Operation
Chapter 5
H Data Display and Action to be Taken when Protective
Mechanism is Actuated
The ALARM indicator lights up when the protective mechanism is actuated. In this
event, Inverter output is shut off, and the motor coasts to a stop.
Check the cause of the error, take the necessary action, and perform fault reset or turn
the power off, then on.
Data
Description
Cause and action
display
%c
Overcurrent (OC)
• The output side of the Inverter is
shorted or grounded.
The Inverter output current
instantaneously exceeded 250% of the
rated amperage.
• Load inertia is excessive.
• The acceleration and deceleration
time settings are too short.
• A special motor is used.
• The motor was started during free
running.
• The magnetic contactor on the output
side of the Inverter was opened and
closed.
• Determine the cause of the error, take
the necessary action, and reset the
system.
Main circuit overvoltage (OV)
%U
• The deceleration time setting is too
short.
Because regenerative energy from the
motor was excessive, the DC voltage
of the main circuit exceeded
approximately 410 V.
• Increase the deceleration time.
• Connect a braking resistor (or braking
resistor unit).
(400-VAC Class, 820 V)
• The regenerative energy becomes
excessive when returning from the
overshoot during acceleration.
• Connect a braking resistor (or braking
resistor unit).
5-4
OMRON [ OMRON ELECTRONICS LLC ]
