Considerations for Arc Fault Protection in 28V DC Systems

As electrical systems grow in complexity, systems engineers must design for enhanced wiring safety, circuit protection, and functionality. 120 VAC arcing faults have been documented as a significant source of concern in the aerospace industry. High and low level arcing currents are dangerous conditions that can lead to catastrophic failure. These are the types of faults that are believed to have contributed to two commercial airplane crashes in the 1990s. In systems utilizing 28VDC circuits, the threat is still significant. This paper explores the characteristics and severity of 28VDC arcing conditions while presenting observations made during preliminary testing. Suggestions for test repeatability as well as mixed-bundle (120VAC and 28VDC) considerations are also explored.