Mitsubishi Electric FR-A700 Series Instruction Manual page 138

(2) Warnings
When the protective function is activated, the output is not shut off.
Operation Panel
Indication
Name
Stall prevention (overcurrent)
During
acceleration
During
constant-
Description
speed
operation
During
deceleration
1. Check that the Pr. 0 Torque boost setting is not too large.
2. Check that the Pr. 7 Acceleration time and Pr. 8 Deceleration time settings are not too small.
3. Check that the load is not too heavy.
Check point
4. Are there any failure in peripheral devices?
5. Check that the Pr. 13 Starting frequency is not too large.
1. Increase or decrease the Pr. 0 Torque boost value 1% by 1% and check the motor status. (Refer to page 51.)
2. Set a larger value in Pr. 7 Acceleration time and Pr. 8 Deceleration time. (Refer to page 53.)
3. Reduce the load weight.
4. Try advanced magnetic flux vector control or real sensorless vector control or vector control.
Corrective action
5. Change the Pr. 14 Load pattern selection setting.
6. Set stall prevention operation current in Pr. 22 Stall prevention operation level. (The initial value is
Operation Panel
Indication
Name
Stall prevention (overvoltage)
During
Description
deceleration
· Check for sudden speed reduction.
Check point
· Regeneration avoidance function (Pr. 882 to Pr. 886) is being used? (Refer to
The deceleration time may change.
Corrective action
Increase the deceleration time using Pr. 8 Deceleration time.
Operation Panel
Indication
Name
PU stop
Stop with
Description
75, refer to
Check point
Check for a stop made by pressing
Corrective action
Turn the start signal off and release with
OL
When the output current (output torque during real sensorless vector control or vector
control) of the inverter exceeds the stall prevention operation level (Pr. 22 Stall prevention
operation level, etc.), this function stops the increase in frequency until the overload
current decreases to prevent the inverter from resulting in overcurrent shut-off. When
the overload current has decreased below stall prevention operation level, this function
increases the frequency again.
When the output current (output torque during real sensorless vector control or vector
control) of the inverter exceeds the stall prevention operation level (Pr. 22 Stall prevention
operation level, etc.), this function reduces frequency until the overload current
decreases to prevent the inverter from resulting in overcurrent shut-off. When the
overload current has decreased below stall prevention operation level, this function
increases the frequency up to the set value.
When the output current (output torque during real sensorless vector control or vector
control) of the inverter exceeds the stall prevention operation level (Pr. 22 Stall prevention
operation level, etc.), this function stops the decrease in frequency until the overload
current decreases to prevent the inverter from resulting in overcurrent shut-off. When
the overload current has decreased below stall prevention operation level, this function
decreases the frequency again.
· Check the motor for use under overload.
150%.) 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. 156 Stall prevention
operation selection. (Use Pr. 156 to set either operation continued or not at OL operation.)
oL
· If the regenerative energy of the motor becomes excessive and exceeds the
regenerative energy consumption capability, this function stops the decrease in
frequency to prevent overvoltage shut-off. As soon as the regenerative energy has
decreased, deceleration resumes.
· If the regenerative energy of the motor becomes excessive when regeneration
avoidance function is selected (Pr. 882 = 1), this function increases the speed to
prevent overvoltage shut-off. (Refer to
(applied).)
PS
of the PU is set in Pr. 75 Reset selection/disconnected PU detection/PU stop selection. (For Pr.
Instruction Manual (applied).)
Causes and corrective actions
FR-PU04
OL
FR-PU07
FR-PU04
oL
FR-PU07
Instruction Manual (applied).)
FR-PU04
PS
FR-PU07
of the operation panel.
.
Instruction Manual
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