Gas Turbine Systems Technician – Mechanical (GSM) A School Test 4 Practice

Ignition requires a high-voltage spark to jump the gap in the spark plug under the engine’s hot, pressurized conditions. The ignition exciter takes the 28 VDC from the aircraft electrical system and stores energy, then releases it as a short, high-voltage pulse across the spark plug. That pulse is typically in the kilovolt range; about 3,000 volts is a common, reliable value for turbine ignition systems. A voltage like 28 V, 600 V, or 1,500 V would not be enough to consistently ignite the mixture, whereas a brief 3,000 VDC spark provides the necessary jump across the gap and ionizes the air to start combustion.