1. Review of Sector 45 - 28th of February 20081 Electrical Safety for the interventions during Hardware Commissioning of LHC Anne Funken, TS-ICC

2. Review of Sector 45 - 28th of February 20082 Contents  The procedures in matter of electrical safety  The Electrical Safety Subsectors  How is electrical safety managed ?  How do we proceed to authorise an intervention ?  What could be improved for the next sectors ?

3. Review of Sector 45 - 28th of February 20083 The procedures in matter of electrical safety  General procedure, EDMS 885122 : Identification of the voltage sources and the electrical risks generated Status of the voltage sources during the different phases of HC The UTE C 18-510 applied to HC : consignation in two steps, who does what ? The documents required (Yellow papers) The CERN safety regulation shall be strictly followed, more particularly the Electrical Safety Code C1 which stipulates to follow the instructions of the UTE C 18-510  Specific procedures per type of intervention : Présentation des câbles DC sur les amenées de courant, EDMS 885123 Première connexion des câbles DC sur les amenées de courant des DFBs après la qualification des circuits à froid, EDMS 887589 Identification of the person assuming each role : who is whom ? The different steps and documents issued  Procedure for the disconnection of the warm parts of SC circuits, EDMS 762293 : Extension of the UTE 18-510 required for the superconducting circuits Zero current measurement to be done in the 2 nd step of consignation

4. Review of Sector 45 - 28th of February 20084 Electrical Safety Subsectors  Definition : An Electrical Safety Subsector is a cryogenic section electrically isolated from the rest of the machine. In some cases, two to three Electrical Safety Subsectors belong to the same Powering Subsector. (Source : Matteo Solfaroli)

5. Review of Sector 45 - 28th of February 20085 Electrical Safety Subsectors  List of the 43 Electrical Safety Subsectors, per sector : IT Q4D2 or D3 Q5*Q6 Q7-Q11 Arc Q6Q5* Q4D2 or D3 IT Sector 1-2 XR1LR1A12ML2.Q5ML2.Q4XL2 Sector 2-3 XR2MR2.Q4MR2.Q5A23A23.Q6--- Sector 3-4 ---A34.Q6A34ML4.Q6ML4.Q5ML4.D3- Sector 4-5 -MR4.D3MR4.Q5MR4.Q6A45LL5XL5 Sector 5-6 XR5LR5A56-ML6.Q5ML6.Q4- Sector 6-7 -MR6.Q4MR6.Q5-A67A67.Q6--- Sector 7-8 ---A78.Q6A78ML8.Q5ML8.Q4XL8 Sector 8-1 XR8MR8.Q4MR8.Q5A81.Q6A81LL1XL1 * Q5D4 for the electrical safety subsectors ML4.Q5 and MR4.Q5

6. Review of Sector 45 - 28th of February 20086 Electrical Safety Subsectors  List of circuits and power converters per Electrical Safety Subsector : http://hcc.web.cern.ch/hcc/safety_subsec.php. http://hcc.web.cern.ch/hcc/safety_subsec.php EDMS 885496 Power Converter Name Circuit Name P. C. Location Circuit TypeDFB Name RPHFD.UA47.RD4.R4RD4.R4UA47IPDDFBML.5R4 RPHH.UA47.RQ5.R4B1RQ5.R4UA47IPQDFBML.5R4 RPHH.UA47.RQ5.R4B2RQ5.R4UA47IPQDFBML.5R4 RPLB.UA47.RCBYH5.R4B2RCBYH5.R4B2UA4780-120A_ RPLB.UA47.RCBYV5.R4B1RCBYV5.R4B1UA4780-120A_ e.g. MR4.Q5  Purpose : First introduced for the ElQA tests (near miss on the 5 th of July 2007) The concept is extended to authorise other types of interventions e.g. interventions on or close to a DFB.

7. Review of Sector 45 - 28th of February 20087 Electrical Safety : how is it managed ?  For each intervention taking place in an environment where an electrical risk is present, a Chargé de Travaux (CT, habilitation B2) shall be appointed : For electrical interventions, the CT belongs to the intervention team For non electrical interventions, the CT belongs to HCC  Since Nov 07, the Chargé de Travaux HCC is Thierry Octave (Norisko)  Management of the 1 st steps of consignation requested by HCC and the autorisations de travail given by HCC done via : Paper folders for the yellow papers Status files for the follow up, accessible at http://hcc.web.cern.ch/hcc/http://hcc.web.cern.ch/hcc/

8. Review of Sector 45 - 28th of February 20088 Electrical Safety : how is it managed ? Done by Thierry Octave Summary Detail per sector

9. Review of Sector 45 - 28th of February 20089 Electrical Safety : how is it done ?  Before the powering tests : All the PC, QHPS and EE systems are consignés in 1 st step (requested by HCC). The requests are done by Electrical Safety Subsectors. The Chargé de Travaux HCC executes the 2 nd step of the consignation The DC cables being not electrically connected to the CL : - The DC cables are short-circuited and grounded (done by HCC) - The CL of the DFBs are short-circuited and grounded (done by ElQA Team)  After the powering tests : All the PC, QHPS and EE systems remain déconsignés If an intervention is required on an Electrical Safety Subsector, this subsector shall be consigné  During the powering tests : The PC, QHPS and EE are déconsignés according to the test program Once one circuit of an Electrical Safety Subsector is déconsigné, no intervention is allowed on the same Electrical Safety Subsector

10. Review of Sector 45 - 28th of February 200810 Electrical Safety : how is it done ?  When ElQA activities take place on an Electrical Safety Subsector, other interventions are NOT allowed on the same Electrical Safety Subsector.  For non electrical interventions, an autorisation de travail is given by the Chargé de Travaux HCC to the Chef de Chantier of the intervention team. To intervene on a DFB, all the circuits of the corresponding Electrical Safety Subsector are consignés (PC, QHPS, EE).  For electrical interventions, the Chargé de Travaux from the intervention team requests the 1st steps of the consignation he/she deems necessary and executes the 2nd step of the consignation according to the procedures established.

11. Review of Sector 45 - 28th of February 200811 Electrical Safety : improvements  All requests for intervention shall be addressed to the HCC Quadrant Owner, the autorisation de travail UTE C 18-510 for non electrical intervention is only a consequence : Autorisation de travail UTE 18-510 HCC Quadrant Owner Intervention Team Leader Request for an intervention Authorizes CT HCC Request to issue the Autorisation de travail UTE 18-510 on EDH

12. Review of Sector 45 - 28th of February 200812 Avis d’Intervention on EDH

13. Review of Sector 45 - 28th of February 200813 Avis d’Intervention on EDH What ? Who ? Where ? When ? Consignation ? VIC ? Approved by: - HCC Quadrant Owner - Safety Coordinator - Chargé de Travaux

14. Review of Sector 45 - 28th of February 200814 Electrical Safety : improvements  All requests for intervention shall be addressed to the HCC Quadrant Owner, the autorisation de travail UTE C 18-510 for non electrical intervention is only a consequence : CT HCC HCC Quadrant Owner Intervention Team Leader Request for an intervention Autorisation de travail UTE 18-510 Authorizes Request to issue the Autorisation de travail UTE 18-510  The autorisation de travail UTE C 18-510 shall be returned to the Chargé de Travaux HCC once the intervention is completed. (1) End (2)

15. Review of Sector 45 - 28th of February 200815 Electrical Safety : improvements  Further analysis of the electrical risk generated by : The 60A circuits and locally powered 80-120A circuits of an Electrical Safety Subsector during an intervention on or close to a DFB of the same Electrical Safety Subsector. The circuits of a DFBA during an intervention on or close to the DFBA of the same Electrical Safety Subsector, e.g. : DFBAD.6R2 & DFBAE.7L3 of A23.  Reactivity assured due to the fact that the Chargé de Travaux HCC was present 5 days a week. From week 8 : two days a week (Tuesday and Thursday) : The requests for déconsignations or autorisations de travail are to be planned accordingly. For urgent interventions which could not be planned accordingly : Chargé de Travaux from TS/EL. To be limited.