What is a MAC?

• A. A device used to measure voltage on a distribution line.
• B. A protective ground used to channel fault current.
• C. A temporary bypass for a distribution line which allows work to be done or replacement of circuit components.
• D. A protective device that automatically disconnects when fault occurs.

Answer: (C)

A MAC is a temporary bypass that crews install to bridge around a section of a distribution line so maintenance or replacement of components can be performed without completely taking the circuit out of service. It serves as a short-term work-around, allowing the line to continue to be worked on safely while the specific segment is disconnected or isolated for repair. This is distinct from a device used to measure voltage, a protective ground, or an automatic protective disconnect. When using a MAC, the work must follow proper switching procedures, with the circuit properly isolated, tagged, and removed once the work is finished.