In this context, ‘DIN’ is an acronym that stands for Deutsche Institut für Normung, which translates into English as ‘German Institute of Standards’. The now-familiar rack-mounting system we see supporting components of all kinds in many industrial settings was first devised by the Germans in the late 1920s. It was more widely adopted and developed into its current form during the 1950s, initially by neighbouring European countries and then quite quickly taken up worldwide.
DIN rails exist purely for the purpose of physical (mechanical) component support, rather than as any sort of connective or conductive element within a wider electrical system. In other words, they are not busbars, although they can perform a grounding busbar role in certain scenarios.
The advantages of a DIN rail system for mounting hardware components are numerous:
- They save time and work - components simply snap or slide into place on the rail, rather than having to panel mount each individual component separately.
- They save space - DIN rails allow for tight configurations of components and provide a convenient site for bringing internal and external wiring circuits together, ideal in limited space applications
- They’re cost-effective, both in terms of DIN rail pricing itself and the potential it offers for high-density adjacent mounting - this can significantly reduce the overall amount of wiring and cabinet space needed
- They promote neat and well-organised component layout, which is better for all-round safety and maintenance access
- They adhere to universal sizing and mounting protocols - see below
The real beauty of the DIN rail system is that it was designed (and has continually evolved) to work with to a series of universal standard widths and shapes of mounting hardware. The fact that DIN rail systems are today recognised as a range of fixed and consistent standards means that installers can be guaranteed dimensional uniformity across a whole suite of relevant products, regardless of whichever company is handling manufacture or supply of various individual parts.
This level of cross-brand compatibility gives users of DIN rail systems the flexibility to mix and match components, without having to stick to a single proprietary model range to get the job done. Proprietary systems do exist, but they’re less widely used for precisely this reason.
It’s worth noting that the naming conventions for DIN rail types and sizes might differ slightly from country to country. In the US, for example, you might be less likely to see the common UK name ‘top hat section’ used for standard 35mm DIN rails, and more likely to hear the same products referred to as TS35 rails.
However, these naming conventions are reasonably interchangeable and understood by most installers, and the mounting rail shapes and sizes they refer to will still be fully compatible. We’ll say a bit more sizing and compatibility in subsequent sections.
In the table below, we’ll look more closely at the main types of DIN rails you’ll find on sale for fitting components to a variety of PCL racks and enclosures, and find out some more about exactly how these different grades and shapes of DIN rails are selected, mounted and used in a wide range of everyday workplace applications.