V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

1

Contents

Contents

Electrical circuits in the LHC context Electrical Hazards Preventions Safety Training Habilitation Consignation Flowchart for LHC work

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

2

LHC Electrical Circuit

DFB

EE system

AC

DC

AC

DC

QHPS18kV

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

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

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

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

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 system700 mOhms

AC

DC

Power Converter

10V

550A

385V

395V

385V

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

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

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

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

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

7

Voltage Range / UTE C 18-510

Very Low Voltage

Low Voltage High Voltage

TBTS,P,F BTA BTB HTA HTB

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 MagnetsBTA

- Warm Magnets

BTB

BTA Most of converters HTA - Dipole- Warm Magnets

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

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

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

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/

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)

RR Tunnel: DFB, Current Lead

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

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 forNon Electrical Worker

B0

Habilitation forElectrical WorkerB1, B2, BR, BC

YesNo

No

No

Yes

Yes

BT <30cm

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

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

AT

AT

AC

AC

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

12

1) Separate the equipment from its electrical sources2) 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

1ère étape de consignation

On the work area

2nde étape de consignation

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

13

Procedure: Première Etape de Consignation related to Power

Converters 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

Request Consigne RPHE.UA83.RQD.A78 converter& Measure I=0 on DFBAO.7L8

Chargé de Travaux

1ère 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

2ième étape de consignation

Identify the converter: To be sure that the work will be done on the correct equipment

Chargé Travaux

I=0 @ working point Chargé Travaux

Chargé Consignat. [AB-PO]

V=0, Earthing & Short-circuit Chargé Travaux

Work can start under the responsability of the « Chargé de Travaux » under safe conditions

AC

AC

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

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

ANALYSEHAZARDS:

ELECTRICAL&

OTHERS

~~~~~~~~~~~~~~~~~~~….

~~~~~~~~~~~~~~~~~~~….

~~~~~~~~~~~~~~~~~~~….

~~~~~~~~~~~~~~~~~~~….

AB/PO

~~~~~~~~~~~~~~~~~~~….

~~~~~~~~~~~~~~~~~~~….

~~~~~~~~~~~~~~~~~~~….

~~~~~~~~~~~~~~~~~~~….

AT/MEL

WhereWhat ?

Mr Circuit

C.T.

E.I.C Pt Owner

01

C.T.

OK! PLAN WITH

POINT OWNERAND / OR

E.I.C C.T.

©

OK!

E.I.CPt Owner

When ? 02

REQUEST1ère

ETAPE DECONSIGNATION C.T.

AT/MEL ©

AB/PO

© 03

CONSIGNE1ère

ETAPE AB/PO

©

04

DELIVERATTESTATION

BACK TOC.T. AB/PO

©©©

©©©

©©©

C.T.

©©©

05

DOINTERVENTION

IN SAFECONDITIONS

OK! Work!

El.Ex. Non El.Ex.C.T.

©©©©©©

07

REMOVEMISE A LA

TERREC.T.

©©©©©©

08

DECONSIGNE&

INFORMEIC & P.OWNER

AB/PO

E.I.C

Pt Owner

Done !

AB/PO

©©© ©©

10

GIVE BACK YELLOW

FORM

Job Done.

C.T.

©©© ©

AB/PO

©©© ©©

09

CONSIGNE2ème

ETAPE

V=0V I=0A

VAT VAI MALT

IDs

C.T.

©©©©©©

06

AB/PO

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

15

Documents

Documents:

Attestation de 1ère Etape de Consignation

Autorisation de Travail AT

AT

AC

AC

V.M

on

tab

on

net

- S

afe

ty d

uri

ng

Hard

ware

Com

mis

sion

ing

18

Oct

ob

er

20

07

16