Knockout

A knockout in the electrical industry refers to a partially pre-punched, removable section found on electrical boxes, panels, and enclosures. These knockouts are designed to facilitate the entry and exit of electrical conduits or cables into the enclosure. They come in various standardized sizes to accommodate different types of wiring and conduits. The design ensures that the structural integrity of the electrical box remains intact until the knockout is intentionally removed. The removal process usually involves using a hammer and a screwdriver or a knockout punch to detach the knockout cleanly, allowing for the installation of cables or conduits without the need for additional drilling.

Common Applications

• Electrical Boxes: Knockouts are commonly used in junction boxes, switch boxes, and outlet boxes to introduce electrical wiring.
• Distribution Panels: In electrical panels, knockouts provide entry points for cables that supply electricity to different circuits.
• Conduit Installations: For routing conduits through walls or ceilings, knockouts offer a convenient entry point and help maintain a clean and organized installation.

Safety Considerations

• Secure Connections: Ensure that any conduit or cable entering through a knockout is properly secured with a connector or bushing to prevent damage to the wire insulation.
• Sharp Edges: After removing a knockout, inspect the edges to ensure they are smooth to avoid damaging the conduit or cable insulation.
• Code Compliance: Follow local electrical codes and standards when using knockouts to ensure safe and compliant installations.

Related Terms or Concepts

Conduit

A protective tube through which electrical wires are run. Conduits are often inserted into knockouts to provide a safe path for wiring.

Grommet

A protective ring used to prevent abrasion when cables or wires pass through openings, including knockouts.

Junction Box

An enclosure that houses electrical connections, often equipped with knockouts for wire entry.

Knockout Punch

A tool used to remove knockouts cleanly, typically consisting of a die and a punch.