5 Popular Types of PCB Terminal Block Connectors

PCB Terminal Block Connectors, or printed circuit board terminal block connectors, are the connectors which connect to circuit boards. The PCB terminal blocks are usually soldered onto the board. Terminal blocks are used to connect electrical wires together in appliances ranging from automobiles to telephones.

5 popular types of PCB Terminal Block Connectors

  • Barrier Terminal Blocks
  • Pluggable Terminal Blocks
  • Rising Clamp Terminal Blocks
  • Wire Protect Terminal Blocks
  • Screwless Terminal Blocks

Barrier Terminal Blocks

Barrier terminal block connectors are usually the most sturdy and reliable type of terminal block connectors. This is because they are larger in size, and therefore they can handle larger current ratings. Most barrier terminal block connectors can handle up to 25-30 amps, and they can accept up to 22 AWG cables. Once the connection is secured, they will be reliable until forcefully broken or detached.

Pluggable Terminal Blocks

Pluggable terminal block connectors are used primarily in wire to board situations, and you can find them in computers and cars. The main difference in pluggable terminal block connectors is that they are designed to easily connect and detach. Because of this feature, there are usually wire protecting options available to combat this wear and tear. Some common sizes of these connectors are .150″, .200″, and .250″.

Rising Clamp Terminal Blocks

Rising clamp terminal block connectors are usually one pieced, and are commonly used where there is restricted access. They function similar to screw terminals, in that a screw is tightened to secure the wires. These are ideal in highly active environments, because they are designed to withstand activity and vibrations.

Wire Protect Terminal Blocks

Wire protect terminal block connectors are used to prevent damage from the rising clamps or screw terminals. Wire protect terminal blocks work the same way as rising clamp terminal blocks, except they secure the wires with a flat surface instead of a screw-like surface. This prevents the wires from being twisted, and are intended for use in lighter duty environments. They are lower quality, but still useful if used in the right settings.

Screwless Terminal Blocks

Screwless terminal block connectors are very common because they have a quick assembly time. They work like clamps, where the wire is inserted into the terminal block and snapped into place. Screwless terminal blocks are used in most commonly used appliances because they are easy to set up. A good example of a screwless terminal block would be connecting your stereo speaker wires into the stereo, and snapping the wire in place. There is usually no wear and tear, which is why they’re so commonly used in household appliances.


Modular Terminal Blocks and how they affect process engineering applications

Modular Terminal Blocks

Process Engineering refers to the quality of electrical contact points in an electrical system, and reliability is the most important aspect for the overall system. So how would you define reliability in an electrical system? Some may say that it is in the PLC (Programmable Logic Controller), the DCS (Distributed Control System), or the drives system. However, you can measure the reliability of an electrical system by the point in which the wires meet. To the average person, this is also known as an electrical connector. From an industrial application standpoint, these are also referred to as terminal blocks.

Factors that influence an electrical system

There are many things that influence an electrical system, but extreme conditions such as heat and cold have the biggest impact. Other things to consider include flammability, and this is especially important in the petrochemical industry and food industry. In Northern America, the ATEX 100a (94/9/EC) has been applied to the protective systems and equipment in explosive surroundings. National electrical codes and Canadian electrical codes are used in these environments.

Listed below are the key requirements for modular terminal blocks:

  • Modular terminal blocks need to be secured and should never come loose at the terminal point.
  • Modular terminal blocks need to be fitted with an elastic component if they were originally meant for multi wire conductors
  • The insulating parts must not encounter the pressure point.

These requirements must be tested by a 3rd party testing center and must be certified with the certificate of design approval.

In process engineering, you must be aware of the constant changes in temperature. This test confirms that the terminal points have consistently high contact quality even with the constant changes in temperature. Modular terminal blocks can be attached to the fixing support and wired to a conductor for testing. The testing uses a two chamber method, which test the modular terminal blocks to temperatures close to their higher and lower limits. These limits range from minus 50 degree C to over 105 degree C. They are usually tested in these temperatures for an hour, and the temperature can change multiple times within a minute. This process continues a few dozen times, and if the parts are not damaged after the test, then the requirements have been met.

terminal block heat test

Voltage Drop Test for Modular Terminal Blocks

In order to maintain a strong electrical connection, the terminal blocks contact point should be free of corrosion. The voltage drop test is also known as a corrosion test, and the terminal blocks must past a test where they endure sulphuric acid. The terminal blocks are subjected to sulphuric acid for a few hours and then left out to try. They are manually inspected afterwards to ensure that the contact points are still strong.

Terminal blocks may seem simple, but each and every one of them go through these rigorous tests to ensure their quality and stability. Simply put, if your terminal block fails your entire system fails and production is delayed. From a business perspective this is unacceptable and can cost tens and thousands of dollars. So the lesson here is to make sure you do your research and invest in some high quality terminal blocks for your business.