What is the primary function of a butt set?

The primary function of a butt set is to test a phone line without disrupting service. A butt set allows a technician to tap into a telephone line and listen for dial tone, place calls, and assess the line's quality while the phone service remains active for the customer. This is particularly useful for troubleshooting and maintenance, as it enables the technician to diagnose issues on the line without interrupting service to the end user.

The tool is designed for safety and convenience, allowing quick access to line functionality. The butt set typically connects directly to the line through clips that attach to the wires, providing a straightforward means to interact with the phone system. Other options, such as preparing cables or connecting wires to binding posts, do not describe the specialized functionality of a butt set in the context of line testing, and raising or lowering tools pertains to different work requirements that do not involve line diagnostics.