Representative case · 04
Generator temperature alarm: sensor or real heat?
At high power one winding channel crosses the threshold and the turbine stops; after reset the alarm returns.
Representative case. This page describes a fault pattern that is common in the field, as a diagnostic sequence. It does not describe a specific wind farm, turbine or date; numbers are examples only and limits vary by turbine type. On your own turbine the OEM instructions, LOTO procedure and safety rules apply; work near energised equipment is for authorised personnel only.
Symptom
At high power one winding channel crosses the threshold and the turbine stops; after reset the alarm returns.
What was measured
The same channel still reads high on a cooled machine. Resistance correct at the sensor, a few ohms higher at the controller input.
Root cause
An oxidised, loose terminal connection adding resistance and pushing the reading up.
Fix and verification
Terminal renewed and tightened; the channel returned to the band of the others. The alarm limit was not changed.
Lesson
Never raise the alarm limit or bypass a channel; verify the measuring chain first.
Full version
The complete diagnostic sequence — possible causes table, step-by-step checks, maintenance checklist and common mistakes — is in the Turkish version of this case.