Yaskawa Z1000U HVAC Matrix Bypass - Manual (Page 252)

HOA Keypad Display Fault Name
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
• Ensure that other equipment such as switches or relays do not cause noise. Use surge suppressors
if required
• Separate all communication wiring from power lines. When the lines must cross, make the lines
cross at a right angle to minimize noise coupling.
Communication Error timeout time not set
properly.
Verify the setting of the serial communications fault time (Z3-06) is set properly.
Controller is not sending data soon enough to stop
the timeout.
Verify the scan rate in the controller that is communicating with the bypass controller is proper. Adjust
as necessary.
HOA Keypad Display Minor Fault Name
AL16 Input Phase Rotation
Cause Possible Solution
Incorrect phase rotation while Z1-52 is set to 1 in
Bypass Mode.
Check the sequence (phase rotation) of the input wiring to the bypass package.
HOA Keypad Display Minor 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 power supply voltage is low. Increase the power supply voltage.
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.
Voltage detection failed. Correctly wire r1/ l11, s1/ l21, and t1/ l31.
HOA Keypad Display Minor Fault Name
bb
Baseblock
Drive output interrupted as indicated by an external baseblock signal.
Cause Possible Solutions
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
bUS
Option Communication Error
• The connection was lost after initial communication was established.
• Assign a Run command frequency reference to the option.
Cause Possible Solutions
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.
6.5 Alarm Detection
252 YASKAWA SIEP YAIZ1D 01A Z1000U HVAC MATRIX Drive Bypass Technical Manual