6
Protective Functions
6.1
Error Messages and Remedies
Protective Functions
24
MITSUBISHI ELECTRIC
Error message
Meaning
Description
Remedy
Display
FR-PU04
Display
FR-PA02-02
Overcurrent 1
(acceleration)
A) The output current of the in-
verter has reached or exceeded
200% of the rated current during
acceleration, deceleration, or at
constant speed.
B) The temperature of the main
circuits of the inverter rises ra-
pidly.
The cause for the activation
of the protective function is a
short circuit or a ground fault
across the main outputs, an
exceeding moment of inertia
of the load (GD
2
), too short
acceleration / deceleration
time presets, restart during a
motor idling phase, operation
of a motor with an exceeding
capacity.
Overheating due to insuffi-
cient cooling (defective coo-
ling fan or choked heat sink).
Stedy
Spd OC
Overcurrent 2
(constant speed)
OC
During
Decn
Overcurrent 3
(deceleration)
OV
During
Acc
Overvoltage 1
(acceleration)
The converter voltage has in-
creased highly due to regenera-
tive energy. The overvoltage limit
was exceeded during accelera-
tion, deceleration, or at constant
speed.
In most cases the protective
function is activated due to a
too short deceleration time
preset or a regenerative over-
load.
Increase the deceleration
time or connect an external
brake unit.
An overvoltage in the mains
power supply activates this
protective function as well.
Stedy
Spd OV
Overvoltage 2
(constant speed)
OV Du-
ring Dec
Overvoltage 3
(deceleration)
Motor
Overload
Overload
(motor)
The electronic overload protec-
tion for the motor or inverter was
activated.
The electronic motor protection
switch continually detects the
motor current and the output fre-
quency of the inverter. If a
self-cooling motor operates
over a long period at low speed
but high torque, the motor is
thermally overloaded and the
protective function is activated.
If several motors are operated
by one inverter the motor pro-
tection switch will not operate
properly. In this case deactivate
the motor protection and repla-
ce it by external protection swit-
ches.
Decrease the motor load to
avoid an activation.
Check whether the perfor-
mance range of the motor
and inverter correspond.
Inv.
Overload
Overload
(inverter)
H/Sink
O/Temp
Fin overheat
If the cooling fin overheats, the
fin overheat sensor activates
and halts inverter output.
Check environmental tempe-
rature.
Fan
Failure
Fan breakdown
The cooling fan breaks down or
an operation different from the
setting of parameter 244 (coo-
ling fan operation selection) is
performed.
Replace the cooling fan
