Operating Guide | VLT® AutomationDrive FC 302
8.4.68 ALARM 70, Illegal FC Configuration
Cause
The control card and power card are incompatible.
Troubleshooting
•
To check compatibility, contact the Danfoss supplier with the type code from the unit nameplate and the part numbers on the
cards.
8.4.69 ALARM 71, PTC 1 Safe Stop
Cause
Because the motor is too warm, the VLT
Troubleshooting
•
Once the motor temperature reaches an acceptable level and the digital input from MCB 112 is deactivated,send a reset signal via
bus or digital I/O, or press [Reset].
8.4.70 ALARM 72, Dangerous Failure
Cause
Safe Torque Off (STO) with trip lock.
Troubleshooting
An unexpected combination of STO commands has occurred:
®
•
VLT
PTC Thermistor Card MCB 112 enables X44/10, but STO is not enabled.
•
MCB 112 is the only device using STO (specified through selection [4] PTC 1 alarm or [5] PTC 12 warning in parameter 5-19 Terminal
37 Safe Stop). STO is activated, but X44/10 is not activated.
8.4.71 WARNING 73, Safe Stop Auto Restart
Cause
STO activated.
Troubleshooting
•
With automatic restart enabled, the motor can start when the fault is cleared.
8.4.72 ALARM 74, PTC Thermistor
Cause
The PTC is not working. Alarm is related to VLT
120 | Danfoss A/S © 2019.12
®
PTC Thermistor Card MCB 112 activated the Safe Torque Off (STO).
®
PTC Thermistor Card MCB 112.
Maintenance, Diagnostics, and
Troubleshooting
AQ275652476278en-000101 / 130R0709
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