What type of receptacles must be installed on 15- and 20-ampere branch circuits?

In residential wiring, 15- and 20-ampere branch circuits are required to have grounding type receptacles for safety reasons. Grounding type receptacles are equipped with a third prong that connects to the grounding system of the electrical installation. This grounding feature helps protect people and devices from electric shock and prevents damage to equipment by providing a safe path for stray electricity or short-circuit currents to flow back to the ground.

The National Electrical Code (NEC) emphasizes the importance of grounding in any permanent wiring, particularly in circuits that serve outlets in locations where grounding is crucial for safety, such as kitchens, bathrooms, and outdoor areas. By using grounding type receptacles, you ensure that any faults in the wiring or connected devices can be safely managed, reducing the risk of electrical hazards.

Non-grounding type receptacles are not suitable for modern installations where grounding is necessary, and while weatherproof type receptacles are important for certain outdoor applications, they do not specifically address the grounding requirement for general circuits. Heavy-duty type receptacles are used for higher capacity applications and do not pertain specifically to the grounding needs of 15- and 20-ampere circuits. Therefore, grounding type receptacles are the appropriate choice for safety and compliance.