Yaskawa VCD 723 User Manual
Page 60

4
Troubleshooting/Maintenance
54
Fault and Error Conditions
9/15/93
ERROR/FAULT
PROBABLE CAUSE
CORRECTIVE ACTION
Replace braking transistor or gate drive
board.
Wait for resistor to cool. Check
application requirements for braking
capacity.
Verify proper wiring to the thermistor.
If properly wired, then use the spare
thermistor.
Verify that the correct version of
EPROM's are installed in the VCD 723.
This error indicates that the inverter
portion of the drive is programmed as a
VCD 703.
Verify that the correct version of
EPROM's are installed in the VCD 723.
This error indicates that the inverter
portion of the drive is programmed as a
VCD 703.
Verify wiring to PG-X circuit card CA-1
connector.
Verify all speed parameter settings (i.e.
pulses per revolution, motor rated
speed). Whenever changing parameter
settings the following procedure must
be followed:
➊
Correct the setting.
❷
Use function 994 to transfer the
data from RAM to NVRAM.
❸
Turn power off.
❹
When the charge light is off, then
turn power on.
Replace the inverter control circuit card.
Replace the inverter control circuit card.
Confirm that all parameters are within
allowable ranges. If they are, then
replace the inverter control circuit card.
Replace the inverter control circuit card.
Table 8. Standard Error and Fault Descriptions - Continued
703, BRAKE TRANSISTOR
704, BRAKE RESIST HOT
706, THERMISTOR OPEN
707, TRANSMIT ERROR
712, EXT FLT T INPUT
720, OPEN INV TACH
721, INV OVERSPEED
722, INV SPEED ERROR
741, BASE BLOCK CKT
742, SHADOW RAM FLT
743, NVRAM CHKSUM ERR
744, INV MCU Q/D FLT
Drive declared that the braking
transistor is malfunctioning.
Drive declared that the brake resistor
unit overheated.
Drive declared that the connection to
the motor thermistor is disconnected.
Drive declared that the transmission
between the VCD 723 and the remote
operator was not established within 5
seconds after the power supply was
turned on.
Drive declared that a transmission
error occurred 2 seconds after
transmission was established between
the VCD 723 and the remote operator.
Drive detected that its pulse generator
input is open.
Drive declared an overspeed.
Drive detected a probable speed error.
Drive detected a control circuit failure.
Drive detected that its NVRAM is bad.
Drive detected that the constants in its
non-volatile memory are not valid.
Drive detected that its CPU A/D
converter has failed.