Mitsubishi Electric FR-CC2-N Series, Инструкция по эксплуатации

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6. PROTECTIVE FUNCTIONS
6.5 Causes and corrective actions
*1 Resetting the converter unit initializes the internal cumulative heat value of the electronic thermal relay function.
Operation panel
indication
E.OVT
Name Overvoltage trip
Description
If the converter unit's internal main circuit DC voltage reaches or exceeds the specified value, the protection
circuit is activated to stop the outputs of the inverter. The overvoltage trip protection function may also be
activated by a surge voltage produced in the power supply system or an input phase loss.
Check point
• Check for sudden load change and excessive regeneration.
• Check that any power supply failure did not occur.
Corrective action
• Keep the load stable.
• Check the power supply.
Operation panel
indication
E.THC
Name
Converter overload trip (electronic thermal relay function)
*1
Description
For the protection of converter unit diode, the electronic thermal O/L relay is activated in inverse-time
characteristics against the converter unit input current to shut off the inverter output.
Check point
• Check the motor for the use under overload.
• Check that the capacity of the inverter used is not larger than that of the converter unit.
Corrective action
• Reduce the load.
• Check the configuration of the inverter and the converter unit again.
Operation panel
indication
E.FIN
Name Heat sink overheat
Description
When the heat sink overheats, the temperature sensor is activated, and the inverter output is stopped.
The FIN signal can be output when the temperature becomes approximately 85% of the heat sink overheat
protection operation temperature.
For the terminal used for the FIN signal output, assign the function by setting "26" (positive logic) or "126"
(negative logic) in any parameter from
Pr.190 to Pr.195 (Output terminal function selection) . (Refer to page
90 .)
Check point
• Check for too high surrounding air temperature.
• Check for heat sink clogging.
• Check that the cooling fan is not stopped. (Check that FN is not displayed on the operation panel.)
Corrective action
• Set the surrounding air temperature to within the specifications.
• Clean the heat sink.
• Replace the cooling fan.
Operation panel
indication
E.IPF
Name Instantaneous power failure
Description
If a power failure (converter unit input shut-off) occurs and lasts for longer than 5 ms, the instantaneous power
failure protective function is activated to shut off the inverter output in order to prevent the control circuit from
malfunctioning. If a power failure persists for 100 ms or longer, the fault output is not provided, and the inverter
restarts if the start signal is ON upon power restoration. (The inverter continues operating if an instantaneous
power failure is within 5 ms.)
When instantaneous power failure protection is activated, the IPF signal is output. (Refer to
page 98 .)
Check point Find the cause of instantaneous power failure occurrence.
Corrective action
• Remedy the instantaneous power failure.
• Prepare a backup power supply for instantaneous power failure.
• Set the function of automatic restart after instantaneous power failure
(Pr.57) . (Refer to page 98 .)
Operation panel
indication
E.UVT
Name Undervoltage
Description
If the power supply voltage of the converter unit decreases, the control circuit will not perform normal functions.
In addition, the motor torque will be insufficient and/or heat generation will increase. To prevent this, the output
of the inverter is stopped when the power supply voltage drops to about 440 VAC or lower. The undervoltage
protection function may also be activated by an input phase loss.
When undervoltage protection is activated, the IPF signal is output. (Refer to
page 98 .)
Check point Check if a high-capacity motor is driven.
Corrective action
• Check the devices on the power supply line such as the power supply itself.
• If the problem still persists after taking the above measure, contact your sales representative.