nMPP meeting on Procedures

Tuesday 21 Apr 2009, 09:00 → 12:00 Europe/Zurich

30/7-012 (CERN)

MINUTES:

·        General Information: from next week we should have in place the new structure (after nMPP/Mops, etc.).  ACTION: Nuria is expected to report about this at next meeting.

·        Approval of Previous Minutes: nothing to report

·        Expected start of powering test: end of May with 80/120 A circuits

 

·        BORIS Presentation on 600 A Powering Circuit Procedure:

The procedure was slightly modified compare to 2008 Version, what is changed is:

-          PNO.a3: it will take more time (for splice check); ~ 15 min.

o       Karl Hubert comment: he suggests increasing the duration of one of the two plateaus of PNO.a3 to at least to 20 min.

-          U_DIFF will be used instead of U_RES for the off-line analysis of PNO.a4

-          New proposal to for the “re-commissioning” classifying as “old” and new”, circuits that don’t need or need a full powering re-commissioning. In the proposed classification, “New” could identify circuits in which busbars were “open to air”.

Proposal to release 2 documents:

o       A powering procedure for the all 600 A circuits (the “new circuit” powering scenario) with in appendix the special powering for the “old circuit” powering scenario

o       A document classifying all the circuits of LHC in “new” and “old” for the next HWC 2009.

-          The test plan for the “old” circuit commissioning circuits was shown: PCS is not anymore foreseen.

A WIDE DISCUSSION FOLLOWED WITH THE FOLLOWING MAJOR COMMENTS (not exhaustive list):

o       Rob: he asked about sensitivity and results of PCS during HWC 2008:

ACTION: It will be asked to Walter to report at nMPP about this point.

o       Karl Hubert: he remarks how it is dangerous to extrapolate that a circuit test that was OK in 2008 will be OK also in 2009 (see the case of RCO corrector circuit NC degradation). So, may be better to repeat completely 600 A powering procedure?

o       Rudiger, Gianluigi, Boris, Mirko, Markus et al: various comment about re-powering policy. A proposal could be to re-do PCS for circuit that will be commissioned to a not “nominal” PNO but higher the a threshold value (300 A ?) or for circuits with EE, or for circuits that were completely warmed-up… Anyway for S2-3 (1^st re-powering planned) we should have time to re-do the full procedure without skipping PCS.

o       Policy of powering tests in PGC and other must be also take into account (see ex. EDMS 941796)

ACTION: point to be followed at next nMPP meetings

 

 

·        GIORGIO Presentation on 60 A Powering Circuit Procedure:

Not major changes compare to version 2008 but:

-          In PCC: I-EARTH max from 10 to 5 mA

-          In PCC: dI/dt from 1 A/s to 0.5 A/s. It is not clear from where the request was originated

ACTION for Gianluigi: to clarify who was the requestor and why.

-          Procedure should be available at end of this week.

 

·        GIORGIO Presentation on 80-120 A Powering Circuit Procedure:

Not major changes compare to version 2008 but:

-          In PNO.a1: automatic test analysis under consolidation (available at mid May)

-          In PCC and PNO.d1:PCC: automatic test analysis under development (also available at mid May)

-          Procedure should be available at end of this week.

 

-          Markus comment: for 2009 powering it is proposed to skip the “CRYO-maintain” check at PIC level.

-          Claude: he confirms that the parameter for CRYO-start and CRYO-maintain are the same; only thresholds changes.

 

 

·        ANTONIO Presentation on DFBs re-commissioning/re-cooling procedures:

 

References for electrical aspects are the EDMS 755782 and 829797. They will be updated in two months time (not before) but FINAL DRAFTS dedicated to S2-3 and S4-5 will be available in time.

-          Revised procedures will take advantage by feedback from operation and will follow HW changes and update of the systems.

-          A list of decided changes, but not yet fully implemented was presented (see slides). Majority of the changes concern setting values of process cryo-valves and instrumentation.

-          More extensive re-commissioning procedures will be needed for DFBLC/DSLC (S.3-4) and DFBAC LCM (in 2L).

ACTION for ANTONIO: a small presentation on this point is requested .

-          New system of protection from condensation (dry-air) must be commissioned (it will provide a signal to CRYO-start)

-          Temperature switches for pressure relief valves and CL terminals were added.

-          DFBX: commissioning of new control system for CL terminals.

-          Ramp rates for correctors of triplets will be checked. It is not expect to take major changes. ACTION:TBD on which sector do these tests (S. 2-3 ?)

Hugues comment: are the DFB commissioning times take into account in the general plan? (One week of work AFTER cool down and BEFORE ELQA (eventually small overlap). ACTION: Rudiger will check with Katy.

General ACTION: Matteo has created a Folder in HWC web page where the updated versions (under final check or still in work) of the powering procedures 2009 will be collected ad officially available. https://dfs.cern.ch/dfs/Projects/HardwareCommissioning/Powering%20procedures/2009/

AOB: Details for the installation of the protective covers in front of the DFBs will be discussed between people concerned, mainly Antonio, Nuria and Amalia

Michele Modena, 29 April 2009