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 rolledcarbon 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 in Germany, which have since been adopted as European and international standards. The original concept was developed and implemented in Germany in 1928, and was elaborated into the present standards in the 1950s.
This 35 mm wide rail is widely used to mount circuit breakers, relays, programmable logic controllers, motor controllers, and other electrical equipment. The EN 60715 standard specifies both a 7.5 mm and a 15 mm deep version, which are officially designated
Some manufacturers catalogues also use the terms Top hat section / Type O / Type Omega. The rail is known as the TS35 rail in the USA.
Module width
The width of devices that are mounted on a 35 mm "top hat" DIN rail generally use "modules" as a width unit, one module being 17.5 mm wide. For example, a small device may have a width of 1 module, while a larger device may have a width of 4 modules. Equipment enclosures also follow these module widths, so an enclosure with a DIN rail may have space for 20 modules, for example. Not all devices follow these module widths. Module widths are usually abbreviated as "M" . Some manufacturers use "SU" .
C section
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 section
G-type rail. 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.
Others
In addition to the popular 35 mm × 7.5 mm top-hat rail, several less widely used types of mounting rails have also been standardized:
Miniature top-hat rail, 15 mm × 5.5 mm ;
75 mm wide top-hat rail ;
Related equipment
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.
IECInternational 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.
