Electrical Contracting News (ECN) July 2017 | Page 42

SPECIAL
FEATURE
FIRE DETECTION & SAFETY
CLIP ON TO SAFETY
Ever since 2005 when two firefighters lost their lives tackling a fire in a block of flats in Stevenage after
one became entangled in electrical cabling, the industry has been moving towards metal cable clips as
an alternative to plastic. This event also led to the amendment of BS7671 of the Electrical Regulations,
a body of legislation which states that wiring systems should be supported in such a way that they will
not collapse in the event of a fire. This is particularly relevant for escape routes. However, while the
industry has been forced to adopt metal fixings for public buildings in line with this legislation, these
rules do not cover commercial buildings, where plastic cable clips are still being used in earnest.
Jasmina Prill, associate product manager fastenings and fixings at HellermannTyton, looks at why
metal cable clips should become best practice for industry.
U
nder BS7671 of
the Electrical
Regulations, cabling
in public buildings
must be supported
by fire resistant
fastenings and fixings,
which are not liable
to premature collapse when exposed to
extreme heat. This means that plastic cable
clips, non-metallic cable ties and plastic
trunking to support wiring systems are no
longer compliant with electrical standards.
Instead, these new rules address the
greater need for safety when it comes to
cable management and support in or near
escape routes. It is now the responsibility
of the electrical contractor to ensure
that all cables and associate trunking,
conduits, and cable trays, are securely
attached to suitable fire resistant parts of
the building fabric, using non-combustible
fixings. Whilst this is now mandatory for
public buildings, electricians should be
making this best practice for all projects,
particularly for commercial projects.
Installers are
advised to seek
products which
meet high standards
of fire resistance,
particularly for
escape routes and
areas that may be at
risk of fire.
42 | July 2017
Plastic vs metal:
A heated debate
One of the strongest arguments for the
use of metal nail clips is the improved
safety that these provide when compared
with plastic clips. Products such as
HellermannTyton’s new metal nail clip for
example, can withstand temperatures of
well over 1,000°C, whilst the melting point
of plastic is typically 170°C. This means