8 Fault Diagnosis
197
Protective
Operation
Output is
turned OFF
and motor
coasts to a
stop.
UV2 (Control power sup-
ply fault)
Inverter detected voltage fault
of control power supply dur-
ing running.
Replace the Inverter.
OH (Heatsink overheat)
Temperature increased be-
cause of Inverter overload op-
eration or intake air
temperature rise.
• Excessive
load
• Improper V/f pattern set-
ting
• Insufficient
acceleration
time if the fault occurs
during acceleration
• Intake air temperature
exceeding 50
°
C (122
°
F)
• Cooling fan stops.
• Cooling fan has lowered
cooling capability or
stops.
• Heatsink
is
clogged.
• There is a thermal source
around the Inverter
⇓
Check the following:
• Load
size
• V/f pattern setting (con-
stants n011 to n017)
• Intake air temperature.
• Cooling fan is turning
while the Inverter is run-
ning.
• Foreign matter on the fan
is not interrupting rotation.
• Fan is mounted properly.
• There is no thermal
source around the
Inverter.
OH9 (Motor overheat-
ing)
• Check the size of the load
and the length of the
acceleration, decelera-
tion, and cycle times.
• Check the V/f characteris-
tics.
• Check the input motor
temperature.
Fault Display
Inverter
Status
Description
Causes and Corrective
Actions
Digital
Operator
RUN (Green)
ALARM (Red)