BRITISH STANDARD BS AU 243 2 1991 ISO 7637 1 1990 Methods of test for Electrical disturbance by conduction and coupling — Part 2 Electrical transient conduction along supply lines only on passenger ca[.]
BRITISH STANDARD BS AU 243-2: 991 ISO 7637-1 : 990 Methods of test for Electrical disturbance by conduction and coupling — Part 2: Electrical transient conduction along supply lines only on passenger cars and light commercial vehicles with V supply BS AU 243-2:1 991 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Automobile Standards Policy Committee (AUE/- ) to Technical Committee AUE/1 6, upon which the following bodies were represented: Association of Trailer Manufacturers British Cable Makers Confederation Department of Transport Institution of Electrical Engineers Motor Industry Research Association National Caravan Council Ltd Society of Motor Manufacturers and Traders Ltd This British Standard, having been prepared under the direction of the Automobile Standards Policy Committee, was published under the authority of the Standards Board and comes into effect on Amendments issued since publication 29 November 991 © BSI 03- 999 The following BSI references relate to the work on this standard: Committee reference AUE/1 Draft for comment 88/73080 DC ISBN 80 20 X Amd No Date Comments BS AU 243-2:1 991 Contents Page Committees responsible Inside front cover National foreword ii Scope Normative reference Test procedure Test instrument description and specifications General techniques to improve electromagnetic compatibility of device 10 Annex A Failure mode severity classification 12 Figure — Conducted voltage transients measurement test setup Figure — Conducted current transients measurement test setup Figure — Transient immunity test setup Figure — Schematic diagram of artificial network Figure — Z PB as a function of frequency from 00 kHz to 00 MHz (AB short- circuited) Figure — Test pulse Figure — Test pulse Figure — Test pulse 3a Figure — Test pulse 3b Figure — Test pulse Figure 1 — Test pulse Figure — Test pulse 10 Figure — Test pulse 10 Table A — Test levels 13 Table A — Example 13 Table A — Example 14 Publication(s) referred to © BSI 03- 999 Inside back cover i BS AU 243-2:1 991 National foreword This British Standard has been prepared under the direction of the Automobile Standards Policy Committee and is identical with ISO 7637- “Road vehicles — Electrical disturbance by conduction and coupling — Part 1: Passenger cars and light commercial vehicles with nominal 12 V supply voltage — Electrical transient conduction along supply lines only”, published by the International Organization for Standardization (ISO) The Technical Committee has reviewed the provisions of ISO 6722- 3, to which reference is made in the text and has decided that they are acceptable for use in conj unction with this standard A British Standard does not purport to include all the necessary provisions of a contract Users of British Standards are responsible for their correct application Compliance with a British Standard does not of itself confer immunity from legal obligations Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages to 4, an inside back cover and a back cover This standard has been updated (see copyright date) and may have had amendments incorporated This will be indicated in the amendment table on the inside front cover ii © BSI 03- 999 ISO 7637-1 :1 990 (E) Scope In special cases, it may be necessary to apply This part of ISO 7637 specifies test methods and procedures to ensure the compatibility to conducted electrical transients of equipment installed on passenger cars and light commercial vehicles fitted with a V electrical system It describes bench tests for both the inj ection and measurement of transients Functional status classifications for immunity to transients are given in Annex A NOTE General guidelines for the evaluation of transient emissions, test procedures for which are given in clause , will form the subj ect of a future addendum Normative reference additional test pulses However, some test pulses may be omitted, if a device — depending on its function or its connection — is not influenced by comparable transients in the vehicle It is part of the vehicle manufacturer’s responsibility to define the test pulses required for a specific device To ensure proper vehicle operation in the electromagnetic environment, on- board testing is essential 3.2 Test temperature and test voltage The ambient temperature during the test shall be 23 °C ± °C The test voltages shall be as follows: The following standard contains provisions which, UA = 3, V ± 0, V through reference in this text, constitute provisions UB = V ± 0, V of this part of ISO 7637 At the time of publication, unless other values are agreed upon by the users of the edition indicated was valid All standards are this part of ISO 7637, in which case such values subj ect to revision, and parties to agreements based shall be documented in the test reports on this part of ISO 7637 are encouraged to investigate the possibility of applying the most recent edition of the standard indicated Members of 3.3 Transient emissions test 3.3.1 Voltage transients IEC and ISO maintain registers of currently valid Voltage transients from the disturbance source, the International Standards device under test, are measured using the artificial ISO 6722- 3: 984, Road vehicles — Unscreened network to standardize the impedance loading on low-tension cables — Part 3: Conductor sizes and dimensions Test procedures 3.1 General the device under test (see 4.1 ) The disturbance source is connected via the artificial network to the shunt resistor R s1 (see 4.2 ) , the switch S (see 4.3 ) and the power supply (see 4.4 ), as given in Figure The leads between the terminals of the disturbance source, the device under test, and the artificial Methods for measuring the transient emission on network shall be laid out in a straight parallel line supply lines and test methods for the immunity of and shall have a length of 0, m ± 0, 05 m devices against such transients are given These The cable sizes shall be chosen in accordance with tests, called “bench tests”, are made in the laboratory 1) ISO 6722- The disturbance voltage is measured at the The bench test methods, some of which require the terminals P and B of the artificial network use of the artificial network, will provide (see Figure ) using a voltage probe and an comparative results between laboratories They also oscilloscope or waveform acquisition equipment give a basis for the development of devices and systems and may be used during the production phase A bench test method for the evaluation of the immunity of a device against supply line transients may be performed by means of a test pulse Repetitive transients are measured with switch S closed If the transient is caused by a supply disconnection, measurement is started at the moment of opening switch S 3.3.2 Current transients generator; this may not cover all types of transients The test setup for measuring the disturbance which can occur in a vehicle Therefore, the test current is shown in Figure pulses described in 4.6 are characteristic of typical The disturbance source is connected via the pulses artificial network to the power supply Resistor Rs2 (see 4.2 ) is connected to the terminals of the artificial network on the power supply side (see Figure 2) 1) A future part of ISO 7637 will cover on- board vehicle tests © BSI 03- 999 ISO 7637-1 :1 990 (E) The leads between the terminals of the disturbance The leads between the terminals of the test pulse source and the artificial network shall be laid out in generator and the device under test shall be laid out a straight parallel line and shall have a length in a straight parallel line and shall have a length of 0, m ± 0, 05 m of 0, m ± 0, 05 m The disturbance source is disconnected by the The test pulse generator (see 4.6 ) is set up to provide switch S the specific pulse polarity, amplitude, duration The disturbance current measurement is started and resistance with switch T (see 4.3 ) open when switch S is opened (The appropriate values are selected from Annex A ) The disturbance current should be measured between the artificial network and the device under test as close to the artificial network as possible 3.4 Transient immunity test The test setup for transient immunity measurements of electrical/electronic devices is given in Figure Next, the device under test is connected to the generator by closing switch T Depending on the real conditions, the function of the device under test should be evaluated during and/or after the application of the test pulses For correct generation of the required test pulses, it may be necessary to switch the power supply on and off The switching can be performed by the test pulse generator if the power supply is integral to it Figure — Conducted voltage transients measurement test setup Figure — Conducted current transients measurement test setup © BSI 03- 999 ISO 7637-1 :1 990 (E) Figure — Transient immunity test setup R and R The shunt resistor Rs1 (see Figure 1) simulates the dc resistance of other vehicle devices which are 4.1 Artificial network connected in parallel to the device under test and The artificial network is used as a reference are not disconnected from it by the ignition switch standard in the laboratory in place of the impedance Rs1 is selected to correspond to the resistance of the vehicle wiring harness in order to determine measured on the wiring harness between the the behaviour of equipment and electrical and disconnected ignition switch terminal and ground, electronic devices A schematic diagram is given in with the switch off, and shall be specified by the Figure vehicle manufacturer In the absence of any The artificial network should be able to withstand a specification, a value of Rs1 = 40 shall be used If continuous load corresponding to the requirements a wire-wound resistor is used, the winding shall be of the device under test bifilar (i.e with a minimum reactive component) The resulting values of impedance ZPB , Shunt resistor Rs2 (see Figure 2) is used during measured between the terminals P and B while current transient measurements In the absence of terminals A and B are connected together, are any specification, a value of Rs2 = shall be used given in Figure as a function of frequency The shunt resistor shall have an adequate power assuming ideal electric components In reality, dissipation rating the impedance of an artificial network should not 4.3 Switch S and switch T deviate more than 10 % from the curve given in The switch S (see Figure and Figure 2) Figure significantly the disturbance transients The main characteristics of the components are as when tests areinfluences performed in accordance with 3.2 follows: NOTE A specification for a switch S with reproducible — maximum continuous load current, I = 70 A properties is in preparation In the interim it is proposed to use a standard production switch that is used with the device under — inductance, L = 4H (air-core winding) test and to perform a sufficient number of tests to ensure a statistically valid sample — internal resistance between terminals P and A: RL < m7 The switch T (see Figure 3) is a disconnecting switch which does not influence the disturbance transients — capacitor, C2 = 0,1 4F for working voltages The current rating of switch T should be sufficient to of 200 Vac and 500 Vdc handle the required loads Test instrument description and specifications 4.2 Shunt resistors s s 4.4 Power supply When a battery is used, a charging source is needed to achieve the specified reference levels If a standard power supply (with sufficient current capacity) is used in bench testing to simulate the battery, it is important that the low internal impedance of the battery also be simulated © BSI 03-1999 ISO 7637-1 :1 990 (E) The continuous supply source shall have an internal 4.5 Measurement instrumentation resistance Ri less than 0,01 dc and an internal impedance Zi = Ri for frequencies less than 400 Hz 4.5.1 Oscilloscope The output voltage shall not deviate more than V This should preferably be a storage oscilloscope with from to maximum load (including inrush current) the following specifications: — band width: at least 100 MHz and shall recover 63 % of its maximum excursion within 100 4s The superimposed ripple voltage, Ur, — writing speed: at least 100 cm/4s shall not exceed 0,2 V peak-to-peak and have a — input sensitivity: at least mV/division maximum frequency of 400 Hz The recording may be made with an oscilloscope camera or any other appropriate recording device Figure — Schematic diagram of artificial network Figure — ZPB as a function of frequency from 00 kHz to 00 MHz (AB short-circuited) © BSI 03-1999 ISO 7637-1 :1 990 (E) 4.5.2 Voltage probe: — attenuation: 100/1 — maximum input voltage: at least kV — input impedance, Z, as a function of the frequency, f: f Z MHz > 40 k7 10 MHz > k7 100 MHz > 0,4 k7 — maximum length of the probe cable: m — maximum length of the probe ground: 0,13 m NOTE The lengths will influence the measurement results and should be stated in the test report 4.5.3 Current measuring probe: — minimum measuring range: 20 A — maximum working voltage: 500 V — bandwidth (– dB): at least to 15 MHz (Hall effect probe) — attenuator accuracy: better than % 4.5.4 Waveform acquisition equipment Equipment that is capable of acquiring fast rise time transient waveforms may be used instead of an oscilloscope 4.6 Test pulse generator The test pulse generator shall be capable of producing the test pulses described in 4.6.1 to 4.6.7 and shall be adjustable within the limits given in Figure to Figure 13 Tolerances for the parameters are ± 10 % for time and resistance, and + 10 % for voltage (Va and Vs) Recommended values for the evaluation of immunity of devices can be chosen from Table A.1 4.6.1 Test pulse This test pulse is a simulation of transients due to supply disconnection from inductive loads; it applies to a device under test if, as used in the vehicle, it remains connected directly in parallel with an inductive load The pulse shape and parameters are given in Figure NOTE The time necessary between the disconnection of the supply source and the application of the test pulse, t3, shall be minimized Figure — Test pulse © BSI 03-1999 ISO 7637-1 :1 990 (E) 4.6.2 Test pulse The p ulse shap e and p arameters are given in This tes t p uls e is a s imulation of trans ients due to the s udden interrup tion of current in an inductor connected in series with a device under tes t Figure 4.6.3 Test pulses 3a and 3b These tes t p uls es are a s imulation of trans ients, It s imulates transients which may for examp le which occur as a res ult of the s witching p roces ses occur due to the following: after the ignition is The characteristics of these trans ients are s witched off, dc motors , which are connected to the influenced b y distrib uted cap acitance and s ame switch as the ignition, may continue rotating inductance of the wiring harnes s due to their inertia, thus acting as generators Their inductance creates a trans ient on switching off the sup p ly line The p uls e s hap es and p arameters for tes t p ulses a and b are given in Figure and Figure res p ectively Figure — Test pulse © BS I - 99 ISO 7637-1 :1 990 (E) Figure — Test pulse 3a Figure — Test pulse 3b © BSI 03- 999 ISO 7637-1 :1 990 (E) 4.6.4 Test pulse This pulse simulates supply voltage reduction caused by energizing the starter- motor circuits of internal combustion engines (excluding spikes associated with starting) The pulse shape and parameters are given in Figure Figure — Test pulse © BSI 03- 999 ISO 7637-1 :1 990 (E) 4.6.5 Test pulse This test pulse is a simulation of load dump The following general considerations of the dynamic behaviour of alternators during load dump apply: transient occurring in the event of a discharged a) The internal resistance of an alternator, in the battery being disconnected while the alternator is case of load dump, is mainly a function of generating charging current at the moment of the alternator rotational speed and excitation battery being disconnected with other loads current remaining on the alternator circuit at this moment; the load dump amplitude depends on the alternator speed and on the level of the alternator field excitation at the moment of the battery being b) The internal resistance, of the load dump following relationship: disconnected The load dump pulse duration Ri depends essentially on the time constant of the field 10 = excitation circuit and on the pulse amplitude Load dump may occur on account of a battery being Ri , test pulse generator shall be obtained from the 0, × Vnom × Nact × Irated × 000 min– where Vnom disconnected resulting from cable corrosion, poor connection or the battery being disconnected is the specified voltage of the alternator; intentionally while the engine is running Irated The pulse shape and parameters are given in is the specified current at an alternator speed of 000 Figure 1 –1 (as given in ISO 8854); Nact is the actual alternator speed, in reciprocal minutes Vs , Ri, and the pulse duration td; in all cases small values of Vs are correlated with small values of Ri and t d, and high values of Vs with high values of Ri and td c) The pulse is determined by the peak voltage the internal resistance 4.6.6 Test pulse This test pulse is a simulation of a transient at the moment of current interruption in the ignition coil The pulse shape and parameters are given in Figure 4.6.7 Test pulse This test pulse is a simulation of the effect of alternator magnetic field decay at the moment of engine switch- off It applies primarily to systems Figure 1 — Test pulse using electro- mechanical voltage regulators The pulse shape and parameters are given in Figure © BSI 03- 999 ISO 7637-1 :1 990 (E) NO TE The time neces s ary b etween the dis connection of the s up p ly s ource and the ap p lication of the tes t p uls e, t3 , s hall b e minim iz ed Figure — Test pulse General techniques to improve electromagnetic compatibility of device 5.1 Limiting emissions from disturbance sources The mos t effective way to s up p res s emis sions is at the s ource D is turb ance trans ients s hould b e s up p res s ed internal to, or at the terminals of, the disturb ance s ource b y means of diodes, Zener diodes , varis tors , damp ing res istors , cap acitors , s up p ress ion filters, etc If it is not p os s ib le to s up p ress trans ients internally or at the terminals, the s up p ress ion unit shall b e p laced as clos e to the source as p os s ib le The us e of a Z ener diode, varis tor and other comp onents at the main network terminals may give sufficient p rotection for s us cep tib le equip ment if no dis connecting s witch is located b etween the transient s ource and the sup p ress or 5.2 Equipment immunity improvement 5.2.1 The immunity of devices can b e imp roved b y using diodes, Zener diodes , varis tors , cap acitors , NO TE The time neces s ary b etween the dis connection of the s up p ly s ource and the ap p lication of the tes t p uls e, m inimiz ed Figure — Test pulse 10 t3, s up p res sion filters , damp ing resistors , etc , which s hall b e s hould b e connected to terminals likely to receive dis turb ance transients Furthermore, the choice of mounting location can aid in p roviding immunity © BS I - 99 ISO 7637-1 :1 990 (E) 5.2.2 The maximum value of V s = – V in test pulse is normally only observed at the terminals of a solenoid- actuated starter- motor or, possibly, at the b attery terminals of a field- coil- actuated starter- motor Users are therefore advised to estab lish the type of starting system prior to 5.3 Additional suppression techniques Practical means of transient suppression may be ob tained by one or more of the following methods: a) provision of a “clean” independent power supply for susceptib le equipment; designing their devices In the interests of good b) insertion of dumped suppression components immunity it is recommended that electronic at strategic points in the wiring harness; equipment not b e connected to the terminals of the c) use of harness with low pass filter properties; starter- motor © BSI 03- 999 d) careful routing of harnesses 11 ISO 7637-1 :1 990 (E) Annex A (normative) Failure mode severity classification Class A A.1 Scope The purpose of this annex is to provide a method of classifying the functional status of automotive All functions of a device/system perform as designed during and after exposure to disturbance Class B All functions of a device/system perform as designed during electronic devices upon application of the test exposure: however, one or more of conditions described in this part of ISO 7637 them can go beyond specified The process described in this annex applies only to tolerance All functions return the bench testing of automotive electronic devices automatically to within normal using the methods described in this part of limits after exposure is removed ISO 7637 Memory functions shall remain A.2 General Class A It must be emphasized that components or systems Class C shall only be tested with those conditions which A function of a device/system does not perform as designed during represent the environments to which the device exposure but returns automatically would actually be subj ected, i e as used in a vehicle to normal operation after exposure This will help ensure sound technical and is removed economically optimized designs for susceptible systems Class D A function of a device/system does not perform as designed during It should also be noted that this annex is not meant exposure and does not return to to be a product specification and cannot function as normal operation until exposure is one Nevertheless, using the concepts described in removed and the device system is this document and by careful application and reset by simple “operator/use” agreement between manufacturer and user, it action would be possible to develop a document giving the functional status requirements for a specific device Class E One or more function of a device/system does not perform as This could then, in fact, be a statement of how a designed during and after exposure particular device could be expected to perform under and cannot be returned to proper the influence of the specified disturbance transients operation without repairing or (see A.7 ) replacing the device/system A.3 Essential elements of failure mode classification system A.5 Classification of test pulse severity There are three elements required to describe a The suggested minimum and maximum severity general failure mode severity classification They levels are given in columns I and IV in Table A are A selected level for testing at or inbetween these Functional status classification: Operational values may be chosen according to the agreement status of a device during and after exposure to an between car manufacturer and supplier In cases electromagnetic environment where no specific values are defined, it Test pulse and method: Reference to the is recommended that levels selected from representative test pulse applied to the device under columns I to IV in Table A be used test and test method (In this case this information A.6 Allocation of functional status to test pulse is contained in the body of this part of ISO 7637 ) severity Test pulse severity: Specification of the severity Manufacturer and user shall specify the level of essential pulse parameters classification of functional status (A.4 ) and of test A.4 Classification of functional status pulse severity (A.5 ) bearing the specific application All classifications given below are for the total device/system functional status NOTE The word “function” as used here only concerns the function performed by the electronic system of the device in mind Test pulses which not reach the specific device under real conditions, i e when the device is operated in a vehicle, may be omitted A functional impairment of Class C may be acceptable for devices which need not work during the occurrence of distinct pulses (e g flashers during cranking) 12 © BSI 03- 999 ISO 7637-1 :1 990 (E) A.7.1 A functional impairment of Class D may b e acceptable for devices the malfunction of which does Example This is an example of how a device supplier might not cause customer annoyance or inconvenience characterize the performance of his device for sales or engineering purposes Tab le A shows the A functional impairment of C lass E is defined primarily for test report purposes and would not characteristics of the device for all applicab le test normally b e acceptable for a device unless under pulses and the functional status after exposure to all special circumstances test severity classification A.7 Presentation of results NO TE The examples in A.7.1 and A.7.2 In testing the device to increasing test pulse severity, care would have to be taken to avoid possible cumulative effects are given to from previous test applications if the same device were used for illustrate how the failure mode severity all tests classification can be used to characterize a device A.7.2 when applying this part of ISO 7637 Example This is an example of how a customer might characterize the minimum requirements for a particular device Table A constitutes a possible product specification to b e used for engineering and purchasing requirements Table A.1 — Test levels Test level Test pulse Selected a test levels I b II c Minimum III IV Pulse cycle time number of pulses or test time max max – 25 – 50 – 75 – 00 000 pulses 0, s s + 25 + 50 + 75 + 00 000 pulses 0, s s 3a – 25 – 50 – 00 – 50 h 00 ms 00 ms 3b + 25 + 50 + 75 + 00 h 00 ms 00 ms e d f – – – – pulse e + 6, + 46, + 66, + 86, pulse e e – 50 – 00 – 00 – 300 pulse e e – 20 – 40 – 60 – 80 pulse e e a Test pulses as in b c 4.6 Values agreed to b etween car manufacturer and sup plier The amplitudes are the values of d See e 5.2.2 V s as defined for each test pulse in 4.6 Since the minimum number of test pulses is , no pulse cycle time is given When several pulses are to b e applied, a minimum delay of between pulses shall b e allowed f See 4.6.5 c) The test levels reflect the situation of load dump at generator rated speed Table A.2 — Example Test pulse Functional status (see A.4) according to test levels I II III Remarks IV Not applicable D evice connected with battery positive Not applicable D evice connected with battery positive 3a A A B C 3b A A B C B B C D D evice need not be operative during cranking etc © BSI 03- 999 etc 13 ISO 7637-1 :1 990 (E) Table A.3 — Example Test pulse 3a 3b 14 Test level V – 75 + 50 – 25 + 25 A A C C Functional status in Minimum number of pulses accordance with A.4 or test time Remarks 000 pulses 000 pulses 1h 3h Not applicable Not applicable – 50 – 50 B B pulse pulse © BSI 03-1999 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