Checking The Inverter And Converter Modules - Mitsubishi Electric FR-D720-0.4K Instruction Manual

6.1.5

Checking the inverter and converter modules

<Preparation>
(1) Disconnect the external power supply cables (R/L1, S/L2, T/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/L1, S/L2, T/L3, U, V, W,
continuity.
NOTE
1. Before measurement, check that the smoothing capacitor is discharged.
2. At the time of discontinuity, the measured value is almost
smoothing capacitor, the tester may not indicate
several tens-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>
Three-phase 200V class, Three-phase 400V class, single-phase 200V class
Tester Polarity
Measured
R/L1 P/+ Discontinuity
D1
P/+ R/L1 Continuity
S/L2 P/+ Discontinuity
D2
P/+ S/L2 Continuity
T/L3∗ P/+ Discontinuity
D3∗
P/+ T/L3∗ Continuity
U P/+ Discontinuity
TR1
P/+ U Continuity
V P/+ Discontinuity
TR3
P/+ V Continuity
W P/+ Discontinuity
TR5
P/+ W Continuity
(Assumes the use of an analog meter.)
* T/L3, D3 and D6 are only for the three-phase power input specification models.
Single-phase 100V class
Tester Polarity
Measured
S/L2 P/+ Discontinuity
D1
P/+ S/L2 Continuity
S/L2 N/- Continuity
D2
N/- S/L2 Discontinuity
U P/+ Discontinuity
TR1
P/+ U Continuity
V P/+ Discontinuity
TR3
P/+ V Continuity
W P/+ Discontinuity
TR5
P/+ W Continuity
(Assumes the use of an analog meter.)
Tester Polarity
Value
R/L1 N/- Continuity
D4
N/- R/L1 Discontinuity
S/L2 N/- Continuity
D5
N/- S/L2 Discontinuity
T/L3∗ N/- Continuity
D6∗
N/- T/L3∗ Discontinuity
U N/- Continuity
TR4
N/- U Discontinuity
V N/- Continuity
TR6
N/- V Discontinuity
W N/- Continuity
TR2
N/- W Discontinuity
Tester Polarity
Value
R/L1 P/+ Discontinuity
P/+ R/L1 Discontinuity
—
R/L1 N/- Discontinuity
N/- R/L1 Discontinuity
U N/- Continuity
TR4
N/- U Discontinuity
V N/- Continuity
TR6
N/- V Discontinuity
W N/- Continuity
TR2
N/- W Discontinuity
∞
. When there is an instantaneous continuity, due to the
∞
. At the time of continuity, the measured value is several to
Measured
Value
Converter module
D1 D2
R/L1
S/L2
T/L3
D4 D5
Measured
Value
Converter module
D1
R/L1
S/L2
D2
Inspection items
+ and -, and check for
P/ N/
P/+
Inverter module
TR1 TR3
D3
C
D6
TR4 TR6
N/-
P/+
Inverter module
TR1 TR3
C
C
TR4 TR6
N/-
TR5
U
V
W
TR2
TR5
U
V
W
TR2
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