BS EN 2794 is a European standard on aerospace that discusses single-pole circuit breakers.
BS EN 2794-004 provides the product standard for UNC thread terminals to ensure manufacturing efficient quality circuit breakers.
BS EN 2794-004 is the fourth part of a multi-part series that specifies characteristics of single-pole circuit breakers, temperature compensated with a rated current from 20 A to 25 A, used in aircraft on-board circuits at a temperature between ‒ 55 °C and 125 °C and at an altitude of 15000 m max.
The circuit breakers under BS EN 2794-004 are operated by a push-pull type single push button (actuator), with delayed action "trip-free" tripping. They will continue to function up to the short-circuit current.
BS EN 2794-004 on product standard for UNC thread terminals is relevant for:
UNC is generally used for mass production of threaded fasteners, such as bolts, screws, nuts, etc and are often used within the agricultural industry because of their strong coarse threads. The thread is deeper and more generic than that of a fine thread and allows for easy removal, whilst they also have a higher tolerance for manufacturing and plating.
A pole refers to the number of separate circuits a switch can control, a single-pole switch can operate one circuit. It has one switch and only needs to connect two wires.
A single-pole breaker is mainly used for the general lighting circuit of houses and installed in a standard outlet with a two-slot outlet receptacle.
BS EN 2794-004 guides in the production of these applications and assist in improving their production.
BS EN 2794-004 provides best practice guidance on the mass, material, surface treatment, and panel mounting.
BS EN 2794-004 also provides you with the dimensional, mechanical, electrical, and environmental characteristics of single-pole circuit breakers.
With compliance and obedience to guidelines under BS EN 2794-004, you can build efficient quality circuit breakers that support aircraft electrical systems.
EN 2794-004:2014