OH51
PTC Monitoring
Lenze · 9300 Servo Controller
What does OH51 mean?
The drive has triggered the PTC monitoring function. This indicates that the Positive Temperature Coefficient (PTC) thermistor, likely in the motor, has exceeded its threshold temperature, signifying an overtemperature condition. The drive continues to operate in a controlled manner.
Source: Lenze 9300 Servo Controller
Open Manual (Page 449)