Which of the following is NOT a valid application for junction boxes?

Junction boxes serve several specific functions within electrical systems, and understanding these roles helps in identifying valid applications. One of the primary purposes of a junction box is to house splices, which allows for the safe joining of conductors in an electrical system. Junction boxes also facilitate the connection of conduits, enabling the transition from one conduit run to another while providing a secure and compliant method of connection. Additionally, they are used to accommodate conductor changes, such as when conductors need to be redirected or when splicing is necessary.

However, acting as service entrances is not a typical function of junction boxes. Service entrances are usually established with a specific type of enclosure designed to manage incoming electrical feeds from the utility company, typically including a means of disconnect and proper protection against tampering and environmental factors. This role is more suitably handled by service entrance equipment and enclosures that comply with electrical codes, rather than junction boxes which are meant for distribution and not as points of entry for service feeds.

Thus, the assertion that junction boxes are not valid as service entrances highlights the specialized nature of electrical components and their specific applications.