Mitsubishi Electric FR-D720S SC EC, Instruction Manual

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Maintenance and inspection Inspection
FR-D700 SC EC 8 - 5
8.1.5 Checking the inverter and converter modules
Disconnect the external power supply cables (R/L1, S/L2, T/L3) and motor cables (U, V, W).
Prepare a tester. (Use 100
Ω
range.)
Change the polarity of the tester alternately at the inverter terminals R/L1, S/L2, T/L3, U, V, W,
P/+ and N/
−
, and check for continuity.
At the time of discontinuity, the measured value is almost
앝
. When there is an instantaneous
continuity, due to the smoothing capacitor, the tester may not indicate
앝
. At the time of conti-
nuity, the measured value is several to several ten’s-of ohms depending on the module type, cir-
cuit tester type, etc. If all measured values are almost thesame, the modules are without fault.
T/L3, D3 and D6 are only for the three-phase power input specification models.
b
CAUTION:
Before measurement, check that the smoothing capacitor is discharged. The measu-
ring device can otherwise be destroyed
Fig. 8-1:
Module device numbers and terminals to be
checked
I002039E
Tester Polarity
Measured Value
Tester Polarity
Measured Value
Converter
module
D1
R/L1 P/+ Discontinuity
D4
R/L1 N/– Continuity
P/+ R/L1 Continuity N/– R/L1 Discontinuity
D2
S/L2 P/+ Discontinuity
D5
S/L2 N/– Continuity
P/+ S/L2 Continuity N/– S/L2 Discontinuity
D3
T/L3 P/+ Discontinuity
D6
T/L3 N/– Continuity
P/+ T/L3 Continuity N/– T/L3 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
Tab. 8-3: Continuity check of the modules
Converter module Inverter module
N/–
P/+