SIST EN 50362:2004

SLOVENSKI SIST EN 50362:2004

STANDARD
januar 2004
(istoveten EN 50362:2003)
Method of test for resistance to fire of larger unprotected power and control cables
for use in emergency circuits
ICS 13.220.40; 29.060.20 Referenčna številka
SIST EN 50362:2004(en)
©  Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljeno

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EUROPEAN STANDARD EN 50362
NORME EUROPÉENNE
EUROPÄISCHE NORM February 2003

ICS 13.220.40; 29.060.20


English version


Method of test for resistance to fire of larger unprotected
power and control cables for use in emergency circuits


Méthode d'essai de résistance au feu  Prüfung des Isolationserhaltes im
des câbles de contrôle et d'énergie de Brandfall von Kabeln und Leitungen mit
grande dimension non protégés großen Durchmessern für die
pour utilisation dans les circuits de Verwendung in Notstromkreisen bei
secours ungeschützter Verlegung






This European Standard was approved by CENELEC on 2002-12-01. CENELEC members are bound to
comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and
notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,
Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta,
Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2003 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 50362:2003 E

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EN 50362:2003 – 2 –
Foreword
This European Standard was prepared by the Technical Committee CENELEC TC 20, Electric cables.

The text of the draft was submitted to the formal vote and was approved by CENELEC as EN 50362
on 2002-12-01.

The following dates were fixed:

- latest date by which the EN has to be implemented
 at national level by publication of an identical
 national standard or by endorsement   (dop) 2003-12-01

- latest date by which the national standards conflicting
 with the EN have to be withdrawn    (dow) 2005-12-01

__________

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– 3 – EN 50362:2003
Contents
Page
1 Scope.4
2 Normative references.4
3 Definitions .4
4 Duration of survival.4
4.1 Time.4
4.2 Point of failure.4
5 Test environment.5
6 Test apparatus.5
6.1 Test equipment.5
6.2 The test ladder and its mounting .5
6.3 Continuity checking and voltage withstand arrangement .6
6.4 Source of heat.6
6.5 Shock producing device.7
7 Verification procedure for the source of heat .7
8 Test sample.7
8.1 Sample preparation.8
8.2 Sample mounting.8
9 Cable test procedure.8
9.1 General.8
9.2 Electrical test procedure .8
9.3 Ignition and shock production .9
9.4 Test voltage application .9
9.5 End point.9
10 Retest procedure .9
11 Test report.10
Bibliography.21

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EN 50362:2003 – 4 –
1 Scope
This European Standard specifies a test method for cables designed to have intrinsic resistance to fire
and intended for use as emergency circuits.
The standard is applicable to power and control cables for emergency circuits of rated voltage not
exceeding 0,6 /1 kV.
The test method is intended for cables with an overall diameter exceeding 20 mm. Cables of smaller
diameter shall be tested in accordance with EN 50200.
The test method is based on the direct impingement on the cable of the flame from a propane burner
giving a constant temperature attack of a notional 842 °C and under the influence of mechanical
impact.
2 Normative references
This European Standard incorporates by dated or undated reference, provisions from other
publications. These normative references are cited at the appropriate places in the text and the
publications are listed hereafter. For dated references, subsequent amendments to or revisions of any
of these publications apply to this European Standard only when incorporated in it by amendment or
revision. For undated references the latest edition of the publication referred to applies (including
amendments).
EN 50200 Method of test for resistance to fire of unprotected small cables for use in emergency
circuits
EN 60269-3 Low voltage fuses — Part 3: Supplementary requirements for fuses for use by
unskilled persons (fuses mainly for domestic and similar applications)
EN 60584-1 Thermocouples — Part 1: Reference tables
EN 60695-4 Fire hazard testing — Part 4: Terminology concerning fire tests
3 Definitions
For the purposes of this standard, the definitions given in EN 60695-4 apply.
4 Duration of survival
4.1 Time
The duration of survival, measured in minutes, to the point of failure shall be recorded for each cable
tested up to a maximum survival time of 120 min, or the required survival time given in the particular
cable standard.
4.2 Point of failure
The criteria for determining the point of failure shall be as follows:
– the voltage is not maintained during the test duration, as indicated by fuse failure or by
interruption of the circuit breaker;
– a conductor ruptures during the test duration, as indicated by the lamp extinguishing.

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– 5 – EN 50362:2003
Failure by either one of the criteria listed shall be sufficient to show failure for that cable.
5 Test environment
The test shall be carried out in a suitable chamber with facilities for disposing of any noxious gases
resulting from the burning. Sufficient ventilation shall be available to sustain the flame for the duration
of the test.
The chamber and test apparatus shall be in the range 10 °C to 40 °C at the start of each test.
The same ventilation and shielding conditions shall be used in the chamber during both the verification
and cable test procedures.
NOTE 1 The test given in this standard involves the use of dangerous voltages and temperatures. Suitable precautions
should be taken against shock, burning, fire and explosion risks that may be involved and against any noxious fumes that may
be produced.
NOTE 2 An example of a suitable chamber is the 3 m smoke cube as specified in EN 50268-1.
NOTE 3 Shields, such as those described in EN 50268-1, may need to be placed in an appropriate position to protect the
burner from draughts that may influence the flame geometry.
6 Test apparatus
6.1 Test equipment
The test equipment consists of the following:
a) a test ladder on to which the cable is mounted, comprising steel framework fastened to a rigid
support as described in 6.2;
b) a continuity checking and voltage withstand arrangement as described in 6.3;
c) a source of heat comprising a horizontally mounted ribbon burner as described in 6.4;
d) a shock producing device as described in 6.5;
e) a test wall equipped with thermocouples for verification of the source of heat as described in
Clause 7.
A general arrangement of the test equipment is shown in Figures 1, 2 and 3.
6.2 The test ladder and its mounting
The test ladder consists of a steel framework as shown in Figure 1. The two central vertical elements
of the ladder are adjustable in order to accommodate different sizes of cable under test. The test
ladder is approximately 1 200 mm long and 600 mm high, and the total mass of the test ladder shall be
(18 ± 1) kg. Ballast, if required, shall be placed on the steel supports.
Each horizontal element shall have a mounting hole not more than 200 mm from each end, the exact
position and diameter being determined by the particular supporting bush and supporting framework
used. The test ladder shall be fastened to a rigid support by four bonded rubber bushes of hardness
50 to 60 Shore A fitted between the horizontal steel elements of the ladder and the support framework,
as shown in Figures 1 and 2 so as to allow movement under impact.

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EN 50362:2003 – 6 –
NOTE 1 Angle iron approximately 45 mm wide and 6 mm thick, with suitable slots cut to allow for movement of vertical
elements and fixing of the bolts and clips, has been found to be a suitable material for construction of the ladder.
NOTE 2 A typical rubber bush which has been found to be suitable is shown in Figure 4.
6.3 Continuity checking and voltage withstand arrangement
During the test a current for continuity checking is passed through all conductors of the cable and this
shall be provided by a three phase star-connected or single phase transformer(s) of sufficient capacity
to maintain the test voltage up to the maximum leakage current allowable.
NOTE 1 Due note should be taken of the fuse characteristics when determining the power rating of the transformer.
This current is achieved by connecting, at the other end of the sample, a suitable load and indicating
device (e.g. lamp) to each conductor, or group of conductors.
NOTE 2 A current of 0,25 A at the test voltage, through each conductor or group of conductors, has been found to be
suitable.
6.4 Source of heat
The source of heat shall be a ribbon type propane gas burner with a nominal burner face length of
500 mm with Venturi mixer. A centre feed burner is recommended. The nominal burner face width
shall be 10 mm. The face of the burner shall have three staggered rows of drilled holes nominally
1,32 mm in diameter and drilled at centres 3,2 mm from one another, as shown in Figure 5.
Additionally, a row of small holes milled on each side of the burner plate, to serve as pilot holes for
keeping the flame burning, is permitted.
Guidance on the choice of recommended burner systems is given in EN 50200, Annex A.
Mass flow meters shall be used as the means of controlling accurately the input flow rates of fuel and
air to the burner.
NOTE 1  Rotameter type flow meters may be used as an alternative, but are not recommended. Guidance on their use, and
the application of appropriate correction factors, may be found in EN 50200. Figure 6 shows an example of a rotameter type
system.
By reference to the centre point of the cable to be tested, the burner shall be positioned centrally at a
horizontal distance of (H ± 2) mm from the burner face to the centre of the cable and at a vertical
distance of (V ± 2) mm from the burner centre line to the centre of the cable, as shown in Figure 3.
The burner shall be positioned in the test chamber such that it is at least 200 mm above the floor of
the chamber or any solid mounting table and 500 mm from any chamber wall.
The flow rates used for the test at reference conditions (1 bar and 20 °C) shall be
...