Speed Varies During Operation; Operation Mode Is Not Changed Properly; 6.5.10 Operation Panel Display Is Not Operating - Mitsubishi Electric 700 Series Instruction Manual

6.5.8

Speed varies during operation

When Advanced magnetic flux vector control or the slip compensation is selected, the output frequency varies between 0 and
2Hz as load fluctuates. This is a normal operation and not a fault.
Check
points
Load Load varies during an operation.
Input
Frequency setting signal is varying.
signal
Pr. 80 Motor capacity and Pr. 81 Number of motor poles
setting is improper for the capacities of the inverter and
the motor for Advanced magnetic flux vector control or
General-purpose magnetic flux vector control.
Fluctuation of power supply voltage is too large.
Parameter
Setting
Hunting occurs by the generated vibration, for example,
when structural rigidity at load side is insufficient.
Wiring length exceeds 30m when Advanced magnetic
flux vector control or General-purpose magnetic flux
vector control is performed.
Others
Wiring length is too long for V/F control, and a voltage
drop occurs.
6.5.9

Operation mode is not changed properly

Check
points
Start signal (STF or STR) is ON.
Input
signal
"0" is set in the X12 signal (Bit11), which gives a control
input command through FL remote communication.
FL-net dedicated cable is not installed properly. (The
Others
cable has contact faults and breaks.)

6.5.10 Operation panel display is not operating

Check
points
Main
Wiring or installation is improper.
Circuit
Main
Circuit
Power is not input.
Control
Circuit
Possible Cause
Possible Cause
Possible Cause
Check first when you have a trouble
Countermeasures
Select Advanced magnetic flux vector control or
General-purpose magnetic flux vector control.
Check the frequency setting signal.
Check the Pr. 80 Motor capacity and Pr. 81 Number of
motor poles setting.
Change the Pr. 19 Base frequency voltage setting (about
3%) under V/F control.
Disable automatic control functions, such as energy
saving operation, fast-response current limit function,
regeneration avoidance function, Advanced magnetic
flux vector control, General-purpose magnetic flux
vector control, and stall prevention.
Adjust so that the control gain decreases and the level of
safety increases.
Change Pr. 72 PWM frequency selection setting.
Perform offline auto tuning.
Adjust Pr. 0 Torque boost by increasing with 0.5%
increments for low-speed operation.
Change to Advanced magnetic flux vector control or
General-purpose magnetic flux vector control.
Countermeasures
Check that the STF and STR signals are OFF.
When either is ON, the operation mode cannot be
changed.
Set "1" in the X12 signal (Bit11), which gives a control
input command through FL remote communication.
Install the FL-net dedicated cable properly.
Countermeasures
Check for the wiring and the installation.
Make sure that the connector is fitted securely across
terminal P/+ and P1.
Input the power.
Refer
to
page
95
—
95
107
—
163
127
94
95
Refer
to
page
57, 74
57
48
6
Refer
to
page
14
14
207