DIN rail is the metallic rail that is used to mount various electrical components in an electrical control cabinet. DIN rail enables mounting a wide variety of control components, devices, terminal blocks, circuit breakers, etc. on the same platform.
Using DIN rails enhances design capabilities, saves area, and reduces labor.
The name DIN-Rail was situated on the DIN (Deutsche Industrie Norm) (translation: German Industrial Standard) that defined the sizes and tolerances of the rail to permit producers to design mounting and assembly methods for products destined for assembly onto the rail.
The current standard that defines DIN rail is the IEC EN 60715.
Titled; Dimensions of low-voltage switchgear and controlgear Standardized mounting on rails for mechanical support of electrical devices in switchgear and controlgear installations.
Since the middle of the last century, this standard was adopted by the European Union and the National Electrical Manufacturers Association in the US. Australian standards for DIN rails are also similar.
DIN rails are used for establishing terminal blocks to attach multiple components to a single terminal, creating a power bus, or installing equipment such as relays, contactors, or miniature circuit breakers.
Din rails are manufactured from steel, copper, aluminum. DIN rail is available in various base metal and finish combinations such as zinc-plated and trivalent chromate (Cr3). Zinc protects the base metal against corrosion. The trivalent chromate protects the zinc plating against the wear and formation of zinc oxide.
Stainless steel DIN rail provides the optimum strength and corrosion resistance. Nevertheless, it is the most expensive option compared to zinc-plated steel or aluminum.
Aluminum DIN rail is used in humid environments where zinc-plated steel does not provide the optimum protection against corrosion. However, aluminum is just not as robust as zinc-plated steel. And more expensive than zinc-plated.
Zinc-plated steel is the best solution for general applications due to its strength, corrosion prohibitive plating, and cost-effectiveness.
The copper rail can be used as a grounding busbar in the panels.
DIN rail types
All dimensions on DIN-Rail are metric with a common length of 2 meters, which suits many control cabinet heights when installed vertically. Over time, DIN-Rail has evolved from an asymmetric design into a family of symmetrical designs in differing widths, and heights. DIN rails have different sizes and can be cut in length.
Types and dimensions (sizes) of din rail are:
TS-32 rail is in most cases known as G, J, or C rail due to its physical shape. It has 32mm wide. This rail was the first generation of DIN rail. Many newer designs of DIN rail-mounted components do not accommodate this rail or require an additional accessory item for mounting. However, it is still used for mounting large digital devices, control transformers, contactors, or power supplies.
TS-35 rail is the industry standard. It has 35 mm wide. Most existing and new designs of DIN rail mountable components incorporate this rail. The TS-35 is available in two profiles:
“The Standard” which is 7.5mm in height: The 7.5mm high rail is suitable for the majority of applications and is the most cost-effective.
TS-15 rail is more than half the width of both the TS-32 and TS-35 rail (15mm vs. 32/35mm) and is used for mounting terminal blocks in confined spaces or whenever space reduction is required. It is also called the mini rail. The typical application for the TS-15 rail would be in a small consumer unit.
What is the standard size DIN rail?
Today, the 35 / 7.5 top-hat rail described in DIN EN 60715 is the most commonly used.