58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Long
Shutdown 1 Status Report Energy Extraction Systems On behalf of all
EE teams involved
Slide 2
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Energy
Extraction ; what, where & how? Split: 13 kA EE and 600 A EE
LS1 actions and details Findings Status + open issues General
lessons learnt Overview
Slide 3
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Energy
Extraction principle
Slide 4
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Energy
Extraction Systems 13 kA main circuits: 32 systems for Main Dipole
RB and Main Quadrupoles RQF/RQD circuits. Stored energy between 22
and 1300 MJ 600 A corrector magnet circuits : 202 systems for
circuits with stored energy between 2.2 and 150 kJ In 15 different
locations; 8 x UA parallel service tunnel and 6 x RR/tunnel and 1 x
UJ33/tunnel caverns
Slide 5
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE 13 kA
main circuits Energy Extraction Systems
Slide 6
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Overview
of the 13kA EE systems Interface electronics BCMs Extraction
switches DQRQ R=7.7 or 6.6 mOhms
Slide 7
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE 13 kA EE
LS1 goals / actions list 1. 1. Main quadrupole switches:
Installation of new arc chambers with higher voltage rating (from
200 to 1050 VDC) and snubber capacitors for voltage transient and
arc suppression during commutation 2. 2. Mechanical modifications
of all extraction resistors in the main dipole circuit preventing
damage and short-circuit in the case of double energy deposit 3. 3.
Replacement of thermostats on the extraction resistors in the main
dipole circuit by a different type with higher switching point (80
C).
Slide 8
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE 13 kA EE
LS1 goals / actions list cntd 4. 4. Replacement of the power
switching relays and circuit breakers in all 64 switch controller
units (DJPC). New relay with different (hardened) contact surfaces
5. 5. Re-configuration of all extraction resistor values - back to
the origin (2 x 70 m for dipole circuits and 7.7 m/6.6 m for quads)
6. 6. Relocation of EE components in LHC points 1 and 5 (both
sides) 7. 7. General preventive maintenance program incl.
verifications of all bolted contacts and of multi-pin connectors in
all elements applied to all 32 switch facilities
Slide 9
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Energy
Extraction ; what, where & how? LS1 actions and details
Findings Status Lessons learnt Overview
Slide 10
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Findings
upgrade / maintenance Switches: Broken or misaligned micro-
switches/status indicators (8 cases) Switches: support - Broken
insulators (4 cases) General: Burndy connector pins deformed or
pushed inwards (> 60 cases) or wire insulation damage General:
ODU connectors - broken or partially melted pin (2 cases)
Electronics chassis: Power resistor insulation damaged (one
case)
Slide 11
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Examples
Untightened screws in electronic cabinets and racks Broken or badly
fixed pins in connector or socket
Slide 12
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Broken
cable insulation 2250 cables / 51000 pins checked: 67
cables/socket/pins with problems were found
Slide 13
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Findings
Individual System Tests Insulation Tests Several problems reported
with high leakage currents. Causes: - Dust mixed with metallic
particles (due to grinding close to the Resistor body) leading to
breakdown voltages on RQD resistor -Flexible water connections
Functional Tests Breaker Control Module with problems on PCB called
On-Off control card Collateral damage due to maintenance
interventions. broken connectors/pins and cables/ wires not well
connected (again???) Cold welds UA67 Equipment suffered from mains
voltage oo spec.
Slide 14
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Findings
Short Circuit Tests Heat run or thermal evaluations included
Interconnections water cooled cables Rcc < 0.6 So called conical
connections show resistances higher than specified. In some points
> 30% of all connections show high resistance even if
cables/connections were not touched during LS1 Will lead to thermal
runaway at currents above 7 kA Permanent measurement systems will
be developed and installed! (2015/2016)By who?
Slide 15
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Findings
Short Circuit Tests ctnd. Heat run and / or thermal evaluations
included During heat-run RQF.A78: Switch Open Failure Most likely
EMI related. Double signal reaction 1- Fire all heaters: was
already decommissioned in 2008 2- Fast Power Abort leading to
opening of the breakers. Now also interrupted. High contact
resistances on breaker contacts Rbc < 20
Slide 16
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Energy
Extraction ; what, where & how? LS1 actions and details
Findings Status Lessons learnt Overview
Slide 17
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE STATUS 13
kA EE All findings corrected / repaired : EE Maintenance and
Upgrade: 100% completed IST/SCT: 100% completed
Slide 18
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE STATUS 13
kA EE Open issues: 1 Non-opening of switches on FPA request After
installation of earth-fault detection cards. Workaround: installing
100 parallel resistor on opto coupler Completed except RR57 (no
access) 2 Former polarity check of CB holding coil and pulse coil
not fail safe. New test equipment and procedure established.
(on-going, 50% completed) 3 Final check before handover of systems
to HWC List established, treated like consignation
yellow-paper
Slide 19
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE 600A
corrector circuits Energy Extraction Systems
Slide 20
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE 600A
Energy Extraction Systems
Slide 21
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE LS1
Upgrade - main goals 600 A EE 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 Prevent > 90 % of all problems of
period pre-LS1
Slide 22
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE 600 A 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 Holding coil
fixation 9Visual inspection main axle (new) 10Interlock PCB
resistor change 11Interface card firmware upgrade 12Acquisition and
Monitoring board upgrade 13New measurement PCB 14Replacement of
transformer (- overheated zener) 15Dump Resistor modification RQTL9
systems in P3 and P7
Slide 23
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Energy
Extraction ; what, where & how? LS1 actions and details
Findings Status Lessons learnt Overview
Slide 24
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Findings
during maintenance Zener diode overheated patch from 2008 to lower
DC voltage on CB holding coil Decided to remove zener and change
the transformer Several loosened screws (>20) were reported
randomly located (> 27000 checked) Visual inspection show one
suspect breaker with possible weak main axle fixation UA27 -
RSF1.A23B1 - B Breaker (decided to keep under observation)
Slide 25
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Findings
Individual System Tests + Closing failures reduced by 90% -
Collateral damage due to maintenance interventions Mainly connector
pins and wires but also water-damageUA67
Slide 26
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Findings
Short Circuit Tests During SCT many breakers (50 oo 606) found with
high contact resistance despite cleaning of contacts during
maintenance period in 2013 Increasing number of breakers towards
the end of SCT period: P6, P7, P1, P2: < 5%. short time between
maintenance and SCT P8 & P3: 30%. Reasons: One year after
cleaning, high humidity (or water on the floor during long time)
systems unpowered and breakers opened P4 and P5: 10 % of breakers.
Reason: almost one year after cleaning systems unpowered and
breakers open).
Slide 27
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Findings
Short Circuit Tests ctnd Breaker A : ROD.A45B2 - Uph_r: 79 mV @
600A Breaker B : ROF.A45B1 - Uph_t: 82 mV @ 600A Limit: 70 mV
normally 50-65 mV Contacts are clean and current sharing is
excellent. First time happening. Two breakers to be monitored
closely during HWC In case of further degradation breakers will be
changed.
Slide 28
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Energy
Extraction ; what, where & how? LS1 actions and details
Findings Status Lessons learnt Overview
Slide 29
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE STATUS
600A EE All findings corrected / repaired / monitored : 100%
completed 600 A EE Upgrade: 100% completed IST: 100 % completed
SCT: 100 % completed..
Slide 30
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE STATUS
600A EE Open issues: 1 - All AMS cards to be reprogrammed (Sector
67 done) init. not foreseen by 600 A EE team now it is (AS+MB) 2
PLI3.b1 and PNO.b1 automatic measurement system Was developed to
register (without tunnel team presence) of each system: Opening
time + Voltage drop (two measurement wires and two trigger wires
per system) After conclusions of SCT: Now also current sharing (4
wires per system)(still not enough to qualify system)
Slide 31
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Energy
Extraction ; what, where & how? LS1 actions and details
Findings Status Lessons learnt Overview
Slide 32
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Lessons
learnt Problems reconnecting cables to current leads after SCT
(Alignment). Flexibles needed instead of copper blocks In future
LS: Before any action: Nominal infrastructural conditions: -
Cooling and ventilation - Mains power preferably on UPS Meaning
starting late(r) But also: - WorldFip communications preferably
with PM operational (as from start of IST) Meaning starting even
later?
Slide 33
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE More
Lessons learnt ctnd. 13 kA Power converter ground fault on start-up
because of water-cooled cable-connections (nipple) touching
(electrical) ground. Correction has lead in several cases to water
leakage. Torque control of screwed and bolted connections each LS
by skilled & trained technicians! Valid for all interventions.
600 A EE FPA signal hardwired as close as possible to switches LS2.
Change of motherboard, FPA card and 2 breaker control cards
Slide 34
58 th MPE-TM October 2, 2014 G.J. Coelingh, TE-MPE-EE Thank you
for your attention