electrical safety for technician

C751 Rev 1 – October 2012October 2012

Ecrit par Initiales Verifie par Initiales Valide par Initiales

S OLYMPIE – Fevrier 2012

SO ME DELSAUT – Fevrier 2012

MED ME DELSAUT – Fevrier 2012

MED

NF C 18-510 FRENCH ELECTRICAL SAFETY

Module L1 / L1V – H1 / H1VELECTRICAL TECHNICIAN2 Days of Training


NF C 18 510 – Electrical Technician L1-H1

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Program

FOR ELECTRICAL TECHNICIANS :FOR ELECTRICAL TECHNICIANS :1 – IP Protection Symbols

2 – Electrical hazards

3 – Voltage ranges

4 – Accreditation certificates

5 – Earthing system diagrams

6 – Works and spot works



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IP SYMBOLS ON ELECTRICALEQUIPMENT



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« IP » Symbols

Marking on equipment = 2 Symbols : First Symbol = Solid in Protection

(Symbols 0 to 6)

2nd Symbol = Liquid in Protection (Symbol 0 to 8)

Example = IP 3.1

An other IK symbol gives the mechanical shock protection



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1st symbol 0 to 6 3rd symbol 0 to 9

Solids penetration Liquids

penetration

Mechanical shocks

0 : non protected1 : 50 mm2 : 12 mm3 : 2,5 mm4 : 1 mm5 : dust6 : hermetical

0 : non protected1 : 0,225 joules3 : 0,5 joules5 : 2 joules(ex: 0,5KG on 0,4m)7 : 6 joules9 : 20 joules

Replaced by IK symbol

0 : non protected1 : vertically2 : at 15°3 : ay 60°4 : projections5 : jet6 : splash water7 : immersion8 : submersion

2nd symbol 0 to 8

« IP » Symbols



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ELECTRICAL HAZARDS

Electrical Hazards at site



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VIDEO 6

« Electrical hazards at site »

Electrical Hazards at siteExercise



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1 - Electrical Panel

2 - Electrical cable on the ground

3 - Multiple socket-outlets

Electrical Hazards at siteExercise Correction

4 - Wires in the socket-outlet

5 - « Jump » on electrical breaker

6 - Bad isolation on breaker



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7 - Worker at site without helmett protection

8 - Engine at site with no earth protection

9 - Engine near OHL


10 - No barricade

11 - Care to the protection zone

12 - Main gate of site is opened



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13 - A technician take an electronic card from a PLC without de-energized the power




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VOLTAGE RANGESREFRESHERS

Voltage ranges



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Voltage rangesRefreshers

Alternative current Continuous current

VLV :VeryLowVoltage

LV : LowVoltage

LV

HV : HighVoltage

HVAHVB

VLV



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Voltage rangesRefreshers

Alternative current Continuous current

VLV :VeryLowVoltage

LV : LowVoltage

LV

HV : HighVoltage

HVAHVB

UN ≤ 50 UN ≤ 120

50< UN ≤ 1000 120 < UN ≤ 1500

1000 < UN ≤ 50 000

UN >50 000

1500 < UN ≤ 75 000

UN > 75 000

VLV

Roger KSPM

Line

Roger KSPM

Text Box

Direct



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Voltage rangesVery Low Voltage : VLV (≤ 50V ~)

FVLV(Functional Very Low Voltage)

PVLV(Protection Very Low Voltage)

SVLV (Safe Very Low Voltage)Metallic

mass Double insulationmassonly 2 wires

Supply with aninsulated transformeror with batteries 12 VDC / 6VDC/….



Hazards with Very Low Voltage Electrical Hazards exist in Very Low Voltage. Very Low Voltage could be as dangerous as Low viltage : Short-circuit electrical fault current in Very Low Voltage situation ;

Short-circuit fault current in Very Low Voltage : • In FVLV for any range of Voltage ; • In SVLV for a voltage greater than 25 Vac and 60 Vdc ;• In PVLV for a voltage greater than 12 Vac and 25 Vdc.

Voltage rangesVery Low Voltage : VLV (≤ 50V ~)

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ACCREDITATION CERTIFICATES

Accreditation certificates



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Accreditation certificatesExercise

Electrical safety accreditation is necessary for : Yes No

Have access without supervision in electrical room

Perform electrical works or spot worksIn charge of electrical works or spot works and non electrical worksPerform electrical tests, measures, or electrical checksEnsure Electrical safety supervisor



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Yes NoX

X

x X

X

X

Have access without supervision in electrical room

Perform electrical works or spot worksIn charge of electrical works or spot works and non electrical worksPerform electrical tests, measures, or electrical checksEnsure Electrical safety supervisor

Electrical safety accreditation is necessary for :




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Accreditation certificatesThe standard

Isolated distribution Zone 1 DLVS LV & HV Zone 2 DLVR HV

NO ACCREDITATION !

No accreditation

is required

No accreditation

is required

No accreditation

is required

No accreditation

is required

No accreditation

is required

No accreditation

is required

FORBIDDEN !

NonElectrical

WorkFor

MaintenanceOr production

NonElectrical

WorkOther type

In charge of work

In charge of work

In charge of workPerformer Performer Performer

LV

LV

HV

HV



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nettoyage

Zone 2 DLVR

HV

Zone 3 DMA

HV

Zone 4 DMA LV

Zone 1 DLVS

LV & HV

Isolated Distribution

HV

LV

Performer

Performer

Performer

Performer

Performer

Performer

In chargeO

f work

In chargeO

f work

In chargeO

f work

In chargeO

f work

In chargeO

f work

In chargeO

f work

NO ACCREDITATION !

NO ACCREDITATION !

Work off-voltage Work with voltage


PrasitPh

Text Box

L1

PrasitPh

Text Box

L2

PrasitPh

Text Box

L1V

PrasitPh

Text Box

L2V

PrasitPh

Text Box

L1

PrasitPh

Text Box

L2

PrasitPh

Text Box

L1T L1N

PrasitPh

Text Box

L1T L1N

PrasitPh

Rectangle

PrasitPh

Text Box

H1

PrasitPh

Text Box

H2

PrasitPh

Text Box

H1

PrasitPh

Text Box

H2

PrasitPh

Text Box

H1T H1N

PrasitPh

Text Box

H1V

PrasitPh

Text Box

H2V

PrasitPh

Text Box

H2T H2N



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SPOT WORKSIn Charge Of

isolations

LV

HV

Zones 1,2 and 4

Zones1,2 and 4

Off-voltageAnd off Zone 4

Specific WORKS

Specific WORKSZones 1, 2 and 4

In charge of work

PerformerL

* LE and HE certificates must be completed with test, Measuring, checking or Manoeuvre


PrasitPh

Text Box

LC

PrasitPh

Text Box

HC

PrasitPh

Text Box

LR

PrasitPh

Text Box

LS

PrasitPh

Text Box

LE *

PrasitPh

Text Box

HE *

PrasitPh

Text Box

LP

PrasitPh

Text Box

HP

PrasitPh

Text Box

L1X

PrasitPh

Text Box

H1X

PrasitPh

Text Box

L2X

PrasitPh

Text Box

H1X



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Accreditation certificatesResponsibilities

Level zero «0»

Level one «1»

Level two «2»

Non electrician. Person who is accredited.

Electrical technician. Able to ensure his own safety.

Electrical supervisor. Able to ensure his own safety and for others.



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Exercise

Accreditation certificates"0". "1". "V"




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Electrical safety accreditation procedure

• Adequate electrical safety training

• Abilities after test evaluation.

• Deliveries of electrical safety accreditations.

Accreditation certificatesRefreshers



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He ensures his own safety

He has to follow instructions from the supervisor

Start work only with work order / work permit

Respect the boundaries (DMA / DLVR / DLVS)

Wear personal protective equipment (PPE)

Use only adequate tools

Check and maintain tools

Accreditation certificatesElectrical Technician



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EARTHING SYSTEM DIAGRAMS

Earthing System Diagrams



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In L.V

Electrical distribution is in general with: • 3 phases• Neutral conductor (not always distributed)

If the neutral conductor is distributed : • it is directly connected to earth• it is not connected to earth.




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Three possible diagrams :

T Neutral is connected to earthI Neutral is connected to earth through one impedance

T mass of equipment is connected to earthN Mass of equipment is connected to Neutral conductor

1st letter the

Neutral connection

2nd letterthe

Mass connection




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TT diagram : Neutral conductor connected to earth & Mass of equipment connected to earth

IT diagram : Neutral conductor connected to earth through an impedance Mass of equipment connected to earth

TN diagram : Neutral conductor connected to earth Mass of equipment connected to Neutral conductor




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TT Neutral conductor and mass connected to earth

TNS Neutral conductor connected to earth, Mass connected to neutral. Neutral and earth are separated.

TNC Neutral conductor connected to earth, Mass connected to neutral. Neutral and earth are combined.

TNCS Neutral conductor connected to earth, Mass connected to neutral. Mix diagrams TNS & TNCIT Neutral isolated or impedant and and mass connected to earth

The 5 diagrams




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TT DIAGRAM

Ph 1

Ph 2

Ph 3

N

RmRn




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IT DIAGRAM

Ph 1

Ph 2

Ph 3

N

RmRn

CPI

Neutre isolé galvaniquement ou impédent limitant le courant du 1er défaut d'isolement à une valeur telle que le potentiel des masses ne puisse atteindre un seuil dangereux




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SCHEMA TNC

Ph 1

Ph 2

Ph 3

Rn

PEN




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SCHEMA TNS

Ph 1

Ph 2

Ph 3

N

PE

Rn




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Les régimes de neutre

TNC DIAGRAM

Ph 1

Ph 2

Ph 3

Rn

PEN



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TNS DIAGRAM

Ph 1

Ph 2

Ph 3

N

PE




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WORKS AND SPOT WORKS

Works and Spot Works



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Works

HV

LV

HV

LV

It needs preparationIs short in duration, It needs

analyse at site

Spot works

Works and Spot Works



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Works :

•Realise•Maintain•Modify•Répair

An electrical network,A network at the vicinity of live equipment.

Works and Spot WorksElectrical Works



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Electrical technician must have :

The person in charge of works must :

Works must be performed prior to the adequate boundary

• Level 1 minimum accreditation and have a work order / work permit

• Write safety procedures and Job safety analyses

Works and Spot WorksElectrical Works



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Specific supply of a part of a network distribution

After isolation of a part of a network, test of this part using an auxiliary power supply (small generator).

Works and Spot WorksUse of an auxiliary power supply

electrical safety for technician

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