Mitsubishi Electric FR-B-750 to 75K Instruction Manual page 281

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
Operation Panel
Indication
Name
Description
Check point
Corrective action
Operation Panel
Indication
Name
Description
Check point
Corrective action
272
E.IPF
Instantaneous power failure
If a power failure occurs for longer than 15ms (this also applies to inverter input shut-off), the instantaneous
power failure protective function is activated to stop the inverter output in order to prevent the control circuit
from malfunctioning. If a power failure persists for longer than 100ms, the alarm warning 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 15ms.) In some operating status (load magnitude, acceleration/
deceleration time setting, etc.), overcurrent or other protection may be activated upon power restoration.
When instantaneous power failure protection is activated, the IPF signal is output. (Refer to page 148)
Find the cause of instantaneous power failure occurrence.
· 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 148.)
E.BE
Brake transistor alarm detection
Appears only for the 75K or more.
This function stops the inverter output if an alarm occurs in the brake circuit, e.g. damaged brake transistors.
In this case, the inverter must be powered off immediately.
· Reduce the load inertia.
· Check that the frequency of using the brake is proper.
Replace the inverter.
E.UVT
Undervoltage
If the power supply voltage of the inverter decreases, the control circuit will not perform normal functions.
In addition, the motor torque wiil be insufficient and/or heat generation will increase. To prevent this, if
the power supply voltage decreases below about 150VAC (300VAC for the 400V class), this function
stops the inverter output.
When a jumper is not connected across P/+-P1, the undervoltage protective function is activated.
When undervoltage protection is activated, the IPF signal is output. (Refer to page 148)
1. Check for start of large-capacity motor.
2. Check that a jumper or DC reactor is connected across terminals P/+-P1.
1. Check the power supply system equipment such as the power supply.
2. Connect a jumper or DC reactor across terminals P/+-P1.
If the problem still persists after taking the above measure, please contact your sales representative.
E.ILF
Input phase failure
This alarm is output when function valid setting (=1) is set in Pr. 872 Input phase failure protection selection and
one phase of the three phase power input opens. (Refer to page 158.)
Check for a break in the cable for the three-phase power supply input.
· Wire the cables properly.
· Repair a brake portion in the cable.
· Check the Pr. 872 Input phase failure protection selection setting.
E.OLT
Stall prevention
If the frequency has fallen to 0.5Hz by stall prevention operation and remains for 3s, an alarm (E.OLT)
appears to shutoff the inverter output. OL appears while stall prevention is being activated.
· Check the motor for use under overload. (Refer to page 75.)
· Check that the Pr. 865 Low speed detection values are correct. (Check the Pr. 22 Stall prevention
operation level setting if V/F control is exercised.)
· Reduce the load weight.
· Change the Pr. 22 Stall prevention operation level, Pr. 865 Low speed detection values. (Check the Pr. 22
Stall prevention operation level setting if V/F control is exercised.)
FR-PU04
Inst. Pwr. Loss
FR-PU07
FR-PU04
Br. Cct. Fault
FR-PU07
FR-PU04
Under Voltage
FR-PU07
FR-PU04 Fault 14
FR-PU07 Input phase loss
FR-PU04 Stll Prev STP ( OL shown during stall
prevention operation)
FR-PU07