Solve Splicing Problems with Lever Wire Connectors

Anyone who has had to splice wires knows how much of a hassle it can be. In the United States, wires are often spliced by twisting them together using wire nuts. This is a time-consuming, error-prone process that can be difficult to execute when space is tight or the wires are short.

It can be particularly challenging to achieve a secure connection when splicing together different types of wire. A typical example is ceiling lighting, where the stranded fixture wires need to be spliced into the solid mains wires. Twisting these conductors together tends to fray the stranded wire, potentially leading to a dangerously loose connection. Similar problems crop up when joining wires of different gauges, as the smaller wire can come loose.

Let’s look at how WAGO Corporation has elegantly addressed these issues.

A faster, safer way to splice: lever wire connectors

WAGO has been designing leaf-spring terminals since the 1950s, so it’s not a surprise they would make “a better mousetrap,” specifically, the 221 Series wire splicing connectors, also known as LEVER-NUTS. The 221 Series provides a quick and safe method to splice wires from 10 to 24 American wire gauge (AWG), i.e., wires with a cross-section of 0.14 to 6.0 square millimeters (mm²). The connectors accommodate both solid and stranded wires and can splice together two, three, or five wires.

The basic operating principles of the LEVER-NUTS are shown (Figure 1) using the three-position 221-413/K194-4045. First, strip the wire as indicated on the terminal housing (11 to 14 mm, or about 0.5 inches (in.)). Second, pull up one of the orange levers to open a clamping unit. Third, insert the wire and push the lever back down.

Figure 1: Shown is the three-step process for securing a wire in the 221 Series LEVER-NUTS. (Image source: WAGO, modified by author)

While LEVER-NUTS are comparable in size to wire nuts, LEVER-NUTS are considerably easier to use in confined spaces. Instead of requiring the user to intertwine wires, each conductor can be secured one at a time. This makes the 221 Series a good solution for applications with limited working room, such as small junction boxes or wiring within a luminaire or ceiling fixture.

Because each conductor is individually attached, the 221 Series makes it easy to securely splice together any combination of solid, stranded, or fine-stranded wires. Similarly, in applications where small wires need to tie into larger conductors, a common situation in applications like heating, ventilation, and air conditioning (HVAC) systems, the 221 Series offers a straightforward solution.

It’s also worth noting that the 221 Series offers ease-of-use features that benefit not only initial installation but also subsequent maintenance. The clear case makes it easy to inspect splices to ensure proper installation. If a wire needs to be removed or replaced, a technician can do so without damaging the wire or disturbing any of the other conductors in the connector. Plus, the family is supported by a variety of mounting systems that simplify installation.

These advantages have made lever wire connectors popular across Europe for residential, commercial, and industrial use. Indeed, they have become a de facto standard for German residential construction.

Using lever wire connectors for power distribution

LEVER-NUTS can also address applications where twisted splices simply aren’t suitable, such as in a distribution panel. Here, many wires need to be electrically connected, and twisted splices are not a safe option.

For example, in a distribution cabinet setup built around the 221-500 DIN rail mount (Figure 2), two of the five-position 221-415/K194-4045 splice connectors are installed onto the rail mount. The 221-941 jumper then joins the two lever wire connectors. The resulting setup accommodates a total of eight wires.

Figure 2: Shown is a distribution cabinet with two five-position 221-415/K194-4045 splice connectors deployed on a 221-500 DIN rail mount and joined by a 221-941 jumper to accommodate a total of eight wires. (Image source: WAGO)

This capability is particularly noteworthy given the 221 Series’ current-carrying capacity. The base product line supports wires up to 12 AWG and is rated up to 32 amperes (A) and 450 volts per EN 60664 (20 A and 600 volts per UL 486C). A larger variant supports wires up to 10 AWG and is rated up to 41 A and 450 volts per EN 60664 (30 A and 600 volts per UL 486C).

Using lever wire connectors as inline splice connectors

The LEVER-NUTS lineup also includes the 221-2401 inline splice connector (Figure 3). This variant is useful for situations where a straight-through connection is preferable, such as a suspended lighting fixture. This connector is also a good choice for applications like test setups, where wires need to be frequently connected and disconnected.

Figure 3: The 221-2401 inline splice connector can extend lines or provide a temporary connection. (Image source: WAGO)

Like the rest of the LEVER-NUTS lineup, the inline splice connector is supported by various mounting hardware, which helps streamline installation.

Conclusion

Wire splicing may not seem like a major design consideration, but in the field, it can significantly impact worker efficiency and electrical safety. The WAGO 221 Series lever wire connectors were created with these factors in mind. They provide a fast, safe method of splicing nearly any conductor commonly used in residential settings, as well as a wide range of commercial and industrial applications.