Guidelines on the requirements of BS EN 60439-1

SCOPE OF THE STANDARD

The standard applies to low-voltage switchgear and controlgear assemblies (type-tested assemblies (TTA) and partially type-tested assemblies (PTTA)), the rated voltage of which does not exceed 1000V a.c. at frequencies not exceeding 1000Hz, or 1500V d.c.

The standard applies to:

• assemblies incorporating control and/or power equipment, the frequencies of which are higher. In this case appropriate additional requirements will apply.
• stationary or movable assemblies with or without enclosure.
• assemblies intended for use in connection with the generation, transmission, distribution and conversion of electrical energy, and for the control of electric energy consuming equipment.
• assemblies designed for use under special service conditions, for example in ships, in rail vehicles, for machine tools, for hoisting equipment or in explosive atmospheres, and for domestic (operated by unskilled persons) applications, providing that the relevant specific requirements are complied with.

However, the standard does not apply to individual devices and self-contained components, such as motor starters, fuse switches, electronic equipment, etc. complying with their relevant standards.

Type-tested (TTA) and partially type-tested assemblies are defined as follows:

• Type-tested low-voltage switchgear and controlgear assembly (TTA)
  a low-voltage switchgear and controlgear assembly conforming to an established type or system without deviations likely to significantly influence the performance, from the typical assembly verified to be in accordance with this standard.
• Partially type-tested low-voltage switchgear and controlgear assembly (PTTA)
  a low-voltage switchgear and controlgear assembly, containing both type-tested and non-type-tested arrangements, provided that the latter are derived (e.g. by calculation) from type-tested arrangements which have complied with the relevant tests.

 NOTE: The definition of partially type-tested low-voltage switchgear and controlgear assembly (PTTA) indicates that all design aspects of a PTTA must be based directly or indirectly, on the results of type tests.