Yaskawa Z1000U HVAC Matrix Bypass - Manual (Page 235)

6.4 Fault Detection
u Fault Displays, Causes, and Possible Solutions
Faults are detected for drive protection, and cause the drive to stop while triggering the fault output terminal MA-MB-MC.
Remove the cause of the fault and manually clear the fault before attempting to run the drive again.
Table 6.8 Detailed Fault Displays, Causes, and Possible Solutions
HOA Keypad Display Fault Name
Aov
Power Supply Overvoltage
The input power supply voltage became equal to or higher than the Input Power Supply Overvoltage
Detection Level.
200 V Class: Approximately 277 Vrms
400 V Class: Approximately 630 Vrms
Cause Possible Solution
• The power supply voltage exceeded the range
listed in drive input power specifications.
• Regenerative operation was performed when the
power supply capacity was too small.
• The power supply circuit opened during
regeneration.
• Reduce the voltage to within the range in the power supply specifications.
• Increase the capacity of the power supply.
HOA Keypad Display Fault Name
AUv
Power Supply Undervoltage
The input power supply voltage became equal to or lower than the Input Power Supply Undervoltage
Detection Level (L2-21).
200 V Class: Approximately 150 Vrms
400 V Class: Approximately 300 Vrms
Cause Possible Solution
The capacity of the power supply is too small. Increase the capacity of the power supply.
The distortion in the power supply is too large. Lower the impedance of the input power supply wiring.
A phase loss occurred in the input power supply. Check the input power supply for phase loss or an imbalance in the interphase voltages. Investigate
and correct the cause and then reset the fault.
The built-in fuse is open.
An internal transistor was destroyed. The input wiring is grounded or short circuited.
The output transistor has failed because the drive output has grounded or short circuited.
Replace the board or the drive. For instructions on replacing the control board, contact Yaskawa or
your nearest sales representative.
HOA Keypad Display Fault Name
bAT HOA Keypad Battery Voltage Low
Cause Possible Solution
The HOA keypad battery is low Replace the HOA keypad battery.
HOA Keypad Display Fault Name
bUS
Option Communication Error
• The connection was lost after establishing initial communication.
• Only detected when the run command frequency reference is assigned to an option card.
Cause Possible Solution
No signal was received from the PLC • Check for faulty wiring.
• Correct the wiring.
• Check for disconnected cables and short circuits and repair as needed.
Faulty communications wiring or an existing short
circuit
Communication data error occurred due to noise
• Check the various options available to minimize the effects of noise.
• Counteract noise in the control circuit, main circuit, and ground wiring.
• Ensure that other equipment such as switches or relays do not cause noise. Use surge absorbers if
necessary.
• Use only recommended cables or other shielded line. Ground the shield on the controller side or
the drive input power side.
• Separate all communication wiring from drive power lines.
The option card is damaged Replace the option card if there are no problems with the wiring and the error continues to occur.
6.4 Fault Detection
YASKAWA SIEP YAIZ1D 01A Z1000U HVAC MATRIX Drive Bypass Technical Manual 235
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Diagnostics & Troubleshooting