YASKAWA T1000V - Page 262

6.5 Alarm Detection
262 YASKAWA ELECTRIC SIEP C710606 44B YASKAWA AC Drive T1000V Technical Manual
LED Operator Display Minor Fault Name
UL3
Undertorque Detection 1
Drive output current (or torque in OLV) less than L6-02 for longer than L6-03 time.
Cause Possible Solutions
Minor Fault
Output
(H2- = 10)
Inappropriate parameter settings. Check parameters L6-02 and L6-03. YES
Load has dropped or decreased
significantly.
• Check for broken parts in the transmission system. YES
LED Operator Display Minor Fault Name
UL4
Undertorque Detection 2
Drive output current (or torque in OLV) less than L6-05 for longer than L6-06 time.
Cause Possible Solutions
Minor Fault
Output
(H2- = 10)
Inappropriate parameter settings. Check parameters L6-05 and L6-06. YES
The load has dropped or decreased
significantly.
• Check for broken parts in the transmission system. YES
LED Operator Display Minor Fault Name
Uv
Undervoltage
One of the following conditions was true when the drive was stopped and a run command was entered:
• DC bus voltage dropped below the level specified in L2-05.
• Contactor to suppress inrush current in the drive was open.
• Low voltage in the control drive input power. This alarm outputs only if L2-01 is not 0 and DC bus
voltage is under L2-05.
Cause Possible Solutions
Minor Fault
Output
(H2- = 10)
Phase loss in the drive input power. Check for wiring errors in the main circuit drive input power. Correct the wiring. YES
Loose wiring in the drive input power
terminals.
• Ensure the terminals have been properly tightened.
• Apply the tightening torque specified in this manual to fasten the terminals. Refer to
Wire Gauges and Tightening Torque on page 53
YES
There is a problem with the drive input
power voltage.
• Check the voltage.
• Lower the voltage of the drive input power so that it is within the limits listed in the
specifications.
YES
Drive internal circuitry is worn.
• Check the maintenance time for the capacitors (U4-05).
• Replace the drive if U4-05 exceeds 90%.
YES
The drive input power transformer is not
large enough and voltage drops when the
power is switched on.
• Check for a tripped alarm when the magnetic contactor, line breaker and leakage
breaker are turned on.
• Check the capacity of the drive input power transformer.
YES
Air inside the drive is too hot. • Check the temperature inside the drive. YES
The CHARGE indicator light is broken
or disconnected.
• Replace the drive. YES