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Mr. Harethe El Ouadhane IEC member for IEC62271-200 MT14.

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IEC 62271-100High-voltage alternating-current circuit-breakers

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Harethe El OuadhaneIEC Expert: Member of MT14 of IEC62271-200Testing, design & calculation / MVSG & MVCBExpert for internal arc, making, breaking and STC

Schneider Electric – IEC 62271-100: Chapter 6 Type tests 3

Content

1. Introduction

2. Type Tests

3. ISO 17025

4. Routine Tests

5. ISO 9001

6. Extension of the validity of test results and derivations

7. Safety

8. Conclusion


1. IntroductionHistory of the IEC 62271-100

First and second Edition of IEC 56 in 1937 and 1954, dealing only with rules for short-circuit conditions

Third Edition of 1971 split in 6 parts. Part No. 4 dealing with Type Tests and Routine Tests. First specification of mechanical tests, tests on insulation properties, tests on auxiliary and control circuits and temperature rise tests

Edition 4 of 1987 including, among others, out-of-phase specifications, restriking performance for capacitive current switching tests and increasing of mechanical operations from 1000 to 2000.

The common requirements for HV switching equipment (CB, disconnector, earthing switch, switchgear, etc.) were published as separate standard in 1980 in IEC 694 (Nowadays IEC 62271-1). Only specific requirements for HV a.c. CB remained in IEC 56.


1. Introduction Next revision, published as IEC 62271-100 in 2001, including among others:

Classification of mechanical, electrical endurance and restrike behavior at capacitive switching

Limitation on number of test specimen for type tests Critical current tests, single-phase and double-earth fault tests

Second valid Edition of IEC 62271-100 in 2008 with the major changes of harmonization between IEC and IEEE on TRV wave shapes 100kV and above, distinction between cable and line systems with the specific TRVs below 100kV.

Currently valid Edition 2.1 of 2012 consolidating with Amendment 1


1. Introduction Scope of IEC 62271-100

This part of IEC 62271 is applicable to a.c. circuit-breakers designed for indoor or outdoor installation and for operation at frequencies of 50 Hz and 60 Hz on systems having voltages above 1000 V.

Normal and special service conditions Definition Ratings: Rated characteristics to be given for all circuit-breakers / on request Design and construction Type tests Routine tests Guide to the selection of circuit-breakers for service Information to be given with enquiries, tenders and orders Rules for transport, storage, installation, operation and maintenance Safety Influence of the product on the environment


2. Type tests Purpose

Type tests are for the purpose of proving the ratings and characteristics of switchgear and controlgear, their operating devices and their auxiliary equipment.

A High level of safety and reliability are proved by type tests and additional tests performed under worst case test parameters and arrangements according the standards.

Mandatory Tests


3. ISO 17025

Purpose

The purpose of this accreditation standard is to ensure a highest level of testing Labs in terms of test and measurement systems, testing personnel, procedures and test documentation. This standard do not deal with safety issues

Type tests or generally tests performed according the IEC standards in Test labs with

ISO17025 accreditation have a highest level of reliability and accuracy


4. Routine tests Purpose

The routine tests are for the purpose of revealing faults in material or construction. They do not impair the properties and reliability of a test object. The routine tests shall be made wherever reasonably practicable at the manufacturer's works on each apparatus manufactured, to ensure that the product is in accordance with the equipment on which the type tests have been passed.

By agreement, any routine test may be made on site.

The routine tests given in this standard comprisea) dielectric test on the main circuit in accordance with 7.1;b) tests on auxiliary and control circuits in accordance with 7.2;c) measurement of the resistance of the main circuit in accordance with 7.3;d) tightness test in accordance with 7.4;e) design and visual checks in accordance with 7.5.


5. ISO 9001

Purpose

The purpose of this accreditation standard is to ensure a highest level of factory testing results in terms of procedures and processes. This standard do not deal with safety issues or measurement accuracy. The calibration requirements are defined in the ISO17025

Routine tests or generally customized tests performed according the IEC standards in

factories with ISO9001 accreditation ensure a highest level of quality and accordance to the type tested samples.


6. Extension of the validity of test results and derivations Circuit-breakers which have satisfactorily completed type tests for a combination of

rated values (i.e. voltage, normal current, making and/or breaking current) are suitable for any lower rated values (with the exception of rated frequency) without further testing.

When circuit-breakers rated 50 Hz are tested at 60 Hz and vice versa, care should be

exercised in the interpretation of the test results, taking into account all significant facts such as the type of circuit-breaker and the type of test performed.For some test duties Tests done with 50Hz can be extended to 60Hz (e.g. breaking or Temperature rise under given performances) and vice versa some test duties performed with 60Hz can be extended to 50Hz (e.g. STC, Making, Temperature rise)

The informativ guide IEC 62271-307 which will appear on August 2014 will better define the main rules how to extend test results and derivate news between similar designs.


7. Safety High-voltage switchgear and controlgear can be considered safe when installed in

accordance with the relevant installation rules including those provided by the manufacturers and used and maintained in accordance with the manufacturer's instructions

High-voltage switchgear and controlgear is normally only accessible by instructed persons. It shall be operated and maintained by skilled persons. When unrestricted access is available to distribution switchgear and controlgear, additional safety features may be required.

High-voltage switchgear in accordance with IEC offers a high level of safety


8. Conclusion

The design and technology of high-voltage circuit-breakers is continuously developing and will continue also in the future.

The required type tests demonstrate the circuit-breaker capability for installation and operation under various network conditions while the routine tests ensure that the manufactured product is in accordance with the equipment on which the type tests have been passed.

These conditions are based on the past and present experience of utilities and industries, and so conform to their needs and specifications.

Most of the failures are due to inappropriate human behaviors either during the project management phase (wrong product definition) or during operations (installation, operation, maintenance, etc.)

Thus, considering additional regulation should not bring more safety


8. Conclusion

IEC 62271-306:“Standards should be written fit for purpose, i.e. they should reflect general system requirements to ensure that the installed equipment works properly. Although it is recognized that not 100% of all conditions occurring in service can be covered, long term experience with high-voltage switchgear standards shows that system conditions are generally covered adequately.”

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