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MEASUREMENT AND TESTING MT INFRASTRUCTURE FOR THE

By Herbert Ferguson,2014-03-26 14:23
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The full implementation of LVD and EMC directives in the Czech Republic was according to harmonized standards in the framework of LVD sphere.

    The role of suppliers of testing and measuring equipment related to LVD

František Jelínek

    Czech Metrology Institute

    Tel: +420 257 323 308, Fax: +420 257 324 982

    Email: fjelinek@cmi.cz http://www.cmi.cz

Abstract

    This paper deals with complex assurance of the safe operation of electrical appliances and installations. Completeness of regulations, harmonized standards and involved bodies is being discussed. The paper is focused on examples of LVD implementation and use of LVD (and EMC) directive by manufacturers of electrical appliances and measuring instruments. Some illustrative cases of proper measuring instruments for testing of safety of electrical household appliances are given. Importance and impact of activities of their manufacturers is pointed out.

    Objective of this paper is to point out the complex of administrative and technical issues which, as an integral system, can only ensure that electrical equipment will be safely operated over its technical life. In this sense the paper goes beyond the problems of placement of products on the market. The system used in the Czech Republic is briefly described.

1. Introduction

    The full implementation of LVD and EMC directives in the Czech Republic was documented at stpapers presented at the 1 INCOLAB Conference in Prague, 2003. The LVD directive requires that the

    Member States shall take all appropriate measures to ensure that electrical equipment may be

    placed on the market only if, having been constructed in accordance with good engineering

    practice in safety matters, it does not endanger the safety of persons, domestic animals or property

    when properly installed and maintained and used in applications for which it was made. Principal

    technical requirements are also stated.

    Objective of this paper is to point out the complex of administrative and technical issues as an integral

    system, which can only ensure that electrical equipment will be safely operated over its technical life.

    In this sense the paper goes beyond the problems of placement of products on the market.

    The fact is that a such complex system in the Czech Republic has been step by step developed since ththe beginning of the 20 century and complies with European directives in its nowadays harmonized

    form. Due to efforts of involved bodies, there is existing the proper system of legislature,

    infrastructure of metrology and testing, also active market surveillance body operates, systematic

    inspection of safety at work and health protection is provided and finally the manufacturers of

    electrical appliances and measuring instruments benefit from these facts on the free European market.

    2. Safety matters related to the electrical equipment

    Safety of products, safety of power distribution and safety at work are ensured in the web of

    regulations and their relations. Principal binding acts shown below are the base for coordinated

    activities of involved bodies (presented schema, of course, can not be taken as a complete description).

    All the acts are meant in the amended versions; numbers correspond to the official Collection of Law

    (CR).

    examples of

    other binding harmonized and activities and Law official acts designated involved bodies

    standards

     Ordinance No. Labour Law No. 65/1965 EN 50110-1 50/1978 on the testing, inspection, Operation of qualification in Czech authority of electrical Law on the State electrical safety at work installations surveillance on safety at technology work No. 174/1968

    Law on general safety of EN 61557-1 products No. 102/2001 testing and testing. inspection Civil engineering law (on measuring authorized inspectors, territorial planning, instruments, general building authorities constructions, etc.) requirements

    and 61557 series No. 50/1976

    EN 61010-1 electrical appliances, implemented el. meas., control and measuring instruments, LVD and lab. equipment, conformity assessment Law on technical EMC directive safety requirements Czech Office for requirements for products Standards, Metrology No. 22/1997 (Government ČSN 33 1610 tech. and testing,, notified Decrees) requirements on bodies, economic revision of electrical operators appliances

     traceability issues,

    Czech Metrology Law on metrology 505/1990 ordinances on Institute, and next implementation of technical Czech Office for the MID requirements Standards, Metrology

    and Testing Law on trade inspection No.

    64/1986 market surveillance, Law on consumer protection Czech Trade Inspection No. 634/1992

3. LVD implementation by the manufacturer of electrical appliances

    Traditional manufacturer of household electrical appliances, ETA a.s. in Hlinsko, has been CMI

    INCOLAB partner.

    Two directives, 73/23/EEC (LVD) and 89/336/EEC (EMC) are applicable to all products of the

    company.

    ETA declares conformity with both mentioned directives using harmonized standards. Some tests are

    provided by testing and certifying laboratories. Independent testing house provides tests and certifies

    that the product complies with requirements of relevant standards. Test protocols are documented and

    manufacturer may use it issuing the declaration of conformity. ETA cooperates typically wit the

    Electrotechnical Testing Institute (1926).

    Other tests are conducted in own testing laboratory. All present products are CE marked.

    Complete set of documents contains:

a) Description (vacuum cleaner Type 3454 was selected as an example)

    very reduced description

    ? Middle class vacuum cleaner

    ? Input power IEC…………………..…1800W

    ? max. input power ……..…… ..…….2000W

    ? max. suction power …………..…….. 430W

    ? max. underpressure …………………27 kPa

    ? acoustic power …………………... .78 dBA

    ? volume of dust filter ………… .….…3.l

    ? length of cable ………… ….... 8m

    ? effective radius……………..…….……..11m

    ? filtration…6-times or folded . „HEPA“

    ? rich set of accessories

    ? elektronická posuvná regulace výkonu

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b) EC Declaration of conformity

c) CCA certificate No.CCA-CZ-461, ETI

    d) VDE-Zeichengenehmigungsausweis No. 40009790, VDE-Institute, Germany e) Company QS certificate ISO 9001

    f) Operating instructions (Czech, German, English).

    g) Test reports as well as complete technical documents are stored in the company library. This documentation is maintained by design and development department. The samples of production are

    periodically tested and reports are stored.

    We can conclude, that manufacturer works in compliance with the Czech regulations, it means also

    with LVD and EMC directives. Testing and metrological services are available. Completed interview

    has documented high level of knowledge in the field at different levels of company management. No

    problems concerning LVD were identified.

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4. LVD implementation by the manufacturer of measuring instruments (METRA

    a.s.)

    Metra, a.s. covers broad programme of products. It was forced to find new strategy after the political

    and economical changes in 1989. One of the strategy points is concentration to the instrumentation for

    the revision of electrical equipment, clamp-on instruments, tachographs and control systems.

    Production of universal and laboratory instruments was closed. The next strategy point is the

    substantial growth of productivity and, of course, first class quality assurance.

The present production programme includes (besides others)

    - Electric measuring instruments

    - Instruments for revision

    - Clamp on instruments

    - Converters of electric quantities

    One instrument was chosen as typical example of LVD application and supporting instrument for

    broad LVD applications. It is PU 194 DELTA instrument for electrical devices (appliances)

    revision.

Extract of the Declaration of conformity:

    PU 194 DELTA and PU 194 DELTA 10A instruments for electrical devices revision,

    are produced in METRA BLANSKO a.s.

    and meet in full requirements of the following standards:

    Safety: EN 61010 - 1

    Electromagnetic compatibility: EN 61326 1

    The conformity evaluation is supported by the Technical Specification file

    No. TPZ 700/014 stored at the manufacturer.

    CE mark is placed on the product since 2002

Technical characteristics:

    Instruments are designed to be used for the revision of electrical appliances and transportable electrical

    tools.

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Its parameteres are as follows:

    QUANTITY RANGE VOLTAGE PERMISSIBLE ERRORS REMARKS mains voltage (180 ?253)V ? (1%MH+5D) ?(1% MH+10D) ULN

    (50 to 70) V (0,1 ? 3,999) MΩ insulation (100 to 130) V ?4mA IK? (3%MH+10D) ? (5%MH+10D) resistance (1,0 ? 39,99) MΩ (250 to 300) V I=1,0?1,5mA nR ISO(500 to 600) V (10 ? 399,9) MΩ

    ? (200? 210) (0,10 ? 3,999) Ω IM = resistance of ? (3%MH+10D) ? (5%MH+10D) max.20V/DC mA(0,10?19,99) Ω protective (0 ? 1,000) Ω conductor ? (2%MH+10D) ? (5%MH+10D) I10 ?12A/AC M = max. 25V/AC (PU 194 10A) R PE

    contact current cont. voltage ? (1%MR) ? (1%MR) (0 ? 3,999) mA I ? U= 8 V Fmaxprotective

    conductor (0 ? 19,99) mA ? (2%MR) ? (2%MR) current

    I PE

    leakage current (0 ? 19,99) mA max.35V/AC ? (2%MH+5D) ? (2%MH+10D) I O

    dif. current

    I ? (0 ? 19,99) mA ? (2%MR) ? (2%MR)

    consumption

    current (0 ? 16) A ? (2%MH+5D) ? (2%MH+10D) I N

    effective input max.current power (0 ? 3700) W ? (3%MH+10D) ? (5%MH+10D) 10 A steadily

    P 16 A / 5 min. apparent input

    power (0 ? 3700) VA ? (3%MH+10D) ? (5%MH+10D)

    S

    power factor 0,50 ? 1,00 ? 5D ? 10D 0,5A ?I?16A Ncos φ -1 revolutions (200 ? 9999) min ? (1%MH) ? (2%MH) temperature (-20 ? + 350)?C ? 3?C ? 5?C t

Complete documentation is controlled and stored by the quality assurance department.

    METRA operates its own testing laboratory as well as metrological centre. Ambient conditions and

    layout of laboratories comply with highest requirements. Working standards are traceable to those of

    the Czech Metrology Institute. EMC tests are conducted by subcontractor, accredited laboratory.

    Staff of the QA department maintains good relations and exchange of experience with other players in

    the in institutional triangle (particularly with the Czech Metrology Institute and Czech Institute for

    Accreditation).

5. ILLKO, s.r.o., manufacturer of instruments for testing of electrical appliances

    The last interview mentioned in this paper was conducted with the director of a small dynamic

    company ILLKO. The company develops, manufactures and sells measuring instruments and testing

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    devices in the field of electrical safety. One of interesting products is the multifunctional measuring instrument EUROTEST 61557, designed for measurements on electrical installations.

    It measures parameters necessary for revisions according to the standard ČSN 332000-6-61 “Rules for

    electrical equipment. Part 6: Revision. Procedures for the initial revision”.

    - contact resistivity and conductive joint contacts

    - insulation resistivity with measuring voltage 50 V to 1000 V

    - parameters of current protections

    - impedance of protective loops and

    networks, short circuit current

    - sequence of phases

    - resistivity of grounding

    - loop currents (clump-on)

    - mains voltage, frequency

    - power, energy

    st- harmonic analysis of AC up to 21

    overwave

    - voltage surge protection

    All products of the ILLKO company comply with the LVD and EMC directives. It is documented by declarations of conformity according to the Law on technical requirements No. 22/1997 and relevant Government Orders. Declarations give the list of used harmonized standards for both LVD and EMC directives.

    Company provides trainings not only for users of its products but also for electrical revision engineers. It participates at specialized fairs and workshops. Marketing and training support the general awareness of LVD directive and its requirements.

    6. Market surveillance

    Market surveillance plays a very important role related to the safety of products. Several occurrences of very simple nonconformities show how the user of electrical appliances could be suffered from wrong products. (No product, mentioned below, was of the Czech origin).

    a) Risk of electric shock was caused by insufficient temperature-resistance of the product during its work. According to the results of the tests conducted by the accredited laboratory, the surge protector has not complied with the standard EN 60950:2000 regarding the temperature-resistance of

    thermoplastic parts of the product.

    b) Hot melt glue gun, connected to the mains during its operation, caused the risk of electric shock and burning. The internal wiring may contact the moving parts of the feeder. The sleeves made by insulating material can easily move on the electric components and the wiring, so the unfixed connection made by soldering can freely move in the tool. Mains connection and external flexible wires have the diameter and the size of the engagement face much smaller than requested.

    c) Plug-in unit to repel mosquitoes using ultrasound is wrong as the plug section can become separated from the unit while remaining connected to the mains, meaning that there is a risk of electric shock if touched. Tests carried out revealed the following non-compliances with standard EN 60335-1: no

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    safety markings or instructions are present (chapter 7). The covers over the internal conductors, which serve as additional insulation, are not securely attached. The pins of the plug are not secured against twisting and can easily be moved.

d) Hand-held electric lamp is powered from the internal accumulator, connected to the built-in

    charging power supply. Connection to the mains is made by 2-pole plug. Results of tests identified the risk of electrical shock from following reasons (ČSN EN 60335-1, ČSN EN 60335-2-29):

    - Testing finger can contact metallic bulb socket (under full voltage)

    - One of reflectors is connected with the lamp housing only by the two-line cable

    - Some parts of the lamp do not have sufficient insulation

    - Leakage current is 60 mA ( limit 0,25 mA ! )

    - Voltage breakdown occurred by 300 V (limit 3 750 V !)

    - AC cable is not properly fixed

    2 2- Wire cross-section of the AC cable is only 2 x 0,0115 mm(required minimum 0,5 mm)

    Intervention of the market surveillance inspectors and following matters saved probably human lifes. Some of cases described above occured even if these products were marked with the CE mark.

7. Conclusions

    The role of involved bodies in implementing technical EU directives is very varied. It was shown that

    safe use of electrical appliances requires not only compliance with technical directives applied at the phase of production and placing products on the market but also consistent supervision of their

    condition, systematic market surveillance and sufficient users awareness of risks as well as skill of

    service technicians. Also design, construction and periodic revision of electrical installations are of substantial importance. The proper functioning of metrological and testing infrastructure is also

    necessary. This situation is reflected in regulations covering all the fields of interest and creating robust base of user and customer protection as far as electrical equipment is concerned.

    It was shown that manufacturers of measuring instruments can significantly contribute to the best

    practice on testing of electrical appliances according to harmonized standards in the framework of

    LVD sphere. They play important role also in testing and revision of electrical installations and, last but not least, in dissemination of technical skill and knowledge.

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