Understanding Arc Flash and Arc Flash Protection
What is an Arc Flash?
An Arc Flash is the release of energy that travels through the air from one conductor to another or from a conductor to ground. An Arc Flash may occur as a result of the following items:
Fault Installation
Material Failure
Corrosion
Dust
Dropping of tools while working on equipment
Accidental Touching
Condensation
What are the results of an Arc Flash?
An Arc Flash could result in minor and major damage to electrical equipment and serious injury to people.
Results of a typical Arch Flash can include:
Fire
Flying Objects
Heat
Blast-with Pressure and Sound
Burns
Loss of Life
Why you should conduct an Arc Flash Study in your facility
NFPA 70 (NEC), Article 110.16 requires that electrical equipment have labels to identify the potential for electric arc flash hazards. The equipment shall be labeled of the hazard to identify the risk for qualified persons working on the equipment while energized. There are five Hazard Risk Categories identified by NFPA-70E and the Arc Flash Study will identify the hazard at the equipment by affixing the appropriate label and indicating appropriate Personal Protective Equipment (PPE) required by both NFPA and OSHA.
What does the Study Provide?
An Arc Flash Study will provide information on the incident energy and the levels of Personal Protective Equipment required at each buss in the system. Adhesive stickers will be provided to label each device as required by NFPA 70E.
This study will also include a Fault Current Study which will provide a comprehensive fault analysis for three phase, line-to-line ground faults on the electrical system based on field observations and engineering calculation. The fault analysis will identify the magnitude of the fault current at any point in the system.
Using the Arc Flash and fault analysis information, a Protective Device Coordination study can also be generated to ensure that all device trip settings and short circuit levels are properly coordinated in the system. Under normal conditions a fault should be cleared by the protective device serving the load. A properly coordinated system will trip the device closest to the fault and prevent any incidental tripping of upstream devices under fault conditions. The Protective Device Coordination study can identify where arc flash incident energy can be reduced by time adjustments on the protective device. A properly coordinated system can eliminate the risk of unnecessary downtime of critical equipment or unwanted building shutdown.