159
Errors (Alarms)
PROTECTIVE FUNCTIONS
6
(2) Minor failure
When the protective function is activated, the output is not shut off.
(3) Warnings
When the protective function is activated, the output is not shut off.
*4. The stall prevention operation current can be set as desired. It is factory-set to
150%.
Operation Panel
Indication
CPU FR-PU04 CPU Fault
Name CPU error
Description
If the arithmetic operation of the built-in CPU does not end within a
predetermined period, the inverter self-determines it as an alarm and stops
the output.
Check point
Corrective action Please contact your sales representative.
Operation Panel
Indication
FN FR-PU04 FN
Name Fan trouble
Description
For the inverter that contains a cooling fan, appears on the operation
panel when the cooling fan stops due to a fault or different operation from
the setting of Pr. 76 "cooling fan operation selection".
Check point Check the cooling fan for a fault.
Corrective action Replace the fan.
Operation Panel
Indication
OL FR-PU04 OL
Name Stall prevention (overcurrent)
Description
During
acceleration
If a current of more than 150% (*4) of the rated inverter
current flows in the motor, this function stops the increase in
frequency until the overload current reduces to prevent the
inverter from resulting in overcurrent shut-off. When the
overload current has reduced below 150%, this function
increases the frequency again.
During
constant-
speed
operation
If a current of more than 150% (*4) of the rated inverter
current flows in the motor, this function lowers the frequency
until the overload current reduces to prevent overcurrent
shut-off. When the overload current has reduced below
150%, this function increases the frequency up to the set
value.
During
deceleration
If a current of more than 150% (*4) of the rated inverter
current flows in the motor, this function stops the decrease in
frequency until the overload current reduces to prevent the
inverter from resulting in overcurrent shut-off. When the
overload current has reduced below 150%, this function
decreases the frequency again.
Check point Check the motor for use under overload.
Corrective action
• The acceleration/deceleration time may change.
• Increase the stall prevention operation level with Pr. 22 "stall prevention
operation level", or disable stall prevention with Pr. 21 "stall prevention
function selection".
• Check that the torque boost (Pr. 0) setting is not higher than required.
