Additional Faults
oPr: Digital Operator Connection Fault

- Issue: The LCD operator has been disconnected from the drive.
+ Solution:
++ Check the connection between the LCD operator and the drive.
++ Replace the cable if damaged.
++ Turn off the drive input power, disconnect the LCD operator, then reconnect it and turn the drive input power back on.

oS: Overspeed (Simple V/f with PG)

- Issue: Motor speed feedback has exceeded the F1-08 setting.
+ Solution:
++ Adjust the gain using pulse train input parameters.
++ Increase the settings for speed control proportional gain and reduce the speed control integral time.
++ Check and set the correct PG pulse settings and overspeed detection parameters.

ov: Overvoltage

- Issue: Voltage in the DC bus has exceeded the overvoltage detection level.
+ Solution:
++ Increase the deceleration time and install a braking resistor or dynamic braking resistor unit if needed.
++ Enable stall prevention during deceleration.
++ If acceleration time is too short, increase it and use longer S-curve acceleration and deceleration times.

PF: Input Phase Loss

- Issue: Drive input power has an open phase or a large imbalance of voltage between phases.
+ Solution:
++ Check for wiring errors in the main circuit drive input power and correct them.
++ Ensure the terminals are tightened properly and apply the specified tightening torque.

PGo: PG Disconnect (for Simple V/f with PG)

- Issue: No PG pulses are received for longer than the time set to F1-14.
   Solutions:
++ Check if the pulse input (RP) is disconnected and reconnect it.
++ Verify the wiring of the pulse input (RP) and correct it if necessary.
++ Ensure that the motor brake is releasing properly.

rH: Braking Resistor Overheat

- Issue: Braking resistor protection was triggered due to excessive regenerative energy or short deceleration time.
   Solutions:
++ Review the load, deceleration time, and speed. Reduce the load if necessary.
++ Increase the acceleration and deceleration times (C1-01 through C1-08).
++ Consider replacing the braking option with a larger device that can handle the discharged power.
++ If the braking inertia is excessive, recalculate the braking load and power, and adjust the braking resistor settings to improve capacity.
++ Ensure the proper braking resistor is installed according to its specifications and conditions.

rr: Dynamic Braking Transistor Failure

- Issue: The built-in dynamic braking transistor has failed.
   Solutions:
++ Cycle power to the drive and check if the fault reoccurs. If it does, refer to the troubleshooting section for diagnosing and resetting faults.
++ If the fault persists, replace the drive. Additionally, check if the control circuit is damaged and address accordingly.

SEr: Excessive Speed Search Restarts

- Issue: The number of speed search restarts has exceeded the limit set to b3-19.
   Solutions:
++ Adjust the speed search parameters to correct values. Reduce the detection compensation gain (b3-10), increase the current level for speed search (b3-17), and increase the detection time (b3-18).
++ Repeat the auto-tuning process.
++ If the motor is coasting in the opposite direction of the run command, enable bi-directional speed search (b3-14 = "1").

STO: Pull-Out Detection

- Issue: Motor pull-out has occurred, possibly due to incorrect motor code, heavy load, or short acceleration/deceleration times.
   Solutions:
++ For Yaskawa motors, enter the correct motor code into E5-01. For special-purpose motors, enter the correct data into all E5 parameters as per the provided test report.
++ Reduce the load or increase the motor or drive capacity if the load is too heavy.
++ Increase the value set to n8-55 (Load Inertia for PM) and n8-51 (Pull-In Current during Accel/Decel for PM) if needed.
++ Adjust the acceleration and deceleration times (C1-01 through C1-08) and the S-curve acceleration and deceleration times (C2-01) if they are too short.

UL3: Undertorque Detection 1

- Issue: The current has fallen below the minimum value set for torque detection for longer than the allowable time.
   Solutions:
++ Check and adjust the settings of parameters L6-02 and L6-03 to ensure they are appropriate for the type of load.
++ If there is a fault on the machine side, inspect the load for any issues.

UL4: Undertorque Detection 2

   Solutions: Similar to UL3, ensure the parameter settings are appropriate for the load and check for any faults on the machine side.

UL5: Mechanical Weakening Detection 2

- Issue: The operation conditions matched the conditions set for mechanical loss detection.
+ Solution: Inspect the load side for any issues if undertorque was detected and matched the condition of mechanical loss detection operation selection (L6-08).

Uv1: DC Bus Undervoltage

- Issue: The voltage in the DC bus fell below the undervoltage detection level while the drive was stopped.
   Solutions:
++ Check for input power phase loss and correct any wiring errors.
++ Ensure there are no loose terminals in the drive input power wiring and apply the specified tightening torque.
++ Verify the voltage from the drive input power and adjust it to within the specified range.
++ Address any interruptions in the drive input power.
++ If the drive's internal circuitry has become worn, check the maintenance time for the capacitors (U4-05) and replace the drive if necessary.
++ If the drive input power transformer is not large enough, causing voltage drops after switching on power, check its capacity.
++ Ensure the air inside the drive is not too hot and address any issues with the CHARGE indicator.

Uv2: Control Power Supply Voltage Fault

- Issue: The voltage is too low for the control drive input power.
   Solutions:
++ If L2-02 has been changed from its default value in a drive that is 7.5 kW or smaller without installing a Momentary Power Loss Ride-Thru, correct the parameter setting or install the optional unit.
++ If the wiring for the control power supply is damaged, cycle power to the drive, check if the fault reoccurs, and replace the drive if necessary.
++ If the internal circuitry is damaged, follow the same steps as for damaged wiring.

Uv3: Undervoltage 3 (Inrush Prevention Circuit Fault)

- Issue: The inrush prevention circuit has failed.
   Solutions:
++ If the contactor on the inrush prevention circuit is damaged, cycle power to the drive, check if the fault reoccurs, and replace the drive if necessary.
++ Check the performance life of the inrush prevention circuit (U4-06) and replace the drive if it exceeds 90%.