1. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 1 Contents  Electrical circuits in the LHC context  Electrical Hazards  Preventions  Safety Training  Habilitation  Consignation  Flowchart for LHC work

2. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 2 LHC Electrical Circuit DFB EE system AC DC AC DC QHPS 18kV 18kV / 400V 400V 400V [UPS] Water EE system QHPS Power Converter Power Converter  Power converters supply:  Cold circuits: UA, RR, UJ [High Current]  Warm Circuits: SR [High Voltage] Cold Circuits

3. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 3 Electrical Hazards  Electrical shock due to contact with energized piece AC side  18kV for the Main Dipole and Warm Magnet converters  400V for all the other converter types  400V UPS for the Electronics of the high current converters (> 2kA) DC side (Differential Voltage)  Up to 950V for the warm magnets  180V for the Main Dipole Converter during a ramp  < 20V for all the other converters AC DC Power Converter

4. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 4 Electrical Hazards  Electrical shock due to contact with energized piece DC side (Common Mode Voltage)  Common mode of 10V in normal operation  Voltage / Earth could be high during Energy Extraction with additional resistor EE system 700 mOhms AC DC Power Converter 10V 550A 385V 395V 385V

5. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 5  Burn due to short-circuit or opening of the load with current Huge amount of energy stored in the superconducting magnets Main Dipole: 15.7 Henrys – 11.85kA = 1.1 GJ  BE CAREFUL !!! Zero Voltage doesn’t mean Zero Current Converter OFF but still current in the circuit Very long time constant: 4 hours for Main Dipole Electrical Hazards AC DC Power Converter -0.2V 11.85kA Example: 1Q converters after FASTPA, OFF

6. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 6 Preventions  Prevention against accidental contact Signalization Grills added for the protection of the converter DC outputs Converter rack protection  Doors, panels added  Rack closed for the main dipole transformer

7. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 7 Voltage Range / UTE C 18-510 Very Low Voltage Low Voltage High Voltage TBT S,P,F BTABTBHTAHTB DC side 0 120V 750V 1500V 75kV 0 50V 500V 1000V 50kV AC side TBTF: Très Basse Tension Fonctionnelle Most of converters TBT - Dipole - Circuits with Extraction Energy Resistor - Warm Magnets BTA - Warm Magnets BTB BTA Most of converters HTA - Dipole - Warm Magnets

8. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 8 Energized piece Voltage Range / UTE C 18-510  Conclusion / UTE C 18-510: BT domain even for DC output with low voltage (<10V) Rules to apply  BT: Minimal distance from energized pieces >30cm if not contain in IP2X envelope Ø 12mm Envelope IP2X Definition

9. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 9 LHC Safety Training  LHC Machine Not considered as a “Local Electrique” / UTE C 18-510 Safety Training “Level 4” mandatory: http://sir.cern.ch/ http://sir.cern.ch/  BUT, not all the equipments are IP2X at the moment “ Keep away from electrical installations. Minimum distance is 50 cm.” LHC machine safety training (level 4) RRTunnel: DFB, Current Lead

10. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 10 Habilitation: for who ? Electrical Work ? Near energized electrical piece ? Under the supervision of trained person ? “Electrical Worker” for measurement maintenance reparation modification “Chargé de Travaux” “Chargé d’Intervention” “Chargé de Consignation” No Habilitation Habilitation for Non Electrical Worker B0 Habilitation for Electrical Worker B1, B2, BR, BC Yes No Yes BT <30cm

11. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 11 Habilitation: Actors B2 B1 B0 BC BR “Chargé de Travaux” B2 “Chargé d’ Interventions” BR Supervise on the field - the work planned Ex: extension, modification - the “intervention” Ex: reparation, measurements Ensure his own safety and the safety of people under his supervision “Exécutant électricien” B1 Execute electrical work Responsible for his own safety “Exécutant non électricien” B0 Execute or supervise non electrical work Habilitation not mandatory if all electrical hazards have been removed “Chargé de Consignation” BC Execute or get execute the consignation or part of it ATAT ATAT ACAC ACAC

12. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 12 1)Separate the equipment from its electrical sources 2) Lock in open position the separation devices 3)Identify the equipment 4) Check that the voltage is zero Earth and short-circuit (not mandatory in BT) Consignation: Principle 1 ère étape de consignation On the work area 2 nde étape de consignation

13. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 13 Procedure: Première Etape de Consignation related to Power Converters http://www.edms.cern.ch/853633 http://www.edms.cern.ch/853633 Procedure for any work of disconnection of warm parts of the superconductive circuits of LHC: Safety Aspects https://edms.cern.ch/document/762293 Consignation in 2 steps RequestConsigne RPHE.UA83.RQD.A78 converter & Measure I=0 on DFBAO.7L8 Chargé de Travaux 1 ère étape de consignation Separate the converter from AC sources Chargé de Consignation C.C. [AB-PO for power converter] Lock in open position On the field 2 ième étape de consignation Identify the converter: To be sure that the work will be done on the correct equipment Chargé Travaux I=0 @ working pointChargé Travaux Chargé Consignat. [AB-PO] V=0, Earthing & Short-circuitChargé Travaux Work can start under the responsability of the « Chargé de Travaux » under safe conditions ACAC ACAC

14. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 14 Work Flowchart in LHC Context ChargéTravaux I HAVE A JOB TO ORGANIZE ON POTENTIALLY DANGEROUS INSTALLATION. I AM RESPONSIBLE FOR MY TEAM SAFETY C.T. JOB WAS DONE IN SAFE CONDITIONS. FOLLOW STEPS  EASIER & SAFER ANALYSE HAZARDS: ELECTRICAL & OTHERS ~~~~~~ ~~~~~ ~~~…. ~~~~~~ ~~~~~ ~~~…. ~~~~~~ ~~~~~ ~~~…. ~~~~~~ ~~~~~ ~~~…. AB/PO ~~~~~~ ~~~~~ ~~~…. ~~~~~~ ~~~~~ ~~~…. ~~~~~~ ~~~~~ ~~~…. ~~~~~~ ~~~~~ ~~~…. AT/MEL Where What ? Mr Circuit C.T. E.I.CPt Owner 01 C.T. OK! PLAN WITH POINT OWNER AND / OR E.I.C C.T. © OK! E.I.C Pt Owner When ? 02 REQUEST 1 ère ETAPE DE CONSIGNATION C.T. AT/MEL © AB/PO © 03 CONSIGNE 1 ère ETAPE AB/PO © 04 DELIVER ATTESTATION BACK TO C.T. AB/PO ©©©©©© ©©© ©©©©©© C.T. ©©©©©© 05 DO INTERVENTION IN SAFE CONDITIONS OK! Work! El.Ex. Non El.Ex. C.T. ©©©©©© ©©©©©© 07 REMOVE MISE A LA TERRE C.T. ©©©©©© ©©©©©© 08 DECONSIGNE & INFORM EIC & P.OWNER AB/PO E.I.C Pt Owner Done ! AB/PO ©©© ©© 10 GIVE BACK YELLOW FORM Job Done. C.T. ©©© © AB/PO ©©© ©© 09 CONSIGNE 2 ème ETAPE V=0VI=0A  VAT  VAI  MALT  IDs C.T. ©©©©©© ©©©©©© 06 AB/PO

15. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 15 Documents  Documents: Attestation de 1 ère Etape de Consignation Autorisation de Travail ATAT ATAT AC

16. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 16

17. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 17 Attestation Première Etape Consignation Form Bon pour Accord: EiC DUPONT Dep/Group Convertisseur: RPHE.UA83.RQF.A78 DURAND 169935 Le chargé de travaux s’engage à réaliser la vérification d’absence de courant au niveau de la DFBAO avec le support d’AB-PO 10.10.07 10 CC CT DUPONT Dep/Group DURAND 12.10.07 à 10h CC CT Déconnexion des câbles DC au niveau de la DFBAO du circuit RQF.A78

18. V.Montabonnet - Safety during Hardware Commissioning 18 October 2007 18 Autorisation de Travail Form