Mitsubishi Electric FR-A800, Instruction Manual

Page: 929 / 1042

Protective functions Check first when you have a trouble
FR-A800 6 - 41
6.6.6 Speed greatly differs from the setting
6.6.7 Acceleration/deceleration is not smooth
Check
points
Possible cause Countermeasure
Refer to
page
Input
signal
Frequency setting signal is incorrectly input. Measure the input signal level.
⎯
The input signal lines are affected by
external EMI. Take countermeasures against EMI, such as
using shielded wires for input signal lines.
3-6
Parameter
Setting
Pr. 1 "Maximum frequency," Pr. 2 "Minimum
frequency", Pr. 18 "High speed maximum
frequency", and calibration parameter C2 to
C7 settings are improper.
Check the settings of Pr. 1, Pr. 2, and Pr. 18. 5-310
Check the calibration parameter C2 to C7
settings.
5-401
Pr. 31 to Pr. 36, Pr. 552 (frequency jump)
settings are improper.
Narrow down the range of frequency jump. 5-312
Load
Stall prevention (torque limit) function is
activated due to a heavy load.
Reduce the load weight.
⎯
Parameter
Setting
Set Pr. 22 "Stall prevention operation level"
(torque limit level) higher according to the load.
(If Pr. 22 is set too high, an overcurrent trip
(E.OC
첸
) is likely to occur.)
2-36,
5-314
Motor
Check the capacities of the inverter and the
motor.
⎯
Check
points
Possible cause Countermeasure
Refer to
page
Parameter
Setting
Acceleration/deceleration time is too short. Increase the acceleration/deceleration time. 5-233
Torque boost (Pr. 0, Pr. 46, Pr. 112) setting is
improper under V/F control, so the stall
prevention function is activated. Increase/decrease the Pr. 0 "Torque boost"
setting value by 0.5% increments so that stall
prevention does not occur.
5-652
The base frequency does not match the
motor characteristics.
Under V/F control, set Pr. 3 "Base frequency",
Pr. 47 "Second V/F (base frequency)", and Pr. 113
"Third V/F (base frequency)".
5-654
Under vector control, set Pr. 84 "Rated motor
frequency".
5-56
Regeneration avoidance operation is
performed
If the frequency becomes unstable during
regeneration avoidance operation, decrease
the setting of Pr. 886 "Regeneration avoidance
voltage gain".
5-685
Load
Stall prevention (torque limit) function is
activated due to a heavy load.
Reduce the load weight.
⎯
Parameter
Setting
Set Pr. 22 "Stall prevention operation level"
(torque limit level) higher according to the load.
(If Pr. 22 is set too high, an overcurrent trip
(E.OC
첸
) is likely to occur.)
2-36,
5-314
Motor
Check the capacities of the inverter and the
motor.
⎯