5.1.12 When Ov Alarm Occurs - Mitsubishi Electric FATEC FR-A800 Manual

5
BREAKDOWN MAINTENANCE

5.1.12 When OV alarm occurs

Is the lift YES
operation
performed?
NO
YES
Does a flying
start occur?
Is the
NO
NO
inverter the
800 series?
YES
Select the
regeneration
avoidance function.
Set G120 (Pr.882)
to G124 (Pr.886).
YES
Is it a resonant
10-A
phenomenon?
NO Resonance phenomenon
The inverter is faulty.
Replace it with a substitute or
return it to the factory to repair.
OV alarm occurs.
YES
Is the power
supply voltage
high?
NO
Is the
YES
surge overlapped
with the power
supply?
NO
YES
Is it caused
by mechanical
factors?
NO
Are
YES
multiple motors
operating?
NO
What is
1 3
the OV value?
(Accelerating) (Decelerating)
2
(Constant speed)
Is the
YES
continuous regenerative
operation performed?
NO
Is the lift
YES
operation
performed?
NO
Improve the
regeneration capability.
Improve the regeneration capability.
Use the power
Use the power regeneration converter.
regeneration converter.
YES
Is it a press
machine or reciprocating
motion?
NO
The inverter is faulty.
Replace it with a substitute
or return it to the factory to repair.
Set the power supply voltage correctly.
Power supply improvement
AC or DC reactor installation
Rail joint check
Reduction gear/wheel check
Mechanical looseness adjustment
YES Are motor
shafts coupled?
NO
Is the
YES
droop function
selected?
Set the droop related Pr.
NO
Gain, filter time constant, or others
Has it occurred
at a start or during
acceleration?
YES
Power supply shut-off check
MCCB, MC check
YES
Does a flying
start occur?
Is the
NO
NO
inverter the
800 series?
YES
Select the regeneration
avoidance function.
Set G120 (Pr.882) to
G124 (Pr.886).
Is the
NO
inverter the
800 series?
YES
Select the regeneration
avoidance function.
Set G120 (Pr.882) to
G124 (Pr.886).
5.1 Troubleshooting
12-A
Braking capability
NO
Is the
YES
deceleration time
too short?
Set F011 (Pr.8)
NO
correctly.
Is the
YES
regenerative driving
torque insufficient?
Increase the brake
NO
resistor capacity.
Is the
YES
control capacity
insufficient?
Use the brake unit.
NO
Use the power
regeneration
The inverter is faulty.
Replace it with a substitute or
return it to the factory to repair.
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