Adjusting electrical connections to their destination

Connections in electrical devices can be of a permanent or separable type. The former ones are used in places where they are never meant to be separated, as their disassembly would be troublesome, time-consuming, and might pose a risk of damaging the installation.

Permanent connections are created by soldering, or seldom by welding or wire wrapping.

Whereas separable connections are used in situations where frequent assembly and disassembly of the same components is required. A variety of connectors is used for this type of joints.

Permanent connections

• Permanent connections include the popular crimped joints.

They are commonly used in automotive, electrical engineering, electronics, and other technical applications. The advantages of this type of joints include good contact parameters, durability, resistance to vibrations, and simplicity of implementation, and consequently low price.

To create crimped joints, the following components can be used:

• pins,
• connectors,
• terminal sleeves (photo 1).

These joints are working, providing that the cable is appropriately crimped, i.e. the core of the cable and the connection element are clean, well prepared, and crimped using a dedicated tool.

Preparations involve removing a part of the sheath without damaging the structure of the wires conducting electricity, and matching the type and cross-section of the cable with pin or connector parameters.

Only multicore strands can be crimped – you cannot use this method for solid wire cables.

The number of wires in such a cable shall be as high as possible. The more wires, the thinner they will be, and the thinner the wires, the more flexible and susceptible to crimping they are. What’s important, if the strand is composed of numerous wires, (the so-called thin-wire strand), damage to a few cores will not affect connection parameters.

In harsh environmental conditions, strands with tinned copper wires should be used.

See also: Crimped joints

• Welded connections are primarily used in high-power applications in the energy sector.

This form of connecting system components is also used in battery assembly.

• Wire wrapped connections can be found in telecommunications and military equipment, where the most important factors are simplicity and resistance to vibrations.

See also:

• Welded joints
• Wire wrapped joints
• Soldered joints

Separable joints

These joints, which can be separated, are based on connectors. The connection element may be in the form of:

• screw terminal,
• plug and socket,
• connector with a spring clip.

Screw terminal allows for the connection of a solid wire or a strand. It’s easy and durable. It can be found in electrical engineering and medium- and high-power applications.

Plugs and sockets include a wide range of products, enabling the use of cable-cable or cable-board connections in virtually any configurations.

Connectors with a spring clip allow you to make a connection by inserting a cable into a hole in the connector, where it is mechanically jammed and connected. The connectors are suitable for solid wires and strands of ca. 0.5mm2 to 2-4mm2 diameter. They can be found in electrical engineering and electronics. This type of connections becomes more and more popular due to their durability and ease of implementation, with no dedicated tools needed.

See also: Separable joints

Summary

When choosing a cable for separable or permanent joint, usually we pay attention to its type, i.e. if it’s a solid wire or a multi strand wire. Additionally, we’re driven by its effective cross-section. However, you should also remember about the quality of insulation, i.e. pay attention to operational voltage and temperature range. The number of wires in a strand may be important as well, as all these elements influence the quality of connection.