Mitsubishi Electric Freqrol Z024-UL Instruction Manual page 130

Protectlve Functlonr
The inverter has the following protective function built in it to protect itself. If a protective function is
activated, inverter output
is
shut
off, an alarm message is displayed, and an alarm signal is output. The
motor stops after coasting. To restart the motor, the inverter should be reset.
Funotlon Da8crlptlon
Overcurrent
shut
off
When 200% or more of the inverter rated output current flows
during acceleration, deceleration or constant
speed operation,
this protective circuit is activated to stop the inverter. This
protective function is also activated when the cooling fan in
the inverter fails.
In
acceleration
In constant
speed
operation
In
deceleration
Regenerative
ovewo,tage shut off
Overload
shut off
Electronic
thermal
relay
('1)
if regenerative energy at braking causes DC voltage of the main circuit in the
inverter to exceed the rated value, the protective circuit will be activated to
shut off the inverter output.
Motor
Inverter
i
The electronic thermal relay in the inverter detects overheating of motor
caused by overload or reduction in cooling capacity during constant speed
operation, and shuts off inverter output. Provide a thermal relay on the
inverter output side when running a multipole motor or several motors.
When 150% or more of
the
inverter rated output current flows but the
overcurrent shut off is not activated (under 200%), the electronic thermal relay
functions and shuts off inverter output to protect the output transistor.
Indlccltlon
(Parameter unlt)
1-11-
, I
(oc3)
L
u c
-1
-
124
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