Representative case · 05
Converter overcurrent only at high power
Intermittent converter overcurrent trips; every check on the stopped turbine is clean.
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
Intermittent converter overcurrent trips; every check on the stopped turbine is clean.
What was measured
Events matched high power. A thermal scan done with an OEM-approved method showed a hot DC busbar joint.
Root cause
A DC busbar joint that had lost its torque, heating at high current and stressing the neighbouring module.
Fix and verification
After LOTO, discharge and a verified zero-voltage test, the joint was renewed and torqued to OEM value; the stressed module was replaced.
Lesson
With intermittent faults, look for the condition that triggers them — not the fault message.
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.