oL7
High-Slip Braking oL
The output frequency stayed constant for longer than the time set in n3-04 during
High-slip Braking.
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).
oS
Overspeed (Simple V/f with PG)
Pulse input (RP) indicates that motor speed feedback exceeded F1-08 setting.
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, -04, -06, -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.
5.2 Fault Detection
YASKAWA ELECTRIC TOEP C710606 47A YASKAWA AC Drive – V1000 Quick Start Guide
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5
Troubleshooting
