Motor Overtemperature (PTC Warning)

What does OH51 mean?

The motor's PTC thermistor has detected an overtemperature condition, triggering a WARNING (not a TRIP). This typically occurs when the motor operates under impermissible high currents or frequent/long acceleration processes, or if the PTC sensor is not connected while monitoring is active (C0119 = 2 or 5). While a warning, continued operation can still lead to motor damage if the condition escalates.

Complete Troubleshooting Guide

1. 1

   Evaluate the motor and drive dimensioning against the application's load and duty cycle. Reduce load or consider a larger motor/drive if necessary.

2. 2

   Check if the PTC thermistor is correctly connected to the drive's input terminals.

3. 3

   If no PTC is used and monitoring is not desired, switch off PTC monitoring via parameter C0119.