There are a number of codes that all address arc flash study evaluations and why they are required. I’ll list them in the next blog post but first a brief explanation of what an arc flash hazard is and why it’s so dangerous.
Arcing from electrical equipment can produce extremely high temperatures. They can exceed 30,000 degrees Fahrenheit, which is hotter than the surface of the sun. An arc flash occurs when a rapid release of energy due to an arcing fault between a phase bus bar and another phase bus bar, neutral or a ground bar occurs. During this type of fault, air becomes the conductor and it expands dramatically. This causes metal conductors to vaporize and can cause an intensely hot blast. The danger lies when employees are working on electrical equipment and are not wearing adequate Personal Protective Equipment (PPE). Workers can be seriously injured or killed when an arc occurs.
Wilder Engineering is trained in performing the electrical engineering needed to evaluate the electrical system and provide the necessary field labeling for all equipment. A number of steps are required for an arc flash analysis.
First, a short circuit study is performed to ensure the interrupting devices are appropriately designed and sized to interrupt a circuit in the event of a fault. The associated equipment is then evaluated for adequate bracing and last these fault currents are calculated into arc fault currents for additional analysis.
Next, a coordination study is performed. This study evaluates that over-current protection devices are properly designed and coordinated. Over-current devices may be adjusted so only the fault carrying device nearest the fault opens in order to isolate the faulted circuit from the system. This provides further protection to all electrical workers by containing the fault in the system to as small an area as possible.
Finally, an arc flash hazard analysis is performed. Once complete an entire packet of labels with all incident energy calculations and required PPE is included. Wilder Engineering can provide these to the client or install the stickers to provide a full service.