What causes an IDG fault?

What causes an IDG fault?

• A. HOTLOP (High Oil Temp, Low Oil Pressure)
• B. High Oil Temperature
• C. Low Oil Pressure
• D. Hydraulic failure

Answer: (A)

An IDG fault is triggered when the engine’s oil system is both overheated and under-lubricated. The Integrated Drive Generator sits in the accessory drive gearbox and relies on oil for cooling and lubrication. If oil temperature is too high while oil pressure is too low, lubrication and cooling are insufficient, risking gear damage. To protect itself, the IDG faults and disconnects when this HOTLOP condition is detected. If only one parameter is out of range—either high temperature or low pressure—the system may alarm or indicate an oil-system issue, but the specific IDG fault condition is the combination of HOT and low oil pressure. Hydraulic failure involves a different subsystem and isn’t the direct cause of an IDG fault.

An IDG fault is triggered when the engine’s oil system is both overheated and under-lubricated. The Integrated Drive Generator sits in the accessory drive gearbox and relies on oil for cooling and lubrication. If oil temperature is too high while oil pressure is too low, lubrication and cooling are insufficient, risking gear damage. To protect itself, the IDG faults and disconnects when this HOTLOP condition is detected. If only one parameter is out of range—either high temperature or low pressure—the system may alarm or indicate an oil-system issue, but the specific IDG fault condition is the combination of HOT and low oil pressure. Hydraulic failure involves a different subsystem and isn’t the direct cause of an IDG fault.