construction details of iec 60950:1999

1. 31.07.03 ETL SEMKO Division Template 1 Construction Details of IEC 60950:1999 By Sammy Wu Intertek ETL SEMKO Taiwan Feb. 5, 2004

2. 31.07.03 ETL SEMKO Division Template 2

3. 31.07.03 ETL SEMKO Division Template 3 1.1 Scope This standard is also applicable to such information technology equipment designed and intended to be connected directly to a Telecommunication Network, regardless of the source of power. This standard is also applicable to such information technology equipment designed to use the AC Mains Supply as a telecommunication transmission medium (HomePlug Equipment).

4. 31.07.03 ETL SEMKO Division Template 4 1.2 Definitions 1.2.3.3 Transportable equipment: Movable Equipment that is intended to be routinely carried by User Note: Examples � laptop personal computer, pen-based tablet computers (PDAs), and their portable accessories (Printer, CD-R), Charger for mobile phone. (New term; relevant evaluations of 4.2.6, drop test, and 4.6.4, openings be considered) 1.2.4.3 Class III equipment:�. - OSM, If the safety strategy of an equipment containing SELV and TNV circuits relies on Protective Earthing, this equipment is considered to be Class I and not Class III. - equipment contains low current / high voltage components, Inverter for fluorescent lamp of Laptop PC or Scanner, which do not comply with Limited Current Circuit limits shall be considered as Class I / II not Class III.

5. 31.07.03 ETL SEMKO Division Template 5 1.2 Definitions (Cont.) 1.2.6.4 Electrical enclosure: A part of the equipment intended to limit access to parts may be at Hazardous Voltages or Hazardous Energy Levels or in TNV circuits. (TNV circuits other than the permission of 2.1.1.1 shall be enclosed by a suitable enclosure.) 1.2.8.2 AC mains supply:� Note: See Annex V for typical examples TN and TT power distribution systems are more popular used on the world 1.2.8.9 TNV circuit: � A TNV circuit is considered to be a secondary circuit in the meaning of this standard. 1.2.9.1 Functional insulation: Insulation that is necessary only for the correct functioning of the equipment. (Operational Insulation of old version of std.). Line to Neutral is Functional Insulation in IEC60950.

6. 31.07.03 ETL SEMKO Division Template 6 1.2 Definitions (Cont.) 1.2.9.9 Mains transient voltage: The highest peak voltage expected at the power input to the equipment, arising from external transients on the AC Mains Supply. 1.2.11.1 Temperature Limiter: A temperature-sensing control which is intended to keep a temperature below or above one particular value during normal operating conditions and which may have provision for setting by operator. 1.2.11.3 Thermal cut-out: A temperature-sensing control intended to operate under abnormal operating conditions and �. 1.2.11.6 Interconnecting cable: A cable that ��.Netwok. Such a cable may carry any type of circuit from one unit to another. 1.2.13.3 Routine test: A test to which each individual sample is subjected during or after manufacture to check if the sample complies with certain criteria. (Production Line Test) Routine Tests for EN 60950 is described in EN 50116.

7. 31.07.03 ETL SEMKO Division Template 7 1.2 Definitions (Cont.) 1.2.13.9 Functional earthing: The earthing of a point in equipment or in a system, which is necessary for the purpose other than safety. Shall not be marked with or . If marked so, PE shall be evaluated. (New term; relevant evaluations shall refer to 2.6.2) 1.2.13.11 Protective bonding conductor: A conductor connecting a main protective earthing terminal to a part of the equipment that is required to be earthed for safety purpose. (New term; relevant evaluations shall refer to 2.6.3) 1.12.13.12 Touch current: Detailed in 5.1 1.12.13.13 Protective conductor current: Detailed in 5.1

8. 31.07.03 ETL SEMKO Division Template 8 1.3 General requirements 1.3.4 Constructions not specifically covered: where the equipment involves technologies and materials or methods of construction not specifically covered in this standard, the equipment shall provide a level of safety not less than that generally afforded by this standard and principles of safety contained herein. 1.3.8 Examples mentioned in the standard: where examples of equipment, parts, methods of construction, design techniques and faults are given in this standard, prefaced by �e.q.� or �such as�, other examples are not excluded.

9. 31.07.03 ETL SEMKO Division Template 9 1.4 General conditions for tests 1.4.2 Type tests: Except where otherwise stated, the tests specified in this standard are TYPE TESTS. 1.4.3 Test samples: The tested sample shall be representative of the EUT, or shall be the actual equipment ready for shipment to the user. Alternative: Tests may be carried out separately on circuits, components or subassemblies outside the EUT, if inspection of the EUT and circuit arrangements ensures that such testing will not influence the conformance of the complete EUT.

10. 31.07.03 ETL SEMKO Division Template 10 1.4 General conditions for tests (Cont.) 1.4.5 Supply voltage for tests: In determining the most unfavorable voltage for the power to energize the EUT, the following: - Multiple rated voltage; - tolerance on rated voltage as specified below; - extremes of rated voltage ranges. if the equipment is intended for direct connection to a AC mains supply, the tolerances on rated voltage shall be taken as +6% and �10%, unless - the rated voltage is 230 V single-phase or 400 V three-phase, the tolerances shall be taken as +10% and �10%; (mainly for EU) or - a wider tolerance is declared by the manufacturer, in which case the tolerance shall be taken as this wider value. e.g.: EUT is tested with 264 V, +10% of 240 V, may be specified for CCC China deviation.

11. 31.07.03 ETL SEMKO Division Template 11 1.4 General conditions for tests (Cont.) 1.4.9 Measurement of voltage to earth: Where the standard specifies a voltage between a conductive part and earth, all of the following earthed parts are considered: - the protective earthing terminal (if any); and - any other conductive part required to be connected to protective earth; and - any conductive part that is earthed within the equipment for functional reasons Parts that will be earthed in the application by connection to other equipment,�� (Ex Class II power supply for notebook PC) 1.4.11 Power from a telecommunication network: For the purpose of this standard, the power available from a telecommunication network is considered to be limited to 15 VA

12. 31.07.03 ETL SEMKO Division Template 12 1.5 Components 1.5.1 General: Where safety is involved, components shall comply either with the requirements of this standard or with the safety aspects of the relevant IEC component standards. (OSM) - RFI filters with components meeting IEC 60384-14 are accepted. - Resistors connected across the mains or between the mains and the PE need not to comply with EN 60 065. If the resistor is accepted to EN 60 065, it need not be short-circuited during fault condition tests in � 5.4. This decision does not apply to resistors bridging RI/DI. See 1.5.7.2 - Capacitors connected after a rectifier (Bridge Diode) in a primary circuit of a SMPS need not be separately approved. In a primary circuit before a rectifier the�re is installation category II and therefore class X1 capacitors should be used. The use of a mains fuse, a mains filter or a varistor cannot be a method to reduce installation category. Secondary circuits are normally in installation category I when the primary is in installation category II.

13. 31.07.03 ETL SEMKO Division Template 13 1.5 Components (Cont.) � 1.5.1 General: (OSM) Varistors across the mains Accepted by all countries (when it is separately certified) � Varistors across the mains after fuse: Accepted by all countries (whether the varistor is separately certified or not) � Varistors between the mains and the protective earth:? Not accepted due to some countries not accept. 1. For Pluggable equipment type A: Accepted by all countries (when it is separately certified) except Austria, Belgium, Denmark, Finland, Norway, Sweden, United Kingdom � A combination of a varistor(when the varistor is separately certified) in series with a spark gap /Gas-Tube (complying with Basic Insulation ie. electric strength test and external creepage distances applies to the spark gap / Gas-Tube) between the mains and the protective earth and with a protective device to guard against short-circuit:� 1. Pluggable equipment Type A: Accepted by all countries(two fuses are required to ensure that ,even when using a non-polarised plug, a fuse is provided) except DK and UK. �Note: "separately certified" means that the varistor is separately certified according to IEC 61051-1 and IEC 61051-2 or according to CECC 42200.

14. 31.07.03 ETL SEMKO Division Template 14 1.5 Components (Cont.) 1.5.1 General: (OSM) Resistors in the primary used as �protective device � (Fusible resistor), shall comply with all following conditions: Shall operate satisfactory when the EUT is tested to EN 60950. Compliance is checked by repeating at least 10 times, each case with a new resistor during worst case fault condition test, when the appliance is directly connected to the mains. The resistor may not interrupt with explosion or spark/flame which are not in compliance with the standard. Not accepted in operator access area The resistor is to be listed as critical component in the test report. Identification using part number or the like is to be located adjacent to the resistor, or use of cross-reference in the service documentation as described in 1.7.6, last paragraph. the component shall be available as spare part in the country where the appliance is sold. A data sheet is provided showing all the relevant data for the resistor

15. 31.07.03 ETL SEMKO Division Template 15 1.5 Components (Cont.) 1.5.2 Evaluation and testing of components: Evaluation and testing of components shall be carried out as follows: - Components comply with a standard harmonized with relevant IEC standard: the application of their ratings shall be checked, and applicable tests of this standard shall be carried out. - Components do not comply with relevant IEC standards: the application of their ratings shall be checked, and applicable tests of this standard and the component standard shall be carried out. - Components without relevant IEC standard exit or not be used according to their ratings: tested according to the condition of the equipment.

16. 31.07.03 ETL SEMKO Division Template 16 1.7 Markings and instructions 1.7.1 Power rating: Unit not provided with a means for direct connection to the AC mains supply, it need not be marked with any electrical rating, such as its Rated Voltage, Rated Current or Rated Frequency. (OSM) - Laptop computers, which are supplied by SELV and in which hazardous voltages are generated, cannot be Class III and therefore must be Class I or Class II. If they are designated Class II, the double square symbol is required. - Safety related components shall be marked with a trade mark (logo) and an identification number or code. For a component without independent certification that is dedicated for use in one or more specific models the identification may be in the form of a code

17. 31.07.03 ETL SEMKO Division Template 17 1.7 Markings and instructions (Cont.) 1.7.2 Safety instructions: NOTE 4 � In Norway and Sweden, Pluggable Class I Equipment intended for connection to a telephone network or similar communications system may require a marking stating that the equipment must be connected to an earthed mains socket-outlet. (OSM) - A Class III equipment with an enclosure made of HB-material and using a non-special connector for the AC/DC input has to have a marking stating the following: "For use only with power supply MANUFACTURER, MODEL" This statement shall also be in the user-manual. - CCA certificate can be issued for separate power supply units for office machines and information technology equipment which are tested according to Publication EN 60950. E.g. �For I.T.E use only� Sweden: The kind of information supplied with the unit shall include a statement that the unit is intended for office machines/equipment only Germany: The above information has to be in the Users Manual.

18. 31.07.03 ETL SEMKO Division Template 18 1.7 Markings and instructions (Cont.) 1.7.6 Fuse identification: Where fuses with special fusing characteristics such as time delay or breaking capacity are necessary, the type shall also be indicated. For fuses not located in operator accessible areas and for soldered-in fuses located in operator accessible area, it is permitted to provide an unambiguous cross-reference (e.g. F1, F2, etc.) to the servicing instructions which shall contain the relevant information (OSM) The wording "special fusing characteristics" includes breaking capacity. To be able to accept one fuse marking in Europe, in the USA and in Canada, markings "mA" and "A" can still be accepted. Therefore the following kind of markings are accepted:T315mA L 250 V F4A H 250 V

19. 31.07.03 ETL SEMKO Division Template 19 1.7 Markings and instructions (Cont.) 1.7.8.3 Symbols: It is permitted to use the symbol O and I to indicate the �OFF� and �ON� positions of any primary or secondary power switches, including isolating switches. A �STAND-BY� condition shall be indicated by the symbol (OSM) - It is not acceptable to mark "I" and "0" on a functional switch of a lap-top or notebook computer where for example the charging circuit is energised at all times.If marked, it should be "I" and stand-by No marking at all is acceptable. The marking �POWER� is not acceptable.

20. 31.07.03 ETL SEMKO Division Template 20 1.7 Markings and instructions (Cont.) 1.7.15 Replaceable batteries: (OSM) - Lithium batteries included in integrated circuits are not considered as replaceable.There must be an advice in the service manual concerning the disposal of these parts.

21. 31.07.03 ETL SEMKO Division Template 21 2 Protection from hazards 2.1 Protection from electric shock and energy hazards 2.1.1 Protection in operator access areas: this clause specifies requirements for protection against electric shock from energized parts based on the principles that operator is permitted to have access to (Energized circuits): - bare parts of SELV circuits; and - bare parts of Limited Current Circuits; and - TNV circuits under the conditions specified in 2.1.1.1 (OSM) - A modem-card if it is separately sold and intended for use in operator access areas, has to be tested for the relevant protection of TNV-circuits

22. 31.07.03 ETL SEMKO Division Template 22 2.1 Protection from electric shock and energy hazards (Cont.) 2.1.1.1 Access to energized parts: the EUTshall be so constructed that the operator protected against contact with: - bare parts of ELV circuits; and - bare parts at hazardous voltages; and - Functional or Basic Insulation of parts or wiring in ELV circuits, except as permitted in 2.1.1.3; and - Functional or Basic Insulation of parts or wiring at hazardous voltages; and - unearthed conductive parts separated from ELV circuits or from parts at hazardous voltages by Functional or Basic Insulation only; and - bare parts of TNV circuits, except that is permitted to: Contacts of connectors which cannot be touched by the test probe, (figure 2C); Bare conductive parts in the interior of a battery compartment that complies with 2.1.1.2; Bare conductive parts of TNV-1 circuits that have any point connected in accordance with 2.6.1 e) to a protective earthing terminal; Bare conductive parts of connectors in TNV-1 circuits that are separated from unearthed accessible conductive parts of the equipment in accordance with 6.2.1.

23. 31.07.03 ETL SEMKO Division Template 23 2.1 Protection from electric shock and energy hazards (Cont.) 2.1.2 Protection in service access areas: In a service access area, it shall be that Bare parts at hazardous voltages shall be located or guarded so tat unintentional contact with such parts is unlikely during service operations involving parts of the equipment. Bare parts at hazardous voltage shall be located or guarded so that accidental shorting to SELV circuits or to TNV circuits, for example by tools or test probes used by service personnel, is unlikely. (OSM) - Products which are considered completely hazardous when covers are removed do not need additional protection e.g. monitors. Opening of an enclosure of a monitor is considered to be intentional because inside the equipment there are not parts which need servicing, but repairing. (Normally a SMPS is also considered like this.)

24. 31.07.03 ETL SEMKO Division Template 24 2.2 SELV circuits (Operator can access) 2.2.1 SELV circuits shall exhibit voltages that are safe to touch both under normal and abnormal operating conditions and after a single fault. 2.2.2 Voltages under normal condition: 42.4 Vpaek, or 60 Vdc 2.2.3 Voltages under fault conditions: 42.4 Vpeak, or 60 Vdc (> 0.2 s); 71 Vpeak, 120 Vdc (< 0.2 s) Note: Not all standards with same SELV voltage limit. SELV circuits are not always accessible by operator in all standards.

25. 31.07.03 ETL SEMKO Division Template 25 2.3 TNV Circuits The separation of TNV circuits and other circuits are collected as the table below:

26. 31.07.03 ETL SEMKO Division Template 26 2.4 Limited current circuit (LCC) 2.4.1 Limited current circuits shall be so designed that the limits specified in 2.4.2 are not exceeded under normal operating conditions and in the event of a single failure within the equipment. 2.4.2 Limit values: testing method and requirement shall refer to Tests of IEC 60950. Class II SMPS is critical to comply due to Y-capacitor between Primary and Secondary circuit. Class I SMPS shall be considered when secondary earth is not P.E. SMPS: Two components (50 or 60Hz and 25-100kHz) of leakage current exist in the circuit and shall be considered separately. A filter capacitor (0.1 uF) is recommended. The two components shall comply with different limit (frequency).

27. 31.07.03 ETL SEMKO Division Template 27 2.5 Limited power sources (LPS) A LPS circuit shall incorporate an isolating transformer A limited power source shall comply with one of the following: - the output is inherently limited in compliance with table 2B; or - an impendence limits the output in compliance with table 2B. or - an overcurrent protective device (fuse) is used and the output is limited in compliance with table 2C; or - a regulating network limits the output in compliance with table 2B, both under normal and after single fault; or - a regulating network limits the output in compliance with table 2B, and overcurrent protective device limits the output in compliance with table 2C after any single fault. Why LPS: 4.7.2.2 5th dash, equipment supplied by LPS may not require fire enclosure, if components mounted on V-1 PCB.

28. 31.07.03 ETL SEMKO Division Template 28 2.5 Limited power sources (Cont.)

29. 31.07.03 ETL SEMKO Division Template 29 2.5 Limited power sources (Cont.) Condition 2) of table 2B and 2C - Isc: measured 60s after application the load. Condition 3) of table 2C � S (VA): overcurrent protective devices are by-passed. (OSM) - Higher voltages are not allowed (Tables 2B and 2C to be followed). Behind a limited power source higher voltages can be created within secondary circuits out of the low voltage output of the limited power source. HB material is possible, even if there is for example a 1000V backlight source. However, an assessment has to be made to ensure that there is no fire or ignition hazard.

30. 31.07.03 ETL SEMKO Division Template 30 2.6 Provisions for earthing and bonding 2.6.3.1: Protective earthing conductor in power supply cords supplied with the equipment, shall comply with the minimum conductor size in table 3B (0.75 mm2 for EUT ? 6A; 1.0 mm2 for EUT rated 6-10A) 2.6.3.2: Protective bonding conductors shall comply with one of following: - the minimum conductor sizes in table 3B; or - the earthing resistance test and also , if the current rating of the circuit is more that 16 A, with the minimum conductor size in table 2D; or The current rating of the circuit used in table 2D and in the test of 2.6.3.3 depends on the provision and location of the overcurrent protective devices and shall be taken as the smallest of the following: - the rated current of the equipment; or - the rating of an overcurrent protective device specified by manufacturer to be installed in the building installation wiring to protect equipment - the rating of an overcurrent protective device in the equipment that protects the circuit or part required to be earthed.

31. 31.07.03 ETL SEMKO Division Template 31 2.6 Provisions for earthing and bonding (Cont.) 2.6.3.4 Colour of insulation The insulation of the Protective Earthing Conductor: shall be green-and�yellow. Protective Bonding Conductor: Be bare Is insulated with green-and-yellow color or transparent material Exception: Protective Bonding Conductor in assemblies such as ribbon cables, busbars, printed wiring, etc., any color is permitted provided that no misinterpretation of the use of the conductor is likely to arise the color combination green-and-yellow shall be used only to identify Protective Earthing Conductors and Protective Bonding Conductors

32. 31.07.03 ETL SEMKO Division Template 32 2.6 Provisions for earthing and bonding (Cont.) 2.6.5.2: Protective Earthing Conductors and Protective Bonding Conductors shall not contain switches or overcurrent protective devices. 2.6.5.3: Protective earthing connections shall be such that disconnection of a protective earth at one point in a unit or a system does not break the protective earthing connection to other parts or units in a system, unless the relevant potential hazard is removed at the same time. 2.6.5.4: Protective earthing connections shall make earlier and break later than the supply connections in each of the following: - the connection of a part that can removed by an operator; - a plug on a power supply cord; -an appliance coupler

33. 31.07.03 ETL SEMKO Division Template 33 2.6 Provisions for earthing and bonding (Cont.) (OSM) - It is acceptable to use a trace on a PCB as the safety earth path, provided it meets the requirements of the relevant tests. - Internal connections for earthing continuity purpose achieved by one rivet in combination with a lock washer are acceptable.

34. 31.07.03 ETL SEMKO Division Template 34 2.9 Electrical insulation 2.9.1 Properties of insulating materials: Natural rubber, hygroscopic materials and materials containing asbestos shall not be used as insulation. Driving belts and couplings shall not be relied upon to ensure electrical insulation, unless the belt or coupling is of a special design which removes the risk of inappropriate replacement. 2.9.2 Humidity Conditioning: Where required by 2.9.1, 2.10.6.5, or 2.10.7. Test methods and requirement shall refer to Tests of IEC 60950 2.9.3 Requirements for insulation: Insulation in equipment shall comply with the heating requirements of 4.5.1 and, except with 2.1.1.3 (access to ELV) and 2.1.1.4 (access to H.V circuit wiring) applies, with both of the following: - the application electric strength requirements of 5.2; and - the requirements for Clearance, Creepage Distance and solid insulation of 2.10

35. 31.07.03 ETL SEMKO Division Template 35 2.9 Electrical insulation (Cont.) 2.9.4 Insulation parameters: For the purpose of determining the test voltages, minimum Clearances, minimum Creepage Distances, Solid Insulation criteria and other requirements for a given piece of insulation, two parameters shall be considered: - application of insulation (2.9.5, table 2G and figure 2F); and - working voltage (2.10 and 5.2)

36. 31.07.03 ETL SEMKO Division Template 36 2.9 Electrical insulation (Cont.)

37. 31.07.03 ETL SEMKO Division Template 37 An example of SMPS

38. 31.07.03 ETL SEMKO Division Template 38 2.10 Clearances, creepage distances and distances through insulation (OSM) The insulation between the heat sink and the current carrying parts of an electronic component (oxide layer) can only be considered as functional insulation. Y1 and Y2 capacitors are accepted across basic insulation or supplementary insulation. The enclosures of Y1 capacitors: Considered to comply with RI; The enclosures of X- capacitor and Y2 capacitor: Considered to comply with BI. Insulation between parts directly connected to the mains in front of a fuse has to fulfil the requirements for FI or pass the test of 5.3.4 b) Hi-Pot Test.

39. 31.07.03 ETL SEMKO Division Template 39 2.10 Clearances, creepage distances and distances through insulation (Cont.) 2.10.2 Determination of working voltage: test methods and requirements shall refer to Tests of IEC 60950 (OSM) - Force of 10 N shall be applied to all internal parts whether they are accessible or not. (See 4.2.2) - In a transformer the highest occurring working voltage is the basis for insulation requirements. Outside the transformer the actually measured voltage is used. If two or more secondary windings are connected together even outside the transformer the actually measured voltage on each winding is the basis for insulation requirements provided that the relevant windings are insulated from each other inside the transformer.If the secondary voltage is not accessible only functional insulation is necessary.

40. 31.07.03 ETL SEMKO Division Template 40 2.10 (Cont.) 2.10.3 Clearance: (Decided by mains voltage + Additional Peak voltage) 2.10.3.1 General: For all a.c. power systems, the AC Mains Supply voltage in table 2H, 2J and 2K is Line to Neutral voltage. The specified Clearances are: - 2 mm for an air gap serving as Basic Insulation between a part at hazardous voltage and an earthed accessible conductive part of the external enclosure of Pluggable Equipment Type A When measuring Clearances, 4.2.2 (10N), 4.2.3(30N) and 4.2.4 (250N) apply. 2.10.3.2 Clearances in primary circuits: Clearances in primary circuits shall comply with table 2H and where appropriate, table 2J. For Primary Circuits operating on nominal AC Mains Supply voltage up to 300V, if the peak Working Voltage > peak of AC Mains Supply voltage, the minimum Clearance is the sum of the following two values: - the minimum Clearance value (table 2H) for a Working Voltage equal to Mains Supply voltage. - the appropriate additional Clearance (table 2J). Note: Transformer pin connected to the Drain / Collector is normally presented higher voltage.

41. 31.07.03 ETL SEMKO Division Template 41 2.10 (Cont.) 2.10.3 Clearance:

42. 31.07.03 ETL SEMKO Division Template 42 2.10 (Cont.) 2.10.3 Clearance:

43. 31.07.03 ETL SEMKO Division Template 43 2.10 (Cont.) 2.10.3 Clearance:

44. 31.07.03 ETL SEMKO Division Template 44 2.10 (Cont.) 2.10.4 Creepage distances: (Decided by r.m.s. or d.c. W.V.) If the creepage distance derived from table 2L is less than the applicable Clearances for the insulation, then the value for that Clearance shall be applied for the minimum Creepage Distance. For working voltage to be used in determining Creepage Distances, the actual (measured) r.m.s. or d.c. value shall be used Where determining the Working Voltage for a TNV circuit connected to a Telecommunication Network whose characteristics are not known, the normal operating voltage shall be assumed to be the following values: - 60 Vdc for TNV-1 circuits; - 120 Vdc for TNV-2 and TNV-3 circuits. if material Group is not known, Material Group IIIb shall be assumed.

45. 31.07.03 ETL SEMKO Division Template 45 2.10 (Cont.) 2.10.4 Creepage distances: (Cont.): When measuring Creepage Distances from an Enclosure of insulating material through a slot or opening in the Enclosure, the accessible surface is considered to be conductive as if it were covered by metal foil wherever it can touched by test finger, applied without appreciable force. (OSM) -Table 2L stops at 1kV working voltage for Pollution degree 2 and 3. For higher voltages Table 4 of HD 625.1 S1 (IEC 60664-1) has to be used - In a 5V circuit on the primary side of a switched mode power supply, having a direct connection to the mains (230 V ac), the working voltage to be used for table 2L is 250V ac.If the working voltage is lower than 250V it is seen as 250V.If it is higher, distances have to be calculated according to 2.10 and where a higher working voltage than the mains voltage (250V) is present, higher requirements for creepage distances, clearances and insulation (high-pot) tests have to be taken into account.

46. 31.07.03 ETL SEMKO Division Template 46 2.10.4 Creepage distances: (Cont.):

47. 31.07.03 ETL SEMKO Division Template 47 2.10 (Cont.) � 2.10.5 2.10.5.1 Minimum distance through insulation: Distances Through Insulation (DTI)shall be dimensioned according to Peak Working Voltage and to that application of insulation (2.9) and as follows: - if the Peak Working Voltage does not exceed 71 V, there is no requirement for DTI. - if the Peak Working Voltage does exceeds 71 V, the following rules apply: * For FI and BI no requirement about DTI. * For DI and RI: minimum DTI 0.4 mm There is no DTI requirement for SI or RI consisting an insulating compound completely filling the casing of a semiconductor component (e.g. an optocoupler, epoxy), so that the Clearance and Creepage Distances do not exist, if the component: -passes the tests and inspection criteria of 2.10.8; and - Is subjected to Routine Tests (EN 50116) for electric strength during manufacturing, using the appropriate value of the test voltage in 5.2.2

48. 31.07.03 ETL SEMKO Division Template 48 2.10 - 2.10.5 (Cont.) 2.9.5.2 Thin sheet material - SI by two layers: each shall pass the electric strength of SI - SI by three layers: each two layers shall pass the electric strength of SI. - RI by two layers: each shall pass the electric strength of RI - RI by three layers: each two layers shall pass the electric strength of RI. (BI: By one layer is OK, if pass the Hi-pot test.) As our experience, while two layers of insulating tapes are used as reinforced insulation, each manufacturer and type of insulating tape should pass the electric strength test. Because some insulating tapes could not pass the 3 KV electric strength tested with only one layer.

49. 31.07.03 ETL SEMKO Division Template 49 2.10 - 2.10.5 (Cont.) 2.10.5.4 Wound components At this moment, we do not accept Triple Insulated Winding wires certified according to IEC 60950 2nd edition used in this new standard. This is due to that sub-clause U.2.1 Electric Strength of 2nd edition is required for 3kV and in 3rd edition, it have to be tested with 6000 Vrms. (OSM) - The plastic enclosure of a semiconductor can be considered as basic insulation. These components including alternatives must be listed in the list of critical components and there must be a remark in the service documentation - Insulation between semiconductors (mains) and heat sinks Either a second sheet is required or it must be checked whether the distance through insulation has to be increased to comply with the requirements of clauses 4 and 5.

50. 31.07.03 ETL SEMKO Division Template 50 3 Wiring, connections and supply 3.1 General 3.1.1 Current rating and overcurrent protection: The cross-sectional area of internal wires and Interconnecting Cables shall be adequate for the current they are intended to carry when the equipment is operating under Normal Load such that the maximum permitted temperature of conductor insulation is not exceeded. 3.1.2 Protection against mechanical damage: Wireways shall be smooth and free from sharp edges. Wires shall be protected so that they do not come into contact with burrs, cooling fans moving parts etc., which could cause damage to the insulation of conductors. Holes in metal, through which insulated wires pass, shall have smooth well-rounded surfaces or shall be provided with bushings. 3.1.3 Securing of internal wiring: Internal wiring shall be routed, supported, clamped or secured in a manner that reduces: - excessive strain on wires and terminal connections; and - loosening of terminal connections; and - damage of conductor insulation

51. 31.07.03 ETL SEMKO Division Template 51 3.1 General (Cont.) 3.1.9 Termination of conductors: Conductors cannot, in normal use, become so displaced that Clearance or Creepage Distances are reduced to less than the values specified in 2.10. It is permitted to use soldered, welded, crimped, screwless (push-in) and similar terminations for the connection of conductors for soldered terminations, the conductor shall be positioned or fixed so that reliance is not placed upon the soldering alone to maintain the conductor in position. For the purpose of assessing compliance it is assumed that: - two independent fixings will not become loose (Mechanical securement + soldering) - parts fixed by means of screws or nuts provided with self-locking washers or other means of locking are not liable to become loose.

52. 31.07.03 ETL SEMKO Division Template 52 3.2 Connection to a.c. mains supplies 3.2.1 Means of connection: For safe and reliable connection to an AC Mains Supply, equipment shall be provided with one of the following: - Terminals for permanent connection to supply; or - a non-detachable power supply cord for permanent connection to the supply, or for connection to the supply by means of a plug; or - an appliance inlet for connection of a detachable power supply cord; or - a mains plug that is part of Direct Plug-in equipment

53. 31.07.03 ETL SEMKO Division Template 53 3.2 Connection to a.c. mains supplies (Cont.) 3.2.6 Cord anchorages and strain relief: For equipment with a non-detachable power supply cord, a cord anchorage shall be supplied such as: - the connecting points of the cord conductors are relieved from strain; and - the outer covering of the cord is protected from abrasion It shall not be possible to push the cord back into the equipment to such an extent that the cord or its conductors , or both, could be damaged or internal parts of the equipment could be displaced. The construction of the cord anchorage shall be such that: - cord replacement does not impair the safety of the equipment; and - for ordinary replacement cords, it is clear how to relief from strain is to be obtained; and - the cord is not clamped by a screw which bears directly on the cord; and - methods such as tying the cord into a knot or tying the cord with a string are not used; and - the cord cannot rotate in relation to the body of the equipment. Tests and requirements shall refer to Tests of IEC 60950.

54. 31.07.03 ETL SEMKO Division Template 54 3.2 Connection to a.c. mains supplies (Cont.) 3.2.7 Protection against mechanical damage: Power supply cord shall not be exposed to sharp points or cutting edges within or on the surface of the equipment, or at the inlet opening or inlet bushing. An inlet bushing in a non-metallic enclosure shall be insulating material

55. 31.07.03 ETL SEMKO Division Template 55 3.4 Disconnection from the a.c mains supply 3.4.1 General requirement: A disconnect device or devices shall be provided to disconnect the equipment from the AC mains supply for servicing. 3.4.2 Disconnect devices: Disconnect devices shall have a contact separation of at least 3 mm and, when incorporated in the equipment, shall be connected as practicable to the incoming supply. The following types of disconnect devices are permitted: - the plug on the power supply cord; - a mains plug that is part of the Direct Plug-in equipment; - an appliance coupler; - isolating switches; (all pole disconnection) - circuit breakers; - any equivalent device.

56. 31.07.03 ETL SEMKO Division Template 56 3.4 Disconnection from the a.c mains supply (Cont.) 3.4.8 Switches and disconnect devices: where the disconnect device is a switch incorporated in the equipment, its �ON� and �OFF� positions shall be marked in accordance with 1.7.8 3.4.9 Plugs as disconnect devices: where a plug on the power supply cord is used as the disconnect device, the installation instructions shall comply with 1.7.2 (The socket-out shall be installed near the equipment and shall be easily accessible.)

57. 31.07.03 ETL SEMKO Division Template 57 3.5 Interconnection of equipment 3.5.2 Types of interconnection circuits: each interconnection circuit shall be one of the following types: - an SELV circuits or a Limited Current Circuit; or - a TNV-1, TNV-2 or TNV-3; or - a hazardous voltage circuit.

58. 31.07.03 ETL SEMKO Division Template 58 4 Physical requirements 4.1 Stability Under conditions of normal use, units and equipment shall not become physically unstable to the degree that they could become a hazard to user and service personnel. If units are designed to be fixed together on site and not used individually, stability of each individual unit is exempt from the requirements of 4.1 The requirement are not applicable if the installation instructions for a unit specify that the equipment is to be secured to the building structure before operation Under conditions of operator use, a stabilizing means, if needed, shall be automatic in operation when drawers, doors, etc., are opened. During operations performed by service personnel, the stabilizing means, if needed, shall either be automatic operation, or a marking shall be provided to instruct service personnel to deploy the stabilizing means Tests and their requirements shall refer to Tests of IEC 60950

59. 31.07.03 ETL SEMKO Division Template 59 4.2 Mechanical strength 4.2.1 General Equipment shall have adequate mechanical strength and shall be so constructed as to remain safe in the meaning of this standard when subjected to handling as may be expected. A mechanical enclosure shall be sufficiently complete to contain or deflect parts which, because of failure or for other reasons, might become loose, separated or thrown from a moving part 4.2.1 to 4.2.7: test methods and requirements shall refer to Tests of IEC 60950. 4.2.10: test methods and requirements shall refer to Tests of IEC 60950.

60. 31.07.03 ETL SEMKO Division Template 60 4.3 Design and construction 4.3.1 Edges and corners: where edges or corners could be hazardous to user because of location or application in the equipment, they shall be rounded or smoothed. This requirement does not apply to edges or corners that are required for proper functioning of the equipment. 4.3.2 Handles and manual controls Handles , knobs, grips, levers and the like shall be reliably fixed so that they will not work loose in normal use, if this might result in a hazard. Sealing compounds and the like, other than self hardening resins, shall not be used to prevent loosening. If handles, knobs and the like are used to indicate the position of switches or similar components, it shall not be possible to fix them in a wrong position if this might result in a hazard. Test methods and requirements shall refer to Tests of IEC 60950.

61. 31.07.03 ETL SEMKO Division Template 61 4.3 Design and construction (Cont.) 4.3.8 Batteries: Equipment containing batteries shall be designed to reduce the risk of fire, explosion and chemical leaks under normal conditions and after a single fault in the equipment including a fault in circuitry within the equipment battery pack. For user replaceable batteries, the design shall reduce the like hood of reverse polarity installation if this would create a hazard. Battery circuits shall be designed so that: - the output characteristics of a battery charging circuit are compatible with its rechargeable battery; and - for non-rechargeable batteries, discharging at a rate exceeding the battery manufacturer�s recommendations, and unintentional charging, are prevented; and - for rechargeable batteries, charging and discharging at a rate exceeding the battery manufacturer�s recommendations, and reversed charging, are prevented. Tests methods and requirements shall refer to Tests of IEC 60950.

62. 31.07.03 ETL SEMKO Division Template 62 4.3 Design and construction (Cont.) 4.3.8 Batteries: (cont.) (OSM) - The requirements for lithium cells apply to separate devices such as memory cards, remote control units etc. - When calculating the reverse current, the voltage of the battery is considered to be zero.

63. 31.07.03 ETL SEMKO Division Template 63 4.4 Protection against hazardous moving parts 4.4.1 General: Hazardous moving parts of the equipment, i.e. moving parts which have the potential to cause injury, shall be so arranged, enclosed or guarded as to provide adequate protection against the risk f personal injury. Automatic reset thermal cut-outs or overcurrent protection devices, automatic timer starting, etc., shall not be incorporated if unexpected resetting might create a hazard. 4.4.2 Protection in operator access areas: access is permitted provided that: - the hazardous moving part concerned is directly involved in the process (e.g. moving parts of a paper cutter); and - the hazard associated with the part is obvious to the operator; and - additional measures are taken as follows: * a statement in user manual and a marking is provided: WARNING HAZARDOUS MOVING PARTS KEEP FINGERS AND OTHER BODY PARTS AWAY * a means for stop the moving parts while fingers can be drawn into the moving parts

64. 31.07.03 ETL SEMKO Division Template 64 4.5 Thermal requirements Sub-clause 4.5 specifies requirements intended to prevent: - touchable parts from exceeding certain temperature; and - components, parts, insulation and plastic materials from exceeding temperatures which may degrade electrical, mechanical, or other properties during normal use over the expected life of the equipment. 4.5.1 Temperature rises: Tests methods and requirements shall refer to Tests of IEC 60950. 4.5.2 Resistance to abnormal heat: (ball pressure test) Test method referring to IEC 60695-10-2 and requirement referring to IEC 60950.

65. 31.07.03 ETL SEMKO Division Template 65 4.5 Thermal requirements (Cont.) (OSM) - A thin plastic coating (spraying) on the external surface of the metal enclosure is not taken into account when determining the temperature rise on touchable metal parts. - For the heating test requirements of optocouplers, reference should be made to manufacturer's data for maximum operating temperature as well as manufacturer's data for input and output currents. It should be ensured that the optocoupler is operating within it's design parameters. - a) A declaration with adequate information from the equipment manufacturer is accepted to classify insulating materials.b) Information from the UL-Yellow-Book may be taken into account.c) In the case of different insulating systems the material with the lowest operating temperature is governing the total operating temperature of the system - For the acceptance of coils of RFI filters Table 16 condition 5 should be taken into account.With reference to Condition 5 of Table 4A temperature limits on individual coils, being part of RFI filters, can be accepted according to component rating.

66. 31.07.03 ETL SEMKO Division Template 66 4.6 Opening in enclosures 4.6.1 Top and side openings: - opening that does not exceed 5 mm in any dimension; - opening that does not exceed 1 mm in width regardless of length; - top openings in which vertical entry is prevented; - side openings provided with louvers that are shaped to deflect outwards an external vertically falling object; - top or side openings, as shown in figure 4D that are not located vertically, or within a volume V bonded by 5? vertical projection up to the size of opening L above bare conductive parts: * at hazardous voltage, or * which present an energy hazard within the meaning of 2.1.1.5. (OSM) - The requirements of this Sub-clause are applicable to the fire enclosure and the electrical enclosure.

67. 31.07.03 ETL SEMKO Division Template 67 4.6 Opening in enclosures (Cont.) 4.6.2 Bottom of fire enclosures Acceptable fire enclosure construction: - no opening; - opening in the bottom of any size under an internal barrier, screen or the like; - opening in the bottom, each not larger than 40 mm2, under components and parts meeting the requirements for V-1 and HF-1; - baffle plate construction as figure 4F; - metal plate of fire enclosure conforming to the dimensional limits of any line in table 4B; - metal bottom screens having a mesh with nominal opening not greater than 2 mm center line and with wire diameter of not less than 0.45 mm.

68. 31.07.03 ETL SEMKO Division Template 68 4.6 Opening in enclosures (Cont.) 4.6.2 Bottom of fire enclosures (Cont.) (OSM) - Following construction is accepted:There are openings in the bottom of a fire enclosure which are larger than 40 mm�. Above these openings there is a printed board which is horizontally mounted. The components are on the upper side of the printed board. The printed board fulfils the requirement of V-1 material. - It is acceptable to have a printed circuit board (above a fire enclosure having holes greater than 40mm�) having holes of less than 40mm�, if the components close to the holes comply with flammability class V1.

69. 31.07.03 ETL SEMKO Division Template 69 4.6 Opening in enclosures (Cont.) 4.6.4 Openings in transportable equipment: Acceptable measures include: - providing openings that do not exceed 1 mm in width regardless of length; or - Providing a screen having a mesh with nominal openings not greater than 2 mm center line and with wire diameter of not less than 0.45 mm; or - providing internal barrier

70. 31.07.03 ETL SEMKO Division Template 70 4.7 Resistance to fire Metals, ceramic material and glass shall be considered to comply without test. 4.7.1 Reducing the risk of ignition and spread of flame: Either of the following method may be used: Method 1 � Selection the components and materials according to 4.7.2 (fire enclosure) and 4.7.3 (materials). The requirement of 5.3.6 is also applied except 5.3.6 c). Method 2 � Application of all the simulated fault tests in 5.3.6. Summary of material flammability requirements � Table 4C

71. 31.07.03 ETL SEMKO Division Template 71

72. 31.07.03 ETL SEMKO Division Template 72 4.7 Resistance to fire (Cont.) (OSM) - Declaration of used materials with adequate information from the equipment manufacturer is acceptable. Furthermore, the flame resistance of plastic materials listed in the UL Yellow Book can be taken into account when checking the compliance with � 4.7.3In the flammability assessment of PCB's a declaration that the manufacturer uses V0 or V1 rated PCB's as required is acceptable.The test report should detail material manufacturer, type reference and flammability rating as a minimum for other materialsIn cases where the equipment manufacturer is unable to obtain the appropriate information, due to the unwillingness of the component manufacturer to divulge proprietary data, acceptance may be based on a Certificate of Conformity, or written declaration, from the component manufacturer, detailing the flammability rating of the plastic materials.Note: This exception is not allowed for enclosure materials, which must also meet the requirements of clause 4.2 (Mechanical strength and stress relief) - Components may be considered to have individual fire enclosures.Thin tape can be used to provide a fire enclosure for transformer windings etc, provided the tape meets V1 minimum or the complete transformer including the tape meets Appendix A2 test.

73. 31.07.03 ETL SEMKO Division Template 73 4.7 Resistance to fire (OSM) (Cont.) - Small openings in small electromagnets, motors etc should meet the requirements of 4.6. - Small parts of HB materials in a fire enclosure can be accepted based on the judgement that they have adequate spacings from ignition sources - If the product enclosure is made of HB material there have to be internal fire enclosures for parts where the limited power source output criteria is not met. - If the battery is within a fire enclosure we could accept a material HB or better, based on the experience in EN 50091-1-1 Sect. 4.4.3.3. - Materials of coil formers and partition walls shall fulfil the requirement of V-2 material. - Liquid crystal display (LCD) is tested as a "sandwich" and it shall fulfil the requirement of a fire enclosure. - Functional parts outside the fire enclosure shall fulfil the requirement of HB material. - Enclosures of a keyboard or similar devices (e.g. mouse, trackball) can be accepted to be made of material class HB based on abnormal test.

74. 31.07.03 ETL SEMKO Division Template 74 4.7 Resistance to fire (OSM) (Cont.) - Thin metal foil may be used in the construction of a fire enclosure (on HB material) provided:1. The complete enclosure shall be tested to Appendix A1 or A2.2. The foil covers all areas where there is a source of ignition.The use of metalised coating sprayed on the inside of an enclosure made of HB-material is also acceptable provided the tests according to Appendix A1 or A2 are met - HB material inside a fire enclosure is not allowed

75. 31.07.03 ETL SEMKO Division Template 75 5 Electrical requirements and simulated abnormal conditions 5.1 Touch current and protective conductor current Test method and requirement shall refer to Tests of IEC 60950. 5.2 Touch current and protective conductor current Test method and requirement shall refer to Tests of IEC 60950.

76. 31.07.03 ETL SEMKO Division Template 76 5.3 Abnormal operating and fault conditions 5.3.1: equipment shall be so designed that risk of fire or electric shock due to mechanical or electrical overload or failure, or due to abnormal operation or careless use , is limited as far as practicable. 5.3.2 Motor: Annex B. Running overload test, locked-rotor overload test. 5.3.3 Transformers: Annex C; secondary short-circuit or overload 5.3.4 Functional insulation: For functional insulation, Clearances and Creepage Distances shall satisfy one of the following requirements: a) meets Clearances and Creepage Distances of 2.10; or b) withstand the electric strength test of 5.2.2; or c) they are short-circuited where a short circuit could cause: * overheating of any material creating a risk of fire, unless the material is class V-1; or * thermal damage to Basic Insulation, Supplementary Insulation or Reinforced Insulation, thereby creating a risk of electric shock.

77. 31.07.03 ETL SEMKO Division Template 77 5.3 Abnormal operating and fault conditions (Cont.) 5.3.6 Simulation of faults: For components and circuits other than those covered by 5.3.2, 5.3.3 and 5.3.5 (electromechanical components), compliance is checked by simulating single fault conditions. The following faults are simulated: a) faults in any components in primary circuits; and b) faults of components where failure could affect SI or RI; and c) for components and parts not comply with 4.7.3; and d) faults arising from connection of the most unfavorable load impendence to terminals and connectors that deliver power or single outputs from the equipment, other that mains power outlets. Test methods and requirements shall refer to Tests of IEC 60950.

78. 31.07.03 ETL SEMKO Division Template 78 5.3 Abnormal operating and fault conditions (Cont.) (OSM) - Fault condition tests shall be carried out with 16 A installation fuses - Fault condition tests shall be considered and they have to be done even in the secondary circuit, if there is a risk of damage to supplementary or reinforced insulation. - According to EN 60127 a fuse will not break within 30 minutes at less than 2.1 times the rated current. Therefore, if the current through the fuse does not exceed this value after the failure is introduced, the fuse will not blow and the test is run until steady state conditions are obtained. - PTC resistors which are certified according to Publ. IEC 60738-1 need not be short circuited under fault conditions. - Components can be short-circuited whether they are separately approved or not. However, if a component complies with requirements for reinforced insulation, it shall not be short-circuited. - Higher temperature rises than 300�C can be accepted if the manufacturer has proved that the material in question withstands the temperature. If 16 A circuit breaker is operated during abnormal, it is not accepted due to National Electrical Regulation.

79. 31.07.03 ETL SEMKO Division Template 79 6 Connection to telecommunication networks If the equipment is to be connected to a Telecommunication Network, the requirements of clause 6 apply in addition to the other requirements in this standard. 6.1 Protection of telecommunication networks service personnel, and users of other equipment connected to the network, from hazards in the equipment 6.1.1 Protection from hazardous voltage: Circuitry intended to be directly connected to a telecommunication network shall comply with the requirements for an SELV or a TNV circuit. Where protection of telecommunication network relies on the protective earthing of the equipment, the installation instructions and other relevant literature shall state that integrity of protective earthing shall be ensured.

80. 31.07.03 ETL SEMKO Division Template 80 6.1 (Cont.) 6.1.2 Separation of telecommunication network from earth 6.1.2.1 Requirements: There shall be insulation between circuitry intended to be connected to a telecommunication network and any parts or circuitry that will be earthed in some applications, either within the EUT or via other equipment. Surge suppressors that bridge the insulation shall have minimum d.c. sparkover voltage of 1.6 times the Rated Voltage or 1.6 times the upper voltage of the Rated Voltage Range of the EUT. NOTE 1 � In Sweden, for pluggable equipment type A, SI for primary circuit is required between the telecommunication network and any parts or circuitry that may be earthed. NOTE2 � In Norway, due to IT power distribution system used, SI for a primary circuit is required between any circuit intended for connection to a telecommunication network (SELV or TNV) and any circuit that has a connection to protective earth terminal.

81. 31.07.03 ETL SEMKO Division Template 81 6.2 Protection of equipment users from overvoltages on telecommunication networks 6.2.1 Separation requirements Equipment shall provide adequate electric separation between a TNV-1 or TNV-3 circuit and certain parts of the EUT. These parts are: a) unearthed conductive parts and nonconductive parts of the EUT expected to be held or touched during normal use (e.g. telephone handset or a keyboard); and b) parts and circuits can be touched by test finger, except contacts of connectors that cannot be touched by test probe (figure 2C); and c) Circuitry which is provided for connection of other equipment. Compliance is checked by the test of 6.2.2.1 or 6.2.2.2 (In Australia, both 6.2.2.1 and 6.2.2.2 apply) Tests methods and requirements shall refer to Tests of IEC 60950.

82. 31.07.03 ETL SEMKO Division Template 82 ~ Take a Break ~ Thank you!