During an arc flash risk assessment, the facility’s entire electrical distribution network is modeled and evaluated. At Keynext, our goal is to determine the amount of heat released by each electrical device in a system in the event of an arcing fault at a specific point in the network, thereby calculating the “incident energy.” Once we know that value, we can calculate the “arc flash boundary,” which is the distance from the point of origin of the heat where the level dissipates enough that specialty electrical apparel is no longer necessary. Based on the incident energy value, we assign a level of personal protective equipment (PPE) that would protect workers from injury resulting from exposure to that level of heat.
Arc Flash Risk Transformers
There are various circuit conditions that determine how high the incident energy can be, but the two most impactful variables are the available fault current and the protective device’s clearing time. In any electrical distribution system, the level of fault current that can be delivered can be calculated. The utility company will usually know the level of fault current delivered to the facility and provide that information when asked. Every transformer, whether large or small, dry or oil-filled, has an associated level of electrical impedance. Impedance is the opposition to current flow in a circuit, and it reduces the amount of current that can pass through.
Every transformer in an electrical distribution network will add impedance to the path the current takes to power equipment. That added impedance will then reduce the available fault current, which alters incident energy calculations. Every transformer constructed is tested to measure its internal impedance, and this information is stamped on the data plate of the transformer. It is imperative that we know precisely how much impedance we have in order to accurately arrive at the available fault current at a point in the network, and thereby the precise incident energy.
At Keynext, our goal is to leave your facility safer and more secure through expert electrical testing and arc flash risk assessments. We specialize in electrical services and comprehensive facility maintenance and management. Our team of highly skilled professionals continuously improves their skills to stay ahead of industry standards in meeting complex testing requirements and ensuring customer success.
If your facility is in need of an arc flash risk assessment, contact us today to get started with Keynext >
