Electrical Relay Fault Revealed by Subtle Pitch Box Temperature Anomaly
"A minor electrical defect inside the pitch box went unnoticed until heat patterns exposed a welded relay contact disrupting the box’s temperature control."
The Impact
The Issue
Abnormal behavior was observed in the blade pitch box temperature readings. Possible root causes included fan filter clogging, fan malfunction, heater relay contact welding, or air conditioner underperformance.
The Action
High and persistent temperature anomalies were detected in one of the blade pitch boxes, prompting a recommendation to inspect the cooling components and heater relay contacts. During inspection, the service team discovered that the heater relay contacts had welded, preventing proper heat regulation. The relay was replaced, and temperatures stabilized immediately, confirming the cause of the overheating.