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

Review of Sector th of February 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 ?

Review of Sector th of February The procedures in matter of electrical safety  General procedure, EDMS : Identification of the voltage sources and the electrical risks generated Status of the voltage sources during the different phases of HC The UTE C 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  Specific procedures per type of intervention : Présentation des câbles DC sur les amenées de courant, EDMS Première connexion des câbles DC sur les amenées de courant des DFBs après la qualification des circuits à froid, EDMS 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 : Extension of the UTE required for the superconducting circuits Zero current measurement to be done in the 2 nd step of consignation

Review of Sector th of February 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)

Review of Sector th of February 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 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 A78.Q6A78ML8.Q5ML8.Q4XL8 Sector 8-1 XR8MR8.Q4MR8.Q5A81.Q6A81LL1XL1 * Q5D4 for the electrical safety subsectors ML4.Q5 and MR4.Q5

Review of Sector th of February Electrical Safety Subsectors  List of circuits and power converters per Electrical Safety Subsector : EDMS 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.R4B2UA A_ RPLB.UA47.RCBYV5.R4B1RCBYV5.R4B1UA A_ 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.

Review of Sector th of February 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

Review of Sector th of February Electrical Safety : how is it managed ? Done by Thierry Octave Summary Detail per sector

Review of Sector th of February 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

Review of Sector th of February 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.

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

Review of Sector th of February Avis d’Intervention on EDH

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

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

Review of Sector th of February Electrical Safety : improvements  Further analysis of the electrical risk generated by : The 60A circuits and locally powered A 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.