An Arc-Flash can be caused by a number of ways including:

• Accidental contact with energized parts
• Inadequate short circuit ratings
• Tracking across insulation surfaces
• Tools dropped on energized parts
• Wiring errors
• Contamination, such as dust on insulation surfaces
• Corrosion of equipment parts and contacts
• Improper work procedures

As you would expect, proper procedures, tools and maintenance, can prevent most Arc-Flash situations from occurring.