Mitsubishi Electric FR-A720-0.4K Instruction Manual page 153

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
146
E.BE
Brake transistor alarm detection
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 will 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/+ and P1, the undervoltage protective function is activated.
When undervoltage protection is activated, the IPF signal is output. (Refer to Chapter 4 of
Instruction Manual (Applied))
· Check for start of large-capacity motor.
· Check that a jumper or DC reactor is connected across terminals P/+ and P1.
· Check the power supply system equipment such as the power supply.
· Connect a jumper or DC reactor across terminals P/+ and P1.
If the problem still persists after taking the above measure, please contact your sales representative.
E.ILF
Input phase loss
This fault is output when function valid setting (= 1) is set in Pr. 872 Input phase loss protection selection
and one phase of the three phase power input is lost. When the setting of Pr. 872 Input phase loss
protection selection is the initial value (Pr. 872 = "0"), this fault does not occur. (Refer to Chapter 4 of
the Instruction Manual (Applied).)
Check for a break in the cable for the three-phase power supply input.
· Wire the cables properly.
· Repair a break portion in the cable.
· Check the Pr. 872 Input phase loss protection selection setting.
E.OLT
Stall prevention stop
If the frequency has fallen to 0.5Hz by stall prevention operation and remains for 3s, a fault (E.OLT)
appears and trips the inverter. OL appears while stall prevention is being activated.
When speed control is performed by Real sensorless vector control or vector control, a fault (E.OLT) is
displayed and the inverter output is stopped if frequency drops to the Pr. 865 Low speed detection (initial
value is 1.5Hz) setting by torque limit operation and the output torque exceeds Pr. 874 OLT level setting
(initial value is 150%) setting and remains for more than 3s.
· Check the motor for use under overload. (Refer to Chapter 4 of the Instruction Manual (Applied).)
· Check that the Pr. 865 Low speed detection and Pr. 874 OLT level setting 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 and Pr. 874 OLT level
setting values. (Check the Pr. 22 Stall prevention operation level setting if V/F control is exercised.)
E.GF
Output side earth (ground) fault overcurrent
This function stops the inverter output if an earth (ground) fault overcurrent flows due to an earth
(ground) fault that occurred on the inverter's output (load) side.
Check for an earth (ground) fault in the motor and connection cable.
Remedy the earth (ground) fault portion.
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
FR-PU07
FR-PU04
Ground Fault
FR-PU07
the