1. Upgrade, IST and Powering tests of the 13kA Energy Extraction system Bozhidar Panev – 02.06.2015 LS1 Review

2. OUTLINE 2 1.What was accomplished on 13kA EE systems during LS1 Upgrades Maintenance Measurements and IST 2.Preparation for LS1 activities 3.People and teams involved in work 4.What went well 5.Difficulties 6.Future optimization 7.Conclusions

3. Overview of the 13kA EE system 3 R=7.7 or 6.6 mOhms DQRQ BCMs Interface electronics

4. Upgrades 4 1.Installation of snubber capacitors and new arc chambers in RQD/RQF systems  completed in 35 days instead of 25 foreseen. 2.RB dump resistor – mechanical modification  40 out of 48 resistors were completed in 1 month. “Roman pots” and beam pipe supports postponed the modification of 8 DQRBs. 3.BCM upgrade – powering and protection of the holding coil  completed in 1 month it had been foreseen for 2 weeks 4.Replacement of the Curie-temperature based thermostat on the RB dump resistors by bi-metal type 5.Reconfiguration of all extraction resistors back to the origin (70mΩ for dipole and 6.6/7.7mΩ for quads systems)  performed together with switch maintenance 6.Preventive maintenance – verification of all bolted contacts and multi- pin connectors  completed in 4 months. 7.Relocation of some EE components – both sides of LHC point 1 and 5  completed on time. Well collaborated with CV and transport service

5. Switch maintenance – list of activities 5 1.Examination and inspection of all mechanical and electrical parts 2.Cleaning and alignment of the main and arcing contacts 3.Main contacts mechanical pressure verification 4.Measurement/adjustment of air gaps (∆1 and ∆2) 5.Check visually the main armature – clean and grease if necessary 6.Check status of micro-switches and their performance 7.Verification and re-tightening of flexible BB connections 8.Adding lubricant on the rotating axes if necessary 30 systems maintenance performed between (Jul – Sep) 2013 2 systems (P3) – at the end of 2013

6. Measurements and IST Measurements and IST (March-Aug) 2014 6 HV qualification tests RB systems: 2.5kV – 3min. RQD/F systems: 1kV – 3min After a comprehensive upgrade and maintenance a series of tests were required to qualify the systems functionalities prior to power the associated main circuit. Only a thermal performance of extraction resistors was evaluated during HWC. Functional tests (without current) Scope: To verify the performance of the EE systems comprising all operation aspects. It includes:  regular opening, internal fault, closing failure, powering failure, spurious opening, fan failure, water flow rate, etc.

7. Measurements and IST Measurements and IST (March-Aug) 2014 7 Tests with current using dummy loop between EE system and PC Scope: To verify the proper system performance under current. It includes: regular opening at 1kA, 5kA and 13kA, slow and fast opening at 13kA, spurious opening of one branch at 13kA, etc. Other measurements: Holding coil polarity check Opening delay measurement “Busway” conical connection resistance measurement Breakers contact resistance and current sharing measurement Check list: The very last check of all important parts and connections before release the system for powering

8. Conical joints validation – Heat Runs 8 The measurement of the conical contact resistance was unplanned activity. The EE section kindly agreed to perform it on behalf of EN-EL The initial idea was to carry out the measurements only at those places where the water cooled cables were replaced UA(47,63,67,83,87) Later it was extended to all UA areas. It was worth  7 conical joints having higher contact resistance (>0.6uΩ) were revealed. They had not been subject of intervention during LS1 4 people from AGH and 2 CERN staff were assigned to participate and carry out the measurement The preparation of the measurement setup took 1.5 months

9. Preparation for LS1 activities 9 Planning and preparation for LS1 started well in advance. A large part of the components and materials were available long before LS1. RQD/F systems: snubber capacitors and all their auxiliary parts were prepared for transport and installation at the end of 2011 RQD/F systems: new arc chambers production started in 2011. All were delivered at CERN in the first half of 2012 RB systems: New dump resistor thermostat  available for installation since 2011 BCM upgrade (circuit breakers and contactors)  delivered and tested in Nov 2013. Installation completed at the end of Jan 2014 Cooling station relocations in point 5  all mechanical parts were produced in 2013. Relocation completed on time for the IST IST measurement setup  prepared and tested in Feb 2014 Heat run measurement setup  built in July 2013

10. People involved 10 IHEP Team: 1.Mikhail Ovsienko 2.Sergei Avramenko 3.Aleksander Pushkarev 4.Viktor Iaichkov AGH-UST Team: 1.Marek Ciechanowski 2.Maciej Kosik 3.Tadeusz Jeziorek 4.Stanislav Cyganik Supporting people: Mathieu, Sandor, Bozhidar Planning and coordination: Knud, Felix IHEP team (experts from Russia): They have previously participated in EE system maintenance and upgrades. Arrived in CERN June 2013  15 man-months in 2013 and in 2014 AGH team: High technically skilled, became quickly familiar with many aspects of system design and operation. Contributed significantly during upgrades and IST. Arrived in CERN April 2013  15 man-months in 2013 and in 2014

11. What went well 11 All upgrades and maintenance program planned before and during LS1 were successfully accomplished All main activities were established and presented in November 2012. Only few changes were made during LS1 related to preventive maintenance The IST campaign completed on time – one week before the beginning of the HWC, according to the last version of the general planning During the training quench program all 32 systems performed very well. Very few issues were registered and quickly fixed “Check list” after the IST did not find any mistakes 992 tests were performed in total for all 32 EE systems. ~5GB of data were produced and analyzed. The results from each system were published in the DFS. To be stored in EDMS

12. Difficulties 12 Unexpected issues: –HV test on 3 RB systems (RR13,17,57) initially did not pass. Reason: A layer of impurities deposited inside flexible hoses due to the long period of no water flow. –FPA board modification. The new feature in the DQLPU created a leakage current (1mA) sufficient to blind the EE system Conical connection validation (heat runs)  unforeseen activity. –Six people were involved in 4 months validation campaign The IST test procedure was not approved prior to the beginning of IST campaign Automatic analysis software – not operational at beginning of HWC Signatures of the performed tests. Not enough experts around to sign all tests on time for HWC to continue

13. Future optimization 13 Continuous conical joint monitoring system would be useful to evaluate the status of connections after the “findings” during the heat run. Improvement of the IST measurement setup Automatic analysis tool to be fine-tuned for operation as well as for next HWC. Differentiate between warnings (no immediate action needed but experts must be informed) and faults. Optimize temperature measurements of the dump resistor

14. 14 Conclusions 1.Having experienced and motivated teams, familiar with EE facilities was very important for successful completion of upgrades and maintenance The AGH team was well trained and can be used in future 2.Starting the preparation and planning of upgrades well in advance was another essential point – most of the parts and materials were ready for installation before the beginning of LS1

15. Thank you 15

16. Additional slide 16