The answer to 'how long does junction box last' is that a properly installed and maintained junction box can last for decades, often 30-50 years or more. Junction boxes are made of durable materials like metal or plastic that are designed to withstand the elements and protect the electrical connections inside. As long as the box remains undamaged and the connections are secure, it can continue functioning reliably for many years.
The lifespan of a junction box can vary depending on factors like the quality of the materials, the environment it's installed in, and how much wear and tear it experiences. Boxes in damp or corrosive environments may have a shorter lifespan, while those in dry, protected areas can last even longer. Regular inspection and maintenance can also help extend the useful life of a junction box.