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Improved monitoring and protection RCD-based protection plan COMBT13FR-11/02

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Page 1: RCD Protection

Improved monitoring and protectionRCD-based protection plan

COMBT13FR-11/02

Page 2: RCD Protection

COMBT13FR-11/02 2

Contents

Protection of life and property 3 standard IEC 60479-1 standard IEC 60364 fire protection Disturbances on distribution systems 23 earth-leakage currents non-linear loads overvoltage disturbances Vigirex 27 four mesurement features protection on disturbed distribution systems Applications 36 EMC tests and voltage-dip immunity measurement of fault currents with a DC component RCD coordination protection plans for different system earthing arrangements load leakage currents Vigirex - installation of toroids protection of property

Page 3: RCD Protection

COMBT13FR-11/02 3

Impedance of the human body ZT UC = ZT ID

ZT depends on:

the frequency the touch voltage the path through the body

Protection of life and propertyStandard IEC 60479-1

Internalresistance = ZT

UCZT ID

E92

455

Skin(hand)

Skin(foot)

Page 4: RCD Protection

COMBT13FR-11/02 4

Impedance of the human body ZT UC = ZT ID

ZT depends on:

the frequency the touch voltage the path through the body

The level of danger depends on: the current ID

the duration of current flow

Protection of life and property Standard IEC 60479-1

UCZT

ID

ID

E92

456

Internalresistance = ZT

Skin(hand)

Skin(foot)

Page 5: RCD Protection

COMBT13FR-11/02 5

T(ms)

5000

(mA)0.230 mA

0.1

20001000500

200100

50

2010

10 000

1 2 5 10 50005000.5 mA

100

4321

c3b c2c1

20001000

Time/current zones defining the effects of AC current(15 Hz to 100 Hz)

Protection of life and propertyStandard IEC 60479-1

Zone 1 : perception

Zone 2 : unpleasant sensation

Zone 3 : muscular contractionsb (10 mA) let-go threshold

Zone 4 : risk of ventricular fibrillation(cardiac arrest)c1 (30 mA)

b - c1 : probability 0 %

c1 - c2 : probability ~ 5 %

c2 - c3 : probability ~ 50 %

> c3 : probability > 50 %

E92

444

Duration of current flow

Current flowing through the body

Page 6: RCD Protection

COMBT13FR-11/02 6

Critical current thresholds

Protection of life and propertyStandard IEC 60479-1

Cardiac arrest

Irreversible cardiacfibrillation

Breathing arrest

Muscular contraction

Tingling

1 A

75 mA

30 mA

10mA

0.5 mA

mAE

9245

0

Page 7: RCD Protection

COMBT13FR-11/02 7

Effect of frequency

Protection of life and propertyStandard IEC 60479-1

The human body is most sensitive to frequenciesin the 50 Hz / 60 Hz range

Current-sensitivity thresholds(mA)

E92

451

(f)30

100

500

50 100 1000DC

Page 8: RCD Protection

COMBT13FR-11/02 8

50 V < Uo 120 V 120 V < Uo 230 V 230 V < Uo 400 V Uo 400 V

Disconnecting time (s) AC DC AC DC AC DC AC DC

TN or IT system 0.8 5 0.4 5 0.2 0.4 0.1 0.1

TT system 0.3 5 0.2 0.4 0.07 0.2 0.04 0.1

Standard IEC 60364 converts the current/exposure-time curves ofstandard IEC 60479-1 into tables presenting the disconnecting-time versus the nominal AC-voltage (Uo)

From table 41A of standard IEC 60364

Protection of life and propertyStandard IEC 60364

Page 9: RCD Protection

COMBT13FR-11/02 9

Direct contact "Contact of persons or livestock with live parts of the installation"

Protection of life and propertyStandard IEC 60364

E92

458

Uc

E92

459

Equivalent electrical circuit

Page 10: RCD Protection

COMBT13FR-11/02 10

Out of reachInsulation

IP2X or IPXXB ELV < 25 V 30 mA

Direct contact

Protection of life and propertyStandard IEC 60364

E95

155

Page 11: RCD Protection

COMBT13FR-11/02 11

Indirect contact “Contact of persons or livestock with exposed conductive parts in case

of a fault”

Protection of life and property

E92

454

Standard IEC 60364

Uc

E92

460

Equivalent electrical circuit

Page 12: RCD Protection

COMBT13FR-11/02 12

Standard IEC 60364 defines three system earthing arrangementsto ensure:

Protection of persons against indirect contactProtection against fire hazards

TT system TN system IT system

RCD protection is a fundamental part of the TT system

E568

87

Protection of life and propertyStandard IEC 60364

Page 13: RCD Protection

COMBT13FR-11/02 13

TT system The neutral point of the LV transformer is directly connected to an earth electrode The exposed conductive parts

of the installation are connected to a separate earth electrode

Protection of life and propertyStandard IEC 60364

E95

152

L1L2L3N

RuRn

PE

Page 14: RCD Protection

COMBT13FR-11/02 14

TT systemEarth fault protectionValue of fault currentId = Uo / (Rn + Ru)

= 230 / (10 + 10)= 11.5 A

Ud = Ru x Id= 10 x 11.5= 115 V > UL = 50 V

The fault current createsa dangerous touch voltage

The SCPD is not capableof clearing this type of fault

Protection of life and propertyStandard IEC 60364

E95

153

Load

L1L2L3N

Uo = 230 V

400/230 V

Ru10 Ω

Rn10 Ω

Ud =115 V

Metal exposed conductive partId = 11.5 A

Page 15: RCD Protection

COMBT13FR-11/02 15

TT system Earth fault protectionSolution The SCPD is not capable of

clearing this type of fault (ST setting = 25 A) The solution is a residual-current

device (RCD) designed for the protection of persons

Tripping conditions UCmax UL

Ru x In < UL

(In is the setting for the RCD) In = UL / Ru

= 50 /10= 5 A

SCPD 25 A

400/230 V

Load

L1L2L3N

Ru10 Ω

Rn10 Ω

Uo = 230 V

In = 5A

Protection of life and propertyStandard IEC 60364

E95

154

Metal exposed conductive part

Page 16: RCD Protection

COMBT13FR-11/02 16

At A

I1 + I2 + I3 + IN = IPE Well designed network IPE = 0

Protection of life and propertyStandard IEC 60364

L1L2L3NPE

E92

457

I1 + I2 + I3 + IN = 0

IPE = 0

A

Current in the neutral does not depend on current IPE equal to unbalanced load

currents and/or 3rd orderharmonics (3 k)

IN = Iunbalance + I3 k

TT system

RuRn

Page 17: RCD Protection

COMBT13FR-11/02 17

Measurement of current IPE can be used for protection of persons(values depend on the earthing arrangement) and protection against fire hazards. However, it is necessary to detect the true IPE

Faulty distribution system IPE 0

Protection of life and propertyStandard IEC 60364

L1L2L3NPE

E94

409

I1 + I2 + I3 + IN 0

IPE 0

A

Current in the neutral does not depend on current IPE equal to unbalanced load

currents and/or 3rd orderharmonics (3 k) IN = Iunbalance + I3 k

TT system

RuRn

Page 18: RCD Protection

COMBT13FR-11/02 18

"Deep" earth the earth does not act as an insulator

Protection of life and propertyStandard IEC 60364

"Deep" earth

E92

452

E92

453

Equivalent electrical circuit "Deep" earth is equipotential in nature…

1000 km

1 Ω 15 Ω 10 Ω 10 Ω 5 Ω

"Deep" earth

11 Ω

… whatever the distance!

Page 19: RCD Protection

COMBT13FR-11/02 19

Study carried out in Germany between 1980 and 1990

41% of fires are electrical in origin this risk is far from negligible it can be eliminated

Protection of life and property

Risk analysis - the origins of fires in buildings

E92

446

Fire 37%

Accidents 7%

Lightning 1% Explosions 1%

Electricity 41%Cigarettes 6% Other 7%

Fire protection

Page 20: RCD Protection

COMBT13FR-11/02 20

Ageing of the installation results in: less effective insulation the risk of very small leakage currents Presence of humidity

There is a real risk of fire starting at leakage currents of 300 mA

Main cause

Leakagecurrents

Smalldischarges

Carbonisationof insulation

(dust)

E92

462

E92

461

Protection of life and propertyFire protection

Page 21: RCD Protection

COMBT13FR-11/02 21

Standard IEC 60364, section 3-32, defines premises presenting arisk of fire (BE2) or explosion (BE3)

Standard IEC 60364, section 4-48, deals with premises where there is a risk of fire

imposes use of a 500 mA RCD device recommends use of a TT or IT system for the electrical installation

in such premises prohibits use of a TN-C system

In TT, IT and TN-S systems, a 300 mA RCD eliminates the risk of fire

Standard IEC 60364

IEC 60364

E94

550

Protection of life and propertyFire protection

Page 22: RCD Protection

COMBT13FR-11/02 22

The National Electrical Code (NEC) defines a TN-S system the neutral conductor is not interrupted the PE protective conductor is created by connecting the metal parts

of the equipment The NEC considers that the TN-S system cannot control

the impedance of the insulation-fault loop

The NEC requires specific ground fault protection) (GFP) to protect against fire hazards (maximum setting of 1200 A)

N

In the USA

E92

447

Protection of life and propertyFire protection

Page 23: RCD Protection

COMBT13FR-11/02 23

Cable leakage capacitance continuous leakage current

called "natural leakage current"

Disturbances on distribution systemsEarth-leakage currents

E92

463

Load leakage capacitance continuous leakage current

called "intentional leakage current"

E92

449

N

L1

Page 24: RCD Protection

COMBT13FR-11/02 24

0

20

80

40

60

%

100

1 3 5 7 9 11 13

Harmonic currents non-linear loads cause harmonic currents, as a result, the intentional leakage currents are "amplified"

Disturbances on distribution systemsNon-linear loads

Amplitude

HarmonicorderE

9246

4

IH E94

410

VSD

Page 25: RCD Protection

COMBT13FR-11/02 25

E92

465

- E92

499

Fault currents fault currents have DC components

Disturbances on distribution systemsNon-linear loads

PEUPS

Page 26: RCD Protection

COMBT13FR-11/02 26

Lightning and switching overvoltages cause high transient currentsin distribution-system leakage capacitances

Current in the PE

Disturbances on distribution systemsOvervoltages (surges)

E94

167

Ir1

A

0

2

4

6

-2

-4

-6

T(s)0,02 0,040

10

E94

412

Page 27: RCD Protection

COMBT13FR-11/02 27

Vigirex implements four functions to: analyse leakage currents to avoid nuisance tripping trip immediately when required for the protection of persons

VigirexFour mesurement features

Reduced tolerances

Rmsmeasurement

Inverse time

Frequency filtering

E94

411

Page 28: RCD Protection

COMBT13FR-11/02 28

2

15 x30 mA

5 x30 mA

1 x30 mA

In

50/60 Hz 1000 Hz 10 KHz

1

2

Filtering of harmonic frequencies frequency converters create leakage currents

with high harmonic components

Vigirex

Analyse leakage currents

E94

414

E94

413

Eliminatenuisance tripping

a /a

M

ihfPE

Ich ihf = ihf

Ich = 0

ihf

3

the RCD must not trip 3

these currents are not dangerous 1

Four mesurement features

Page 29: RCD Protection

COMBT13FR-11/02 29

2

RMS measurement non-linear loads can cause leakage currents with high

form factors 1

E94

415

2

RMS measurement is the means to react only to dangerous currents

Eliminatenuisance tripping

1

T (ms)

I

+ In

In

Vigirex

Analyse leakage currents

Four mesurement features

Page 30: RCD Protection

COMBT13FR-11/02 30

Reduced tolerances RCDs never operate below 50% of In RCDs always operate at 100% of In

E94

416

Vigirex has a non-operating current equal to 80% of In,i.e. better immunity to both natural and intentional leakage currents

I faultStandard RCD

Vigirex

OperationNon-operation

0.8 In InIn2

Eliminatenuisance tripping

Vigirex

Analyse leakage currents

Four mesurement features

Page 31: RCD Protection

COMBT13FR-11/02 31

10

T (s)

I

1

2 5

0,3

0,15

0,04

0,1

0,01

1

2

31

1

these currents must not tripthe RCD

Inverse time

energisation of loadswith filters can create major

inrush currents

E94

417

Eliminatenuisance tripping

Vigirex

Analyse leakage currents

2

Four mesurement features

Vigirex does not trip 3

Page 32: RCD Protection

COMBT13FR-11/02 32

10

T (s)

I

1

2 5

0,3

0,15

0,04

0,1

0,01

1

1

Inverse time

dangerous faults can occur 1

Vigirex

E94

418

Schneider guarantees the break time for a Vigirex combined with circuit breakers rated up to 630 A, even for the 30 mA threshold

Ensureeffectiveprotectionof persons

2

Four mesurement features

Vigirex, combinedwith a Compact NS, has an

instantaneous total break time that complies with table B1 of standard IEC 60947-2, appendix B 2

Page 33: RCD Protection

COMBT13FR-11/02 33

Test standard Standardised test as per IEC 60947-2 Vigirex testsElectrostatic-discharge 8 kV contact 8 kV contactimmunity test 8 kV in air 15 kV in airRadiated EM-field 10 V/m 12 V/mimmunity test 80 to 1000 MHz modulated at 1 kHz 80 to 1000 MHz modulated at 1 kHzSurge immunity test - On supply > 100 V AC - For all supplies (*)

4 kV line-to-earth, 4 kV line-to-line 4 kV line-to-earth, 4 kV line-to-line - On supply < 100 V AC - On supply < 100 V AC2 kV line-to-earth, 1 kV line-to-line 4 kV line-to-earth, 4 kV line-to-line - On DC supply - On DC supply 0.5 kV line-to-earth, 0.5 kV line-to-line 2 kV line-to-earth, 1 kV line-to-line - On input/output (I/O) - On input/output (I/O) 2 kV line-to-earth, 1 kV line-to-line 2 kV line-to-earth, 1 kV line-to-line 1.2/50 s wave, open circuit 1.2/50 s wave, open circuit 8/20 s short circuit 8/20 s short circuit

Voltage-dip Single-phase supply: Us 85 V Single-phase supply: Us 85 Vimmunity test Three-phase supply: Us 70%

Vigirex goes beyond the maximum requirements of standard IEC 60947-2 for EMC immunity

Protection on disturbed distribution systemsEMC tests and voltage-dip immunity

(*) for V AC < 48 V, the Vigirex relay does not have a supply transformer

Page 34: RCD Protection

COMBT13FR-11/02 34

T

I IfFault

Loads Linear - frequent Non-linear - frequent Non-linear - rare

Examples Lamps Dimmers, soft starters (*) Variable-speed drives AC motors Variable-speed drives with accessible

Capacitors braking resistors

RCD Type AC Type A Type B

Classification of faults and types of RCDs

Measurement of fault currents with a DC component

For power distribution, a type A RCD is required for effective protection against insulation fault

T

I If

T

I If

E94

419

Protection on disturbed distribution systems

(*) Type ACis sufficient

Page 35: RCD Protection

COMBT13FR-11/02 35

Combination of different types of RCDs

Measurement of fault currents with a DC component

Different types of RCDs may be combined as long as noneof the devices are blocked by the fault current

E94

441

Class IIinsulation

type ARCD2

type BRCD2

type A ortype AC RCD

type ARCD

type AVigirexRCD1

300 mAinst

type AVigirexRCD1

300 mA60 ms

Protection on disturbed distribution systems

Page 36: RCD Protection

COMBT13FR-11/02 36

Discrimination rules

two conditions: In (RCD1) > 2 In (RCD2)t (RCD1) > t (RCD2) + t (CB2)(including the interrupting time)

To implement condition , it is necessary to know the total break time guaranteed for the CB2 + RCD2 combination or to run tests on the combination

ApplicationsRCD coordination

CB1RCD1

CB2RCD2

E94

442

2

1

2

Page 37: RCD Protection

COMBT13FR-11/02 37

2

1

Condition is automatically obtained for (RCD2) +1 if RCD2is combined with a circuit breaker/switch disconnector fromthe Multi 9 or Compact ranges

Discrimination rules

two conditions: In (RCD1) > 2 In (RCD2)setting (RCD1) setting (RCD2) +1

ApplicationsCoordination of RCDs

CB1

RCD1

CB2

RCD2

E94

442

2

Page 38: RCD Protection

COMBT13FR-11/02 38

Discrimination rules with a Vigirex upstream

two conditions: In (RCD1) > 1.5 Insetting (RCD1) setting (RCD2) +1

ApplicationsCoordination of RCDs

CB1

RCD1

CB2

RCD2

E94

442

Vigirex2

1

Condition is automatically obtained for (RCD2) +1 if RCD2is combined with a circuit breaker/switch disconnector fromthe Multi 9 or Compact ranges

2

Page 39: RCD Protection

COMBT13FR-11/02 39

RCD1

Protection plans for different system earthing arrangements

In current setting on upstream RCD

E94

479

CB1

CB2

RCD2

E94

478

2,5 A 5 A 1 s

standardised rules (maximum): In = 5 A t = 1 sUL = 50 VRT = 10

In t

Applications

TT system

Page 40: RCD Protection

COMBT13FR-11/02 40

CB1RCD1

CB2

E94

478

In current setting on upstream RCD standardised rules (maximum): In = 5 A t = 1 s

E94

479

ProcessILA

Example. NS250 Vigi 3 A

BA

20 VSDsILB

leakage-current IL withstand (min.):

In t

310150

60

0

0,03 (t = 0)

1

0,3

t(ms)

In(A)

10

HS

T R3 vigi MH

200 / 440 V - 5

vigiNS 250

2 4 6

1 3 5N

Vigi 3 ANS250

Protection plans for different system earthing arrangementsApplications

TT system

In 2 IL = 1.1 A In = 3 AILA = 150 mAILB = 400 mAIL = 550 mA

3 A1,5 A0,55

IL

5 A 1 s

Page 41: RCD Protection

COMBT13FR-11/02 41

2,5 A 5 A 1 s

Vigirex

CB1RCD1

E94

478

In current setting on upstream RCD

standardised rules (maximum): In = 5 A t = 1 s

E94

479

ProcessILA

BA

20 VSDsILB leakage-current IL withstand (min.):

In tMERLIN GERIN

RH99 1ANS250

Example. Vigirex RH99

Protection plans for different system earthing arrangementsApplications

TT system

In 1.5 IL = 825 mA In = 1 AILA = 150 mAILB = 400 mAIL = 550 mA

1 A0,7 A0,55

IL

5 A 1 s

Page 42: RCD Protection

COMBT13FR-11/02 42

?

60 ms

t1 > t2 + break time CB2

5 A3 A0,55

IL

1 s1,5 A

leakage-current IL withstand (min.): In 2 IL = 1.1 A In = 3 A discrimination rules

CB1RCD1

CB2

RCD2

E94

478

In current setting on upstream RCD standardised rules (maximum): In = 5 A t = 1 s

E94

479

In t

Protection plans for different system earthing arrangementsApplications

TT system

In1 In2 x 2 = 600 mA In = 1 A

RCD2300 mA - s

300 mA

In2

Page 43: RCD Protection

COMBT13FR-11/02 43

setting RCD1 setting RCD2 + 1

150 ms

60 ms

310150

60

0

0,03 (t = 0)

1

0,3

t(ms)

In(A)

10

HS

T R150

vigi MH200 / 440 V - 5

vigiNS 250

2 4 6

1 3 5N3

NS250 Vigi3 A - 150 ms 5 A3 A0,55

IL

1 s1,5 A

leakage-current IL withstand (min.): In 1,5 IL = 825 mA In = 3 A discrimination rules (Schneider)

CB1RCD1

CB2

RCD2

E94

478

In current setting on upstream RCD standardised rules (maximum): In = 5 A t = 1 s

E94

479

In t

Protection plans for different system earthing arrangementsApplications

TT system

In1 In2 x 2 = 600 mA In = 1 A

300 mA

In2

RCD2C60 Vigi if s 300 mA

RCD1NS250Vigi

Page 44: RCD Protection

COMBT13FR-11/02 44

150 ms

60 ms

setting RCD1 setting RCD2 + 1

MERLIN GERIN

1 A - 150 msRH99

5 A1 A0,55

IL

1 s0,7 A0,3

discrimination rules

CB1RCD1

CB2

RCD2

E94

478

In current setting on upstream RCD standardised rules (maximum): In = 5 A t = 1 s leakage-current IL withstand (min.): In 1.5 IL = 825 mA In = 1A

E94

479

Vigirex In t

Protection plans for different system earthing arrangementsApplications

TT system

300 mA

In2

In In x 1.5 = 450 mA In = 0.5 A

C60 VigiIf s 300 mA

Page 45: RCD Protection

COMBT13FR-11/02 45

In < 5 A

In < 10 A In < 5 A

Implementation In3 < = 5 A, In2 < = 10 A, In1 < min , = 5 A50 V10

50 V 5

5010

50 V 5

Standardised rule An RCD must be installed at the head of the installation and at thehead of each group of separately earthed exposed conductive parts Settings: current setting In < UL/RT

delay T < 1s

RCD 1RCD 2 RCD 3

RT RT RT

UL

Protection plans for different system earthing arrangementsApplications

RCD at the head

Basic principle

1 5 10

UL = 50 V

Page 46: RCD Protection

COMBT13FR-11/02 46

System leakage capacitance (µF) First-fault current1 70 mA5 360 mA30 2.17 A

Typical leakage currents following a first fault

Standardised ruleIEC 60364-5-53: The RCD current settings must be greater than twice the first-fault current

In setting300 mA1 A5 A

Protection plans for different system earthing arrangementsApplications

TT system

Page 47: RCD Protection

COMBT13FR-11/02 47

Leakage currents IL are due to the natural or intentional capacitances installed between the phases and earth cable leakage currents

Applications

E94

472

Differential-mode capacitance Common-mode capacitanceStandard cable (not shielded) 20 pF/m 150 pF/mShielded cable 30 pF/m 200 pF/m

leakage currents of computer equipment

requirement for RCD protection - an RCD must not trip for these natural currents, yet must protect life and property

Computer equipment Standard IEC 60950 Maximum leakage current (mA)All equipment 0.25

PC Type A fixed or mobile 3.5Computer room Type B fixed 3.5 or 5% In

Equipment

Load leakage currents

Page 48: RCD Protection

COMBT13FR-11/02 48

Implementation of RCDs

for RCDs protecting power outlets, In = 30 mA, IL must therefore not exceed 15 mA

Example. Maximum of 4 PCs per set of outlets

ID6330 mA

IL = 3.5 mAPC

E94

473

for RCDs upstream of a set of loads on a TT system

calculate current IL

RCD current setting In must be greater than 2 IL

check that In < UL / RT

E94

474

IL2 IL1

IL = m IL2 + n IL

xnxm

In?

ApplicationsLoad leakage currents

Page 49: RCD Protection

COMBT13FR-11/02 49

ApplicationsVigirex - installation of toroids

Recommendations centre the conductors respect the operational current In of the toroid, corresponding to a 30 mA operating threshold, on a 6 In overload

E94

484

Improve immunity to disturbances use a toroid with a larger diameter delay the protection function (< 1s) install a magnetic sleeveE

9452

3E

9452

4

< 15 mA

6 In

Toroid mounting on multi-conductor cable with PE run the PE back down through the toroid

Page 50: RCD Protection

COMBT13FR-11/02 50

Protection of motors (TN-S system)

a low insulation fault can cause a short-circuit an RCD with a current setting between 3 and 30 A avoids this risk

ApplicationsProtection of property

R

M

E94

458

MERLIN GERINVigirex

Page 51: RCD Protection

COMBT13FR-11/02 51

PEPEN

A

N

Monitored system

T

PEN

E94

481

N

PE PEPEN

A

N

Monitored system

T

PE

PEN

A

N

Monitored system

T

Toroid T measures all the fault currents downstream of A the neutral is not earthed downstream of A the system earthing arrangement is TT or TN-S TT/ RCD - MS a few A

TN-S RCD - BS / RS-type GFP a few 100 A Protection of life and property

Protecting downstream

ApplicationsProtection of property

Page 52: RCD Protection

COMBT13FR-11/02 52

E94

482PE source

NPEN

PE

ApplicationsProtection of property

Protecting upstream

Page 53: RCD Protection

COMBT13FR-11/02 53

PE amont

PEN amontN amont

PE

E94

482

Toroid T measures all the fault currents upstream of A the neutral is not earthed upstream of A the downstream system earthing arrangement is TN-S, the upstream

system earthing arrangement is TN-C

Monitored system

T

A

PE source

NPEN

PE

ApplicationsProtection of property

Protecting upstream

Page 54: RCD Protection

COMBT13FR-11/02 54

PE amont

PEN amontN amont

PE

E94

482

Monitored system

PEN

PE

T

A

ApplicationsProtection of property

Protecting upstream

Page 55: RCD Protection

COMBT13FR-11/02 55

E94

482

Monitored system

PE source

PEN

PE

T

A

RCD - BS / RS-type GFP The fault current is a few 100 A

ApplicationsProtection of property

Protecting upstream

Page 56: RCD Protection

COMBT13FR-11/02 56

PE amont

PEN amontN amont

PE

E94

482

Monitored system

PE source PE

T

A

2nd source

Protection and/or decoupling of sources

ApplicationsProtection of property

Protecting upstream

Page 57: RCD Protection

COMBT13FR-11/02 57

E94

482PE source

PEN

PET

AMonitored system

SGR

ApplicationsProtection of property

Protecting upstream

Page 58: RCD Protection

COMBT13FR-11/02 58

PE amont

PEN amontN amont

PE

E94

482

PEN

PET

AMonitored system

N

SGR

Note. SGR-type GFP measures the upstream and downstream currents

ApplicationsProtection of property

Protecting upstream

Page 59: RCD Protection

COMBT13FR-11/02 59

PE amont

PEN amontN amont

PE

E94

482

Toroid T measures all the fault currents upstream of A the neutral is not earthed upstream of A the downstream system earthing arrangement is TN-S, the upstream is TN-C

Monitored system

T

A

PE source

NPEN

PE

RCD - BS / RS-type GFPThe fault current is a few 100 A Nota : GFP de type SGR mesure les

courants amont et aval Protection and/or decoupling of sourcesNote. SGR-type GFP measures the upstream and downstream currents

ApplicationsProtection of property

Protecting upstream

Page 60: RCD Protection

COMBT13FR-11/02 60

Upstream system earthing arrangement is TN-C

L

N

PE

PENPE

R

Purpose protection of generators

Restricted Earth Fault (REF)

Unprotectedzone

Protectedzone

E94

483

Generator

Generatorshutdown

RS-type GFP or RCD - BS

ApplicationsProtection of property

Page 61: RCD Protection

COMBT13FR-11/02 61

L

N

PE

PENPE

R

PENPE

R

Generator no. 1

Purpose continuity of service (parallel-connected generators) elimination of a generator if an insulation fault occurs

E94

384

Unprotectedzone

Protectedzone

Generator no. 2

RS-type GFP or RCD - BS

Restricted Earth Fault (REF) - Multisource diagram

ApplicationsProtection of property