Speed Does Not Accelerate; Unable To Write Parameter Setting; Power Lamp Is Not Lit - Mitsubishi Electric 800 Series Instruction Manual

Check first when you have a trouble
6.5.12

Speed does not accelerate

Check
points
Start command and frequency command are
chattering.
The wiring length used for analog frequency
Input
command is too long, and it is causing a
signal
voltage (current) drop.
The input signal lines are affected by external
EMI.
Pr.1 Maximum frequency, Pr.2 Minimum
frequency, Pr.18 High speed maximum
frequency, and Pr.902 to Pr.905 settings are
improper.
The maximum voltage (current) input value is
not set during the External operation. (Pr.125,
Pr.126, Pr.18)
Torque boost (Pr.0, Pr.46, Pr.112) 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.
Parameter
(Pr.3, Pr.14, Pr.19)
setting
Stall prevention (torque limit) function is
activated due to a heavy load.
Auto tuning is not performed under Advanced
magnetic flux vector control, Real sensorless
vector control, or vector control.
The setting of pulse train input is improper.
During PID control, output frequency is automatically controlled to make measured value = set point.
Main
A brake resistor is connected across terminals
circuit P3(P/+) and P1 or across P1 and PR by mistake.
6.5.13

Unable to write parameter setting

Check
points
Input
Operation is being performed (signal STF or
STR is ON).
signal
You are attempting to set the parameter in the
External operation mode.
Parameter
Parameter write is disabled by the Pr.77
setting
Parameter write selection setting.
Operation mode and a writing device do not
correspond.
6.5.14

Power lamp is not lit

Check
points
Main
circuit
Wiring or installation is improper.
Control
circuit
654
PROTECTIVE FUNCTIONS
Possible cause
Possible cause
Possible cause
Countermeasure
Check if the start command and the frequency command are
correct.
Perform Analog input bias/gain calibration.
Take countermeasures against EMI, such as using shielded
wires for input signal lines.
Check the settings of Pr.1 and Pr.2 and set Pr.18.
Check the Pr.902 to Pr.905 settings.
Check the settings of Pr.125 Terminal 2 frequency setting
gain frequency and Pr.126 Terminal 4 frequency setting
gain frequency.
To operate at 120 Hz or higher, set Pr.18 High speed
maximum frequency.
Increase/decrease the 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 (for
example, 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 (torque limit level)
higher according to the load. (If Pr.22 is set too high, an
overcurrent trip (E.OC[]) is likely to occur.)
Check the capacities of the inverter and the motor.
Perform offline auto tuning.
Check the specification of the pulse generator (open collector
output or complementary output) and check the adjustment of
the pulse train and frequency (Pr.385 Frequency for zero
input pulse and Pr.386 Frequency for maximum input
pulse).
Connect a brake resistor across terminals P3(P/+) and PR.
Countermeasure
Stop the operation.
When Pr.77 Parameter write selection = "0" (initial value),
write is enabled only during a stop.
Choose the PU operation mode.
Or, set Pr.77 Parameter write selection = "2" to enable
parameter write regardless of the operation mode.
Check the Pr.77 setting.
Check Pr.79, Pr.338, Pr.339, Pr.550 and Pr.551, and select an
operation mode suitable for the purpose.
Countermeasure
Check for the wiring and the installation.
Power lamp is lit when power is supplied to the control circuit
(R1/L11, S1/L21).
Refer to
page
―
402
69
329
402
329, 402
589
591
593
―
154, 332
―
426
308
488
65
Refer to
page
251
251, 291
251
291, 301
Refer to
page
34