Yes, a 3-prong dryer outlet must be grounded for safety reasons. Grounding is an essential safety feature in electrical systems, and it helps protect both people and appliances from electrical hazards.
In older homes, 3-prong dryer outlets were commonly used, which included two flat prongs for the hot wires and one round prong for the neutral wire. However, these outlets lacked a separate grounding pathway, which could lead to potential shock hazards in the event of a fault or malfunction.
In more recent electrical code standards, 4-prong dryer outlets have become the norm. These outlets include two hot wires, one neutral wire, and one separate grounding wire. The addition of the grounding wire provides an extra safety measure, directing electrical currents away from the user and the appliance's metal components during a fault.
If you have a 3-prong dryer outlet in your home, it is recommended to upgrade to a 4-prong outlet to ensure proper grounding and improved safety. Additionally, when purchasing a new dryer, most modern models are designed for use with 4-prong outlets, so upgrading the outlet would be necessary for compatibility with the new appliance. Always consult a licensed electrician to perform any electrical work or upgrades to ensure it is done safely and in compliance with local electrical codes.