E.OS

Overspeed Occurrence

Mitsubishi · FR-E800 Variable Frequency Drive

What does E.OS mean?

The motor speed has exceeded the configured Pr.374 Overspeed detection level under encoder feedback, Real sensorless vector, Vector, or PM sensorless vector control, leading to an inverter shutdown. This protective function prevents mechanical damage from excessive speed.

Complete Troubleshooting Guide

  1. 1

    Review and correctly set Pr.374 Overspeed detection level to match system requirements.

  2. 2

    If applicable (encoder feedback or Vector control), verify that Pr.369 Number of encoder pulses is accurately set to the actual number of encoder pulses.

Source: Mitsubishi Manual