A terminal block consists of a modular housing and insulator that holds two or more wires together. Terminal blocks (also known as terminal connectors, connection terminals or screw terminals) are widely used in applications that require safe connection of electrical systems. They are ideal for designs that require secure, well-organized semi-permanent wire connections and can be easily replaced for on-site inspections or repairs.

Terminal type

There are many types of terminal blocks that can be used in your design. These are some of the most common:

PCB installation

PCB mount terminal blocks, often referred to as Eurostyle or wire-to-board terminal blocks, work by inserting bare wires into the module and then using clamps to secure the wires in the housing. The housing is then soldered to the PCB with a common footprint. PCB mount terminal blocks can be single, double or multi-layer modules.

Barrier Strips

These terminal blocks have screw-in terminals where a ring or spade terminal is attached to the wire and then a screw is inserted and tightened into the housing. Isolation tape is often used where vibration is a concern.

Feedthrough/DIN Rail

Feed-through terminal blocks are used to connect two wires together for a wire-to-wire connection. This terminal block type has one input and one output contact with two different wires feeding into opposite sides of the enclosure. Like the PCB mounted versions, these modules are also available as single, double or multi-layer modules. Feed-through is most commonly found in DIN rail mounting configurations. DIN rail terminal blocks are usually available as feedthrough or grounding types for wire-to-wire connections. They visually look the same as the feedthrough type, but instead of connecting the incoming wires, they ground them to the DIN rail or panel.