The VGB-Standard “Recommendations for the improvement of H2 safety in hydrogen-cooled generators” was edited by the VGB “H2 Safety” project group. The current VGB-S-165 contains a revision of the previous “VGB Guideline VGB-R 165e” of 2006, which represented an update to the VDEW Guideline of the same name issued in 1989.

The VGB-S-165 takes account of the current authoritative DIN EN 60034-3 “Rotating electrical machines – Part 3: Special requirements of non-salient synchronous machines” Version 2009-03 for the construction and operation of generators using hydrogen (H2) as a coolant. On the basis of the new technical requirements outlined in this standard and the guidelines relating to the implementation of industrial safety regulations, in accordance with ATEX, for safety considerations when operating this equipment, a revision of the previous VGB Guideline was necessary. In doing so, account was taken of the experience of applying VGB-R 165e, and the responsibilities of operational experts for explosion protection were clearly highlighted. Current knowledge of the materials required and the requirements as regards sealing systems was included in a more concrete manner.

The “Generators” project group of the VGB “Electrical machines and equipment” working group also made use of the “H2 Safety” project group, which, in the interests of balance, was made up of representatives of the operators and manufacturers of hydrogen-cooled generators. The content was also agreed with VGB-Kern-AG “Industrial safety regulations” experts.

In order to further improve H2 safety in a harmonised European environment, the aim of the revision was to equip manufacturers and operators with uniform recommendations, in accordance with which new equipment must be designed and/or existing equipment must be operated. Basic recommendations were also derived in this respect for measures involving existing generators, which must nevertheless always be re-evaluated and implemented on a case-by-case basis.