36-WG11/Mannheim/191 08/09/04

INTERNATIONAL ELECTROTECHNICAL COMMISSION TECHNICAL COMMITTEE 36: INSULATORS WG11 – Revision of IEC 60815. Minutes of the 12th meeting held in Mannheim on 6th & 7th September 2004.

Present: Clive Lumb – Project Leader Katsumi Arakawa – Japan Robert Axelsson – Sweden Generoso De Simone – Italy Christophe Elleau – France Ray Houlgate – UK Roy Macey – South Africa (for Wallace Vosloo) Richard Martin – Canada Wolfgang Petrusch – Germany Frank Schmuck – Switzerland Jens Seifert– Germany Jacek Wankowicz – Poland Dong Wu – Sweden Guests: Harald Janssen - Gemany Apologies for absence, Apologies for absence were received from •

Gustav Gödel – Austria

1. Opening of the meeting Wolfgang Petrusch welcomed the experts to Mannheim and to FGH. The Project Leader thanked him on behalf of the WG for his kind hospitality and expressed his appreciation for the excellent organisation. The Project Leader then informed the meeting that the principal aim of the meeting was to study the comments received on drafts of 60815 Parts 1 & 2 circulated to the IEC NCs with the New Work Proposals. 2. Approval of the agenda The agenda 36B-MT10/Mannheim/186 was approved without comment. Note that item 10 was actually discussed between items 8 & 9. 3. Membership The members presented themselves and gave updates on their activities. The membership list was corrected (Version 14 available on the website). Two new members were welcomed:

36-WG11/Mannheim/191 08/09/04 Andy Arakawa who replaces Rick Suzuki and Generoso de Simone who is the new Italian member replacing Franco Marinoni. 4. News from IEC & CIGRE CL explained how the changes in project time limits in IEC had resulted in the project being stopped and restarted (hence the circulation of the drafts as NPs instead of 2CDs) despite strenuous intervention by the TC 36 officers. He also informed the members that the meetings of TC 36 could not be held in Korea in October 2004 due to an administrative misunderstanding at IEC Central Office. The meetings will now be held in Washington on 6th to 11th December 2004. The news from CIGRE included the proposal to create a new “pollution” working group (C4.03.03) to better exploit the expertise present in the previous 33.04 which had been diluted by repeated fusion with other working groups. This group will be headed by Chris Engelbrecht. A proposal has been made by C4.03.02 to D1.14 to work together on the evaluation of pollution severity/surface conductance of encapsulated layers on hydrophobic materials. 5. Approval of the Leaherhead and Stellenbosch minutes (documents 179 and 182) The minutes were checked for exactitude and outstanding task status. No comments were made. 6. Review of matters and tasks arising from the minutes The major points were: CIGRE Application guide: CL to post the latest version on the web site. Part 3. WV had proposed to prepare an outline for November 2004, but had later understood that the task was no longer required. This task has now changed and is general for all (see point 11 below) 7. Project Plan and limit dates The current deadlines are defined by the TC 36 meeting date. They will be updated following the TC 36 meeting. However it was felt that the next versions of the current drafts could not be made available before June 2005. Equally, it was decided that the official activation of the project for Part 3 should be left until mid-2005 in order to have a well-advanced draft ready to circulate with the New Work Proposal. 8. Study of the comments on Part 1 The following documents were taken into consideration: 36/220/NP

TC 36

Part 1

36-WG11/Mannheim/189

TC 36

NC comments on Part 1

The results of the study are shown in document 36-WG11/Mannheim/189a available on the web site. This document will be sent to the Secretary of TC 36 to serve as a support for discussion in Washington. CL . Some notes were made directly on the 36/220/NP draft, these will not be integrated into the draft until after the TC 36 meeting. In the meantime the annotated document is available on the web site as 36/220a/NP Part of the discussion concerned the IT proposal to include examples; this was appreciated as a valid proposal, however there do not appear to be sufficient resources in the WG to prepare useful examples in the timescale available. The IEC NCs will be invited to provide real site data to the WG to serve as a basis examples to be prepared in the future. The -2-

36-WG11/Mannheim/191 08/09/04 possibility of preparing an application guide with such examples (once Parts 1-3 have been published) will also be suggested. 9. Study of the comments on Part 2 The following documents were taken into consideration: 36/221/NP

TC 36

Part 2

36-WG11/Mannheim/190

TC 36

NC comments on Part 2

The results of the study are shown in document 36-WG11/Mannheim/190a available on the web site. This document will be sent to the Secretary of TC 36 to serve as a support for discussion in Washington. CL . Some notes were made directly on the 36/221/NP draft, these will not be integrated into the draft until after the TC 36 meeting. In the meantime the annotated document is available on the web site as 36/221a/NP During the discussion it became clear that 10.3 (overhang & spacing) needed some more attention. WP agreed to review this clause with respect to all his test data. He will try to produce the result by December 2004. DW expressed concern that the factors used in the procedure for verification by testing would result in extremely high test severities – leading either to failure in the test or the inability to carry out the test (ESDD of 0.8 in one case). He agreed to contact CE to discuss this (with AA in the loop). A description of the problem and the changes necessary to remedy it will be prepared by DW/CE/AA and will be presented by the Swedish National Committee as a green meeting document at the TC 36 meeting ( DW to transmit to SE committee). 10. Discussion on classes and creepage distance Documents 187 and 188 were studied. These documents showed that for extremely high NSDD the creepage recommended by Part 2 could be insufficient. It was decided to add an “exclusion zone” at the top right hand corner of figures 1 & 2 with text to indicate that in such extreme conditions simple rules can no longer ensure satisfactory pollution performance. These areas require a careful study and a combination of insulating solutions and palliative measures is necessary. 11. Discussion on the content of Part 3, task attribution A lively discussion of the possible content of Part 3 (polymer insulators) gave the following conclusions: •

Site severity from part 1 is applicable to polymers

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We must differentiate between materials which can transfer hydrophobicity and those that do not. Later christened HTM – Hydrophobicity Transfer Materials

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Non HTM materials also require division between “good” (EDPM) and “cr*p” (some resins)

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We cannot go into great details on the differences between materials in each division (e.g. too complicated to discuss fillers)

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Ageing must be mentioned, but only as a risk/consequence of poor design, under dimensioning or certain site conditions

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Recommended creepage will be the same as for porcelain/glass. The advantage resulting from the more efficient profile of polymer insulators (notably for line insulators) will be used as a “safety margin” against hydophobicity loss and ageing. -3-

36-WG11/Mannheim/191 08/09/04 •

Include a theoretical discussion of the previous point

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SiR can exhibit flashover both with insufficient creepage and with too much creepage distance. According to the applied stress the behaviour is not linear.

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Most of the applicability concerns can be covered in a table (Environments/Materials) using “soft” words. RH volunteered to prepare this table.

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The clause on materials should discuss 2 domains – Flashover and ageing

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Clause 7 Severity: JS volunteered to write a section on the influence of certain areas (cement works …) on hydrophobicity

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Clause 9 Choice of profile will require division into sections for line insulators CL and for post/bushings DW (division at rod diameter =100mm or between solid and hollow core)

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Omit pin-types

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11.2 Diameter: Mention that HTM materials may need less correction, but that the risks due to hydophobicity loss mean that we do not reduce the correction Confirm that the lower end of the curve is correct (i.e. for line insulators)

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13 Confirmation by testing: Rewrite totally for polymers •

No standard lab test

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No standard method to measure surface pollution severity

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Therefore use test stations, trial installations

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Can we define a test on hydrophilic insulators?

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Can we use the heavy wetting procedure instead?

The following supplementary tasks were decided. CL to prepare a preliminary draft for Part 3 and post on the web site as a Word document (before Nov 2004) ALL to send comments, modifications as they wish (up to February 2005) ALL manufacturers to supply IEC 815 parameters for all their profiles (and WMF drawing). For slip-on sheds, supply the most common designs and self-imposed limits on spacing etc. (up to February 2005)

12. Task list, timetables etc. The tasks are shown above LIKE THIS . In general tasks should be completed by early February 2005 in order to allow all to study before the next meeting. 13. Any other business Nothing was tabled 14. Report to TC 36 CL will send a copy of the present minutes to the Secretary of TC 36. He will also prepare a short report on the WG activity for presentation at the TC 36 meeting.

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36-WG11/Mannheim/191 08/09/04 15. Next meeting A short meeting is foreseen in Washington on Saturday morning 11 December 2004 for those members attending the TC 36 meetings. This meeting will serve principally for the attribution of tasks and definition of target dates following the decisions taken by TC 36 on parts 1 & 2. The next full meeting is foreseen, by kind invitation from Jacek, on 8th & 9th March 2005 in Gdansk. 16. Close of the meeting The project leader thanked the members for their hard work and Wolfgang for his hospitality. He then declared the meeting closed

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