Mitsubishi Electric FR-A700 Series Instruction Manual page 142

Operation Panel
E.IPF
Indication
Name
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
Description
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
Check point
Find the cause of instantaneous power failure occurrence.
· Remedy the instantaneous power failure.
· Prepare a backup power supply for instantaneous power failure.
Corrective action
· Set the function of automatic restart after instantaneous power failure (Pr. 57). (Refer to
Instruction Manual (applied).)
Operation Panel
E.BE
Indication
Name
Brake transistor alarm detection
This function stops the inverter output if an alarm occurs in the brake circuit, e.g. damaged brake transistors.
Description
In this case, the inverter must be powered off immediately.
· Reduce the load inertia.
Check point
· Check that the frequency of using the brake is proper.
Corrective action
Replace the inverter.
Operation Panel
E.UVT
Indication
Name 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
Description 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
(applied))
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.
If the problem still persists after taking the above measure, please contact your sales representative.
Operation Panel
E.ILF
Indication
Name
Input phase failure
This alarm is output when function valid setting (=1) is set in Pr. 872 Input phase failure protection selection and
Description
one phase of the three phase power input opens. (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 brake portion in the cable.
· Check the Pr. 872 Input phase failure 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, an alarm (E.OLT)
appears to shutoff the inverter output. OL appears while stall prevention is being activated.
When speed control is performed by real sensorless vector control or vector control, an alarm (E.OLT)
Description
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 the Instruction Manual (applied).)
Check point
· 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.
Corrective action
· 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.)
Causes and corrective actions
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
Instruction Manual (applied).)
FR-PU04
Still Prev STP ( OL shown during stall
prevention operation)
FR-PU07
Instruction Manual (applied))
Instruction Manual
137
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