HOA Keypad Display
Minor Fault Name
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
Minor Fault Name
Backup FdBk Lost
Check/Replace
Backup Feedback Device (H3-
oo
= 24) lost.
Cause
Possible Solution
Wire-break on Analog Input Terminal
programmed for Backup PI Feedback
(H3-
oo
= 24)
Check the connection of the Backup Feedback transducer.
Backup PI Feedback Transducer is broken. Replace Backup PI Feedback Transducer.
HOA Keypad Display
Minor Fault Name
bAT
Keypad Battery Voltage Low
Cause
Possible Solution
The keypad battery is low
Replace the keypad battery.
HOA Keypad Display
Minor Fault Name
bb
Baseblock
Drive output interrupted as indicated by an external baseblock signal.
Cause
Possible Solution
External baseblock signal was entered via
one of the multi-function input terminals
(S1 to S8).
Check external sequence and baseblock signal input timing.
HOA Keypad Display
Minor Fault Name
boL
Braking Transistor Overload Fault
The braking transistor in the drive has been overloaded.
Cause
Possible Solution
The proper braking resistor has not been
installed.
Select the proper braking resistor.
HOA Keypad Display
Minor Fault Name
bUS
Option Communication Error
• The connection was lost after initial communication was established.
• Assign a Run command frequency reference to the option.
Cause
Possible Solution
Connection is broken or master controller
stopped communicating.
• Check for faulty wiring.
• Correct the wiring.
• Check for disconnected cables and short circuits. Repair as needed.
Option is damaged.
If there are no problems with the wiring and the fault continues to occur, replace the option.
The option is not properly connected to the
drive.
• The connector pins on the option are not properly lined up with the connector pins on the drive.
• Reinstall the option.
A data error occurred due to noise.
• Check options available to minimize the effects of noise.
• Take steps to counteract noise in the control circuit wiring, main circuit lines and ground wiring.
• Try to reduce noise on the controller side.
• Use surge absorbers on magnetic contactors or other equipment causing the disturbance.
• Use recommended cables or some other type of shielded line. Ground the shield to the controller side or
on the input power side.
• Separate the wiring for communication devices from the drive input power lines. Install an EMC noise
filter to the drive input power.
HOA Keypad Display
Minor Fault Name
CALL
Serial Communication Transmission Error
Communication has not yet been established.
Cause
Possible Solution
5.4 Alarm Detection
YASKAWA TOEPYAIUPW01A YASKAWA AC Drive - U1000 iQpump Matrix Drive User Manual
199
5
Troubleshooting