Final answer:
The service wire with black, red, and white conductors indicates that black and red are live/hot wires usually carrying 120 volts each, and the white wire is the neutral wire which is safe to handle and at zero volts relative to earth.
Step-by-step explanation:
The service wire described with black, red, and white conductors typically pertains to household electrical systems. The black and red wires are the live/hot conductors that supply voltage and current to operate appliances. The voltage level for each of the live wires is usually 120 volts in a standard North American household setup, but it can be different in other regions. The white wire is the neutral wire and is connected to earth/ground at the source and user's location, which forces it to be at zero volts relative to the earth, making it safe to touch if the insulation is missing. This neutral conductor provides the return path for electric current to complete the circuit. Moreover, it is safeguarded with a ground connection to prevent electric shock. The three-wire system is typically designed to connect through a three-prong plug, with the live, neutral, and ground wires color-coded for easy identification, though colors may vary by region.