Mitsubishi FREQROL-SF Troubleshooting Manual page 43

(22) Alarm No_46(OHM) Motor Overheat
alarm
[This occurs when the thermal protec-
tor which is installed in the motor exceeds
the temperature being set (145"Cl.l
Cause
Item
The motor cooling fan is
1 defective.
The motor cooling systen
is dirty.
Check that the air in-
take portion of the
motor cooling fan is
clogged with foreign
matter or machine com-
ponents.
The motor is overloaded.
The motor built-in
thermal protector is
defective.
The following cable con-
nections are defective.
Motor Amplifier
side side
OHS2 - CON2 pin 2
Check
motor normally rotates.
cooling system, check the
degree of dirt.
of the foreign matter or
components.
using a load meter or the
load display in the status
display mode (see Section
quently started and stopped.
turning the cooling fan to
fully cool the motor, check
that the motor leads OHS1 and
OHS2 is shortcircuited.
(When they are shortcircuited
the thermal protector is
normal.)
connector imperfect contact
using a circuit tester.
1
1.3
Checking method and
remedy of trouble
Remedy
fan with a new one.
(See Section 2.8.)
using the factory utility
air or vacuum cleaner.
machine components.
and tool.
start and stop operations.
of CON2 on the amplifier
side as a temporary repair
and continue the operation.
(See Appendixes l-4 and l-5)
place the motor with a new
one.
with a new one.
imperfect contact or re-
place the connector with a
new one.
B