HOA Keypad Display
Fault Name
AUXFB
PI Aux Lvl Loss
Wire-break detection for PI Aux Feedback Level
Cause
Possible Solution
The analog input programmed for “PI Aux
FB Level” (H3-
oo
= 27) has dropped
below 3 mA or risen above 21 mA for
longer than 1 second.
Repair transducer or wiring.
HOA Keypad Display
Fault Name
bAT
Keypad Battery Voltage Low
Cause
Possible Solution
The keypad battery is low
Replace the keypad battery.
HOA Keypad Display
Fault Name
boL
Braking Transistor Overload Fault
The braking transistor reached its overload level.
Cause
Possible Solution
The wrong braking resistor is installed
Select the correct braking resistor.
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. Install an EMC noise filter to the drive power
supply input.
The option card is damaged
Replace the option card if there are no problems with the wiring and the error continues to occur.
The option card is not properly connected
to the drive
• The connector pins on the option card do not line up properly with the connector pins on the drive.
• Reinstall the option card.
HOA Keypad Display
Fault Name
CE
MEMOBUS/Modbus Communication Error
Control data was not received for the CE detection time set to H5-09.
Cause
Possible Solution
Faulty communications wiring or an
existing short circuit
• Check for faulty wiring.
• Correct the wiring.
• Check for disconnected cables and short circuits and repair as needed.
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.
• Use only recommended cables or other shielded line. Ground the shield on the controller side or the drive
input power side.
• Ensure that other equipment such as switches or relays do not cause noise. Use surge suppressors if
required.
• Separate all communication wiring from drive power lines. Install an EMC noise filter to the drive power
supply input.
5.3 Fault Detection
182
YASKAWA TOEPYAIUPW01A YASKAWA AC Drive - U1000 iQpump Matrix Drive User Manual
