Terminal blocks, also referred to as connection terminals or terminal connectors, are modular blocks that feature insulated frames and can effectively secure two or more wires together between circuits. They usually feature a clamping component and a conducting strip, keeping connections substantially more secure and efficient. The insulating body of a terminal block houses a current conveying component (a metal strip or terminal bar), providing a base for the clasping component.
Furthermore, the body has a mounting design, so the block can be easily mounted on or unmounted from a PCB or a mounting rail. Most terminal connectors are generally secluded and mounted on DIN rails that permit the terminals’ expansion as indicated by the prerequisites. Additionally, they allow quick and easy installation for screw-clamp, spring-clamp, and push-in termination connections.
Why Use Terminal Blocks?
There are various methods by which you can connect two wires. You can strip the insulation at the ends and twist it together, which works, but there are safer methods. You can also apply wire tape to the insulation joint or a wire connector, but this might not work when several wires need to be connected close to each other. This method is then not considered safe or convenient. That is why terminal blocks come into play to perform the function effectively, without any consequences and execute it easily.
Types of Terminal Blocks:
Terminal blocks come in various types; the DIN rail type is the most used today, allowing easy mounting into various enclosures or panels. These are suitable for applications with limited spaces and come as single feed-through, dual, or three levels. Other terminal connectors include:
- PCB terminal blocks
- Barrier strips
- DIN Rail terminals (in single, dual, and triple level)
- Standard terminal strips
- Fused blocks
- Distribution blocks
- Commoning blocks.
Terminal blocks can also be divided into types based on their structure and the device type they connect to.
Structure Types:
- Single Feed-Through Blocks – Single feed items address the fundamental sort of terminal block and are utilized for the wire-to-wire association. Single feed terminal blocks have one input and one output contact: two individual wires are taken care of on one side of the terminal block and are associated inside its lodging.
- Dual-Level Blocks – As the name indicates, dual-level terminal blocks feature two levels of contact. This design saves some space and makes the wiring process simpler. The multi-level items may utilize a bridge to connect one contact level to another to increase the circuit flexibility.
- Three-Level Blocks – are the same as dual-level blocks allowing easy bridging but with an extra stack of contacts.
Device Types:
- Ground Circuit Terminals – These are utilized as ground components or systems. They are considered interchangeable with the standard blocks and can be installed into a block as required.
- Fuse Holder – These blocks can connect several fuses connected to numerous devices. Only the wiring portions connected to the fuse holder are impacted when a short circuit happens.
- Thermocouple Blocks – Such terminal blocks connect thermocouples and provide consistent metal connections to measure temperature effectively.
- I/O Blocks – Input-output blocks connect a device and a controller.
- Sensor Blocks – Terminal blocks that can handle three or four-wire devices such as photoelectric and proximity sensors are known as sensor or actuator blocks.
- Power Distribution Blocks – Terminal blocks terminate power cables effectively and smoothly.
- Disconnect Blocks – also called switch blocks, permit the circuit to disconnect easily with the help of a knife switch without terminating the wires.
Typical Applications:
Terminal blocks offer easy panel or electrical enclosure fixing with DIN rail mounting and are widely used in settings where multiple connections are required. They are used for:
- Domestic, Commercial, and Industrial Power
- Automation
- Control, and
- Signal Applications.
