PTC thermistor operation
The inverter output is shut off if resistance of the PTC thermistor connected between terminal 2 and terminal 10
is equal to or higher than the Pr.561 PTC thermistor protection level setting for a continuous time equal to or
longer than the setting value in Pr.1016 PTC thermistor protection detection time. When the initial value
(Pr.561 = "9999") is set, this protective function is not available.
• Check the connection with the PTC thermistor.
• Check the Pr.561 and Pr.1016 settings.
• Check the motor for operation under overload.
Reduce the load.
• Appears when the AC power supply is connected to terminal R/L1, S/L2, or T/L3 accidentally when a high
power factor converter (FR-HC2) or power regeneration common converter (FR-CV) is connected (when Pr.30
Regenerative function selection = "2").
• Appears when torque command by the plug-in option is selected using Pr.804 Torque command source
selection and no plug-in option is mounted. This function is available under torque control.
• Appears when either one of a Vector control compatible plug-in option or a control terminal option (FR-A8TP)
is not installed during machine end orientation control.
• Appears when the switch for manufacturer setting of the plug-in option is changed.
• Appears when a communication option is connected while Pr.296 Password lock level = "0 or 100".
• Check that the AC power supply is not connected to terminal R/L1, S/L2, or T/L3 when a high power factor
converter (FR-HC2) or power regeneration common converter (FR-CV) is connected (when Pr.30 = "2").
• Check that the plug-in option for torque command setting is connected.
• Check that the Vector control plug-in option and the control terminal option (FR-A8TP) are installed correctly.
Check that the Pr.393 Orientation selection and Pr.862 Encoder option selection settings are correct.
• Check for the password lock with a setting of Pr.296 = "0, 100".
• Check the Pr.30 setting and wiring.
• The inverter may be damaged if the AC power supply is connected to terminal R/L1, S/L2, or T/L3 when a high
power factor converter is connected. Contact your sales representative.
• Check for connection of the plug-in option. Check the Pr.804 setting.
• Install the Vector control plug-in option and the control terminal option (FR-A8TP) correctly. Set Pr.393 and
Pr.862 correctly. (Refer to
• Set the switch on the plug-in option, which is for manufacturer setting, back to the initial setting. (Refer to the
Instruction Manual of each option.)
• To apply the password lock when installing a communication option, set Pr.296 ≠ "0, 100". (Refer to
E.OP1 to E.OP3
Communication option fault
• The inverter output is shut off if a communication line error occurs in the communication option.
• This function stops the inverter output when a communication line error occurs on the CC-Link IE Field network
communication circuit board of the FR-A800-GF.
• When the FR-A8APR is installed to the inverter and a motor with a resolver is used, the inverter output is shut
off if the FR-A8APR fails or the wiring of the resolver is not properly connected.
• Check for an incorrect option function setting and operation.
• Check that the plug-in option is plugged into the connector securely.
• For the FR-A800-GF, check that the CC-Link IE Field Network communication circuit board is securely installed
to the connector of the inverter control circuit board.
• Check for a break in the communication cable.
• Check that the terminating resistor is fitted properly.
• Check that the wiring of the resolver is correct. (When the FR-A8APR is used.)
• Check the option function setting, etc.
• Connect the plug-in option securely.
• Connect the CC-Link IE Field Network communication circuit board of the FR-A800-GF securely.
• Check the connection of communication cable.
• Check the wiring of the resolver (when the FR-A8APR is used).
• If the fault occurs again when the inverter is reset, contact your sales representative.
FR-LU08 indication PTC thermistor oper
FR-LU08 indication Option Fault
FR-LU08 indication Option1 Fault to Option3 Fault
6. PROTECTIVE FUNCTIONS
6.5 Causes and corrective actions