What type of circuit must include disconnect switches for maintenance purposes?

Power circuits are required to have disconnect switches for maintenance purposes due to the higher voltage and current levels they typically handle. These circuits often power large machinery and equipment, making it essential to safely isolate them from the electrical supply during maintenance or repair work. The disconnect switch allows workers to cut off power, ensuring their safety and providing a clear and defined method for shut-off.

In contrast, while lighting, grounding, and branch circuits may have their requirements, they typically do not necessitate the same level of isolation and safety measures during maintenance as power circuits do. Lighting circuits might be less hazardous because they generally operate at lower voltage levels. Grounding circuits, on the other hand, are primarily designed to provide a safe path for electrical fault currents, and branch circuits typically include general-purpose outlets or lighting, which may not require the same level of safety precautions as dedicated power circuits.