Motor hunting occurs.
• Adjust the parameters that control hunting.
• Set the hunting prevention gain (n1-02).
LED Operator Display
Fault Name
PF
Input Phase Loss
Drive input power has an open phase or has a large imbalance of voltage between phases. Detected
when L8-05 = 1 (enabled).
Cause
Possible Solution
There is phase loss in the drive input power. • Check for wiring errors in the main circuit drive input power.
• Correct the wiring.
There is loose wiring in the drive input power
terminals.
• Ensure the terminals are tightened properly.
• Apply the tightening torque specified in this manual to fasten the terminals.
Refer to Wire Gauges
and Tightening Torque on page 37
There is excessive fluctuation in the drive
input power voltage.
• Check the voltage from the drive input power.
• Review the possible solutions for stabilizing the drive input power.
• Disable Input Phase Loss Detection (L8-05 = “0”). PF is detected if DC bus ripple is too high. If it
is disabled, there is no fault but the ripple is still too high, thereby the capacitors are stressed more
and lose lifetime.
There is poor balance between voltage
phases.
• Stabilize drive input power or disable phase loss detection.
The main circuit capacitors are worn.
• Check the maintenance time for the capacitors (U4-05).
• Replace the drive if U4-05 is greater than 90%.
• Check for anything wrong with the drive input power.
• If nothing is wrong with the drive input power, try the following solutions if the alarm continues:
• Disable Input Phase Loss Protection selection (L8-05 = “0”). PF is detected if DC bus ripple is too
high. If it is disabled, there is no fault but the ripple is still too high, thereby the capacitors are stressed
more and lose lifetime.
• Replace the drive.
LED Operator Display
Fault Name
rH
Braking Resistor Overheat
Braking resistor protection was triggered.
Fault detection is enabled when L8-01 = 1 (disabled as a default).
Note:
The magnitude of the braking load trips the braking resistor overheat alarm, NOT the surface
temperature. Using the braking resistor more frequently than its rating trips the alarm even when the
braking resistor surface is not very hot.
Cause
Possible Solution
Deceleration time is too short and excessive
regenerative energy is flowing back into the
drive.
• Check the load, deceleration time and speed.
• Reduce the load.
• Increase the acceleration and deceleration times (C1-01 through C1-04).
• Replace the braking option with a larger device that can handle the power that is discharged.
Excessive braking inertia.
Recalculate braking load and braking power. Then try reducing the braking load and checking the
braking resistor settings and improve braking capacity.
The proper braking resistor has not been
installed.
• Check the specifications and conditions for the braking resistor device.
• Select the optimal braking resistor.
LED Operator Display
Fault Name
Uv1
DC Bus Undervoltage
One of the following conditions occurred while the drive was stopped:
• Voltage in the DC bus fell below the undervoltage detection level.
• For 200 V class: approximately 190 V (160 V for single phase drives)
• For 400 V class: approximately 380 V (350 V when E1-01 is less than 400) The fault is output only
if L2-01 = 0 or the DC bus voltage is below the Uv detection level for a certain time while L2-01 =
1.
Cause
Possible Solution
Input power phase loss.
• The main circuit drive input power is wired incorrectly.
• Correct the wiring.
One of the drive input power wiring terminals
is loose.
• Ensure there are no loose terminals.
• Apply the tightening torque specified in this manual to fasten the terminals.
Refer to Wire Gauges
and Tightening Torque on page 37
There is a problem with the voltage from the
drive input power.
• Check the voltage.
• Correct the voltage to within range listed in drive input power specifications.
The power has been interrupted.
Correct the drive input power.
Drive internal circuitry has become worn.
• Check the maintenance time for the capacitors (U4-05).
• Replace the drive if U4-05 exceeds 90%.
The drive input power transformer is not large
enough and voltage drops after switching on
power.
Check the capacity of the drive input power transformer.
Air inside the drive is too hot.
Check the drive internal temperature.
Problem with the CHARGE indicator.
Replace the drive.
LED Operator Display
Fault Name
Uv3
Undervoltage 3 (Inrush Prevention Circuit Fault)
The inrush prevention circuit has failed.
6.4 Fault Detection
SIEP C710606 33A OYMC AC Drive – J1000 User Manual
127
6
Troubleshooting
