Mitsubishi Electric FR-F740-00023 Instruction Manual page 286

Operation Panel
E.UVT
Indication
Name
Undervoltage
If the power supply voltage of the inverter reduces, 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
Description the power supply voltage reduces below about 300VAC, 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 136)
1. Check for start of large-capacity motor.
Check point
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.
Corrective action
2. Connect a jumper or DC reactor across terminals P/+-P1.
3. If the problem still persists after taking the above measure, please contact your sales representative.
Operation Panel
E.ILF
Indication
Name
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.
Description
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
Check point
Check for a break in the cable for the three-phase power supply input.
· Wire the cables properly.
Corrective action
· Repair a break portion in the cable.
· Check the Pr. 872 Input phase loss protection selection setting.
Operation Panel
E.OLT
Indication
Name
Stall prevention
If the frequency has fallen to 0.5Hz by stall prevention operation and remains for 3s, a fault (E.OLT)
Description
appears and trips the inverter. OL appears while stall prevention is being activated.
Check point
· Check the motor for use under overload. (Refer to
Corrective action
· Reduce the load weight.
Operation Panel
E.GF
Indication
Name Output side earth (ground) fault overcurrent
This function stops the inverter output if an earth fault overcurrent flows due to an earth fault that
Description
occurred on the inverter's output (load) side.
Check point
Check for an earth fault in the motor and connection cable.
Corrective action Remedy the earth fault portion.
Operation Panel
E.LF
Indication
Name
Output phase loss
This function stops the inverter output if one of the three phases (U, V, W) on the inverter's output side
Description
(load side) is lost.
· Check the wiring (Check that the motor is normal.)
Check point
· Check that the capacity of the motor used is not smaller than that of the inverter.
· Wire the cables properly.
Corrective action
· Check the Pr. 251 Output phase loss protection selection setting.
Operation Panel
E.OHT
Indication
Name
External thermal relay operation
If the external thermal relay provided for motor overheat protection, or the internally mounted
temperature relay in the motor, etc. switches on (contacts open), the inverter output is stopped.
Description
Functions when "7" (OH signal) is set to any of Pr. 178 to Pr. 189 (input terminal function selection).
When the initial value (without OH signal assigned) is set, this protective function does not function.
· Check for motor overheating.
Check point · Check that the value of 7 (OH signal) is set correctly in any of Pr. 178 to Pr. 189 (input terminal function
selection).
· Reduce the load and operating duty.
Corrective action
· Even if the relay contacts are reset automatically, the inverter will not restart unless it is reset.
FR-PU04
Under Voltage
FR-PU07
FR-PU04 Fault 14
FR-PU07 Input phase loss
page 146.)
FR-PU04 Stll Prev STP ( OL shown during stall
prevention operation)
FR-PU07
page 71.)
FR-PU04
Ground Fault
FR-PU07
FR-PU04
E. LF
FR-PU07
FR-PU04
OH Fault
FR-PU07
Causes and corrective actions
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