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Nuisance tripping
In a commercial installation it is likely that socket outlets will
supply computers, printers, copiers and other electronic
equipment. This type of equipment produces small amounts
of protective current.
Nuisance tripping could be a problem if several of these are on
one circuit protected by a 30mA RCD. The designer will need to
consider this problem and may decide to reduce the number of
sockets on each circuit by, for example, increasing the number
of final circuits.
Alternatively you can label sockets used for such equipment.
This, plus the occupant/employer operational systems and
health and safety policy, should ensure compliance where RCD
protection is not provided.
Cables in walls
It is likely that metal partitions will separate rooms in a
commercial installation. If this wall has a cable inside it then the
requirements of 522.6.8 will need to be met.
These requirements are similar to those for socket outlets in that
if there is adequate supervision by ‘skilled’ or ‘instructed’ persons
then you do not need to provide additional RCD protection.
If there is some doubt about this, then the designer could make
the decision to apply part (v) of this regulation and provide 30mA
RCD protection.
This applies to all circuits, not just socket outlet circuits.
Electric shock protection - conclusion
More circuits need RCD protection since the introduction of
the 17
th
Edition. In commercial distribution boards, it would be
appropriate to use RCBOs for individual outgoing circuits.
In commercial distribution boards it
would be appropriate to use RCBOs
for individual outgoing circuits.”
“