A DIN rail is a metal rail of a standard type widely used for mounting circuit breakers and industrial control equipment inside equipment racks. These products are typically made from cold rolled carbon steel sheet with a zinc-plated or chromated bright surface finish. Although metallic, they are meant only for mechanical support, and are not used as a busbar to conduct electric current, although they may provide a chassis grounding connection.
The term derives from the original specifications published by Deutsches Institut für Normung (DIN) in Germany, which have since been adopted as European (EN) and international (IEC) standards. The original concept was developed and implemented in Germany in 1928, and was elaborated into the present standards in the 1950s.
There are three major types of DIN rail:
- Top hat section, type O, or type Ω, with hat-shaped cross section.
- C section
- G section
Top hat rail IEC/EN 60715
This 35-mm wide rail is widely used to mount circuit breakers, relays, programmable logic controllers, motor controllers, and other electrical equipment. The EN 50022 standard specifies both a 7.5 mm (shown above) and a 15 mm deep version, which are officially designated
- top hat rail IEC/EN 60715 – 35 × 7.5
- top hat rail IEC/EN 60715 – 35 × 15
Some manufacturers catalogues also use the terms Top hat section / Type O / Type Omega (Ω).
It is known as the TS35 rail in the USA.
These rails are symmetrical within the tolerances given. There are four popular C section rails, C20, C30, C40 and C50. The number suffix corresponds to the overall vertical height of the rail.
G-type rail (according to EN 50035, BS 5825, DIN 46277-1).
G rail is generally used to hold heavier, higher-power components. It is mounted with the deeper side at the bottom, and equipment is hooked over the lip, then rotated until it clips into the shallower side.
In addition to the popular 35 mm × 7.5 mm top-hat rail (EN 50022, BS 5584, DIN 46277-3), several less widely used types of mounting rails have also been standardized:
- Miniature top-hat rail, 15 mm × 5.5 mm (EN 50045, BS 6273, DIN 46277-2);
- 75 mm wide top-hat rail (EN 50023, BS 5585);
- European Standard EN 50022: Specification for low voltage switchgear and control-gear for industrial use. Mounting rails. Top hat rails 35 mm wide for snap-on mounting of equipment. (formerly: German Standard DIN 46277, British Standard BS 5584)
- IEC International Standard 60715: Dimensions of low-voltage switchgear and control-gear. Standardized mounting on rails for mechanical support of electrical devices in switchgear and control-gear installations.
- Australian Standard AS 2756.1997: Low-voltage switchgear and controlgear - Mounting rails for mechanical support of electrical equipment.
- Simpson, Robert (2003). Lighting Control: Technology and Applications. Oxford UK: Focal Press/Elsevier. ISBN 0-240-51566-8.
- Arnold Offner; Phoenix Contact (November 12, 2008). "DIN-Rail in the Electrical Control Cabinet and Junction Box" (PDF). IEEE Power and Engineering Society. Retrieved May 31, 2018.
- Tickoo, Sham (2010). AutoCAD Electrical 2010 for Engineers. India: Dorling Kindersley. pp. 8–46. ISBN 978-81-317-3213-7.
- Media related to DIN rail at Wikimedia Commons