In the field of electrical connections, terminal blocks and terminal strips are two frequently mentioned and easily confused components. This article will delve into the six key differences between terminal blocks and terminal strips to help you make an informed choice.
Terminal Block Vs Terminal Strip
Definição
Terminal Block: Typically refers to a single, modular unit. It has an insulating shell (usually plastic or nylon) and contains a metal conductor (such as a screw or spring) for connecting one or more wires. A terminal block itself is a complete connection point.
Terminal Strip: Typically refers to a long, strip-shaped assembly made up of multiple terminal blocks mechanically connected together. It can be understood as a series of terminal blocks assembled “hand in hand,” mounted on a common track or base.
Simple analogy: If a terminal block is an individual train car, then a terminal strip is a train made up of multiple connected cars.
Basic Forms
Terminal blocks: Various types and independent in appearance. Common types include:
PCB mounting terminals: directly soldered onto the circuit board.
DIN rail mounting terminals: mounted on standard DIN rails.
Barrier terminals: used for power distribution, with a barrier.
Pluggable terminals consist of a plug and a socket.
Terminal Strip: relatively fixed in form, usually a long insulating strip (such as bakelite or plastic) with a row of pre-fabricated metal terminals (such as screws or solder pins). They are usually supplied in fixed lengths (e.g., 6-position, 12-position) or in rolls (which can be cut to size).
Structure And Installation
Terminal Blocks:
Structure: Self-contained system; each terminal has its own independent insulator and conductive component.
Installation: Flexible installation. For example, DIN rail terminals can be individually snapped onto a DIN rail for easy addition or removal; PCB terminals are soldered in place all at once.
Terminal Strip:
Structure: Multiple connection points share a single, integrated insulating base.
Installation: Typically fixed to the circuit board or chassis as a whole using screw holes or slots at both ends. Once installed, the number of connection points is fixed.
Flexibility And Scalability
Terminal blocks: High flexibility. Users can freely combine and arrange different types of terminals on the DIN rail according to the actual number of connection points required. When expanding or modifying the system, simply add new terminals to the empty spaces on the DIN rail.
Terminal Strip: Lower flexibility. Once a terminal block with a specific number of terminals (e.g., 10) is selected and installed, adding connection points requires replacing the entire terminal block or installing a new one, which is relatively cumbersome.
Cenários de aplicação
Terminal blocks: Widely used in complex applications requiring high-density, modular wiring and potentially frequent changes, such as industrial control cabinets, PLC systems, frequency converters, and power distribution. Their advantages include organized structure, easy maintenance, and good vibration resistance.
Terminal Strip: Commonly found inside circuit boards, in instruments, consumer electronics, and home appliance control boards—in situations where space is relatively limited and the number of connection points is fixed, requiring minimal modification for low-to-medium voltage and current applications. They provide an economical and compact multi-wire connection solution.
Terminology Usage
In professional engineering and industrial fields, the distinction between these two terms is usually quite clear. Engineers will explicitly specify the use of “DIN rail terminal blocks” or “PCB terminal blocks.”
However, in everyday conversation or in less formal contexts, the two terms are often used interchangeably. Many people habitually refer to any strip assembly used for multi-wire connections as a “terminal block,” which exacerbates the ambiguity.
3. How To Choose Correctly
When selecting terminal blocks, please follow these principles:
Do you need modularity and flexibility?
Yes: Choose rail-mounted terminal blocks. They facilitate planning, expansion, and later maintenance.
No: If the number of connection points is fixed and space is limited, consider terminal blocks.
What is the installation environment?
Control cabinets, distribution boxes: Terminal blocks are the first choice.
Circuit board (PCB):
If soldering to the board and the points are densely fixed, choose PCB terminal blocks.
If easy plugging and unplugging or field wiring is required, choose PCB-mounted terminal blocks.
Budget and cost considerations?
For large-volume, standardized products, terminal blocks are generally more cost-effective.
For systems requiring customization, high reliability, and ease of maintenance, terminal blocks offer higher overall value.
4. FAQ
When Purchasing, Search For “Terminal Blocks” Or “Terminal Strips”?
This depends on your specific needs.
If you need a self-contained module that can be snapped onto a DIN rail and freely combined, search for “DIN rail terminal block” or “terminal block”.
If you need a long, multi-hole connector that can be directly soldered onto a circuit board, search for “PCB terminal block”, “fence-type terminal block”, or “terminal board”. Checking product images and installation descriptions is key to avoiding making the wrong purchase.
Why Are People Often Using The Two Interchangeably In Daily Life?
There are three main reasons:
1. Functional similarity: Their core function is to achieve electrical connection, leading to conceptual generalization.
2. Visual similarity: A multi-position terminal block looks like a row of fixed terminal blocks.
3. Common terminology: In many work contexts, the term “terminal block” has become a generic term, encompassing both strictly defined terminal blocks and terminal boards.
Maintenance Perspective：Terminal Block & Strip Comparison
Terminal blocks: Excellent maintainability. A single damaged terminal can be replaced individually; when changing wiring, the position and type of terminals can be easily added, removed, or adjusted without downtime or affecting the entire system.
Jack blocks: Poor maintainability. If one connection point fails, the entire terminal block may need to be replaced, which is more complex and may result in longer downtime.
5. Conclusion
A terminal block is a modular, highly flexible, standalone connection unit, while a terminal strip is a fixed-position, one-piece multi-connection assembly.
Although their names may be used interchangeably in everyday life, understanding the fundamental differences in their structure, installation methods, and application scenarios at the technical and engineering levels is the cornerstone of making the right selection, designing reliable systems, and achieving efficient maintenance.
Making an informed choice based on your specific project needs—flexibility, cost, space, and maintainability—will ensure your electrical connections are both safe and efficient.
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