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SIST EN 50483-5:2009
01-julij-2009
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Test requirements for low voltage aerial bundled cable accessories -- Part 5: Electrical
ageing test
Prüfanforderungen für Bauteile für isolierte Niederspannungsfreileitungen – Teil 5:
Elektrische Alterungsprüfungen
Prescriptions relatives aux essais des accessoires pour réseaux aériens basse tension
torsadés -- Partie 5: Essai de vieillissement électrique
Ta slovenski standard je istoveten z: EN 50483-5:2009
ICS:
29.240.20 Daljnovodi Power transmission and
distribution lines
SIST EN 50483-5:2009 en
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST EN 50483-5:2009
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SIST EN 50483-5:2009
EUROPEAN STANDARD
EN 50483-5
NORME EUROPÉENNE
January 2009
EUROPÄISCHE NORM
ICS 29.240.20
English version
Test requirements for low voltage aerial bundled cable accessories -
Part 5: Electrical ageing test
Prescriptions relatives aux essais Prüfanforderungen für Bauteile für isolierte
des accessoires pour réseaux aériens Niederspannungsfreileitungen -
basse tension torsadés - Teil 5: Elektrische Alterungsprüfungen
Partie 5: Essai de vieillissement électrique
This European Standard was approved by CENELEC on 2008-12-01. 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, Bulgaria, Cyprus, the
Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: avenue Marnix 17, B - 1000 Brussels
© 2009 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 50483-5:2009 E
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SIST EN 50483-5:2009
EN 50483-5:2009 – 2 –
Foreword
This European Standard was prepared by a sub-group of WG 11 of 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 50483-5 on 2008-12-01.
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) 2009-12-01
– latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2011-12-01
This is Part 5 of CENELEC standard EN 50483 “Test requirements for low voltage aerial
bundled cable accessories”, which has six parts:
– Part 1: Generalities;
– Part 2: Tension and suspension clamps for self supporting system;
– Part 3: Tension and suspension clamps for neutral messenger system;
– Part 4: Connectors;
– Part 5: Electrical ageing test;
– Part 6: Environmental testing.
__________
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Contents
1 Sc op e . . 4
2 Normative references . 4
3 Terms and definitions . 5
4 Symbols . 7
5 Type test . 8
5.1 Principle . 8
5.2 Test arrangement . 8
5.3 Test spec im en . 11
5.4 Measurement . 13
5.5 Heat cycle . 15
5.6 Requir em ents . 19
Annex A (normative) Equalizers . 29
Annex B (informative) Determination of the value of the short-circuit current . 31
Annex C (informative) Recommendations to improve accuracy of measurement . 32
Bibliography . 33
Figures
Figure 1 – Lengths and configurations of conducting paths . 10
Figure 2 – Location of thermocouples . 14
Figure 3 – First heat cycle . 17
Figure 4 – Use of a concentric return conductor . 18
Figure 5 – Test loop for branch connectors with main and branch conductors having
equal cross-sections and linear resistances . 24
Figure 6 – Test loop for branch connectors with main and branch conductors having
unequal cross-sections and linear resistances . 25
Figure 7 – Test loop for through connectors with conductors having equal or unequal
cross-sections and linear resistances . 26
Figure 8 – Test loop for pre-insulated lugs . 28
Figure A.1 – Equalizers. 30
Figure B.1 – Diagram of short-circuit current . 31
Tables
Table 1 – Conducting path lengths . 11
Table 2 – Testing cross-sections of main and branch conductors . 12
Table 3 – Minimum elevated current heating time . 16
Table 4 – Test requirements . 23
Table A.1 – Dimensions of equalizers . 29
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SIST EN 50483-5:2009
EN 50483-5:2009 – 4 –
1 Scope
EN 50483 series applies to overhead line fittings for tensioning, supporting and connecting
aerial bundled cables (ABC) of rated voltage U /U (U ): 0,6/1 (1,2) kV.
0 m
This Part 5 applies to the connections described in EN 50483-4, including branch connectors,
Insulation Piercing Connectors (IPC), pre-insulated lugs (terminals) and through pre-insulated
connectors (sleeves).
The objective is to provide a method of testing the suitability of connectors when used under
normal operating conditions with low voltage aerial bundled cables complying with HD 626.
Two classes of connectors are covered by this standard:
Class A: These are connectors intended for electricity distribution or industrial networks in
which they can be subjected to short-circuits of relatively high intensity and duration. As a
consequence, Class A connectors will be suitable for the majority of applications.
Class B: These are connectors for networks in which overloads or short-circuits are rapidly
cleared by the operation of protection devices.
Depending on their application, the connectors are subjected to heat cycles and short-circuit
current tests.
Class A: the connectors are subjected to heat cycles and short-circuit current tests.
Class B: the connectors are subjected to heat cycles only.
The object of this Part 5 is to define the heating cycles test methods and requirements which
apply to compression through connectors, insulation piercing connectors and all other type of
connections for low voltage aerial bundled cables.
NOTE This European Standard does not invalidate existing approvals of products achieved on the basis of
national standards and specifications and/or the demonstration of satisfactory service performance. However,
products approved according to such national standards or specifications cannot directly claim approval to this
European Standard. It may be possible, subject to agreement between supplier and purchaser, and/or the relevant
conformity assessment body, to demonstrate that conformity to the earlier standard can be used to claim
conformity to this standard, provided an assessment is made of any additional type testing that may need to be
carried out. Any such additional testing that is part of a sequence of testing cannot be done separately.
2 Normative references
The following referenced documents are indispensable for the application of this document.
For dated references, only the edition cited applies. For undated references, the latest edition
of the referenced document (including any amendments) applies.
EN 50483 series, Test requirements for low voltage aerial bundled cable accessories
EN 61238-1:2003, Compression and mechanical connectors for power cables for rated voltages up to
36 kV (U = 42 kV) – Part 1: Test methods and requirements (IEC 61238-1:2003, mod.)
m
IEC 60050-461, International Electrotechnical Vocabulary (IEV) – Part 461: Electric cables
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3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-461 and the
following apply.
3.1
adiabatic
occurring with no addition or loss of heat from the system under consideration
3.2
aerial bundled cable (ABC)
aerial cable consisting of a group of insulated conductors which are twisted together
including, or not, a non insulated conductor
[IEV 461-08-02, modified]
NOTE The terms bundled conductors, bundled cables, bundled cores, conductor bundles and bundle could be
used as equivalent to the term aerial bundled cable (ABC).
3.3
aerial-insulated-cable
insulated cable designed to be suspended overhead and outdoors
[IEV 461-08-01]
3.4
branch connector
metallic device for connecting a branch conductor to a main conductor at an intermediate
point on the latter
[IEV 461-17-05]
3.5
branch conductor
conductor connected to the main conductor by a connector
3.6
conductor insulation
insulation applied on a conductor
[IEV 461-02-02, modified]
3.7
conductor (of a cable)
part of a cable which has the specific function of carrying current
[IEV 461-01-01]
3.8
connector
metallic device to connect cable conductors together
[IEV 461-17-03]
3.9
core
assembly comprising conductor and its own insulation
[IEV 461-04-04, modified]
3.10
equalizer
arrangement used in the test loop to ensure a point of equipotential in a stranded conductor
[EN 61238-1:2003, 3.8]
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EN 50483-5:2009 – 6 –
3.11
insulation (of a cable)
insulating materials incorporated in a cable with the specific function of withstanding voltage
[IEV 461-02-01]
3.12
insulation piercing connector (IPC)
connector in which electrical contact with the conductor is made by metallic protrusions which
pierce the insulation of the ABC core
[IEV 461-11-08, modified]
3.13
median connector
connector which during the first heat cycle records the third highest temperature of the six
connectors in the test loop
[EN 61238-1:2003, 3.11]
3.14
pre-insulated (terminal) lug
insulated metallic device for connecting an insulated cable conductor to other electrical
equipment
3.15
pre-insulated through connector (sleeve)
insulated metallic device for connecting two consecutive lengths of insulated conductors
3.16
reference conductor
length of conductor(s) without any joints, which is included in the test loop and which enables
the reference temperature and reference resistance(s) to be determined
3.17
reusable connector
connector for connecting ABC to stripped cable or bare conductor where only the branch
connection can be reused
3.18
sheath
uniform and continuous tubular covering of metallic or non metallic material, generally
extruded
[IEV 461-05-03]
3.19
shear head
head of a bolt, or a device fitted over the head of a bolt or a nut, which is designed to break at
a specified torque
3.20
type test
test required to be made before supplying a type of material covered by this standard on a
general commercial basis, in order to demonstrate satisfactory performance characteristics to
meet the intended application
NOTE These tests are of such a nature that, after they have been made, they need not be repeated unless
changes are made to the accessory materials, design or type of manufacturing process which might change the
performance characteristics.
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4 Symbols
A, A , A electrical cross-sectional area of the conductors
1 2
D conductor diameter
D equalizer diameter
Eq
d conductor length between connectors
I direct current flowing through a connection during resistance measurement
I equivalent r.m.s. short-circuit current
rms
I alternating current necessary to maintain the reference conductor at its
N
equilibrium temperature
l , l , l lengths of the conductor assembly associated with the measurement points after
a b j
jointing
l length of equalizer
e
l l , l length of the reference conductor between measurement points
r, ra rb
R , R linear resistance of conductors of respectively cross-section A and A
1 2 1 2
R , R , R the calculated resistance between two equalizers and corrected to 20 °C
20 ra rb
TC thermocouple
t heating period within heat cycle
1
t cooling period within heat cycle
2
t time period to reach the required temperature on the reference cable
1-a
t time period of stable temperature on the median connector
1-b
U potential difference between measurement points of reference conductor of
AB
cross-section A
1
U potential difference between measurement points of the connector
CD
U potential difference between measurement points of reference conductor of
EF
cross-section A
2
α temperature coefficient of resistance at 20 °C
β mean scatter of the connector resistance factors
∆θ temperature difference between reference cable and connector
j
δ initial scatter of the connector resistance factors
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EN 50483-5:2009 – 8 –
λ resistance factor ratio; change in the resistance of the connector relative to its
initial resistance
θ temperature of a connector while measuring resistances
θ maximum temperature recorded on a connector over the total period of test
max
θ highest rated temperature of insulating compound in normal operation
N
θ temperature of the reference conductor determined in the first heat cycle
R
θ temperature of the reference conductor while measuring resistances
r
θ temperature of the reference conductor at the moment of measuring θ
ref max
5 Type test
5.1 Principle
Connectors shall be subjected to 1 000 cycles of heating and cooling. The cold resistance of
the connectors shall be measured at specific steps to determine their suitability when used
with conductors carrying a load.
Heat cycle and, short-circuit tests shall be made with alternating current.
NOTE Direct current may be used for heat cycle only when agreed between customer and manufacturer.
5.2 Test arrangement
5.2.1 Installation
The test circuit shall be as shown in Figure 5, 6, 7 or 8.
Figures 5, 6, 7 and 8 represent the test circuits respectively for main and branch connectors
having equal cross-sections and linear resistance(s); for main and branch connectors having
unequal cross-sections and linear resistance(s); for through connectors having equal or
unequal cross-sections and linear resistance(s); for terminal lugs.
5.2.1.1 Optional immersion test
EN 50483-6, 8.4.3.1 provides an optional immersion test for samples which are intended for
use in saline polluted areas. When the inclusion of this test has been agreed between the
manufacturer and the customer this heat cycle test shall be modified to accommodate
immersion of the test samples during each cycle.
5.2.2 Disconnection devices
The test circuit may include sectioning joints so that it can be dismantled and short-circuit
tests can be made easily.
In Figure 6, the disconnection devices (X) are
• closed when the circuit is carrying heating current, and
• opened when resistance measurements and short-circuit applications are being made.
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The sectioning joints shall be arranged and constructed so that they do not significantly affect
the measurements.
5.2.3 Conductors
Phase and neutral conductors including reference conductors used in the test circuit shall
remain insulated (except bare conductors).
5.2.4 Method of measuring ambient temperature
It is important that ambient temperature is measured accurately and is not affected by the
heating produced by the test. The following provides a proven method for achieving this
measurement though alternative methods can be used.
Ambient temperature shall be measured at the middle of the test loop with a thermocouple
whose junction is placed in a polished metallic tube manufactured from metal foil formed into
a cylinder. Its height shall be 100 mm and its diameter shall be between 35 mm and 45 mm.
The thermocouple shall be located approximately at one third of the tube height from its upper
end and fitted to it (e.g. with a cross-support).
5.2.5 Ambient conditions
The test loop shall be installed in a location where the air is not disturbed. The ambient
temperature of the test location shall be between 15 °C and 30 °C.
During the connector installation and resistance measurements, ambient temperature shall
remain within the limits of (23 ± 3) °C and recorded.
5.2.6 Equalizers
For stranded conductors, potential between the strands at measuring points can cause errors
in measuring electrical resistance.
Welded or soldered equalizers, as shown in Annex A, shall be used to overcome this problem,
and to ensure uniform current distribution in the reference conductor. Welded or soldered
equalizers shall be the recommended methods to ensure reliable measurements.
NOTE Other methods may be used provided that they give comparable results and do not affect the temperature
of the connectors or the reference conductor.
Annex A provides details on the construction of welded equalizers.
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EN 50483-5:2009 – 10 –
5.2.7 Lengths and configurations of conducting paths
Key
A, B, C, D, E, F equalizers (see Annex A). 1 conductor 1
A and A cross-sections relative to conductivity of the conductors 1 and 2 2 conductor 2
1 2
in mm²
A, B potential points for measuring the potential difference between the 3 insulation
extremities of the reference conductor corresponding to conductor of
cross-section A
1
E, F potential points for measuring the potential difference between the 4 branch connector
extremities of the reference conductor corresponding to conductor of
cross-section A
2
5 sleeve connector
l distance between potential points A and B
ra
l distance between potential points E and F
rb
C, D potential points for measuring the potential difference between the
extremities of the related connector
l distance between C and the nearest surface of the connector body
a
l distance between D and the nearest surface of the connector body
b
l and l are dependent on the cross-section A of the related conductor
a b
according to the Table 1 below
Figure 1 – Lengths and configurations of conducting paths
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The conducting path lengths (see Figure 1, 5, 6, 7 or 8) shall comply with Table 1.
Table 1 – Conducting path lengths
Conductor cross-section A
Distances l or l
a b
mm²
mm
150
A ≤ 50
50 < A ≤ 120 200
250
120 < A ≤ 240
If A ≠ A , the cross-section of the reference conductor related to conductor A shall be A and
1 2 1 1
the cross-section of the reference conductor related to A shall be A . Both reference
2 2
conductors shall have the same length l = l + l .
r a b
Potential points shall be placed at a distance l and l from the nearest surface of the
a b
connector body.
Conductor length between connectors shall be a distance d, expressed in millimetres, at least
equal to 80 √A, subject to a minimum of 500 mm. In the case of branch connectors, A shall be
the cross-section of main conductor.
Where a test loop comprises of only one cross-section of conductor, a single reference
conductor shall be used.
Where a test loop comprises of more than one cross-section of conductor, one reference
conductor shall be required for each cross-section.
One (two) insulated length(s) of conductor(s) that constitute the heating loop shall be called
the reference conductor(s); there shall be a potential point at each of its (their) extremities.
The reference conductor shall not have its insulation removed if insulated. In order to control
the test a thermocouple shall be placed at the mid point of the reference conductor.
The reference conductor shall be of sufficient length to prevent thermal interference from its
end terminations.
In the case of unequal cross-sections, both references conductors of lengths l and l shall
ra rb
reach the defined reference temperatures.
5.3 Test specimen
5.3.1 Setting up of the test loop
The conductors shall be identified by their cross-section A and A so that the resistance R of
1 2 1
the conductor with cross-section A is less than the resistance R of the conductor with cross-
1 2
section A .
2
Where R = R then the conductor will be referred to by its cross-section A .
1 2 1
Conductor resistances R and R are measured in the same periodicity as connector
1 2
resistance.
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EN 50483-5:2009 – 12 –
Various types of test loops are defined in Figures 5 to 8.
Where A = A , the test loop shall consist of
1 2
• six identical connectors,
• one conductor of cross-section A with linear resistance R ,
1 1
• one reference conductor of length l on cross-section A .
ra 1
Figure 5 shows the diagrammatic layout of the loop, where l = l = l .
a b
Where A ≠ A , the test loop shall consist of
1 2
• six identical connectors,
• one conductor of cross-section A with linear resistance R ,
1 1
• one conductor of cross-section A with linear resistance R ,
2 2
• one reference conductor of length l on cross-section A ,
ra 1
• one reference conductor of length l on cross-section A .
rb 2
Figure 6 shows the diagrammatic layout of the loop.
The configuration and dimensions of the test loops shall be recorded.
Two test loops shall be used for each type of connector as given in Table 2.
Table 2 – Testing cross-sections of main and branch conductors
Loop Main conductor cross-section Branch conductor
cross-section
st
1 loop max. max.
nd a
2 loop max. or min. min.
a
The choice of max. or min. cross-section should be agreed between the customer and the manufacturer.
5.3.2 Preparation of cables and cores before tests
New insulated cores or cables shall be used.
The same core of a cable cross-section (e.g. Phase 1), shall be used for the whole test.
Insulated cores shall be conditioned beforehand. The purpose of this treatment is to ensure
the dimensional stabilisation of the insulating sheath. The core sections shall be kept, in an
enclosure at (30 ± 2) K above the conductor normal operating temperature indicated in
Annex C of EN 50483-1 for approximately 1 h and letting them cool down naturally to ambient
temperature.
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5.3.3 Installation of the connectors
Connectors shall be installed according to the manufacturer’s installation instructions.
5.3.3.1 For bolted connectors
A torque meter shall be used for all tightening operations. The accuracy and resolution of the
torque meter is given in EN 50483-1.
The connectors shall be held in position during tightening.
Connectors shall be tightened to the minimum manufacturer’s declared torque (connectors
with shear head) or 90 % of the nominal manufacturer’s declared torque (connectors without
shear head).
Tightening shall be realised in accordance with EN 50483-1, 9.1.8.
The rate of tightening shall be in accordance with EN 50483-1, 9.1.10.
When a connector provides independent tightening facility for main pierced and branch
stripped connections, the branch stripped connection shall be mounted 4 times and fully
removed 3 times. The branch conductor shall be prepared before the first installation and this
prepared end shall be used for the whole of the test. The orientation of the branch cable, with
respect to the connector, shall be maintained.
5.4 Measurement
5.4.1 Method of temperature measurement
The temperature of a reference conductor or of a connector shall be measured with a
thermocouple located at the point shown in Figure 2.
Accuracy of temperature measurement shall be ± 2 K or better.
Connectors shall have a small hole drilled in the outer housing, to allow a thermocouple to be
applied directly at the midpoint of the metallic current path between the connector and the
connected conductors.
The hole shall be drilled so that the connector’s mechanical performance is not affected.
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EN 50483-5:2009 – 14 –
Key
1 metallic current path 3 main conductor
2 thermocouple position 4 branch conductor
a) Location of thermocouple in an IPC
Key
1 thermocouple position 3 connector
2 metallic part
b) Location of thermocouple in a through connector
Key
1 thermocouple 4 adhesive tape: thermocouple and insulation
are covered with 2 half-lap layers adhesive
tape
2 open position to place the thermocouple 5 small windows in the insulation of the
reference conductor
3 conductor insulation
c) Location of thermocouple on the reference cable
Figure 2 – Location of thermocouples
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In the case of the reference conductor, the thermocouple shall be positioned as close as
possible by the midpoint of the conductor and securely located, by sliding it under the strands
of the outer layer of a stranded conductor and under the cable insulation.
An equivalent method can be used.
5.4.2 Electrical resistance measurement
The resistance of the connectors and the reference conductor(s) shall be measured between
two adjacent measurement points. These measurements shall be carried out using a direct
current not exceeding 10 % of I , the heat cycling current required to maintain the stable
N
conductor temperature and measuring the voltage drop between measurement points. The
resistance value is the ratio of the voltage drop to the direct current.
While measuring the resistance, the reference conductor(s), connectors, direct current and
ambient temperatures shall be noted in the test report. Reference conductors and connectors
temperatures shall not exceed ambient temperature +2 K.
Indirect resistance measurements:
• voltage measurements shall have an accuracy within ± 0,5 % or ± 10 µV, whichever is
the greater;
• current measurements shall have an accuracy within ± 0,5 % or ± 0,1 A, whichever is
the greater.
Direct resistance measurements:
• resistance measurements shall have an accuracy within ± 1 % or ± 0,5 µΩ, whichever
is the greater when t
...