B&S Group manufacture LV switchboards up to 6300A and can incorporate all Forms of Separation in accordance with BS EN 61439-2-2011. Form of Separation is one of the most important aspects when it comes to specifying an LV (low-voltage) assembly such as a switchboard and control gear assembly, affecting both overall safety and build costs. Form of separation refers to internal barriers or partitions which are classified in the standard as Forms. The principle is to provide protection against contact with hazardous parts and against the passage of foreign bodies.
The fundamental objective of Separation is to separate an assembly in order to allow access to part of that assembly, whilst other parts remain energized, live and in service. Separation does not affect electrical performance but provides protection against contact with live parts in adjacent assemblies and against foreign bodies passing from one assembly into an adjacent one.
In terms of legal obligations, BS EN 61439 reflects good practice but does not fully encompass the requirements of national or local legislation. BS EN 61439 is a standard and in the UK, legal obligations take precedence over standards like this. For LV assemblies, the Low Voltage Directive (LVD) and the Electricity at Work Act are the most relevant and Regulation 14 of the Electricity at Work Act must be respected.
Regulation 14 stipulates that ‘No person shall be engaged in any work activity on or near any live conductor (other than one suitably covered with insulating material so as to prevent danger) that danger may arise unless (a) it is unreasonable in all the circumstances for it to be dead; and (b) it is reasonable in all the circumstances for him to be at work on or near it while it is live; and (c) suitable precautions (including where necessary the provision of suitable protective equipment) are taken to prevent injury’.
When it comes to specifying the best form of Separation for an assembly, it is necessary to consider the consequences of isolating an assembly or part of an assembly, the nature of the task to be performed and the competence of the person undertaking the work whilst the remainder of the assembly is energized.
BS EN 61349-2 covers four main categories of separation:
- Forms 1 and 2: isolation available for all internal operations (except changing fuse links)
- Form 3: adjust setting and carry out limited maintenance in functional units, as applicable whilst adjacent to live circuits
- Form 4: connect and disconnect cables, adjust setting and carry out limited maintenance in functional units as applicable whilst adjacent to live circuits
Form 2, 3 and 4 also have levels (‘a’ and ‘b’) and Type of Construction levels 1-7.
At B&S Group we have over 25 years of experience in the design and manufacture of LV switchboards and power control solutions. One of the largest panels we have manufactured and install measures over 21m and includes additional features such as including power factor correction and multi-function power and energy metering. For more information on Forms of Separation please review the BEAMA Guide To Selecting Forms of Separation or contact our project engineering team on +44-(0)1244 390 215 or email us.