B513 Planning Meeting, 19th December 2002

Present:           Tony Cass, Anne Funken, Jose Miranda-Vizuete

1.             Previous Minutes

  1. Approved.

2.             Substation Planning

  1. The Design study bureau visited CERN on 11th December. They have been given Nigel’s draft plans, photographs of the transformers and some geological information. Following feedback from the firm, the plans for the various openings in the dalle have been revised to avoid creating weak points. The firm will evaluate the cost-effectiveness of using a thicker dalle (45cm vs 30cm ) instead of beams. We expect an “avant-projet’ by mid-January.
  2. Tony said that he now considers it rather unlikely that the substation will be even part commissioned in February 2003. We should maintain momentum with the bunker but accept that the full substation would be commissioned in Autumn 2004. He asked what impact such a delay would have on the power distribution in B513 and on ordering schedules.
    1. The equipment load will be limited to 800kVA by the UPS capacity (1200kVA total capacity, but one module required for redundancy). We need to await the results of the live diesel tests in January to understand if the full UPS capacity can supported by the diesels.
    2. Anne said that we can order the 18kV cells in February whenever we expect the substation to be commissioned. Although we would have to pay for the equipment on delivery it can be stocked until required and the guarantee only starts at installation time. Further, Anne considered that we should order the protections for the cells now as the purchase limit on the contract is close to being reached. We should avoid a situation in which we have to launch a tendering process for the substation equipment.
  3. Anne reported on discussions she had had with Yannic Body about the electrical supply arrangements for air conditioning equipment.
    1. To support a 2.5MW equipment load, a new 1.6MW chiller is required (to be installed in 2005) and the existing 1.2MW chillers would be progressively replaced by 1.4MW chillers as part of the regular maintenance. With present plans, although the chillers would be split across PDUs the overall system would still depend on a single connection for the control system.
    2. To support a 4MW load three 2MW chillers would be installed requiring a 3.3kV supply. This supply would clearly be independent from the 400V supply but it is extremely unlikely that the chillers connected to the 400V supply would be able to provide adequate cooling to cover a failure in the 3.3kV supply.
    3. Given the need for a 3.3kV supply for a 4MW solution, it is not possible to plan a redundant supply for 2.5MW that could be upgraded to support a 4MW solution. ST/CV are uncertain how to proceed.
  4. Tony felt that we have a choice between planning for
    1. a poor 2.5MW solution (no redundancy and keeping obsolete PDUs),
    2. a solid and reliable 2.5MW solution that we know cannot be upgraded to 4MW, and
    3. a 4MW solution.

Put like this, we have to choose option “b”. However, we must clearly identify the investment that would be wasted if we were ever to implement a 4MW solution.

3.             Machine Room Distribution

  1. Anne will revisit planning for an upgrade of the machine room electrical distribution in late January once the substation design is complete. Anne felt that this is still adequate to allow work to start in the second half of 2003. Most of the implementation will be a straight copy of work in the vault, but with PDUs rated at 400A, not 250A. The one issue that has still to be settled is provision for harmonic filters.

4.             AOB

  1. Next meeting: 14:00 Friday 17th January.