Справочник Пользователя для Mitsubishi Electronics FR-D720S-0.1K to 2.2K

∗1 Resetting the inverter initializes the internal cumulative heat value of the electronic thermal relay function.
∗2 This protective function does not function in the initial status.

∗3 This protective function is available with the three-phase power input specification model only.

* For further information on troubleshooting, refer to the 

Instruction Manual (Applied).

Operation of the component where parameters 
are stored (control circuit board) has become 
abnormal.

Please contact your sales representative.
When performing parameter write frequently for communication 
purposes, set "1" in Pr. 342 to enable RAM write. Note that 
powering OFF returns the inverter to the status before RAM write.

y

A communication error has occurred between 
the PU and the inverter.

y

The communication interval has exceeded the 
permissible time period during RS-485 
communication via the PU connector.

y

The number of communication errors has 
exceeded the number of retries.

y

Connect the parameter unit cable securely.

y

Check the communication data and communication settings.

y

Increase the Pr. 122 PU communication check time interval setting. 
Or set "9999" (no communication check).

 ∗2

Operation restart within the set number of retries 
has failed.

Eliminate the cause of the error preceding this error indication.

An error has occurred in the CPU and in the 
peripheral circuits.

y

Take measures against noises if there are devices producing 
excess electrical noises around the inverter.

y

If the situation does not improve after taking the above 
measure, please contact your sales representative.

 /

 ∗2

Output current has exceeded the output current 
detection level, which was set in a parameter.

Check the settings of Pr. 150 Output current detection level, Pr. 151 
Output current detection signal delay time, Pr. 166 Output current 
detection signal retention time, Pr. 167 Output current detection 
operation selection.

The resistor of the inrush current limit circuit has 
overheated.

Configure a circuit where frequent power ON/OFF is not 
repeated.
If the situation does not improve after taking the above measure, 
please contact your sales representative.

A voltage (current) has been input to terminal 4 
when the setting in Pr. 267 Terminal 4 input 
selection and the setting of voltage/current input 
switch are different.

Give a frequency command by a current input or set Pr.267 
Terminal 4 input selection, and set the voltage/current input switch 
to voltage input.

While a safety circuit fault is occurring, the 
terminals across S1 and PC, or across S2 and 
PC are opened.

y

When not using the safety stop function, short across terminals 
S1 and SC and across S2 and SC with shorting wire.

y

When using the safety stop function, check that wiring of 
terminal S1, S2 and SC is correct and the safety stop input 
signal source such as safety relay module is operating properly. 
Refer to the Safety stop function instruction manual (BCN-A211508-
000) for causes and countermeasures.
(Please contact your sales representative for the manual.)

Motor does not start.

Check start and frequency command sources and enter a start command (STF, etc.) and a 
frequency command.

Motor or machine is making abnormal 
acoustic noise.

Take EMC measures if a steady operation cannot be performed due to EMI. Alternatively, set 
the Pr.74 Input filter time constant setting higher. 

Inverter generates abnormal noise.

Install the fan cover correctly.

Motor generates heat abnormally.

Clean the motor fan. Improve the environment.

Motor rotates in the opposite direction.

Connect phase sequence of the output cables (terminal U, V, W) to the motor correctly.
Alternatively, check the connection of the start signal. (STF: forward rotation, STR: reverse 
rotation)

Speed greatly differs from the setting.

Check the settings of Pr.1 Maximum frequency, Pr.2 Minimum frequency, Pr.18 High speed maximum 
frequency, and calibration parameters C2 to C7.

Acceleration/deceleration is not smooth.

Reduce the load. Alternatively, increase the acceleration/deceleration time.

Speed varies during operation.

Check the frequency setting signals. If the load fluctuates, select General-purpose magnetic 
flux vector control. 

Operation mode is not changed properly.

Turn OFF the start signal (STF or STR). Check if Pr.79 Operation mode selection is set 
appropriately.

Operation panel display is not operating.

Check the wiring and the installation.

Motor current is large.

Increase/decrease the Pr.0 Torque boost setting value by 0.5% increments so that stall 
prevention does not occur. Set the rated motor frequency to Pr.3 Base frequency.

Speed does not accelerate.

Check the settings of Pr.1 Maximum frequency, Pr.2 Minimum frequency, and calibration parameters 
C2 to C7. To operate at 120Hz or higher, set Pr.18 High speed maximum frequency.  

Unable to write parameter setting.

Check Pr.77 Parameter write selection setting.