Electrical Safety for the interventions during Hardware Commissioning of LHC

Review of Sector 45 - 28th of February 2008 1

Electrical Safety for the interventions duringHardware Commissioning of LHC

Anne Funken, TS-ICC


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 ?


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 2nd step of consignation


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.

D3

QPSarc

A45 LL5

Sector 45

XL5MR4

IT QPS IT PCs

USC55600A

EE

13kA EE

LL5 PCs

ARC PCs

RR53

ARC PCs

13 kA EE

600 EE

D4Q5PCs

D3PCs LL5

QPS

UA47

ITD2 D1Q6 Q5 Q4D4 Q5 Q6

D4Q5QPS

Q6QPS

Q6 PCs

D3QPS

LU

ARC QPS

MR4.D3 MR4.Q5MR4.Q6 A45 LL5 XL5

D3

QPSarc

A45 LL5

Sector 45

XL5MR4

IT QPS IT PCs

USC55600A

EE

13kA EE

LL5 PCs

ARC PCs

RR53

ARC PCs

13 kA EE

600 EE

D4Q5PCs

D3PCs LL5

QPS

UA47

ITD2 D1Q6 Q5 Q4D4 Q5 Q6

D4Q5QPS

Q6QPS

Q6 PCs

D3QPS

LU

ARC QPS

MR4.D3 MR4.Q5MR4.Q6 A45 LL5 XL5

(Source : Matteo Solfaroli)



List of the 43 Electrical Safety Subsectors, per sector :

ITQ4D2

or D3

Q5* Q6 Q7-Q11Arc Q6 Q5*

Q4D2or D3

IT

Sector 1-2 XR1 LR1 A12 ML2.Q5 ML2.Q4 XL2

Sector 2-3 XR2 MR2.Q4 MR2.Q5 A23 A23.Q6 - - -

Sector 3-4 - - - A34.Q6 A34 ML4.Q6 ML4.Q5 ML4.D3 -

Sector 4-5 - MR4.D3 MR4.Q5 MR4.Q6 A45 LL5 XL5

Sector 5-6 XR5 LR5 A56 - ML6.Q5 ML6.Q4 -

Sector 6-7 - MR6.Q4 MR6.Q5 - A67 A67.Q6 - - -

Sector 7-8 - - - A78.Q6 A78 ML8.Q5 ML8.Q4 XL8

Sector 8-1 XR8 MR8.Q4 MR8.Q5 A81.Q6 A81 LL1 XL1

* Q5D4 for the electrical safety subsectors ML4.Q5 and MR4.Q5



List of circuits and power converters per Electrical Safety Subsector : http://hcc.web.cern.ch/hcc/safety_subsec.php. EDMS 885496

Power ConverterName

CircuitName

P. C.Location Circuit Type DFB Name

RPHFD.UA47.RD4.R4 RD4.R4 UA47 IPD DFBML.5R4

RPHH.UA47.RQ5.R4B1 RQ5.R4 UA47 IPQ DFBML.5R4

RPHH.UA47.RQ5.R4B2 RQ5.R4 UA47 IPQ DFBML.5R4

RPLB.UA47.RCBYH5.R4B2 RCBYH5.R4B2 UA47 80-120A _

RPLB.UA47.RCBYV5.R4B1 RCBYV5.R4B1 UA47 80-120A _

e.g. MR4.Q5

Purpose : First introduced for the ElQA tests (near miss on the 5th of July 2007) The concept is extended to authorise other types of interventions

e.g. interventions on or close to a DFB.


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 1st 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/


Electrical Safety : how is it managed ?

Done by Thierry Octave

Summary

Detail per sector


Electrical Safety : how is it done ?

Before the powering tests : All the PC, QHPS and EE systems are consignés in 1st step (requested by HCC).

The requests are done by Electrical Safety Subsectors. The Chargé de Travaux HCC executes the 2nd 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


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.


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 theAutorisation de travail

UTE 18-510

on EDH


Avis d’Intervention on EDH


Avis d’Intervention on EDH

What ?

Who ?

Where ? When ?

Consignation ?

VIC ?

Approved by:

- HCC Quadrant Owner- Safety Coordinator- Chargé de Travaux



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 theAutorisation 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)



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.

Electrical Safety for the interventions during Hardware Commissioning of LHC

Documents

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