Choosing Wire Connector Types
When connecting electrical wires, the goal is to make a solid and trustworthy connection that allows electricity to flow freely between the two. Wire connectors do this by enclosing the ends of the wires in a protective shell or exerting pressure to hold them in place. They can be used to connect individual wires or multiple wires in a single connector.
Choosing the right wire connector type for your project will depend on several factors, such as how many conductors you need to connect and what environmental conditions they will be exposed to. You will also want to consider the electrical requirements of your wiring project, including voltage, current and frequency. Selecting a connector that is not rated for the load you are running could result in overheating and system failure.
There are many different types of connectors, each designed for specific applications. Some of the most common include:
Terminal blocks or terminal strips, which accept stripped and crimped wires and secure them with small metal fittings called terminal lugs. These take up very little space and are available for a wide range of wire sizes. Some are hermetically sealed and can be submerged in water, others are ESD shielded for protection against electrostatic discharge. Printed circuit board (PCB) mounted screw terminals allow for the connecting of individual conductors to a PCB by means of leads soldered onto them.
Standard twist-type wire nuts are roughly conical in shape with ridges on the sides for gripping, and some have small side wings. When tightened, these hold a plastic spring that provides tension to hold the conductors in place. The spring can be removed to disconnect the wires. Twist-type connectors are often used with switch, light fixture, and receptacle wires and work well with both stranded and solid wires. They are usually not suitable for use with data or telephone wires, which require a more reliable back-stab device type connection.
Push-in connectors are easy to use and provide a reliable, consistent, and repeatable connection. They are usually designed to work with both stranded and solid copper wires, although some only work with solid. Push-in connectors are easier to use than twist-on wire nuts and have a smaller form factor. It is possible to remove and re-use a push-in connector once it has been installed, but this can damage the conductor ends and deteriorate the rubber spring inside the connector.
Some connectors are UL listed for use in commercial and residential environments, while others are rated for industrial or hazardous locations. They are designed to withstand harsh conditions, such as extreme temperatures and high levels of humidity. The UL listing will indicate the connector’s minimum and maximum temperature ratings, as well as its electrical compatibility. You will also want to check whether the connector is RoHS compliant, which ensures it is free of lead and other harmful substances. The UL rating will also provide information on the connector’s resistance to corrosion and its ability to withstand heat. wire connector types