Although simple in design, It could be a little more complex to select the right terminal blocks for your application. Understanding the critical electrical and mechanical properties, as well as the different safety ratings of common types of terminal blocks, is essential to making the right selection.
You should take the popular designs, electrical specifications, Mechanical specifications, and safety ratings into consideration. first, there are three of the most common terminal block types: PCB mount, barrier strips, and feed-through. To choose them, you can note the mounting style, configuration, and how to use them.
Second, Electrical specifications. The most important specification to consider when selecting a terminal block is its current rating. The three specific areas that should be considered are the conductivity of the terminals, the cross-sectional area, and the corresponding temperature rise. A good rule of thumb is to select a terminal block that has a current rating of at least 150% of the system’s expected maximum current.
The voltage rating should also be greater than the maximum system voltage. When thinking about this, voltage surges must be taken into consideration to prevent damaging the connection.
Third, know their mechanical specifications clearly. Terminal blocks can be arranged in several ways, either horizontally, vertically, or at a 45° angle (Figure 1). If you are using a horizontal and vertical orientation, you will also need to specify if this is at 90° or 180°. The most suitable orientation will be decided by what offers the best accessibility to the terminal block, as well as what fits in terms of board space.
And the last element is safety rating, which matters a lot. When looking at the datasheet for a terminal block, you are likely to see either UL or IEC safety standards — and sometimes both. The ratings will give different values for each standard, so it is important to ensure you know the overall system safety requirements to ensure power compliance from the terminal block you choose.
