What is the RPM maintained by an Integrated Drive Generator (IDG) on the 737?

What is the RPM maintained by an Integrated Drive Generator (IDG) on the 737?

• A. 12,000 rpm
• B. 6,000 rpm
• C. 24,000 rpm
• D. 8,000 rpm

Answer: (A)

The function being tested is how an Integrated Drive Generator keeps electrical power stable by maintaining a constant generator speed. On the 737, the system operates at 400 Hz. For a typical 4-pole generator, 400 Hz requires the rotor to spin at 12,000 rpm. The constant-speed drive inside the IDG adjusts to engine speed so the generator stays at 12,000 rpm regardless of how fast the engine is turning, keeping the electrical frequency and voltage steady for the aircraft systems. Other RPM values would correspond to different pole counts and aren’t the standard setup for this aircraft, so 12,000 rpm is the maintained speed.

The function being tested is how an Integrated Drive Generator keeps electrical power stable by maintaining a constant generator speed. On the 737, the system operates at 400 Hz. For a typical 4-pole generator, 400 Hz requires the rotor to spin at 12,000 rpm. The constant-speed drive inside the IDG adjusts to engine speed so the generator stays at 12,000 rpm regardless of how fast the engine is turning, keeping the electrical frequency and voltage steady for the aircraft systems. Other RPM values would correspond to different pole counts and aren’t the standard setup for this aircraft, so 12,000 rpm is the maintained speed.