Forms of Separation - Part 1

B S EN 60439 Part 1 describes a system for classifying the various forms of separation to be provided principally for:

  • Protection against contact with live parts belonging to the adjacent functional units

  • Limitation of the probability of initiating arc faults

  • Protection against the passage of solid foreign bodies from one unit of an assembly to an adjacent unit


Manufacturers of switchboard assemblies employ many variations of design to meet this protection and any other additional market requirements.

This means utilised to achieve these conditions may be partitions or barriers of metallic or non-metallic materials. The partitions or barriers may provide individual separate compartments or alternatively, barriered sub-sections. In general, the cost of an Assembly increases with enhanced levels of separation, but choosing the most expensive arrangement will not necessarily lead to the most appropriate solution.


Achieving Separation

The fundamental requirements in the standard are performance criteria and not constructional details on how separation should be achieved. There is a requirement that assemblies are divided by means of partitions or barriers (metallic or non-metallic) into separate compartments or barriered sub-sections, but not for example:

  • Each functional unit to be in its own compartment;

  • partitions & barriers to be manufactured from earthed metal, etc


Separation can be achieved in several ways. Depending on a particular application & the requirement for maintenance, this may include:

a) PVC sleeving, wrapping or plastic coating of conductors 
b) Insulated terminals shields or PVC ‘boots’ 
c) Rigid insulated barriers or partitions 
d) Compartments formed from earthed metal 
e) A device’s integral housing


Where a Specifier or user has a particular preference, this should be clearly stated at the enquiry stage

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