Which power source is primarily used to initiate engine start on the ERJ-145?

Which power source is primarily used to initiate engine start on the ERJ-145?

• A. External power unit on the ground.
• B. APU.
• C. Battery.
• D. Standby inverter.

Answer: (C)

Starting an engine requires spinning the compressor to a high enough speed for ignition. On the ERJ-145, that cranking is done by an electric starter motor, which is powered from the aircraft’s electrical system. The main battery provides the surge current needed to drive the starter and bring the engine up to the point where fuel can ignite. The APU can provide electrical power and bleed air for various systems (and can assist in starting in some situations), but the engine start motor is normally fed by the battery, making it the primary source for initiating the start. The standby inverter is there to support the standby AC bus and is not used to crank the engines.

Starting an engine requires spinning the compressor to a high enough speed for ignition. On the ERJ-145, that cranking is done by an electric starter motor, which is powered from the aircraft’s electrical system. The main battery provides the surge current needed to drive the starter and bring the engine up to the point where fuel can ignite. The APU can provide electrical power and bleed air for various systems (and can assist in starting in some situations), but the engine start motor is normally fed by the battery, making it the primary source for initiating the start. The standby inverter is there to support the standby AC bus and is not used to crank the engines.