During a Lamp Test for Polarity on a Three-Wire Service, which wire causes the lamp to burn?

In a Lamp Test for Polarity on a Three-Wire Service, the wire that causes the lamp to burn is the hot wire. The hot wire is responsible for carrying electrical current from the power source to the load, such as a lamp. When the lamp is connected to the hot wire, it allows current to flow, illuminating the lamp.

The grounded wire serves to provide safety by directing fault currents to the ground, while the neutral wire is intended to complete the circuit by providing a return path to the power source. The return wire concept usually aligns with the neutral wire in residential electrical systems, but in this context, it does not directly cause the lamp to illuminate.

Understanding the function of each wire in this context is crucial for anyone working in electrical services, as it ensures safety and proper connections are observed during testing and installations.