Motor Overheat
Yaskawa · J1000 AC Drive
What does oH3 mean?
The motor overheat signal, typically from a PTC thermistor input to a multi-function analog terminal (H3-02, H3-06, or H3-10 = E), has exceeded its alarm level. Possible causes include faulty motor thermostat wiring, a locked-up machine, or the motor itself overheating due to excessive load or an inappropriate V/f pattern. Continued operation with an overheated motor risks winding insulation breakdown and costly motor failure.
Additional Steps
Steps 1–2 are listed in Priority Fix.
- 3
Reduce the mechanical load on the motor, increase acceleration/deceleration times (C1-01 to C1-08), or adjust the preset V/f pattern (E1-04 through E1-10, mainly E1-08 and E1-10) to decrease motor stress.
- 4
Verify the motor-rated current matches the motor nameplate and is correctly entered in parameter E2-01. Ensure the motor's external cooling system is operating normally and repair/replace if necessary.