DIN-Rail

What is a DIN-rail?

A DIN-rail is a standardized component for static mounting of energy carrier lines. They are made of steel, aluminium, copper or plastic. DIN-rails are also called “mounting rails“.

The standard DIN EN 60715:2018-07 “Dimensions of voltage switch gear“ describes DIN-rails in detail. The standard includes a wide variety of rails which may be described as a DIN-rail. The two most commonly used types of mounting rails are:

• DIN top hat rail
• G-rail

Top hat rails are standardized in accordance with the EN 50022 standard. There are three types of top hat rails:

1. Tall: 35 mm wide, 15 mm high
2. Medium: 35 mm wide, 7,5 mm high
3. Narrow: 15 mm wide, 5 mm high

The material thickness for all variants is 1 mm.

G-rails (or G32) are standardized according to the EN 50035 standard. They are characterized by a G-shaped profile. The longer crosspiece is 15 mm high, while the shorter one is only 8 mm high. The supporting element on top is 10 mm wide while the width of the lower support frame is not standardized. The outside of the G-rail is 32 mm wide.

Usage of DIN-rails

DIN-rails were developed to simplify installation of electric components. DIN-rails can be purchased by the meter. They can be mounted without special tools on every sufficiently sound wall. DIN-rails that are made of metal can also be used as zero conductor. They are more expensive compared to similar DIN-rails made out of plastic. The products mounted on a mounting rail typically are:

• relays
• circuit breakers
• impulse switches
• terminal blocks
• timers

All the components mentioned above are available in accordance with standards. This allows them to easily be mounted on a DIN-rail. When clamped on to the rail, further mounting is obsolete. Thus the installation is quick, efficient and user friendly.

How does installation of devices in top hat rails work?

Devices mounted on a top hat rail are called rail-mounted devices or DIN-rail mounted devices. The outside measurements of such devices are standardized. Their backside imitates the shape of the top hat rail. User interfaces (switches, buttons, counters, sensors) are mounted on the front side. The width is standardized in accordance with an 18 mm grid. The length may be used ideally by using cut-to-length top hat rails.

Cramping mechanisms are used to keep devices in the same spot when using them or when facing vibration. Additionally, stops which are secured by screws may be used. By using these, movement to each side is prevented. When such stops are used, devices are permanently and safely mounted in their location.

Where are DIN-rails used?

DIN-rails are a standardized component of control cabinets and switch boxes. Additionally they may also be used to mount components directly on a wall.

Control cabinets are equipped with DIN-rails by default. This allows efficient, safe and fail proof installation of central control units. Much smaller switch boxes are usually equipped with equally smal top hat rails. G-rails are commonly used for uncovered domestic application since they offer a lot of mounting space.

DIN-rails in Automation Technology

While top hat rails have already been used for a long time within industry 4.0, they are still highly relevant. Modules responsible for communication between human and machine (like network sockets) are all available in accordance with necessary standards for mounting on top hat rails. The cases of mini computers such as Raspberry PI or Arduino are available ready to be mounted on a top hat rail. The area of application for top hat rails exceeds the connection of computing nodes. Even complex switch gear units may be mounted on it. The potential of these simple yet effective tools has not been maxed out yet. DIN-rails are expected to be of high relevance even years into the future.