1. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE Long Shutdown 1 Status Report The upgrade of 600 A Energy Extraction Systems

2. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE   600 A Energy Extraction ; what, where & how does it work?   Intervention statistics   600 A EE upgrade; why & what ?   LS1 actions and details   Findings   Planning Overview

3. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE Energy Extraction 600 A circuit

4. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE 600A Energy Extraction Systems   202 systems installed in the LHC tunnel in corrector circuits with stored energy between 2.2 and 150 kJ   In 15 different locations; 8 x UA parallel service tunnel and 6 x RR and 1 x UJ tunnel caverns   Systems developed in close collaboration between CERN and the Budker Institute of Nuclear Physics (BINP), Novosibirsk, Russia.   It is a bit more than a switch and a dump resistor…

5. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE 600A Energy Extraction Systems

6. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE

7. Intervention Statistics  21 interventions stopped (or delayed startup of) LHC  Total time for 143 interventions approx. 775 hours - analysis, intervention and follow up - often more persons involved  Between 2010 – 2013: 143 interventions 113 Preventive Maintenance (Technical stops) 30 Corrective Maintenance (Piquet Service)

8. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE Intervention Statistics ctnd.  61 breakers were changed 90 %: holding-coil issues – Action for LS1 – Plate Gluing 10 %: main axle, micro switch, thread, unknown – Action for LS1 – Precise voltage measurement and an extra interlock  40 interventions during TS only for: Preventive Breaker maintenance

9. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE LS1 Upgrade - main goals   Improve circuit-breakers availability/reliability (reduce nr. of closing failures) Decrease nr. of interventions for corrective and preventive maintenance   Improve voltage measurement system (main axle) From V to mV level =>Early warning on increasing system resistance With additional interlock on over-temperature  Catch > 90 % of all problems

10. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE LS1 actions LIST 1New Voltage divider board 2New voltage measurement wires + Vtap 3Thermostats on equalizing Resistors 4New Thermostat connection PCB 5Wiring Thermostat PCB to connector SK24 6Replacement of A and Z imbus to hexag. Screws 7Screwed connections "torque" check 8Breaker maintenance general and Breaker plate gluing 9Visual inspection main axle 10Interlock PCB resistor change 11Interface card firmware upgrade (IST) 12Acquisition and Monitoring board upgrade (IST) 13New measurement PCB (IST) 14Replacement of transformer (- overheated zener) 15Dump Resistor modification RQTL9 Added activities - unscheduled at start of LS1

11. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE LS1 Actions details Power Part: Remove orange measurement wire Replace orange wire by new V-tap Replace imbus screws by hexagonal

12. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE LS1 Actions details Power Part: Dismount Burndy 48 pin-and 28 pin-support And Insert 2 wires /pins in correct empty places Inside 60x90 cm rack without side space

13. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE LS1 Actions details Power Part: PCB for thermostat series connection Thermostats on all 606 Req. Prepared at the surface in building 281

14. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE LS1 Actions details CHASSIS: DQAMS (firmware) upgrade Voltage measurement Gain adjustment Interface Firmware Upgrade New Measurement card

15. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE LS1 actions LIST 1New Voltage divider board 2New voltage measurement wires + Vtap 3Thermostats on equalizing Resistors 4New Thermostat connection PCB 5Wiring Thermostat PCB to SK24 6Replacement of A and Z imbus to hexag. Screws 7Screwed connections "torque" check 8Breaker maintenance - general and Breaker plate gluing 9Visual inspection main axle 10Interlock PCB resistor change 11Interface card firmware upgrade 12DQAMS (firmware) upgrade 13New measurement PCB 14Replace transformer (- overheated zener) > 27.000 screwed connections checked

16. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE   Loosening of holding coil mechanism Weak design of the support (U-shape) and dimensional tolerances Breaker consolidation   Actions Plate Glue Action in all 606 breakers Open all breakers (foreseen for periodical maintenance) Plate gluing Periodical Maintenance: Tuning gaps and forces Cleaning main contacts

17. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE Solution

18. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE Main axle problem/solutions Improved Voltage measurement  Any increase in system resistance due to loose or bad contacts will be detected in an early stage  If not detected early, or degrading very fast, a new interlock will open the circuit breakers (over temperature of Equalizing Resistors)

19. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE - Visual inspection by endoscope - Several images per breaker - > 2700 pictures for 606 breakers Visual inspection

20. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE Findings during maintenance  Zener diode overheated – patch from 2008 to lower DC voltage on holding coil Decided to change transformer ; costs 8 kCHF  Several loosened screws were reported – randomly located  Visual inspection show one suspect breaker – with possible weak main axle fixation UA27 - RSF1.A23B1 - B Breaker

21. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EECompleted 600 A EE UPGRADE Hardware : 100% COMPLETED Firmware upgrade installation: before start of IST BUT….

22. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE UA67..

23. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE UA67.. unforeseen > 340 hours of extra work (not including CERN staff) Costs estimated at 70-80 kCHF Cost also 16 out of 20 spare-systems..

24. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE Planning 2014  Replacement of 8 racks (16 systems) in UA67 Completed IST and SCT completed  Individual System Tests February – June 2014  Short Circuit Tests March – August 2014  Hard-Ware Commissioning tests – CCC + TTT August – December 2014

25. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE Thank you for your attention

26. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE Spare slides

27. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE - Data base of the pictures for each breaker & system with the names of the circuit – Traceability for each breaker Visual inspection cntd.

28. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EECompleted

29. Availability:99.999852 % MTBF: 1.357.036 Hours Not so bad considering electro-mechanical breakers 2011 Reliability per EE system

30. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE 3 high speed electro-mechanical AC circuit breakers Snubber capacitor bank – 0.8 mF – 450VDC 4 layers of redundant (power) electronics 15 printed circuit boards 5 pcbs with microcontrollers 6-fold redundancy (9 fold remote-drive opens after 50ms but not accounted for) Stainless steel energy absorber capable of extracting 100 kJ Typical opening time at 600 A: 10 ms Electrical Lifetime of circuit breakers 5000 (!) cycles Mechanical Lifetime of circuit breakers 2000 cycles (20 years LHC operation incl. HWC!) More than just a breaker and a resistor

31. 41 st LSC – March 21, 2014 G.J. Coelingh, TE-MPE-EE LS1 Flow Chart