UL5
Mechanical Weakening Detection 2
The operation conditions matched the conditions set to L6-08.
Uv1
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 (L2-05).
• 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 L2-01 = 1 and the DC bus voltage is
under L2-05 for longer than L2-02.
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.
for details.
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.
Uv2
Control Power Supply Voltage Fault
Voltage is too low for the control drive input power.
Cause
Possible Solution
L2-02 changed from its default
value in drive that is 7.5 kW or
smaller without installing a
Momentary Power Loss Ride-
Thru.
Correct parameter L2-02 setting or install optional Momentary Power Loss Ride-
Thru unit.
The wiring for the control power
supply is damaged.
• Cycle power to the drive. Check if the fault reoccurs.
• Replace the drive if the fault continues to occur.
Internal circuitry is damaged.
• Cycle power to the drive. Check if the fault reoccurs.
• Replace the drive if the fault continues to occur.
Uv3
Undervoltage 3 (Inrush Prevention Circuit Fault)
The inrush prevention circuit has failed.
Cause
Possible Solution
5.2 Fault Detection
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YASKAWA ELECTRIC TOEP C710606 47A YASKAWA AC Drive – V1000 Quick Start Guide
