A time and cost saving development for panel and machine builders

Over recent years wire termination technology has slowly migrated away from the traditional screw terminal and moved towards ‘screwless’ terminations. This was first seen on the simple DIN rail terminal and then on other hardware such as PLCs, relay sockets and more.

Initially this change to screw-less was done with a ‘spring clamp’, however this still required a screwdriver to open the spring to allow the cable to be inserted. More recently, the spring clamp has fallen out of favour and the ‘push-in termination’ has taken the lead, as Alan Vincent, sales director at Foremost Electronics, explains.

Safe and reliable electrical connections are critical for machine builders, especially under harsh conditions such as those encountered in the process industry, special vehicles and applications subjected to high levels of vibration. The latest push-in termination technology provides easy installation with full safety guarantees, optimal contact security and ease of handling, even in demanding applications. Reductions in assembly time resulting from the use of push-in connections directly reduces manufacturing and assembly costs.

This technology is particularly user-friendly. A stripped solid or fine-stranded conductor with a crimped ferrule is inserted into the clamping point as far as it will go, and a safe and secure connection is instantly complete. Alternatively, if connecting stranded wire, the wire is inserted while holding down the contact pusher with a flat-bladed screwdriver. Connection is as easy as that.

With push-in connection technology, the force on the conductor is generated by a pressure spring made of high-quality stainless steel. The spring sits in a cage and is automatically opened on connection and only released when a release tool is used. Tool-less connection means ferrules and solid wires can be connected simply by push-in insertion, without a screwdriver or other tools. To remove the ferrule, a flat-blade screwdriver is inserted into the pusher.

Push-in connections are made simple by direct insertion of the wire, reducing wiring time by approximately 55% compared to conventional screw terminals, while providing a high conductor retention force and a complete way of handling multiple conductor types. Since the wiring can be done regardless of the skill level of the operators, this also contributes to time saving.

Push-in connection technology provides a finger-safe structure and vibration and shock resistance. In addition, the space-saving design means better workability in a smaller space. Since the ferrule is held in place by a spring-loaded terminal, the wiring remains taut and vibration resistance is improved. IP20 finger-safe protection enables wiring to be performed without direct contact between screwdriver and any conductive parts.

Components which benefit from push-in termination technology include control panel switches, pilot and indicator lights, relays, sockets, timers, emergency-stop switches, relay sockets and PLCs.