What is Arc Flash?
A dangerous condition associated with the release of energy caused by an electric arc.
Properties Of Arc Flash:
- Arc temperature can reach 35,000°F – this is four times hotter than the surface of the sun.
- Fatal burns can occur at distances over 10 ft.
- Sound associated with these pressures can exceed 160 dB.
- Energy liberated during an arc flash can lift Space Shuttle weighing approximately 4.5 million Pounds to 27 feet
Causes of Arc Flash
- Dust accumulation
- Corrosion, Dirt contamination or Dielectric Breakdown
- Faulty equipment
- Poor maintenance
- Tool dropped into an equipment
- Careless removal or replacement cover and device
- Entry of foreign bodies.
- Misalignment of moving contacts.
Hazards of Arc Flash:
- Severe burns
- Blindness
- Blast injuries
- Shrapnel wounds
- Lung blast injuries
- Ruptured eardrums
- Pressure wave injuries
Scope of Arc Flash Studies
- A method to determine the risk of personal injury as a result of exposure to incident energy from an electrical arc flash.
- Determines the incident energy evolved, safe flash protection boundary and PPE requirements as a function of location and work activity.
- To provide designers and facility operators to apply in determining the arc-flash hazard distance and the incident energy to which employees could be exposed during their work on or near electrical equipment
Survey Methodology:
- Collect the system Installation and equipment data.
- Determine the power system’s modes of operation.
- Determine the bolted fault currents.
- Determine the arc fault currents.
- From the protective device characteristics, Find the Arcing Duration
- Record the system voltages and equipment classes for each bus or arc hazard location.
- Determine the working distance
- Determine the incident energy
- Determine Flash protection boundary for all equipment.
- Protective device coordination evaluation for bolted fault as well as arcing fault.
- Generate Arc Flash Hazard labels.
Arc Flash Regulation
- IEEE Std 1584-2002, IEEE Guide for Performing Arc-Flash Hazard Calculations and IEEE Std. 1584a-2004 (Amendment 1)
- NFPA 70E.
Software Used
- ETAP – Electrical Transient Analysis Program
Expertise
The auditor holds expertise in the field of engineering, design and consulting services in the field of power system and Arc flash survey over a period of 15 years and holds PG diploma degree in the field of Energy Efficiency.