A clear plastic cover lets you inspect your terminal block while keeping out dirt and liquids. These blocks come mounted in an enclosure that you can pop directly onto walls or equipment. They also reduce hassle because you can wire your circuits before installing the enclosure. Enclosures protect the terminal blocks from water, oil, and corrosion. Knockouts make it easy to run wire in and out of the enclosure. For enclosures without knockouts, you’ll need to drill your own holes for the wiring.

The screw-clamp terminals flatten your wire so it stays put when vibrated or pulled. For an even stronger and more conductive connection, crimp a terminal or wire ferrule onto the end of the wire. If you need to change wiring frequently without adjusting a screw, consider a quick-connect terminal block with spring-clamp terminals.