1. Christer Eriksson 11 March 2010 JWG1 - Wind Turbine Gearboxes IEC/ISO 61400-4 - Design Requirements for Wind Turbine Gearboxes

2. © Det Norske Veritas AS. All rights reserved. JWG1 - Wind Turbine Gearboxes 11 March 2010 2 IEC/ISO 61400-4 - Design Requirements for Wind Turbine JWG1 works as a formal level 5 liaison with ISO TC60 (Gears) under IEC-lead with active though informal participation from ISO TC4 (Rolling Bearings) and ISO TC28 (Lubricants). Scope  The proposed work shall result in an application standard for specifying, designing, verifying and manufacturing wind turbine gearboxes. As far as possible the work shall be undertaken in close co-operation with ISO TC 60 (Gears).  2005 the JWG issued ISO 81400-4 as an international double-logo standard that was a fast-track acceptance of the US national standard ANSI/AGMA/AWEA 6006.  The liaison agreement with ISO TC60 is that the second edition of that standard will be issued as double-logo standard as part of the IEC 61400-family as IEC/ISO 61400-4.

3. © Det Norske Veritas AS. All rights reserved. JWG1 - Wind Turbine Gearboxes 11 March 2010 3 IEC/ISO 61400-4 - Design Requirements for Wind Turbine Status  The CD was circulated to IEC TC88 and ISO TC60 by October ‘09. The hearing period closed in January ’10. In total, 930 comments were received for the CD, and about 50% were deemed editorial. Two meetings are planned to deal with these comment.  ISO TC60 had a formal vote at the end of the committee stage, resulting in 2 out of 11 P- members who participated in the ballot voted against passing the document on to enquiry stage. Because of this negative vote, we are advised by the TC60 chairman that after all comments to the first CD are resolved, we will need to issue a second CD and repeat the comment, ballot and resolution process.  The first meeting dealing with CD comments was held in March 2010. - We addressed a bit more than half of the substantive comments (53%). - A little less than 60% of those were accepted as submitted or in modified form. - 6 of the 202 decisions taken could not be resolved by consensus but required a vote, 4 of which votes ended with a close call (less than 2/3 majority). These constitute a potential risk in proceeding to CDV/DIS. - The progress was satisfactory and about half of the comments have been reviewed, and there are no substantial disagreements that could not be resolved within the agreed meeting schedule until April ’10. An updated document is still planned to be available by June ‘10.

4. © Det Norske Veritas AS. All rights reserved. JWG1 - Wind Turbine Gearboxes 11 March 2010 4 IEC/ISO 61400-4 - Design Requirements for Wind Turbine Time frame  2010-06CD-2 or CDV ?  2011-01CDV (if CD-2 is required)  2011-10FDIS (if CD-2 is required)

5. © Det Norske Veritas AS. All rights reserved. JWG1 - Wind Turbine Gearboxes 11 March 2010 5 IEC/ISO 61400-4 - Design Requirements for Wind Turbine Challenges  Different procedures in TC60 and TC88 for the CD level (committee stage). There is no guidance in the Directives as to how such conflict can be resolved.  Further, a more formal decision process on how to move forward in the absence of consensus could be beneficial towards a more effective. The model proposed by PT 61400-12-2 is considered helpful, but would need to be formalized to be of use in a liaison like the JWG.  Administration of membership has been a permanent struggle, both with respect to removing passive members, but also with respect to keeping the size of the JWG at a manageable size.  Support from IEC CEO resolving formal issues towards ISO which may cause significant delays.

6. © Det Norske Veritas AS. All rights reserved. JWG1 - Wind Turbine Gearboxes 11 March 2010 6 Safeguarding life, property and the environment www.dnv.com