Faster, safer lap method: lever-type wire connector
WAGO has been designing reed terminals since the 1950s, and it is no surprise that they have produced better solutions - especially the 221 series lap connectors known as LEVER-NUTS. Series 221 provides a fast, safe method of lapping 10 to 24 AWG conductors, i.e. wires with a cross-sectional area of 0.14 to 6.0 mm2 (mm ²). This connector is suitable for both solid conductors and multi-strand flexible wires and can be used to lap two, three or five wires together.
The basic operating principle of LEVER-NUTS is shown in Fig. 1. A three-position 221-413/K194-4045 device is used. First, strip the wire (11 to 14 mm, or approximately 0.5 in.) according to the number indicated on the terminal housing. Then, open the clamping mechanism by pulling one of the orange levers. Third, insert the wire and push the lever back.
Figure 1: Three Steps for Fixing Wires with 221 Series LEVER-NUTS Connectors. Image source: WAGO, modified by the author)
Although the dimensions of LEVER-NUTS are comparable to wire nuts, it is much easier to use the former in confined spaces. Instead of twisting the wires together, the user can fix one conductor at a time. This makes the Series 221 connectors ideal for applications with limited workspace, such as wiring in small junction boxes, or in lighting fixtures or ceilings.
Because each conductor is individually connected and fastened, the Series 221 can easily and safely lap any combination of solid, flexible, or thin flexible wires together. Likewise, in applications such as HVAC systems, where small wire sizes are connected to large wires, Series 221 provides a direct connection method.
It should be noted that the Series 221 is also easy to use, not only for initial installation, but also for subsequent maintenance. Transparent housings facilitate inspection of connectors to ensure proper connection. If the wire needs to be removed or replaced, the technician can do this without damaging the wire or interfering with any other wires in the connector. In addition, the series is equipped with various installation systems to simplify the installation process.
These advantages make lever-type wire connectors popular in residential, commercial and industrial areas in Europe. In fact, these connectors have become the actual standards for residential buildings in Germany.
Use of pole type wire connectors in power distribution systems
LEVER-NUTS can also be used in applications such as switchboards where twisted-pair lapping is not appropriate. In this case, many wires need to be lapped together, and a twisted-pair connector is not a safe option.
For example, in a power distribution cabinet constructed based on a 221-500 DIN rail bracket (Figure 2), two five-position 221-415/K194-4045 lap connectors are mounted on the rail bracket. The two lever connectors are then connected together using a 221-941 jumper. This arrangement can accommodate a total of eight wires.
Figure 2: A power distribution cabinet is shown with two five-position 221-415/K194-4045 jumper connectors mounted on the 221-500 DIN rail mounting frame and connected via 221-941 jumper to accommodate a total of eight wires. Image source: WAGO)
This capability is particularly noteworthy given the current-carrying capacity of the Series 221. The basic product family supports up to 12 AWG of wire rated to 32 amperes (A) and 450 volts (V) per EN 60664 (20 A and 600 V per UL 486C). Larger models support up to 10 AWG wires with current rating up to 41 A and voltage up to 450 V per EN 60664 (up to 30 A and voltage up to 600 V per UL 486C).
Use lever connectors as inline lap connectors
The LEVER-NUTS series also includes 221-2401 inline lap connectors (Figure 3). This model is applicable to the situation where straight-through connection is required, such as suspended lighting fixture. This connector is also a good choice for applications such as test units that require frequent connection and disconnection of wires.