Halogen-free Security Cables & Wires
Sealcon, Inc, European & Domestic cable |
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In
all locations, due to damages of large
amount of materials and more of importance
to protect human life and technical equipment
against damages caused by fire and also
for technical enquiries of insurance,
the installation of halogen-free security
cables is required.
You will find on the next following pages
the instructions for installation as well
as the test methods and laying indications
of the halogen-free security cables. |
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Halogens "formation of
salt" are the elements as fluorine, chlorine,
bromine and iodine.
Fluorine and chlorine are important for cables
and wires as atoms in the plastic molecules,
for example fluorine plastics or PVC (polyvinyl
chloride) are of significance; and bromine as
component of flame protection additives. |
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| When
is a cable halogen-free? |
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| The burning behavior of cables
and wires is very important for the installation
in buildings and also in control panels. |
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| Thereby
the following points are very important: |
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- Behavior under flame influence i.e. the
inflammability as well as the propagation
to fire
- Subsequent damage by formation of corrosive
and toxic gases
- Development of smoke density (darkening of
emergency exits hindered the fire extinguishing
works)
Cables produced of not halogen-free
materials such as mainly the materials with
chlorine in the molecule chain: Polyvinyl
chloride (PVC), chloroprene rubber (CR),
chlorinated polyethylene (CM), chlorsulfonated
polyethylene (CSM) and fluor-hydrocarbons.
Polytetrafluorethylene (PTFE)
Fluoethylenepropylene (FEP)
Perfluoralkoxypolymeric (PFA)
These material have better
behavior in case of fire.
These are hardly combustible or not flammable
and vastly self-extinguishing. Due to this
effect and in case of fire the released molecules
constituents chlorine and fluorine, which hinder
the admittance of oxygen to the fire location
and suffocate the flame.
The remarkable disadvantages
of these materials are existing in the fact
that the released chlorine and fluorine atoms
composite themselves with hydrogen which is
decomposed from plastic material as well as
with hydraulic acid or hydrofluoric acid from
the existing air.
These compositions are extremely
corrosive and also toxic. In consequence the
damage caused by corrosion are often higher
than the actual damage caused by fire.
Halogen-free cables contain
no halogens, i.e. the insulation and jacket
materials of these cables are composed with
polymers on the basis of pure hydrocarbons.
By burning such kind of materials, produce
no corrosive or toxic gases but only water
vapor and carbon dioxide. Polymers like polyethylene
(PE) or polypropylene (PP) are halogen-free.
These materials are easy flammable and not
self-extinguishing.
Halogen-free cables for security
requirements must be hardly flammable and self-extinguishing.
This happens by using the special polymer compounds,
containing the considerable percentage of flame
protective materials.
Such kind of protective materials
consist of, for example, an aluminum hydroxide
which on one side cools the fire location by
setting free crystal water and on the other
side the released water vapor hinders the admittance
of oxygen and thereby this suffocates the flame.
By using additional supporting tapes and filling
yarns of glass web, micra and similar materials,
the functionality of for example E 90 can be
realized with the suitable cable accessories.
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The application
of halogen-free security cables and
wires are specified more and more with
increasing numbers of buildings where
people gather or everywhere, where
safety consciousness to protect human
life and valuable materials take a
special significance. For example:
- Hospitals, airports, multistory
buildings, stores and shops, hotels,
theaters, schools
- Fire warning plants, alarm systems,
ventilation systems, escalators,
elevators, safety lights, operation
and intensive stations, maintenance
equipment
- Underground railways and other
railway plants
- Data processing installations
- Power stations and industrial
plants with highly valuable machines
and materials or risky potentials
- Mining works
- Ship building and offshore plants
- Emergency power supply works
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| European -Security
cables and wires and the advantages |
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- Flame retardant and hardly combustible
so that no flame propagation in case of fire
can develop
- Halogen-free; no development of corrosive
gases
- In case of burning the halogen-free cables
emit low smoke
- The danger of toxic gases caused by fire
is far inferior
- Low caloric load
- Remarkable longer electrical functionality
under flame influence
- Insulation integrity for at least 60 minutes
as well as 180 minutes at 800°C under
fire condition
- Suitable for emergency service up to 180
minutes
- Radiation resistance up to 200 x 106 cJ/kg
(up to 200 Mrad)
These characteristics are obtained by using
a flexible halogen-free basis material -
aluminum hydroxide Al (OH)3 |
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| Caloric
load values (heat of combustion) |
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For designing a building
the criterions of the caloric load values are
very important. The caloric load values of
modern halogen-free cables are reduced by corresponding
additives.
The specific heating values of the non metallic
raw materials for cables are specified to
DIN 51900. The values of the caloric load
or heat of combustion for electrical cables
are given per running meter in the following
tables.
Combustible cable insulations or open building
materials of class B1 are regarded as harmless
so far as the resulted caloric load is distributed
as proportion ale as possible and is
valid ≥ 7 kWh/m2.
The conversion of the values:
| 1 MJ/ m2 |
= |
0.278 kWh/
m2 |
| 1 kWh/ m2 |
= |
3.6 MJ/ m2 |
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According to DIN VDE 0108
supplement 1:
- The total caloric load of the cables
are allowed up to 14 kWh per m2 of
the field areas if only halogen-free cables
with improved characteristics in the case
of fire are used.
If you use PVC cables the total caloric load
is only up to 7 kWh per m2 |
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The characteristics of security
cables are tested to DIN VDE specifications
(DIN VDE 0472 part 804, test methods A, B and
C)
Test Method A - test on single cable
(IEC 60332-2)
- Test sample of 600 mm cable length shall
be in a position vertically hanging. A
propane gas burner (Ø 8 mm) shall
be at an angle of 45° to the axis and
the flame of approximately 100 mm below
the lower edge of the sample. Flame influence
max. 20 sec.
- The test is passed if the sample has not
burned or the flame extinguished by itself
and the damage by fire doesn't reach the
remotest upper side of the sample.
Test Method B - test on single cable
(IEC 60332-1, HD 405.1, EN 50265-2-1, DIN VDE
0482 part 265-2-1)
- Test sample of 600 mm cable length shall
be in a position vertically hanging. A
propane gas burner (Ø 8 mm) shall
be at an angle of 45° to the axis and
the flame of approximately 100 mm below
the lower edge of the sample. Flame influence,
depending on cable weight, 1 to 2 minutes.
- The test is passed if the sample has not
burned or the flame extinguished by itself
and the damage by fire doesn't reach the
remotest upper side of the sample.
Test Method C - test on bunched cables
(similar to IEC 60332-3, HD 405.3, EN 50226-2,
DIN VDE 0482 part 2)
- Test samples of 360 cm cable length are
laying parallel side-by-side attached to
a test ladder, which is hanging vertically
with a distance of 150 mm to the furnace.
The sample should be flamed with a flame
length of 60 cm on the test sample at approximately
800 °C by a burner width of approximately
250 mm. The test duration should be 20 minutes.
- The test is passed if the sample has not
burned or the flame extinguished by itself
and the damage by fire doesn't reach the
remotest upper side of the sample.
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| Corrosiveness
of combustion gases |
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According to DIN VDE 0472 part
813, IEC 60754-2 and HD 602, DIN VDE 0482 part
267, EN 50267-2-2. For the performance of the
test procedure the insulation and jacket materials
are to be put in the moveable furnace, preheated
to 750 to 800°C. The burning gas is conducted
through two gas-washing bottles.
- The test shall be regarded as passed when
the measured pH value is ≥
100 µS.cm-1
- During this test
all the not desired
components of the
materials are precipitated
such as all halogens,
sulphur and nitrogen
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| Continuance
of insulation effect under direct
fire conditions |
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According to DIN VDE 0472
part 814, IEC 60331
Test sample of 1200 mm cable length is fixed
in a horizontal position, 75 mm over the
gas burner. The rated voltage of 3 A fuse
is fixed between the conductor groups. The
burner flame is to regulate so that the temperature
on the cable is 800°C (± 50°C)
The measuring can be effective until the
fuse is blown.
Test voltage 400 V for power cables and wires
Test voltage 110 V for telecommunication
cables
- The test shall be regarded as passed
when no 3 a fuse has blown during the test
period between 20 to 180 minutes
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According to DIN VDE 0472
part 815, IEC 60754-1, Din VDE 0482 part 267
an dEn 50267-2-1
The corrosion test of gases caused by fire
is carried out to the test materials, not
of complete cable samples. The proof of halogen
is effected by chemical analysis.
Materials with content of:
≤
0.2 % chlorine and
≤0.1 % fluorine
are regarded as halogen-free.
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According to DIN VDE 0472
part 816, IEC 61034-1 and IEC 61034-2, DIN
EN 61304-1+2, HD 606 and BS 7622 part 1 and
2
The test of smoke density is effected to a single
cable, laid in a horizontal position within a
room of 3 meter cube. The photo metrically measured
absorption of light is a measuring unit (in %)
of light transmittance for the smoke density.
The test is regarded as passed when the
light absorption appears within 40 minutes
and the following values shall be obtained
for light transmission:
Cable Ø |
Transmission
of light |
| > 3 - 5 mm |
40
% |
| > 5 - 10 mm |
50
% |
| > 10 - 20 mm |
60
% |
| > 20 - 40 mm |
60
% |
| > 40 mm |
70
% |
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| Functionality
of electric cable systems |
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According to DIN 4102 part
12 (system test)
DIN 4102 part 12 describes the requirements and
measurements necessary in achieving circuit
integrity of a complete electric cable system
in case of fire.
Cable systems
Regarded as cable systems are power
cables, insulated power cables and wires,
telecommunication installation cables for
telephone and data transmission and rail-distributors
including their corresponding connecting
devices such as the necessary ducts and conduits,
coatings and coverings, connecting elements,
supporting devices, cable trays and clamps.
Functionality
According to DIN VDE 4102 part 12
The functionality is given when during the
test under fire no interruption of current
flow occur in the tested electrical cable system.
According to this standard, the security cables
are always to be tested together with the corresponding
supporting devices, clamps, holder and mounting
accessories.
Note: The above defined functionality has
no relationship with the continuance of insulation
effect under fire conditions according to DIN
VDE 0472 part 814. |
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| Test:
Functionality under fire |
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During this test under fire
a complete cable installation will be tested
in a large combustion chamber, i.e. cables
and wires including clamps, supporting devices,
holders, dowels etc.
| Test voltage
for power cables: |
380 V |
| Test voltage for telecommunication
cables: |
110 V |
| Current load: |
3 A |
The combustion chamber is to be heated up according
to ETK (standard temperature curve). The
test period is distinguished in 3 classes:
- E 30 for the functionality ≥ 30 minutes
- E 60 for the functionality ≥ 60 minutes
- E 90 for the functionality ≥ 90 minutes
Raise of temperature in combustion chamber:
- For E 30 approximately 820°C
- For E 60 approximately 870°C
- For E 90 approximately 980°C
After passing the functionality test, this
will be certified with the class identification
as E 30, E 60, E 90.
Note: At the moment the class E 60, which
is specified in DIN VDE standards, is not applied
for economical and technical reasons.
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