NFPA 70E states that an Arc Flash Risk Assessment should be updated every five years or when significant electrical system changes occur. How important is this? Even if all equipment within your electrical distribution system has remained the same, it is still essential to perform an updated risk assessment based on possible changes undertaken outside of your system. This article explores the arc flash impacts to an electrical system based on changes performed by others (i.e. the utility company) — specifically pertaining to the available utility fault currents and/or the utility protection system.