This document provides explanations for reasons why electricity supply may be interrupted. It describes key engineering terms related to electricity distribution and defines concepts like load shedding, local load shedding, and bypassing. Load shedding occurs when power needs to be shared across consumers to prevent transformers from overloading. Local load shedding involves dropping some loads on a specific feeder. The document also lists other potential causes of outages like system collapse, damage to equipment, unit exhaustion, disconnection for non-payment, and violence against utility workers.