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Digital Operator Display
Fault Name
oPr
External Digital Operator Connection Fault
• The external operator has been disconnected from the drive.
Note:
An oPr fault will occur when all of the following conditions are true:
• Output is interrupted when the operator is disconnected (o2-06 = 1).
• The run command is assigned to the operator
(b1-02 = 0 and LOCAL has been selected).
Cause
Possible Solution
External operator is not properly connected to
the drive.
• Check the connection between the operator and the drive.
• Replace the cable if damaged.
• Turn off the drive input power and disconnect the operator. Next reconnect the operator and turn the
drive input power back on.
Digital Operator Display
Fault Name
oS
Overspeed (Simple V/f with PG)
Pulse input (RP) indicates that motor speed feedback exceeded F1-08 setting.
Cause
Possible Solution
Overshoot or undershoot is occurring.
• Adjust the gain by using the pulse train input parameters (H6-02 through H6-05).
• Increase the settings for C5-01 (Speed Control Proportional Gain 1) and reduce C5-02 (Speed Control
Integral Time 1).
Incorrect PG pulse settings.
Set the H6-02 (Pulse Train Input Scaling) = 100%, the frequency of the PG pulses at maximum motor
speed.
Inappropriate parameter settings.
Check the setting for the overspeed detection level and the overspeed detection time (F1-08 and F1-09).
Digital Operator Display
Fault Name
ov
Overvoltage
Voltage in the DC bus has exceeded the overvoltage detection level.
• For 200 V class: approximately 410 V
• For 400 V class: approximately 820 V (740 V when E1-01 is less than 400)
Cause
Possible Solution
Deceleration time is too short and regenerative
energy flows from the motor into the drive.
• Increase the deceleration time (C1-02, C1-04, C1-06, C1-08).
• Install a braking resistor or a dynamic braking resistor unit.
• Enable stall prevention during deceleration (L3-04 = “1”).
Stall prevention is enabled as the default setting.
Fast acceleration time causes the motor to
overshoot the speed reference.
• Check if sudden drive acceleration triggers an overvoltage alarm.
• Increase the acceleration time.
• Use longer S-curve acceleration and deceleration times.
Excessive braking load.
The braking torque was too high, causing regenerative energy to charge the DC bus.
Reduce the braking torque, use a braking option, or lengthen decel time.
Surge voltage entering from the drive input
power.
Install a DC link choke.
Note:
Voltage surge can result from thyristor convertor and phase advancing capacitor using same drive
main input power supply.
Ground fault in the output circuit causing the
DC bus capacitor to overcharge.
• Check the motor wiring for ground faults.
• Correct grounding shorts and turn the power back on.
Improper Setting of Speed Search related
parameters. (Includes Speed Search after a
momentary power loss and after a fault
restart.)
• Check the settings for Speed Search related parameters.
• Enable Speed Search Retry function
(b3-19 greater than or equal to 1 to 10).
• Adjust the current level during Speed Search and the deceleration time (b3-02 and b3-03 respectively).
• Perform Line-to-Line Resistance Auto-Tuning and then enable Speed Estimation Type Speed Search
(b3-24 = 1).
Excessive regeneration when overshoot
occurs after acceleration.
• Enable the Overvoltage Suppression function (L3-11 = 1).
• Lengthen the S-curve at acceleration end.
Drive input power voltage is too high.
• Check the voltage.
• Lower drive input power voltage within the limits listed in the specifications.
The dynamic braking transistor is damaged.
Replace the drive.
The braking transistor is wired incorrectly.
• Check braking transistor wiring for errors.
• Properly rewire the braking resistor device.
6.4 Fault Detection
YASKAWA ELECTRIC SIEP C710606 18F YASKAWA AC Drive – V1000 Technical Manual
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Troubleshooting