Yaskawa Z1000U User Manual
Page 205

Communications wiring is faulty, there is a short
circuit, or something is not connected properly
• Check for wiring errors.
• Correct the wiring.
• Check for disconnected cables and short circuits. Repair as needed.
Programming error on the master side
Check communications at start-up and correct programming errors.
Communications circuitry is damaged
• Perform a self-diagnostics check.
• If the problem continues, replace either the control board or the entire drive. For instructions on
replacing the control board, contact Yaskawa or your nearest sales representative.
Termination resistor setting is incorrect
Install a termination resistor at both ends of a communication line. Set the internal termination resistor
switch correctly on slave drives. Place DIP switch S2 to the ON position.
HOA Keypad Display
Minor Fault Name
CE
MEMOBUS/Modbus Communication Error
Control data was not received correctly for two seconds.
Cause
Possible Solutions
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.
• Reduce noise on the controller side.
• Use surge absorbers for the magnetic contactors or other components that may be causing the
disturbance.
• Use only recommended shielded line. Ground the shield on the controller side or on the drive input
power side.
• Separate all wiring for communication devices from drive input power lines.
Communication protocol is incompatible
• Check the H5 parameter settings and the protocol setting in the controller.
• Ensure settings are compatible.
The CE detection time (H5-09) is set shorter than
the time required for a communication cycle to take
place
• Check the PLC.
• Change the software settings in the PLC.
• Set a longer CE detection time using parameter H5-09.
Incompatible PLC software settings or there is a
hardware problem
• Check the PLC.
• Remove the cause of the error on the controller side.
Communications cable is disconnected or
damaged
• Check the connector to make sure the cable has a signal.
• Replace the communications cable.
HOA Keypad Display
Minor Fault Name
CrST
Cannot Reset
Cause
Possible Solutions
Fault reset was being executed when a Run
command was entered
• Ensure that a Run command cannot be entered from the external terminals or option during fault
reset.
• Turn off the Run command.
HOA Keypad Display
Minor Fault Name
dnE
Drive Disabled
Cause
Possible Solutions
“Drive Enable” is set to a multi-function contact
input (H1-oo = 6A) and that signal was switched
off
Check the operation sequence.
HOA Keypad Display
Minor Fault Name
doH
Damping Resistor Overheat
The temperature of the built-in damping resistor exceeded the set value.
HOA Keypad Display
Minor Fault Name
EF
Forward/Reverse Run Command Input Error
Both forward run and reverse run closed simultaneously for longer than 0.5 s.
Cause
Possible Solutions
Sequence error
Check the forward and reverse command sequence and correct the problem.
Note:
When minor fault EF detected, motor ramps to stop.
5.5 Alarm Detection
YASKAWA ELECTRIC TOEP C710636 10B Z1000U HVAC MATRIX Drive User Manual
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Troubleshooting