YASKAWA A1000 Technical Manual page 137

Motor hunting occurs
Digital Operator Display
Cause
There is phase loss in the drive input power
There is loose wiring in the drive input power
terminals
There is excessive fluctuation in the drive
input power voltage
There is poor balance between voltage phases • Stabilize drive input power or disable phase loss detection.
The main circuit capacitors are worn
Digital Operator Display
Cause
Deceleration time is too short and excessive
regenerative energy is flowing back into the
drive
Excessive braking inertia
The braking operation duty cycle is too high
The proper braking resistor has not been
installed
Note: The magnitude of the braking load trips the braking resistor overheat alarm, NOT the surface temperature. Using the braking resistor more
frequently than it is rated for trips the alarm even when the braking resistor surface is not very hot.
Digital Operator Display
Cause
The braking transistor is damaged
The control circuit is damaged
YASKAWA ELECTRIC TOEP C710616 41B YASKAWA AC Drive - A1000 Quick Start Guide
• Adjust the parameters that control hunting.
• Set the gain for Hunting Prevention (n1-02).
• Adjust the AFR time constant (n2-02 and n2-03).
• Adjust the speed feedback detection suppression gain for PM motors (n8-45) and the time constant for
pull-in current (n8-47).
Input Phase Loss
PF
Drive input power has an open phase or has a large imbalance of voltage between phases. Detected when
L8-05 = 1 (enabled).
• Check for wiring errors in the main circuit drive input power.
• Correct the wiring.
• Ensure the terminals are tightened properly.
• Apply the tightening torque as specified in this manual.
Torque on page
• Check the voltage from the drive input power.
• Review the possible solutions for stabilizing the drive input power.
• Check the maintenance time for the capacitors (U4-05).
• Replace the capacitor if U4-05 is greater than 90%. For instructions on replacing the capacitor, contact
Yaskawa or a Yaskawa representative.
• Check for problems with the drive input power. If drive input power appears normal but the alarm
continues to occur, replace either the control board or the entire drive. For instructions on replacing the
control board, contact Yaskawa or a Yaskawa representative.
PG Disconnect (for any control modes using a PG option card)
PGo
No PG pulses are received for longer than the time set to F1-14.
PG Hardware Fault (detected when using a PG-X3 option card)
PGoH
PG cable is not connected properly.
Braking Resistor Fault
rF
The resistance of the braking resistor is too low.
Braking Resistor Overheat
rH
Braking resistor protection was triggered.
Fault detection is enabled when L8-01 = 1 (disabled as a default).
• Check the load, deceleration time, and speed.
• Reduce the load inertia.
• Increase the deceleration times (C1-02, C1-04, C1-06, C1-08, C1-09).
• Replace the dynamic braking option with a larger device that can handle the power that is discharged.
Recalculate braking load and braking power. Reduce the braking load by adjusting braking resistor
settings.
Check the braking operation duty cycle. Braking resistor protection for ERF-type braking resistors
(L8-01 = 1) allows a braking duty cycle of maximum 3%.
• Check the specifications and conditions for the braking resistor device.
• Select the optimal braking resistor.
Dynamic Braking Transistor
rr
The built-in dynamic braking transistor failed.
• Cycle power to the drive and check if the fault reoccurs.
• Replace either the control board or the entire drive. For instructions on replacing the control board,
contact Yaskawa or a Yaskawa representative.
Fault Name
Possible Solution
52.
Fault Name
Possible Solution
Fault Name
Possible Solution
5.2 Fault Detection
Refer to Wire Gauges and Tightening
5
137