What Is a DIN Rail?
A DIN rail is a metal rail used inside a control cabinet.
A DIN is a type of German industrial standard. Although standardized in Germany, DIN rails are now used worldwide and are sometimes referred to as IEC rails because they are also specified in the international standard IEC.
Uses of DIN Rails
DIN rails are mostly used inside industrial control panels. Inside an industrial control panel, electromagnetic switches that switch the power supply on and off, contact relays, and logic controllers that control sequences are all intermingled. If these devices are scattered throughout the panel, they will not look good and may be affected by induced voltages.
DIN rails protect control equipment by arranging these in-panel devices in a neat and orderly manner to improve their appearance and organize them according to their intended use.
Principles of DIN Rails
DIN rails are mainly made of aluminum. One of its characteristics is that it is lightweight and inexpensive. They are not painted because the temperature, humidity, and other environmental conditions inside control panels are often well controlled. Stainless steel and iron are rarely used as materials because they are not expected to be exposed to corrosive environments or to impact.
Viewed from the front, DIN rails resemble rectangular plates with oval holes regularly drilled along the centerline. The oval-shaped holes secure the DIN rails to the board with screws.
DIN rails look like pots and pans when viewed from the side; in-panel devices that can be mounted on DIN rails have detachable claws on the back and are secured in place when the claws catch on the pot-shaped handles. The length is cut and used according to the width of the panel. In most cases, the width of a control panel does not exceed 2m. As such, a maximum length of about 2m is used.
Types of DIN Rails
Most DIN rails are 35mm wide and 7.5mm high, but lengths and hole shapes vary when sold.
1. Length
DIN rails are typically sold in 1,000mm or 2,000mm lengths. Since they do not perfectly match the dimensions of the inside of a control cabinet, they are cut to length. Shorter products may be sold in 100mm or 200mm.
2. Hole Shape
Hole shapes include short and long holes. There is no significant difference in performance. Products with larger hole widths are also available for fastening to control panels with larger screws.
Other Information About DIN Rails
1. DIN Rails Are Used to Fasten In-Panel Components.
DIN rails are used to fasten panel components. The following are examples of parts that are arranged in a panel using DIN rails:
- Electromagnetic contactors
- Programmable logic controllers
- Solid-state relays and contact relays
- No-fuse breakers or ground-fault circuit breakers
- Fuses and circuit breakers
- Rail-type terminal blocks
Since larger rail-type terminal blocks increase weight and make DIN rail mounting more difficult, DIN rails are used for instrumentation terminal blocks and relatively small terminal blocks. Large terminal blocks are attached directly to the board with screws.
2. DIN Rails With Special Specifications
DIN rails are also available in special versions to meet demand. The following is an example of DIN rails with special specifications:
- Mountable DIN Rail
These DIN rails can be mounted on a server rack. Since FA equipment must be used in server rooms on rare occasions, these products are sold to meet the demand. - 15mm height DIN Rail
The height of a standard DIN rail is 7.5 mm, but 15 mm height DIN rails are also available. These DIN rails are used when a step is required on the terminal block. - Steel DIN Rail
DIN rails are generally made of aluminum, which is lightweight and inexpensive. However, DIN rails made of steel plate are also available as special specifications. Steel DIN rails are mainly galvanized.