What Is a Rail Terminal Block?
A rail terminal block is a terminal block that can be mounted on a rail.
In most cases, rail refers to DIN rails, which are widely used both domestically and internationally. Using rail terminal blocks, many wires can be aligned and grouped together. Having all the wiring in one place makes it easier to organize and manage the wiring. Also, when additional wiring or changes are needed, simply adding new wiring to the terminals on the rail simplifies maintenance work.
Note that rail terminal blocks use screws or spring-loaded clamps to securely connect the wiring. This prevents wiring from becoming loose or causing contact failures, thereby improving reliability. Stable contact is especially important for use in environments subject to vibration and shock.
However, it is important to select the appropriate wiring capacity to be connected to rail terminal blocks according to the current and voltage to be used. If excessive current or voltage is applied, overheating or wiring failure may occur.
Uses of Rail Terminal Blocks
Rail terminal blocks are widely used components in industry. In particular, they are used to electrically connect the external and internal wiring of control panels.
They play a very important role in industrial control systems. Industrial machines and controls require wiring connections for power supply and signal transmission. Rail terminal blocks efficiently organize these wires, distribute signals and power, and make connections.
Power distribution and circuit connections are also required in distribution panels. Rail terminal blocks are used to connect circuits and protective devices for distributing power from the power supplier. This allows wiring in the switchboard to be organized and facilitates maintenance work.
Other applications include automobiles and railroads. They are used in vehicle control circuits and navigation system circuits, where connection points can be organized.
Principle of Rail Terminal Blocks
Rail terminal blocks are basically used at the bottom or side of the control cabinet. This is because control panel external wiring is often routed to the bottom or side of the control panel.
Control panel external wiring uses cables with a hard outer jacket, such as CV cables and CVV cables. These cables are strong against external shocks, but not flexible. When used for wiring inside the panel, they are difficult to handle.
Therefore, cables without hard outer sheaths, such as WL1 and IV, are used for wiring inside the panel. These cables have high flexibility and are best suited for wiring in confined spaces such as inside a panel. Rail terminal blocks are used to electrically connect these different types of cables.
Since they are mounted on a DIN rail, the size of the terminal block that can be installed is limited by the strength of the DIN rail. Fixed terminal blocks are often used for thicker wiring.
Most rail terminal blocks are used for control wiring terminal blocks with a thin wire core, but they can also be used for power wiring with a body cross-sectional area of about 100 mm2.
Types of Rail Terminal Blocks
There are various types of rail terminal blocks, depending on the connection method. The following are examples of rail terminal blocks:
1. Screw Type
These terminal blocks use screws to securely tighten the wiring. They are highly reliable and provide a strong connection. They are inexpensive and widely used.
2. Screw-Up Type
Like the screw type, this terminal block is tightened with screws, but the wiring is pulled up during tightening. This facilitates insertion and removal of wiring. Screw-up terminal blocks are useful when wires are frequently added or replaced.
3. Push-Fastening Type
This is a terminal block in which the wiring is secured directly by tightening screws. Wires are inserted into the clamp of the terminal block and connected by tightening the screws. No terminal treatment is required, and wiring can be connected quickly and easily.
4. Push-In Type
This terminal block allows connection to be completed simply by pushing the wiring into the clamp by hand. Simply inserting the wiring into the clamp of the terminal block automatically closes the clamp to make a secure connection.
Quick and easy wiring connections can be made, improving work efficiency. Many products remove wiring by pressing a release button.