What is IEC 60439-2 and why is it important for busbar trunking systems
IEC 60439-2 is an international standard that specifies the particular requirements for low-voltage switchgear and controlgear assemblies of busbar trunking systems (BTS) and their accessories for feeding and distributing electrical power in residential, retail, public, agricultural and industrial premises. It also applies to BTS that are designed to incorporate communication and/or control systems or intended to supply luminaires through tap-off units but does not apply to supply track systems in accordance with IEC 60570[^1^].
The standard defines two categories of assemblies: type-tested assemblies (TTA) and partially type-tested assemblies (PTTA). TTA are assemblies that have been subjected to all the tests specified in clause 8 of the standard, while PTTA are assemblies that have been subjected to some of the tests specified in clause 8 and whose design is derived from a TTA[^1^].
The purpose of the standard is to ensure the safety and reliability of BTS and their accessories by verifying their design, construction, performance and testing. The standard covers aspects such as temperature rise, dielectric properties, short-circuit withstand strength, mechanical operation, protection against electric shock, clearances and creepage distances, markings and documentation[^1^].
IEC 60439-2 is important for BTS because it provides a common basis for the design, manufacture, testing and certification of these products. It also facilitates the international trade and use of BTS by ensuring their compatibility and interoperability. The standard also helps users to select and install BTS that meet their specific needs and expectations.
The current edition of IEC 60439-2 was published in October 2005 and remains valid until 2014. It will be replaced by IEC 61439-6, which is part of the new series of standards for low-voltage switchgear and controlgear assemblies that aims to harmonise and define all general requirements for these products[^2^].
One of the main advantages of BTS is that they offer a flexible and modular solution for power distribution in various types of buildings and applications. BTS consist of a main busbar trunk that can be extended or branched by using elbows, tees, crosses and other accessories. Tap-off units can be plugged into the trunk at any point to supply power to different loads. BTS can also be easily adapted to changes in the layout or demand of the installation by adding or removing components.
BTS also have other benefits such as high efficiency, low voltage drop, reduced fire risk, enhanced protection against short-circuits and overloads, improved electromagnetic compatibility, reduced installation time and cost, and increased aesthetic appeal. BTS are suitable for a wide range of applications such as industrial plants, commercial buildings, data centers, hospitals, airports, stadiums, schools and hotels.
However, BTS also have some challenges and limitations that need to be considered. For example, BTS require careful planning and coordination during the design and installation phases to ensure their optimal performance and compliance with the relevant standards and regulations. BTS also need regular inspection and maintenance to prevent deterioration and damage due to environmental factors, mechanical stress, corrosion or vandalism. BTS may also pose some difficulties in terms of fault detection and isolation, especially in complex or large-scale installations. 061ffe29dd