BS EN 50526-2:2014 BSI Standards Publication Railway applications — Fixed installations — D.C surge arresters and voltage limiting devices Part 2: Voltage limiting devices BS EN 50526-2:2014 BRITISH STANDARD National foreword This British Standard is the UK implementation of EN 50526-2:2014 The UK participation in its preparation was entrusted to Technical Committee GEL/9/3, Railway Electrotechnical Applications - Fixed Equipment A list of organizations represented on this committee can be obtained on request to its secretary This publication does not purport to include all the necessary provisions of a contract Users are responsible for its correct application © The British Standards Institution 2014 Published by BSI Standards Limited 2014 ISBN 978 580 73005 ICS 29.120.50; 29.280 Compliance with a British Standard cannot confer immunity from legal obligations This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 March 2014 Amendments issued since publication Date Text affected BS EN 50526-2:2014 EN 50526-2 EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM February 2014 ICS 29.120.50; 29.280 English version Railway applications Fixed installations D.C surge arresters and voltage limiting devices Part 2: Voltage limiting devices Applications ferroviaires Installations fixes Parafoudres et limiteurs de tension pour systèmes courant continu Partie 2: Limiteurs de tension Bahnanwendungen Ortsfeste Anlagen Überspannungsableiter und Spannungsbegrenzungseinrichtungen Teil 2: Spannungsbegrenzungseinrichtungen This European Standard was approved by CENELEC on 2013-12-30 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 CEN-CENELEC Management Centre 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 CEN-CENELEC Management Centre has the same status as the official versions CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels © 2014 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members Ref No EN 50526-2:2014 E BS EN 50526-2:2014 EN 50526-2:2014 Contents -2- Page Foreword Scope Normative references Terms and definitions Classes of VLD Characteristics and requirements of the VLDs 5.1 Marking 5.2 Service requirements 5.2.1 Normal outdoor service conditions 5.2.2 Normal indoor service conditions 5.2.3 Abnormal service conditions 10 5.3 General characteristics 10 5.4 Minimum requirements 10 5.4.1 Response time 10 5.4.2 Additional requirements for VLDs of class 10 5.4.3 Additional requirements for VLDs of classes and 10 5.5 Electrical characteristics and thermal rating 11 5.6 Protection of VLDs against lightning 11 5.7 Command and control (class and only) 12 5.7.1 Local control 12 5.7.2 Remote signalling 12 5.7.3 Operation and alarm recordings 12 Type tests 13 6.1 General 13 6.2 Nominal triggering voltage UTn and non-triggering voltage UW 14 6.2.1 Procedure for welding shutspark gap VLDs (Class 1) 14 6.2.2 Procedure for thyristor type VLDs (Class2) 14 6.2.3 Procedure for mechanical switching VLDs and for combined thyristors with mechanical switching devices VLDs (Class and Class 4) 15 6.3 Leakage current 15 6.4 D.C current withstand 15 6.4.1 General 15 6.4.2 Procedure to determine the rated current 15 6.4.3 Procedure to determine short time withstand current 16 6.5 A.C current withstand characteristics (optional) 17 6.6 Response time characteristics 18 6.6.1 Response time for d.c voltage 18 6.6.2 Response time for combined a.c.-d.c voltage 20 BS EN 50526-2:2014 -3- EN 50526-2:2014 6.7 Lightning current withstand characteristics for VLDs exposed to direct lightning strikes 21 6.8 Recovery test (Class 3, 4) 23 6.9 Reverse voltage test (Class 2.1) 23 6.10 Dielectric tests for panel type voltage limiting devices (Class and 4) 24 6.10.1 Test conditions 24 6.10.2 Power-frequency voltage withstand test 24 6.11 Degree of protection 24 6.12 Environmental tests for outdoor equipment 25 6.13 Determination of minimum current for safe short circuiting of Class VLDs 25 Routine tests 26 7.1 General 26 7.2 VLDs of classes and 26 7.3 Dielectric tests for panel type voltage limiting devices 26 Annex A (informative) Preferred ranges of the principal properties of the VLDs 27 Bibliography 31 Figures Figure Test circuit for testing of response time 19 Figure TR evaluation 19 Figure Response time characteristic 20 Figure Test circuit for testing of response time TR for combined a.c.-d.c voltage 21 Figure Evaluation of response time TR for combined a.c.-d.c voltage 21 Figure Circuit for the Recovery Voltage test 23 Tables Table Classes of voltage-limiting device Table Type tests 13 Table Maximum response time as a function of d.c voltages 18 Table Maximum response time for combined a.c.-d.c voltages 20 Table A.1 Nominal Triggering voltage UTn 27 Table A.2 Instantaneous Triggering Voltage UTI 27 Table A.3 Rated current Ir 28 Table A.4 Short time withstand current IW 28 Table A.5 Leakage current IL 28 Table A.6 Making and breaking capacity 28 Table A.7 Nominal lightning current (8/20 µs) Iimp-n 29 Table A.8 High current impulse 8/20 μs and 4/10 μs Iimp-high 29 Table A.9 High charge impulse Iimp-hc 29 Table A.10 Current-time characteristic for safe short circuiting of Class VLDs 30 BS EN 50526-2:2014 EN 50526-2:2014 -4- Foreword This document (EN 50526-2:2014) has been prepared by CLC/SC 9XC "Electric supply and earthing systems for public transport equipment and ancillary apparatus (Fixed installations)" The following dates are fixed: • • latest date by which this document has to be implemented at national level by publication of an identical national standard or by endorsement latest date by which the national standards conflicting with this document have to be withdrawn (dop) 2014-12-30 (dow) 2016-12-30 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights CENELEC [and/or CEN] shall not be held responsible for identifying any or all such patent rights This European Standard, Railway applications — Fixed installations — D.C surge arresters and voltage limiting devices, is in three parts: — Part 1: Surge arresters deals with metal oxide arresters without gaps for d.c railway traction systems (fixed installations) and is based on EN 60099-4, Ed 2.2, 2009-5; — Part 2: Voltage limiting devices [the present text] deals with voltage limiting devices for specific use in d.c railway traction systems (fixed installations); — Part Application guide [currently at Enquiry stage] deals with a guide of application of metal-oxide arresters and of voltage limiting devices BS EN 50526-2:2014 -5- EN 50526-2:2014 Scope This European Standard applies to Voltage Limiting Devices (VLDs) to be applied in d.c traction systems in order to comply with protective provisions against electric shock from d.c., and mixed a.c – d.c voltages, in accordance with the EN 50122 series, taking into account stray current provisions VLDs operate in such a way as to connect the track return circuit of d.c railway systems to the earthing system or to conductive parts within the overhead contact line zone or current collector zone Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (including any amendments) applies EN 50122-1:2011, Railway applications Fixed installations Electrical safety, earthing and the return circuit Part 1: Protective provisions against electric shock EN 50122-3:2010, Railway applications Fixed installations Electrical safety, earthing and the return circuit Part 3: Mutual Interaction of a.c and d.c traction systems EN 50123-1:2003, Railway applications Fixed installations D.C switchgear Part 1: General EN 50123-7 (all parts), Railway applications Fixed installations D.C switchgear Part 7-x: Measurement, control and protection devices for specific use in d.c traction systems EN 50124-1, Railway applications Insulation coordination Part 1: Basic requirements Clearances and creepage distances for all electrical and electronic equipment EN 50125-2, Railway applications Environmental conditions for equipment Part 2: Fixed electrical installations EN 50163:2004, Railway applications Supply voltages of traction systems EN 50526-1:2012, Railway applications Fixed installations D.C surge arresters and voltage limiting devices Part 1: Surge arresters EN 60060-1, High-voltage test techniques Part 1: General definitions and test requirements (IEC 60060-1) EN 60085, Electrical insulation Thermal evaluation and designation (IEC 60085) EN 60529:1991, Degrees of protection provided by enclosures (IP Code) (IEC 60529:1989) EN 61643-311, Components for low-voltage surge protective devices Part 311: Performance requirements and test circuits for gas discharge tubes (GDT) (IEC 61643-311) EN ISO 4287, Geometrical product specifications (GPS) Surface texture: Profile method Terms, definitions and surface texture parameters (ISO 4287) EN ISO 4892-1, Plastics Methods of exposure to laboratory light sources Part 1: General guidance (ISO 4892-1) EN ISO 4892-2, Plastics Methods of exposure to laboratory light sources Part 2: Xenon-arc lamps (ISO 4892-2) EN ISO 4892-3, Plastics Methods of exposure to laboratory light sources Part 3: Fluorescent UV lamps (ISO 4892-3) BS EN 50526-2:2014 EN 50526-2:2014 -6- Terms and definitions For the purposes of this document, the terms and definitions given in EN 50526-1:2012 and the following apply 3.1 voltage-limiting device VLD protective device whose function is to prevent existence of an impermissible high touch voltage [SOURCE: EN 50122-1:2011, 3.1.20] 3.2 recoverable VLD VLD that recovers after triggering 3.3 non-recoverable VLD VLD remaining in its low resistance state permanently after triggering 3.4 welding shut spark gap voltage fuse VLD which triggers by electrical discharge across a gap causing a permanent short-circuit by welding shut of metallic parts 3.5 rated current Ir maximum value of the direct current that may flow for the specified long term through the VLD in specified environmental conditions without exceeding the temperature rise limits 3.6 short time withstand current IW current that a VLD can carry in closed status, during a specified short time under prescribed conditions of use and behavior 3.7 making capacity INSS value of prospective making current that a switching device is capable of making at a stated voltage under prescribed conditions of use and behavior Note to entry: The conditions to be prescribed are dealt with in the relevant specifications [SOURCE: IEV 441-17-09, modified — The beginning of the Note has been changed.] 3.8 breaking capacity maximum current that a recoverable VLD can interrupt at a stated voltage 3.9 leakage current IL current which flows through the terminals when the VLD is in open status BS EN 50526-2:2014 -7- EN 50526-2:2014 3.10 lightning current impulse Iimp-n 8/20 µs current impulse with limits on the adjustment of equipment such that the measured values are from µs to µs for the virtual front time and from 18 µs to 22 µs for the time to half value on the tail [SOURCE: EN 60099-4:2004] 3.11 high current impulse Iimp-high peak value of discharge current having a 4/10 µs or 8/20 µs impulse shape which is used to test the ability of the VLD to withstand direct lightning strikes from the dielectric point of view 3.12 high charge impulse Iimp-hc peak value of high charge impulse having a 10/350 µs shape, or a waveshape with the same charge drained and similar duration, which is used to test the ability of the VLD to withstand direct lightning strikes from the energy capability point of view 3.13 triggering voltage UT voltage at which a VLD becomes conductive 3.14 nominal triggering voltage UTn voltage at which the VLD becomes conductive when a d.c voltage is applied for long term Note to entry: This voltage is used to identify the VLD 3.15 instantaneous triggering voltage UTi minimum triggering voltage at which the VLD becomes conductive shortly after its application Note to entry: A maximum delay of ms is taken in this standard 3.16 non-triggering voltage UW maximum voltage below which the VLD will not trigger for any duration of the applied voltage 3.17 residual voltage Ures value of voltage that appears between the terminals of the VLD during the passage of a specified current 3.18 mixed voltage voltage having significant a.c and d.c components 3.19 response time TR time between the application of a voltage until VLD becomes conductive BS EN 50526-2:2014 EN 50526-2:2014 -8- Classes of VLD This European Standard identifies the properties and the technology of a VLD using the classes of VLD which are defined in Table Table Classes of voltage-limiting device Auxiliary Method for switching power supply Class between the high and necessary low resistance status for normal operation Welding shut of metallic parts No Polarity Maximum response time TR ms Yes Yes 2.1 Triggering of thyristors No Unidirectional 2.2 Triggering of thyristors No Bidirectional ms (for voltages equal to or higher than UTI) 3.2 Contactor only Contactor only Can be recoverable in some a conditions Bidirectional ms (for voltages equal to or higher than UTI) 3.1 Able to Recoverable interrupt or not the current in the VLD Yes Bidirectional Yes Bidirectional 3.3 Contactor only Yes Bidirectional 4.1 Combination of thyristors and contactor Yes Bidirectional 4.2 Combination of thyristors and contactor Yes Bidirectional 4.3 Combination of thyristors and contactor Yes Bidirectional Voltage dependent and not exceeding the limits given in EN 50122-1:2011, 9.3.2.2 or EN 50122-3:2010, 7.2 through 7.5 Voltage dependent and not exceeding the limits given in EN 50122-1:2011, 9.3.2.3, EN 50122-3:2010, 7.6 Specified by the manufacturer For voltages up to UTI, voltage dependent and not exceeding the limits given in EN 50122-1:2011, 9.3.2.2 or EN 50122-3:2010, 7.2 through 7.5 For voltages equal to or higher than UTi ms For voltages up to UTI , voltage dependent and not exceeding the limits given in EN 50122-1:2011, 9.3.2.3, EN 50122-3:2010, 7.6 For voltages equal to or higher than UTi ms Specified by the manufacturer No Passive at natural zero crossing of current Passive at natural zero crossing of current Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes Yes NOTE EN 50122-1 defines two functionalities for VLDs, VLD-O and VLD-F In this European Standard a discrimination is not necessary; the functionalities will be described in prEN 50526-3 a For transient low currents associated with low energy dissipation no welding shut may occur BS EN 50526-2:2014 EN 50526-2:2014 - 20 - U1 / V 800 600 400 200 TR (log) /s Figure Response time characteristic For VLDs of Classes 3.2 and 4.2, the response time shall be measured additionally at the voltages given in EN 50122-1:2011, 9.3.2.3 and EN 50122-3:2010, 7.6 as applicable 6.6.2 Response time for combined a.c.-d.c voltage This test applies only to bi-directional VLDs It shall be carried out on one sample of VLD in dry condition at a temperature of 20 °C ± 15 °C The device shall be tested using a test circuit as given in Figure 4, using a combined a.c.-d.c source The a.c source has a frequency of 50 Hz The test shall be carried out at the combined voltages given in Table except voltages lower than or equal to UTn Table Maximum response time for combined a.c.-d.c voltages a a.c voltage d.c voltage Maximum response time according to EN 50122-3:2010 V V s 700 120 0,1 60 625 0,1 560 120 0,2 60 520 0,2 60 85 300 35 120 300 60 300 25 35 300 a a For depots and workshop areas only permanent touch voltages are specified in the EN 50122 series For testing a maximum duration of 300 s is applied BS EN 50526-2:2014 EN 50526-2:2014 - 21 - The test sequence comprises: − select polarity of the d.c part; − adjust the test voltage pairs to the highest of the specified values; − turn on the switch S, which is preferably of a bounce-free type; − measure the response time TR: from the first rise of voltage U2 until breakdown of voltage U2 (see Figure 5); − repeat this test with the other specified voltage pairs; measure the respective response times TR; − make a table with the applied voltage pairs and the recorded response time The test shall be performed at both polarities of the d.c part Pass criteria: All measured response times are within the specified limits For VLDs of Classes 3.2 and 4.2, the response time shall be measured additionally at the voltages given in EN 50122-1:2011, 9.3.2.3 and EN 50122-3:2010, 7.6 as applicable S R U1 U2 = f(t) VLD U Figure Test circuit for testing of response time TR for combined a.c.-d.c voltage U2 TR Figure Evaluation of response time TR for combined a.c.-d.c voltage 6.7 Lightning current withstand characteristics for VLDs exposed to direct lightning strikes The test procedure related to the determination of lightning current withstand characteristics of the VLD is described in this section It is intended to check that the device will withstand direct lightning surges BS EN 50526-2:2014 EN 50526-2:2014 - 22 - The procedure described shall be applied to one sample of the VLD in dry condition at a temperature of 20 °C ± 15 °C The test voltages are to be applied terminal to terminal of the VLD The test sequence comprises: − select polarity; − determine nominal triggering voltage UTn and the non-triggering voltage Uw of the test sample as initial measurement; − apply one lightning current impulse, Iimp-n, wave 8/20 µs; measure the residual voltage; − apply one high current impulse, Iimp-high, wave 8/20 µs or 4/10 µs; − cool down to ambient temperature; − apply one high charge impulse, Iimp-hc of specified charge level; − cool down to ambient temperature; − apply one lightning current impulse, Iimp-n wave 8/20 µs; measure the residual voltage; − determine nominal triggering voltage UTn and the non-triggering voltage Uw of the test sample; − determine d.c leakage current for Class 2,3,4 The test shall be performed at both polarities For the lightning current impulse the limits on the adjustment of equipment such that the measured values are from µs to µs for the virtual front time and from 18 µs to 22 µs for the time to half value on the tail The high current impulse shall either have a wave shape of 10/350 µs or shall have an approximately sinusoidal shape with a duration within 200 µs and 230 µs Time duration is counted where the instantaneous value of the impulse current is greater than % of its peak value Pass criteria (Class non-recoverable): − the resistance between the terminals of the device is less than 10 mΩ, measured with a test current of at least 10 A; − no flashover; − no mechanical damage shall occur that has influence on the current carrying capacity of the VLD Pass criteria (Class recoverable, Class 2, 3, 4): − all measured trigger voltages are within the specified limits; − all measured leakage currents are within the specified limits (not applicable for Class 1); − no flashover; − measured residual voltages at lightning current impulse are not higher than the specified value and did not change by more than % (not applicable for Class 1); − no mechanical damage BS EN 50526-2:2014 EN 50526-2:2014 - 23 - 6.8 Recovery test (Class 3, 4) This test shall be carried out on one sample of VLD in dry condition at a temperature of 20 °C ± 15 °C Figure shows the test assembly The test arrangement shall consist of an inductor and a resistor in series with the VLD, and a test voltage source 220 V d.c The resistor R shall be such that the current flowing in the circuit equals the specified breaking capacity The inductor L shall be selected so that the time constant of the complete circuit is ms ± ms The current in the VLD, and the voltage across the contacts of the VLD, shall be recorded versus time, using a suitable sampling rate The results shall be reported The energy dissipated in the VLD shall be calculated and reported R L S U VLD Key VLD: voltage limiting device R: resistor to limit the current to the specified breaking capacity L: inductor to set the time-constant of the circuit U: test voltage source (220 V) Figure Circuit for the Recovery Voltage test The test sequence comprises: – the value of the resistor R is adjusted in such a way as to set the current at the specified value to be switched off; – the value of inductor L is selected in such a way that the time constant of the complete circuit is ms ± ms; – the test voltage is switched on and the VLD is closed; – thereafter the VLD is opened either automatically or under manual control: current through and voltage across the VLD are recorded; – the switch S is then open and the test is concluded The test shall be repeated with reverse polarity Pass criterion: The test is successful if the VLD breaks the current with no re-ignition after current zero 6.9 Reverse voltage test (Class 2.1) This test is applicable for unidirectional devices, only The test sequence comprises: − select triggered polarity; − determine nominal triggering voltage UTn and the non-triggering voltage Uw of the test sample at 20 °C ± 15 °C as initial measurement; − apply specified permanent d.c voltage for 30 to the terminals of the device in reverse direction; − apply specified short time d.c voltage during the specified time to the terminals of the device in reverse direction; BS EN 50526-2:2014 EN 50526-2:2014 - 24 - − determine nominal triggering voltage UTn and the non-triggering voltage Uw of the test sample at 20 °C ± 15 °C Pass criteria: − no triggering in the reverse direction; − all measured trigger voltages are within the specified limits; − no mechanical damage 6.10 Dielectric tests for panel type voltage limiting devices (Class and 4) 6.10.1 Test conditions The panel to be tested shall be mounted complete as in normal service The test voltage specified shall be applied by connecting the conductor from the return circuit to the highvoltage terminal of the test supply The earth conductor of the main circuit and the auxiliary circuits shall be connected to the frame and to the earth terminal of the test supply The test shall be repeated with the earth conductor energised and the conductor to the return circuit to earth The dielectric test shall be made with mechanical short circuiting devices in open position Equipment not suitable to withstand the dielectric tests as surge arresters or voltage transducers shall be disconnected, earthed, shorted out or removed, as applicable, before testing This equipment shall be separately tested in accordance with the applicable product standard 6.10.2 Power-frequency voltage withstand test The test voltages correspond to Max { U max × 1,15 ; 000V} in which Umax3 are the overvoltage values given in Table A.1 of EN 50163:2004 The test voltage shall be reached, from zero Volts to the specified level, in five seconds and maintained for 60 s The test shall be carried out using a test voltage in the range of frequency between 45 Hz and 62 Hz of approximately sinusoidal form (see EN 60060-1) Equipment intended to be installed indoors shall be tested in dry conditions; equipment intended to be installed outdoors shall be tested in wet conditions as a type test and in dry conditions as a routine test The power frequency voltage test value for auxiliary and control circuits shall be 000 V Lower test voltages may be agreed between purchaser and supplier Pass criteria: No flashover 6.11 Degree of protection For devices having a given degree of protection higher than IP00 the following tests apply as type tests General requirements for the tests shall comply with Clause 11 of EN 60529:1991 The tests to verify the degree of protection indicated by the first numeral shall be performed in accordance with the requirements specified in Clause 12 of EN 60529:1991 for protection against access to hazardous parts BS EN 50526-2:2014 - 25 - EN 50526-2:2014 The tests to verify the degree of protection indicated by the second numeral shall be performed in accordance with the requirements specified in Clause 14 of EN 60529:1991 for protection against water 6.12 Environmental tests for outdoor equipment UV test: Test procedure: Three specimens of housing materials shall be selected for this test (with markings included, if applicable) The insulator housing shall be subjected to a 000 h UV light test using one of the following test methods a) xenon-arc methods: EN ISO 4892-1 and EN ISO 4892-2 using method “A” without dark periods: 1) standard spray cycle; 2) black-standard/black panel temperature of 65 °C; 3) an irradiance of around 550 W/m²; b) fluorescent UV Method: EN ISO 4892-1 and EN ISO 4892-3, using type “I” fluorescent UV lamp; 1) exposure method Only tests with simultaneous water spraying and UV radiation are acceptable Markings on the housing, if any, shall be directly exposed to UV light Acceptance criteria: After the test, markings on housing material shall still be legible; surface degradations such as cracks and blisters are not permitted In case of doubt concerning such degradation, two surface roughness measurements shall be made on each of the three specimens The crack depth, Rz as defined in EN ISO 4287, shall be measured along a sampling length of at least 2,5 mm Rz shall not exceed 0,1 mm NOTE 6.13 EN ISO 3274 gives details of surface roughness measurement instruments Determination of minimum current for safe short circuiting of Class VLDs For Class VLDs the welding shut characteristic with a resistance of less than 10 mΩ at minimum current shall be verified The test shall be carried out on one sample of VLD in dry condition at a temperature of 20 °C ± 15 °C If a manufacturer states for a VLD different current-time characteristics the test shall be carried out for each parameter Preferred time and current characteristics are given in Table A.10 The test sequence comprises: − the test samples are connected to a d.c voltage generator with an open circuit voltage equal to or higher than the triggering voltage of the VLD; − the specified minimum current-time characteristic according to Table A.10 shall be applied; BS EN 50526-2:2014 EN 50526-2:2014 - 26 - − the current, residual voltage and temperatures shall be monitored during the test and plotted versus time in a diagram Pass criteria: − no interruption of the current during the test; − the resistance between the terminals of the device is less than 10 mΩ, measured with a test current of at least 10 A; − no mechanical damage shall occur that has influence on the current carrying capacity of the VLD Routine tests 7.1 General The following tests shall be carried out: − leakage current test as in 6.3 with a duration also less than (this test is not applicable for VLDs with a type test leakage current less than µA); − triggering voltage test, only one test at each polarity, or response time test 7.2 VLDs of classes and The following checks and controls are mandatory: − the fail safe behaviour (for example: automatic immediate closing if the power supply is cut); − the correct operation of the closing and opening command of the VLD (see 6.2); − the accurate measurement of voltage and current according to EN 50123-7 (all parts); − the signalling of the operating state (open or closed) (see 5.7); − the push or touch button to an autonomous manual self test (see 5.7); − the signals on the potential-free contacts (VLD open, VLD closed, warnings, alarms (see 5.7)); − the analogue outputs for voltage and current (see 5.7); − the recordings (operations, warnings, alarms, time…) (see 5.7); − the correct functioning of the counters of the several operations (see 5.7) 7.3 Dielectric tests for panel type voltage limiting devices The requirements and procedures given in 6.10 apply BS EN 50526-2:2014 EN 50526-2:2014 - 27 - Annex A (informative) Preferred ranges of the principal properties of the VLDs The following tables indicate the preferred range of sizes of the various classes of VLD, in order to fulfil the majority of applications of VLD For information on the applications, see prEN 50526-3 Table A.1 Nominal Triggering voltage UTn Minimum UTn Maximum UTn V V 60 870 2.1 60 300 2.2 60 300 3.1 120 175 3.2 60 60 3.3 120 300 4.1 120 175 4.2 60 60 4.3 120 300 Class of VLD The non-triggering voltage UW should typically be 80 % of UTn Table A.2 Instantaneous Triggering Voltage UTI Minimum UTi Maximum UTi V V 60 870 2.1 60 870 2.2 60 870 3.1 120 870 3.2 60 870 3.3 120 870 4.1 120 870 4.2 60 870 4.3 120 870 Class of VLD BS EN 50526-2:2014 EN 50526-2:2014 - 28 - Table A.3 Rated current Ir Minimum Ir Maximum Ir A A 250 500 50 500 200 500 200 500 Class of VLD Table A.4 Short time withstand current IW a 2 Class of VLD Minimum I t a kA s Maximum I t a kA s 60 100 0,4 50 80 625 80 625 Duration to specify between 20 ms and 250 ms Table A.5 Leakage current IL Class of VLD Maximum IL mA 50 50 Table A.6 Making and breaking capacity Class of VLD Minimum making capacity Maximum making capacity Minimum breaking capacity Maximum breaking capacity A A A A 20 000 50 000 50 500 The control system of the VLD should ensure that the VLD will not attempt to open until the current in the VLD is below its breaking capacity BS EN 50526-2:2014 EN 50526-2:2014 - 29 - Table A.7 Nominal lightning current (8/20 µs) Iimp-n Iimp-n a Class of VLD kA Minimum Maximum 20 a For VLDs exposed to lightning strikes only Table A.8 High current impulse 8/20 μs and 4/10 μs Iimp-high Iimp-high kA Class of VLD 8/20 μs 4/10 μs Min Max Min Max 40 100 80 200 Table A.9 High charge impulse Iimp-hc Class of VLD Charge of Iimp-high As Min Max 15 BS EN 50526-2:2014 EN 50526-2:2014 - 30 - Table A.10 Current-time characteristic for safe short circuiting of Class VLDs Imin Tmin A ms 750 250 500 100 500 30 BS EN 50526-2:2014 - 31 - EN 50526-2:2014 Bibliography [1] EN 50122-2, Railway applications — Fixed installations — Electrical safety, earthing and the return circuit — Part 2: Provisions against the effects of stray currents caused by d.c traction systems [2] prEN 50526-3, Railway applications — Fixed installations — D.C surge arresters and voltage limiting devices Part 3: Application guide [3] EN 60099-4:2004, Surge arresters Part 4: Metal-oxide surge arresters without gaps for a.c systems (IEC 60099-4:2004, modified) [4] EN ISO 3274, Geometrical product specifications (GPS) Surface texture: Profile method Nominal characteristics of contact (stylus) instruments (ISO 3274) [5] IEC, Electropedia: The World's Online Electrotechnical Vocabulary, http://www.electropedia.org/iev/iev.nsf/d253fda6386f3a52c1257af700281ce6?OpenForm This page deliberately left blank This page deliberately left blank NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW British Standards Institution (BSI) BSI is the national body responsible for preparing British Standards and other standards-related publications, information and services BSI is incorporated by Royal Charter British Standards and other standardization products are published by BSI Standards Limited About us Revisions We bring together business, industry, government, consumers, innovators and others to shape their combined experience and expertise into standards -based solutions Our British Standards and other publications are updated by amendment or revision The knowledge embodied in our standards has been carefully assembled in a dependable format and refined through our open consultation process Organizations of all sizes and across all sectors choose standards to help them achieve their goals Information on standards We can provide you with the knowledge that your organization needs to succeed Find out more about British Standards by visiting our website at bsigroup.com/standards or contacting our Customer Services team or Knowledge Centre Buying standards You can buy and download PDF versions of BSI publications, including British and adopted European and international standards, through our website at bsigroup.com/shop, where hard copies can also be purchased If you need international and foreign standards from other Standards Development Organizations, hard copies can be ordered from our Customer Services team Subscriptions Our range of subscription services are designed to make using standards easier for you For further information on our subscription products go to bsigroup.com/subscriptions With British Standards Online (BSOL) you’ll have instant access to over 55,000 British and adopted European and international standards from your desktop It’s available 24/7 and is refreshed daily so you’ll always be up to date You can keep in touch with standards developments and receive substantial discounts on the purchase price of standards, both in single copy and subscription format, by becoming a BSI Subscribing Member PLUS is an updating service exclusive to BSI Subscribing Members You will automatically receive the latest hard copy of your standards when they’re revised or replaced To find out more about becoming a BSI Subscribing Member and the benefits of membership, please visit bsigroup.com/shop With a Multi-User Network Licence (MUNL) you are able to host standards publications on your intranet Licences can cover as few or as many users as you wish With updates supplied as soon as they’re available, you can be sure your documentation is current For further information, email bsmusales@bsigroup.com BSI Group Headquarters 389 Chiswick High Road London W4 4AL UK We continually improve the quality of our products and services to benefit your business If you find an inaccuracy or ambiguity within a British Standard or other BSI publication please inform the Knowledge Centre Copyright All the data, software and documentation set out in all British Standards and other BSI publications are the property of and copyrighted by BSI, or some person or entity that owns copyright in the information used (such as the international standardization bodies) and has formally licensed such information to BSI for commercial publication and use Except as permitted under the Copyright, Designs and Patents Act 1988 no extract may be reproduced, stored in a retrieval system or transmitted in any form or by any means – electronic, photocopying, recording or otherwise – without prior written permission from BSI Details and advice can be obtained from the Copyright & Licensing Department Useful Contacts: Customer Services Tel: +44 845 086 9001 Email (orders): orders@bsigroup.com Email (enquiries): cservices@bsigroup.com Subscriptions Tel: +44 845 086 9001 Email: subscriptions@bsigroup.com Knowledge Centre Tel: +44 20 8996 7004 Email: knowledgecentre@bsigroup.com Copyright & Licensing Tel: +44 20 8996 7070 Email: copyright@bsigroup.com