+> Discontinuity W N<-> Continuity
Inverter module
TR5 P<+> W Continuity TR2 N<-> W Discontinuity
D1 D2 D3
D4 D5 D6
TR1 TR3 TR5
TR4 TR6 TR2
U
V
W
R
<L1>
S
<L2>
T
<L3>
C
P<+>
N
<->
Inverter moduleConverter module