What two conditions will result in an automatic manual disconnect of the IDG?

• A. Over temperature only
• B. Over temperature and overtorque
• C. Over torque only
• D. Low oil pressure

Answer: (B)

The IDG is wired with protections to prevent damage to the generator and drive system if conditions stray beyond safe limits. There are two separate triggers that will cause an automatic disconnect: over temperature and overtorque. If the IDG overheats, cooling can’t keep up and the protective system disengages the generator to stop further heat buildup. If the torque exerted on the IDG exceeds what it can safely handle, an overload is detected and the disconnect releases to prevent mechanical damage. Either condition alone is enough to trigger the automatic disconnection, which is why this option is correct. Low oil pressure is not the trigger for this protective disconnect, though it signals engine issues in other contexts.