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Wire & Cable ASIA – September/October 2007
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Abstract
This paper covers the European Commission decision
of October 2006 implementing Council Directive 89/106/
EEC with regard to the classification of the reaction to fire
performance of construction products and the steps being
taken toward implementation.
It reviews progress on various necessary standards
for test methods, classification, products, and rules
for extended application (EXAP); initial output from the
Europacable-funded CEMAC II project to provide technical
background for implementation; and the challenges of
product development.
Introduction
The objective of this paper is to give an overview of the
current status and possible future direction in the way that
regulators, specifiers and cable manufacturers address
reaction to fire performance when cables burn. Specifically,
it addresses the situation in the European Union. It is
not intended to provide a detailed description of the test
methods used or a discussion as to their validity.
The cable industry has had a long history in the
development of test methods and products designed to
lessen the hazards resulting from burning cables, going
back to the 1960s. The industry was one of the first in the
electrotechnical sector to develop
tests for the assessment of the
reaction to fire performance of its
products and has continued to refine
and improve these methods over the
years.
Standards covering flame spread,
heat release, opacity, corrosivity and
toxicity of fire effluent are today in use
and the industry continues to sponsor
research into the improvement of
the fire performance of its products
and the definition of appropriate test
methods.
In the fire area, there has been
a longstanding commitment to
international standards through the
IEC (International Electrotechnical
Commission) and many national and
regional standards eg EN (European
Standard) are based upon the IEC
publications.
Within this international framework there are, of course,
differences from region to region and country to country
in the way that the hazards of combustion of cables
are approached and the applications for which the
established test methods are referenced. The cable
industry therefore provides products with a wide range
of reaction to fire performance to reflect the varying
end user requirements.
Historical Development
Much of the early work relating to improvements in the
fire performance of electric cables was carried out in the
1970s and 1980s
(1,2,3)
. A four stage approach was taken at
the time:
• minimise the hazard by restricting the amount of
burning and reducing the propagation of fire along
cable runs
• minimise the emission of smoke leading to obscuration
of exits and prevention of escape
• minimise the emission of acid gas leading to corrosion
of equipment
• minimise the emission of harmful fumes leading to
incapacity or irritation and prevention of escape by
people
It was recognised that these factors would assume varying
levels of importance according to the particular market
sector and typical installation condition considered
(4)
.
Reaction to fire
performance of cables
By Terence Journeaux, Prysmian Cables & Systems Limited, UK
Extraction
Cables
Tested
Bi-directional Probe
Lamp and Photocell
Measurement
Rack
Controlled Blowing Fan
Measure and Control
of Primary Air flow
Hood
Exhaust
Test Chamber
IEC 60332-3-10
Burner
Air Inlet
❍
❍
Figure 1
: Schematic of prEN50399 test apparatus