TL;DR
A junction box is the listed enclosure where electrical conductors are spliced or terminated, sized by the NEC's cubic-inch fill rules and required to remain accessible, never buried in a wall or above drywall without a cover or hatch. Outdoor lighting and solar rooftop circuits use gasketed, weatherproof versions, while interior splices live in metal or PVC boxes with blank covers.
What it means
A junction box is the listed enclosure where electrical conductors are spliced or terminated, sized by the NEC's cubic-inch fill rules and required to remain accessible, never buried in a wall or above drywall without a cover or hatch. Outdoor lighting and solar rooftop circuits use gasketed, weatherproof versions, while interior splices live in metal or PVC boxes with blank covers. Splices twisted together outside any box are among the most common defects flagged in inspections, since an enclosure exists to contain the heat and sparks of a failing connection.
Where it sits in the glossary
Junction box is part of the Trade jargon group inside the ProFix Directory glossary. Browse every term in this category from the glossary index.
Why Ohio homeowners should know it
This is a term Ohio homeowners encounter when reading contractor quotes, hiring paperwork, or inspection reports. Understanding it well enough to ask one good follow-up question is usually all the protection a homeowner needs.
ProFix Directory keeps definitions short on the index page and saves the longer context — Ohio-specific rules, where the term comes from, and which ProFix tools touch it — for these per-term pages so the term is easy to cite and easy to share.
ProFix tools that touch this term
See also
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