YASKAWA J1000 Technical Manual page 140

Deceleration time is too short and excessive
regenerative energy is flowing back into the
drive.
Excessive braking inertia.
The proper braking resistor has not been
installed.
LED Operator Display
Cause
Input power phase loss.
One of the drive input power wiring terminals
is loose.
There is a problem with the voltage from the
drive input power.
The power has been interrupted.
Drive internal circuitry has become worn.
The drive input power transformer is not large
enough and voltage drops after switching on
power.
Air inside the drive is too hot.
Problem with the CHARGE indicator.
LED Operator Display
Cause
The contactor on the inrush prevention circuit
is damaged.
YASKAWA ELECTRIC SIEP C710606 31B YASKAWA AC Drive – J1000 Technical Manual
• 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.
Recalculate braking load and braking power. Then try reducing the braking load and checking the braking
resistor settings and improve braking capacity.
• Check the specifications and conditions for the braking resistor device.
• Select the optimal braking resistor.
DC Bus Undervoltage
One of the following conditions occurred while the drive was in operation:
• Voltage in the DC bus fell below the undervoltage detection level.
Uv1
• 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.
• The main circuit drive input power is wired incorrectly.
• Correct the wiring.
• Ensure there are no loose terminals.
• Apply the tightening torque specified in this manual to fasten the terminals.
and Tightening Torque on page 39
• Check the voltage.
• Correct the voltage to within range listed in drive input power specifications.
Correct the drive input power.
• Check the maintenance time for the capacitors (U4-05).
• Replace the drive if U4-05 exceeds 90%.
Check the capacity of the drive input power transformer.
Check the drive internal temperature.
Replace the drive.
Undervoltage 3 (Inrush Prevention Circuit Fault)
Uv3
The inrush prevention circuit has failed.
• Cycle power to the drive. Check if the fault reoccurs.
• Replace the drive if the fault continues to occur.
• Check monitor U4-06 for the performance life of the inrush prevention circuit.
• Replace the drive if U4-06 exceeds 90%.
http://nicontrols.com
Fault Name
Possible Solution
Fault Name
Possible Solution
6.4 Fault Detection
Refer to Wire Gauges
6
139