HRVATSKA ELEKTROPRIVREDA-TRAINING AND EDUCATIONAL CENTER’S ACCREDITATED HIGH- VOLTAGE TESTING LABORATORY EXPERIENCES Vladimir Caha, HEP – Training and educational center Velika Darko Vidović, HEP – Distribution System Operator

1. WHAT IS ACCREDITATION ? It is a process conducted by national accreditation body where certain institution (e.g. laboratory) is evaluated in its professional and technical capability according to internationally recognized rules.

2. WHAT IS THE MAIN PURPOSE OF ACCREDITATION AGENCY ? HAA is formed in order to conduct technical laws in Republic of Croatia which will: support quality systems, reduce business risks increase competitiveness on national and international market

3. WHAT HAA INSURES ? Quality of testing, measurement, calibration, certificiation and inspection in Republic of Croatia. Acceptance of test reports and conformity certificates in foreign countries Technical support for industry in the field of competitiveness Confidence in safety and quality of product and services Technical support for national bodies responsible for safety and health, environment protection, costumer protection and other public interests.

4. INTERNATIONAL ASPECTS ? HAA represents Republic of Croatia in European and international accreditation organizations. HAA is a full member of EA (European co-operation for Accreditation ) since November 17th HAA is associated member of ILAC (International Laboratory Accreditation Cooperation) since HAA follows the work of IAF (International Accreditation Forum).

5. WHAT ARE THE BENEFITS? Reliable testing and measurements reduce production costs, products flaws, increase innovation processes, help in deciding and risk assessment. Accredited laboratory is continuously monitored and periodically audited. If some costumer applies complaint on laboratory HAA conducts special check. Since audit was performed by independent accreditation body customers are sure in competence, accreditation is saving time, money and reduces business risk.

6. UPON WHAT STANDARDS ACCREDITATIONS ARE PERFORMED ? Testing and calibration laboratories HRN EN ISO/IEC Certification organizations for products HRN EN Certification organizations for quality control systems and environment control systems HRN EN ISO/IEC Certification organizations for personnel HRN EN ISO/IEC Control/inspection organizations HRN EN ISO/IEC Medical laboratories HRN EN ISO 15189

7. HEP NOC HV LABORATORY REASONS? Required tests according to valid standards for live work tools and protective equipment. Training center has its own stock of live work tools and equipment that needs periodical testing. HEP uses large quantities of live work tools.

8. HOW MANY PERSONNEL? 3 employees are enough: 1 laboratory manager, 1 quality manager and 1 technical manager. All employees are qualified for testing procedures. With head manager they form quality insurance team.

9. EQUIPMENT? The modern Haefely test transformer 100 kV with capacitive divider, continuous regulation… Hand-made test frame according to standards EN 60855, EN 60832, EN and EN 62193

10. PERIODICAL TEST IN 4 STANDARDS?

11. OTHER REQUIRED STANDARDS AND COVERED SPECIMENS? IEC and for high voltage tests conditions, EN for determination of dielectric strength of insulating materials and other related standards hot sticks – all types

12. CONTENT OF TEST REPORT? according to accreditation rules includes all necessary report elements such as conditions, part of applied standard, nominal and test voltage… Finally, it gives assessment “PASSED” or “NOT SATISFIING”. Level of confidence in test result is greater than 97 %.

13. RESULTS? Each negative test result is recorded in document with observation and archived for further analyses. In 6 years over 4000 pieces of tool and equipment has been tested. Average result is approx.: 86% in satisfactory condition, 14 % damaged, completely broken or doubtful according to visual inspection criteria (all types of insulating tools and equipment included-the most negative are ins. gloves and barriers). Flashovers are rare on FRP hot-sticks, happening on older tools with long scratch marks, average 0,2 %. Noticeable rise of temperature on some hot-stick.

FLASHOVER AND FLASH THROUGH

14. FUTURE DEVELOPMENT? constant improvement of test conditions and personnel through professional education

HRN EN ISO/IEC 17025:2007 requirements applied in HEP-NOC To introduce and improve general quality policy of service with achievable policies and goals To establish quality system organization To maintain and improve quality system control To develop procedures that cover: relations with customers including main and additional services, managing their complaints and comments To describe the manner of acquiring materials and services necessary for proper laboratory function

HRN EN ISO/IEC 17025:2007 requirements applied in HEP-NOC To have manner of dealing with non-conformities To objectively audit quality management control system To constantly enhance competences of laboratory personnel and have a manner of education of new employees To develop and maintain environmental conditions in laboratory

HRN EN ISO/IEC 17025:2007 requirements applied in HEP-NOC To properly use, service and calibrate test and measuring equipment To apply validated test methods and take concern of measurement uncertainty To be able in proving measurement traceability To handle test specimen with needed care To control test results To issue valid test reports with accompanying diaries, notes and opinions

Trainees schedule Introduction to live work technology – regulations New requirements – work performance conditions New tools and equipment, common and individual Individual training approach Setting roles for each exercise Practical knowledge and comparison to non-live work Responsibilities

Visiting training center’s HV testing laboratory Presentation of laboratory’s staff and equipment Introduction to laboratory rules for behavior and its general role Explanation of testing conducted and types of insulating equipment that should come for periodical check Giving the samples of tool’s cross-sections Explanation of the most common observations Insight on some parts of testing procedures

Visiting training center’s HV testing laboratory Importance of visual inspection – what to look for Presentation of hot-stick test frame Presentation of rubber glove testing method with explanation of measured results Presentation of insulating barrier test set Procedure with specimens that did not pass some of testing criteria Meaning of standards applied for live work tools according to HRN EN 60900:2008

Insulated tools according to HRN EN 60900:2007

Dielectric test of insulating gloves

Other demonstrations and reminders Voltage detector threshold voltage set Jump of the arc to an object on floating potential Hot-stick test on test frame 100 kV/30 cm How to read markings and labels How to properly clean hot-stick Grounding wire Stress for insulating barriers and weak points Clean working clothes and bad „ozone”

Trainees can participate in hot stick testing

CONCLUSION To fulfill mentioned requirements it is obligatory to write Quality Manual as a top document, describing the manner of creating all other documents such as procedures, work instructions, forms and raw notes. Whole system must be continuously monitored by objective internal auditor(s) and periodically audited once per year by accreditation agency. Accreditation according to HRN EN ISO/IEC 17025:2007 is valuable upgrade and fully compatible with simpler systems like IS series.

CONCLUSION HV laboratory demonstrations represent valuable addition to live work training process. Trainees truly appreciate opportunity to see the physical meaning of some conditions learned, as well as all practical usage aspects and recommendations given with explains. Presented tests of live work tools and equipment cause appreciation of safety level given by live work equipment. Trainees learn part of standard procedures when facing described situations in practice.

Thank you!