Chapter 7 Checking and Troubleshooting
7-15
Ar
ea
Ch
ec
ki
ng
po
in
ts
Description
How to Check
Judgment Criterion
In
st
ru
m
en
t
D
io
de
,
IG
BT
Check if they are
stained with trash or
dust
Check by eyes.
Remove them by
blowing a dry air.
-
C
irc
ui
t B
oa
rd
1) Check if they
generate unusual
smell are discolored,
rusted, covered with
dust or oil mist
2) Check if the
connector is mounted
Check by eyes
1) Clean it using anti-
static cloth or cleaner.
If not, replace with new
circuit board
2) Do not clean the
circuit board using the
solution.
3) Remove trash or
dust by blowing a dry
air.
4) Mount the
connectors again.
5) If the damaged area
cannot be repaired or
is the part that cannot
be replaced, replace
the inverter itself.
-
C
on
tro
l c
irc
ui
t p
ro
te
ct
in
g
cir
cu
it
O
pe
ra
tio
n
1) Check the
unbalance of the
output voltage during
the operation of
inverter
2) Display circuit must
not have any unusual
phenomenon after the
sequence protecting
operation test is done
1) Measure the
voltage among the U,
V, and W at the
Inverter output
terminal.
2) Have the inverter
protecting circuit
output shorted out or
open it by force.
1) Balance of inter-
phase voltage
200V (400V) Use:
Within 4V(8V)
2) Unusual circuit to be
operated in sequence
D
ig
ita
l M
ul
ti-
M
et
er
/
D
C
ty
pe
V
ol
t M
et
er
C
oo
lin
g
Sy
st
em
C
oo
lin
g
fa
n,
C
oo
lin
g
pi
n
1) Isn't there any
looseness on the
junction?
2) Isn't cooling pin or
cooling fan covered
with dust
1) Fasten it once
again.
2) Check with eyes
and then remove dust
1) There must be no
unusual record
2) There must be no
dust
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