Mitsubishi Electric FR-D720S SC EC Instruction Manual page 450

Causes and corrective actions
Operation Panel
Indication
Name
Description
Check point
Corrective action
Operation Panel
Indication
Name
Description
Check point
Corrective action
Operation Panel
Indication
Name
Description
Check point
Corrective action
7 - 14
E.PTC
PTC thermistor operation
Inverter trips when resistance of PTC thermistor connected between terminal 2 and termi-
nal 10 is more than the value set in Pr. 561. This protective function does not function when
Pr. 561 setting is initial value (Pr. 561 = "9999").
Check the connection of the PTC thermistor.
Check the Pr. 561 setting.
Check the motor for operation under overload.
Reduce the load weight.
E.PE
Parameter storage device alarm (control circuit board)
Appears when a fault occurred in the stored parameters. (EEPROM fault).
Check for too many number of parameter write times.
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.
E.PUE
PU disconnection
This function stops the inverter output if communication between the inverter and PU
(FR-PU04/FR-PU07) is suspended, e.g. the parameter unit is disconnected, when "2", "3",
"16" or "17" was set in Pr. 75 "Reset selection/disconnected PU detection/PU stop selec-
tion". This function stops the inverter output when communication errors occurred consecu-
tively for more than permissible number of retries when a value other than "9999" is set in
Pr. 121 "Number of PU communication retries" during the RS485 communication with the
PU connector (use Pr. 502 "Stop mode selection at communication error" to change). This
function also stops the inverter output if communication is broken within the period of time
set in Pr. 122 "PU communication check time interval" during the RS485 communication
with the PU connector.
Check that the parameter unit (FR-PU04/FR-PU07) is fitted tightly.
Check the Pr. 75 setting.
Check that RS485 communication data is correct. And check that the settings of
communication parameter at inverter match settings of the computer.
Check that data is transmitted from the computer within a time set in Pr. 122.
Connect the parameter unit (FR-PU04/FR-PU07) securely.
Check the communication data and communication settings.
Increase the Pr. 122 setting or set "9999" (no communication check).
FR-PU04 Fault 14
FR-PU07 PTC activated
FR-PU04
Corrupt Memry
FR-PU07
FR-PU04
PU Leave Out
FR-PU07
Troubleshooting