YASKAWA A1000 HHP, Programming Manual

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Digital Operator Display Fault Name
UL3
Undertorque Detection 1
The current has fallen below the minimum value set for Torque Detection Level 1 (L6-02) for longer than
the allowable time (L6-03).
Cause Possible Solution
Parameter settings are not appropriate for the
load
Check the settings of parameters L6-02 and L6-03.
There is a fault on the machine side Check the load for any problems.
Digital Operator Display Fault Name
UL4
Undertorque Detection 2
The current has fallen below the minimum value set for Torque Detection Level 2 (L6-05) for longer than
the allowable time (L6-06).
Cause Possible Solution
Parameter settings are not appropriate for the
load
Check L6-05 and L6-06 settings
There is a fault on the machine side Check the load for any problems.
Digital Operator Display Fault Name
UL5
Mechanical Weakening Detection 2
The operation conditions matched the conditions set to L6-08.
Cause Possible Solution
Undertorque was detected and matched the
conditions for mechanical loss detection set to
L6-08
Check the load side for any problems.
Digital Operator Display Fault Name
<1>
UnbC
Current Unbalance
Current flow has become unbalanced.
Cause Possible Solution
The internal current sensor has detected a
current unbalance situation.
• Check wiring
• Check for damaged transistors.
• Check for short circuits or grounding problems on the connected motor.
<1> Detected in models 4A0930 and 4A1200.
Digital Operator Display Fault Name
Uv1
DC Bus Undervoltage
Voltage in the DC bus fell below the undervoltage detection level (L2-05).
• For 400 V class drives: approximately 380 V (350 V when E1-01 is less than 400)
• For 575 V class drives: approximately 475 V
• For 690 V class drives: approximately 570 V
The fault is output only if L2-01 is set to 0 or 1 and the DC bus voltage has fallen below the level set to
L2-05 for longer than the time set to 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.
• Check for loose terminals.
There is a problem with the voltage from the
drive input power
• Check the voltage.
• Correct the voltage to be within the range listed in drive input power specifications.
• If there is no problem with the power supply to the main circuit, check for problems with the main
circuit magnetic contactor.
The power has been interrupted Correct the drive input power.
The main circuit capacitors are worn
• Check the maintenance time for the capacitors (U4-05).
• Replace either the control board or the entire drive if U4-05 exceeds 90%. For instructions on replacing
the control board, contact Yaskawa or a Yaskawa representative.
2.4 Fault Detection
200 YASKAWA ELECTRIC SIEP YEAHHP 01B YASKAWA AC Drive – A1000 HHP Programming Manual