Mitsubishi Electric FR-A800, Instruction Manual

Page: 938 / 1042

Inspection item Precautions for maintenance and inspection
7 - 4
7.1.4 Checking the inverter and converter modules
Preparation
●
Disconnect the external power supply cables (R/L1, S/L2, T/L3) and motor cables (U, V, W).
●
Prepare a tester. (For the resistance measurement, use the 100
Ω
range.)
Checking method
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 the electric continuity.
Module device numbers and terminals to be checked
(Assumes the use of an analog meter.)
NOTES Before measurement, check that the smoothing capacitor is discharged.
At the time of electric discontinuity, the measured value is almost
∞
. When there is an instantane-
ous electric continuity, due to the smoothing capacitor, the tester may not indicate
∞
. At the time
of electric continuity, the measured value is several
Ω
to several tens of
Ω
. If all measured values
are almost the same, although these values are not constant depending on the module type and
tester type, the modules are without fault.
Fig. 7-1:
Module device numbers and terminals to be
checked
I001305E
Tester polarity
Result
Tester polarity
Result
C
o
n
v
er
te
r modu
le
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
In
v
e
rt
er modu
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
Tab. 7-2: Continuity check of the modules
Converter module Inverter module