
196
Fault Display
Fault Displays and Meanings
Fault Display
Inverter
Status
Description
Causes and Corrective
Actions
Digital
Operator
RUN (Green)
ALARM (Red)
Protective
Operation
Output is
turned OFF
and motor
coasts to a
stop.
OC (Overcurrent)
Inverter output current mo-
mentarily exceeded approx.
250% of rated current.
Operation is restored, if no
fault is found, after confirming
the following:
• Short circuit or grounding
at Inverter output side
• Excessive load GD
2
• Extremely
rapid
Acceleration/Deceleration
Time (constants n019 to
n022)
• Special motor used
• Starting motor during
coasting
• Motor of a capacity
greater than the Inverter
rating has been started.
• Magnetic
contactor
opened/closed at the
Inverter output side
• Leak current increased
because of excessively
long wiring
Note: Before turning the pow-
er ON again, make sure that
no short-circuit or ground fault
occurs at the Inverter output.
OV (Main circuit over-
voltage)
Main circuit DC voltage level
exceeded the overvoltage de-
tection level while the Inverter
was running.
Detection level (DC voltage:
Voltage between terminals
"+1" and "-")
200 V: Approx. 410 V or more
400 V: Approx. 820 V or more
1. Regenerative energy is
large.
• The setting of decelera-
tion time is too short.
• Negative load (e.g., ele-
vator) is excessive at
lowering.
• Confirm that the load
does not have any prob-
lem.
2. Input voltage is errone-
ous.
Confirm that DC voltage
exceeding the left value
is not input.
UV1 (Main circuit low
voltage)
Main circuit DC voltage
dropped below the low-volt-
age detection level while the
Inverter output is ON.
200 V: Stops at main circuit
DC voltage below ap-
prox. 200 V (160 V for
single-phase)
400 V: Stops at main circuit
DC voltage below ap-
prox. 400 V.
Check the following:
• Power supply voltage
• Main circuit power supply
connections
• Terminal screws: Loose?
• Monitor
value
Confirm voltage (DC volt-
age) between terminals
"+1" and "-".
⇓
If there is no problem, the In-
verter may be faulty.