6.5.11 Motor Current Is Too Large; 6.5.12 Speed Does Not Accelerate; 6.5.13 Unable To Write Parameter Setting - Mitsubishi Electric 700 Series Instruction Manual

Check first when you have a trouble

6.5.11 Motor current is too large

Check
points
Torque boost (Pr. 0, Pr. 46) setting is improper under V/F
control, so the stall prevention function is activated.
V/F pattern is improper when V/F control is performed.
(Pr. 3, Pr. 14, Pr. 19)
Parameter
Setting
Stall prevention function is activated due to a heavy
load.
Auto tuning is not performed under Advanced magnetic
flux vector control or General-purpose magnetic flux
vector control.

6.5.12 Speed does not accelerate

Check
points
Pr. 1, Pr. 2, Pr. 18 settings are improper.
Torque boost (Pr. 0, Pr. 46) setting is improper under V/F
control, so the stall prevention function is activated.
V/F pattern is improper when V/F control is performed.
(Pr. 3, Pr. 14, Pr. 19)
Parameter
Setting
Stall prevention function is activated due to a heavy
load.
Auto tuning is not performed under Advanced magnetic
flux vector control or General-purpose magnetic flux
vector control.
Main
Brake resistor is connected between terminal P/+ and
Circuit P1 or between terminal P1 and PR by mistake.

6.5.13 Unable to write parameter setting

Check
points
Operation is being performed (signal STF or STR is
Input
ON).
signal
"0" is set in the X12 signal (Bit11), which gives a control
input command through FL remote communication.
You are attempting to set a parameter from the
operation panel while in Network operation mode.
Parameter
Parameter is disabled by the Pr. 77 Parameter write
Setting
selection setting.
Key lock is activated by the Pr. 161 Frequency setting/key
lock operation selection setting.
208
Possible Cause
Possible Cause
Possible Cause
Countermeasures
Increase/decrease Pr. 0 Torque boost setting value by
0.5% increments to the setting.
Set rated frequency of the motor to Pr. 3 Base frequency.
Use Pr. 19 Base frequency voltage to set the base voltage
(e.g. rated motor voltage).
Change Pr. 14 Load pattern selection according to the load
characteristic.
Reduce the load weight.
Set Pr. 22 Stall prevention operation level higher according
to the load. (Setting Pr. 22 too large may result in
frequent overcurrent trip (E.OC ).)
Check the capacities of the inverter and the motor.
Perform offline auto tuning.
Countermeasures
Check the settings of Pr. 1 Maximum frequency and Pr. 2
Minimum frequency. If you want to run the motor at 120Hz
or higher, set Pr. 18 High speed maximum frequency.
Increase/decrease Pr. 0 Torque boost setting value by
0.5% increments so that stall prevention does not occur.
Set rated frequency of the motor to Pr. 3 Base frequency.
Use Pr. 19 Base frequency voltage to set the base voltage
(e.g. rated motor voltage).
Change Pr. 14 Load pattern selection according to the load
characteristic.
Reduce the load weight.
Set Pr. 22 Stall prevention operation level higher according
to the load. (Setting Pr. 22 too large may result in
frequent overcurrent trip (E.OC ).)
Check the capacities of the inverter and the motor.
Perform offline auto tuning.
Connect an optional brake transistor (MRS type, MYS
type, FR-ABR) between terminal P/+ and PR.
Countermeasures
Stop the operation.
When Pr. 77 = "0" (initial value), write is enabled only
during a stop.
Set "1" in the X12 signal (Bit11), which gives a control
input command through FL remote communication.
Choose the PU operation mode.
Or, set Pr. 77 = "2" to enable parameter write regardless
of the operation mode.
Check Pr. 77 Parameter write selection setting.
Check Pr. 161 Frequency setting/key lock operation selection
setting.
Refer
to
page
94
107
109
—
101
—
127
Refer
to
page
105
94
107
109
—
101
—
127
25
Refer
to
page
166
57
166
166
183