Mitsubishi Electronics FR-D720S-008 Marine Battery User Manual


 
251
5
TROUBLESHOOTING
Causes and corrective actions
(2) Warnings
When a warning occurs, the output is not shut off.
Operation panel
indication
Err.
Name
Inverter reset
Description
Executing reset using RES signal, or reset command from communication or PU
Displays at powering off.
Corrective action
Turn off the reset command
Operation panel
indication
OL
FR-PU04
FR-PU07
OL
Name
Stall prevention (overcurrent)
Description
During
acceleration
When the output current 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 trip. When the overload current has
reduced below stall prevention operation level, this function increases the frequency again.
During
constant-
speed
operation
When the output current 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 trip. When the overload current has reduced below
stall prevention operation level, this function increases the frequency up to the set value.
During
deceleration
When the output current 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 trip. When the overload current has
decreased below stall prevention operation level, this function decreases the frequency again.
Check point
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.
4. Are there any failure in peripheral devices?
5. Check that the Pr. 13 Starting frequency is not too large.
6. Check that the Pr. 22 Stall prevention operation level is appropriate
Corrective action
1. Increase or decrease the Pr. 0 Torque boost setting by 1% and check the motor status. (Refer to page 73)
2. Set a larger value in Pr. 7 Acceleration time and Pr. 8 Deceleration time. (Refer to page 96)
3. Reduce the load weight.
4. Try General-purpose magnetic flux vector control.
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 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. (Operation at OL
occurrence can be selected using Pr. 156.)
Operation panel
indication
oL
FR-PU04
FR-PU07
oL
Name
Stall prevention (overvoltage)
Description
During
deceleration
If the regenerative energy of the motor becomes excessive to exceed the regenerative energy
consumption capability, this function stops the decrease in frequency to prevent overvoltage trip.
As soon as the regenerative energy has reduced, 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 trip.
(Refer to page 226).
Check point
Check for sudden speed reduction.
Check that regeneration avoidance function (Pr. 882, Pr. 883, Pr. 885, Pr. 886) is used. (Refer to page 226).
Corrective action
The deceleration time may change. Increase the deceleration time using Pr. 8 Deceleration time.