When is it permissible to splice conductors outside of a box?

The correct answer highlights an important safety and regulatory guideline in electrical work. Splicing conductors outside of a box or enclosure is generally not permissible because it can expose the splice to environmental factors, mechanical stress, and inadvertent contact, potentially leading to electric shock hazards, short circuits, or even fire. The National Electrical Code (NEC) and similar regulations in Canada require that all splices be made within approved junction boxes or enclosures to ensure they are protected from these risks.

Safety enclosures serve several purposes: they protect the connections from moisture, dirt, and physical damage, and they provide a way to secure components effectively. Furthermore, having splices inside a box makes it easier to inspect connections and conduct maintenance.

Other possible situations, such as using a heat-shrink method or insulating the splices, might seem at first to provide a lesser degree of risk, but they do not substitute for the fundamental requirement of using an enclosure. An underground splice may involve additional considerations but still generally requires an appropriate enclosure unless specifically exempted by the code for unique applications.

In summary, the requirement for splices to be made within a box or enclosure is focused on ensuring safety and maintaining compliance with electrical codes. It’s critical for anyone working in the