Kimball Midwest Blog

The Basics of Electrical Connectors

Written by Kimball Midwest | January 24, 2019
Electrical connectors are critical to the functionality of nearly all vehicles, industrial equipment and electrical and electronic devices. It’s important that connectors perform properly to prevent electrical shorting and arcing that may damage your equipment and cause failure.
There are different types of connectors for different applications. Knowing which connector to use for your application will ensure that you create a reliable electrical connection. Over the long term, this will save you time and money by reducing equipment downtime.

Terminals

Terminals are basic connectors linking two or more wires to a single contact point, transferring electrical current from the power source to the device using the power. There are a variety of terminals meant for different applications.

The two most popular types of electrical connectors are crimp-on terminals, which require a crimping tool to secure the terminal to the wire, and heat-shrink terminals that completely seal the connection to protect it from corrosion that can lead to failure and downtime. Heat-shrink terminals are available in a variety of forms: crimp and shrink; solder and shrink; and crimp, solder and shrink styles.
  • Ring terminals are so named because of the ring on one end. The barrel on the other end is crimped or soldered onto the wire, then screwed or bolted down through the ring to make the contact point. Ring terminals come in different sizes – identified by color coding – to accommodate the gauge of the wire and diameter of the fastener. Ring terminals create a very reliable connection, as they cannot separate from the terminal block until the fastener is removed.
  • Like ring terminals, spade, snap spade, flange and hook terminals also attach to terminal blocks with screws, but they have an open side for easier installation. These have slightly less reliability, as the fastener does not need to be completely removed for the terminal to disengage.
  • Butt connectors seamlessly make a new electrical connection or repair one by joining wire together. They are also color-coded according to size, so you can choose the appropriate one for your wire gauge.
When selecting terminals, you need to consider which material will work best for your needs. Heat-shrink terminals are ideal for the toughest applications, as they are designed to resist corrosive and environmental elements that can damage a connection. Nylon terminals are not as protective as heat-shrink terminals for connections exposed to the elements.

Other types of terminals include:
  • High-temperature terminals – Designed for ovens and furnaces, these terminals can withstand constant temperatures of 900°F and intermittent temperatures up to 1200°F.
  • Insulated ferrules – These are used to terminate stranded wire and prevent fraying in screw-type connections. They can accommodate single or double wires and require a crimper to secure the connection.
  • Automotive terminals – These terminals come in male and female parts that mate together. Some are specific to the make of the vehicle. Others are made for connections in turn signals, radios, headlights and more.
  • Deutsch terminals – Designed for electrical systems on off-road construction equipment, over-the-road trucks and other heavy-duty applications, Deutsch terminals create very reliable sealed wire or cable connection on the engine or chassis as well as under the hood or cab.
Insulation Displacement Connectors

Insulation displacement connectors (IDC) are useful for many applications and do not require crimping or soldering. Instead, they connect to insulated wire by forcing the contact through the insulation, creating the connection. This process eliminates the need for stripping the wire.

There are different types of IDCs for different types of connections: Pigtail, tap, inline or parallel. Some, such as the Blue Scotchlok® 801 Instant Auto-Electric Connector, can be used for all types of connections. Some of these connectors are filled with dielectric grease, which makes the connection completely sealed for reliability.

Battery and Cable Connectors

Automotive battery terminals and connectors are used in fleet and vehicle maintenance. The lugs and terminals can be connected by soldering, crimping or twisting on, depending on their design. Raised identification markings allow you to quickly identify the polarity and wire gauge size to ensure a proper connection.

Safe-Mate Industrial battery and cable connectors are used in battery-powered equipment and vehicles such as golf carts, forklifts, pallet jacks, scissor lifts and sweepers, as well as their charging units. The connectors are color-coded, allowing you to easily identify the correct connector for your system. Choose from 50, 175 or 350 amps. They are available in crimp-on or solder-on (fusion) styles. Others only require you to add heat and insert the battery cable.

Industrial Connectors

Split bolt connectors are made for copper- to-copper, copper-to-aluminum and aluminum-to-aluminum wire and cable connections. They are a simple way to splice wire and cable together.

Mechanical lugs come in straight and offset tongue styles and are designed to connect wire and cable to bus bars and terminal blocks.

Motor pigtail connectors come in male and female components, which are snapped together to change out electric motors and transformers quickly and easily.

With reliable connections, you can feel confident your equipment will perform well. To ensure you have the connectors and other products you need to make new connections or electrical repairs,