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Guide to commercial installations | Part 2 Panelboard: Standards and Regulations
12
Protection against electric
shock
People and livestock must be protected from electric shock
by providing both basic protection and fault protection.
Basic protection
Basic protection includes the insulation of live parts and the
use of barriers or enclosures such as distribution boards.
You can provide basic protection during operation of the
assembly by fitting appropriate devices or blanks to maintain
IP2X or IPXXB. If the top of the horizontal surface is readily
accessible then you should ensure that the protection there is
IP4X or IPXXD.
If any work or maintenance is required on the panelboard,
then you must consider which form of internal separation is
suitable. Internal separation is described in BS EN 61439-2
and covers the following:
• Protection against contact with hazardous parts
• Protection against the passage of solid foreign bodies
Forms of separation
The definition of separation in this context is:
Forms of separation are divided into four main criteria from
form 1, where there is no internal separation, up to form 4,
where there are different levels of internal separation.
Separation is achieved by using partitions or barriers,
insulation of live parts or through the integral housing of a
device, e.g. a moulded case circuit breaker.
When you need to access the assembly’s interior, your first
consideration is to isolate the assembly from the supply.
This is a requirement of Regulations 14 of the Electricity at
Work Regulations 1989 which states:
‘No person shall be engaged in any work activity on
or so near any live conductor (other than one suitably
covered with insulating material so as to prevent
danger) that danger may arise unless:
• It is unreasonable in all the circumstances for it to be dead;
and