Mitsubishi FREQROL-SFJ - Page 114

c
c
c
Cause
Checkup
Remedy
Dynamic unbal-
Large vibration and noise
Balance the control
ante
occur during coasting of
system and motor
motor.
dynamically.
Insulation
Disconnect the power cable
if insulation resis-
resistance de-
(R, S, T) and measure in-
tance is found de-
creased
sulation resistance, using
creased, identify the
500V megger (each ground-
part where insulation
ing wire should have been
is deteriorated and
disconnected.
remedy.
(a) Between entire main
circuit and ground
. . .
At least 20Megohm 1
(Terminals R, S, T, U,
V, W, MS1 and MS2,
and E)
(b) Between control cir-
cuit COM and ground
. . .
At least 20Megohm
(Terminal CH23 of
card SFJ-CA1 and.
ground)
Cc> Between entire main
circuit and control
circuit COM
. . .
At least 20Megohm
Trouble with
Turn the motor shaft by
If the motor shaft
motor bearing
hand to check.
cannot be rotated
smoothly, replace
bearing.
Motor mounting
Check motor mounting screws
Retighten bolts.
screws loose
for looseness.
Motor shaft run-
Check if any trace of phy-
Remedy or replace
out
sical damage is found on
the motor.
motor shaft.
Pin -2 and 3 of
Refer to (2).
card SFJ-CA1
Refer to (2).
set improperly.
._.
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