11.example calculation -transformer

8/11/2019 11.Example Calculation -Transformer

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High-Tech RangeIRI1-ER(Stablized Earth Fault Current Relay)

C&S Electric Limited(Protection & Control Division)


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IRI1-ER- Stablized Earth Fault Current Relay

2

Contents

1. Introduction

2. Applications

3. Characteristics and features

4. Design

4.1 Connections

4.1.1 Analog inputs

4.1.2 Output relays

4.2 Front plate4.2.1 LEDs

4.2.2 DIP-switches

4.2.3 push button

4.3 Code jumper

5. Working principle

6. Operations and settings

6.1 Layout of the operating elements

6.2 Set ting of the p ick-up value for thedifferential current ID

6.2.1 Indication of fault

6.3 Reset

6.3.1 Reset by pressing the pushbutton

6.3.2 Automatic reset

6.4 Calculation of the tripping current andthe stabilizing resistance

6.4.1 Sample calculation - alternator

6.4.2 Example calculation - transformer

6.5 Application of IRI1-3ER relay as HighImpedance Bus Differential Protection

7. Housing

7.1 Individual housing

7.2 Rack mounting7.3 Terminal connections

8. Relay testing and commissioning

8.1 Power On

8.2 Checking the set values

8.3 Secondary injection test

8.3.1 Test equipment

8.3.2 Example of a test circuit for a IRI1-3ER-relay

8.3.3 Checking the pick-up and tripping values( IR I1-ER)

8.3.4 Checking the operating and resettingvalues (IRI1-3ER)

8.4 Primary injection test

8.5 Maintenance

9. Technical Data

9.1 Measuring input

9.2 Auxiliary voltage

9.3 General data

9.4 Output relay

9.5 System data

9.6 Setting ranges and steps

9.7 Dimensional drawing

10. Order form


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1. Introduction

The application of powerful microprocessors withMR-and IR-relays of the HIGH TECH RANGEprovides alarge variety of advantages over power protectionsystems of the traditional type.

TheMR-protection relays are based exclusively on themicroprocessor technology. They represent our mostefficient generation of power protection systems.

Because of their capabilities to process measuredvalues digitally and to perform arithmetical and logicaloperations, they are superior to the traditional analogsystems.

Besides, the digital protection relays offer importantadditional advantages such as very low powerconsumption, adaptability, flexible construction,selection of relay characteristics etc.

The IR-protect ion re lays are based on themicroprocessor technology or on the analogtechnology. They represent a more cost savinggeneration of relays of the HIGH TECH RANGE,used

for basic equipment protection.

The IR-protection relays are superior to conventionalprotective devices because of their followingcharacteristics:

Integration of multiple protective functions intoone compact housing

User-friendly setting procedure by means of DIP-switches

Compact construction type by SMD-technology

MR-protection relays are used for more complexprotective functions, such as earth fault directional

detection, and also in cases where easy operation,quick fault-analysis and optimal communicationcapabilities are required.

All relays of the HIGH TECH RANGE are availablefor flush mounted installation, as well as for 19 rackmounting. Plug-in technology is used. Of course, allrelays comply with the IEC/DIN regulations requiredfor the specific protection application.

2. Applications

The stabilized earth fault current relay IRI1-ERserves asa supplement for the transformer differential

protection. It allows for example implementation of azero-current differential protection by integrating thestar-point current (IRI1-ER).With the view to its higherresistance to disturbances from outside the protectionarea, it can be set much more sensitively than thesimple transformer differential protection, in order toprevent false trippings.

The IRI1-ERcan be used as:

Zero-current differential protection of the starpoint winding (restricted earth fault) of atransformer (IRI1-ER), see figure 2.1

Highly stabilized differential current relay for

alternator, transformers and motors (IRI-3ER),see figure 2.2

Fig. 2.1: Zero-current differential protection ofa transformer in star-connection (IRI1-ER)

Fig. 2.2: Highly s tabi l i zed di f ferent ialprotection for al ternators, transformers andmotors (IRI-3ER)

L1

Transformer

L2

L3

Rsr

IRI1-ERI>

L1

L2

L3

IRI1-3ER

Rsr Rsr Rsr

MotorTransformer

Alternator

3. Characteristics and features

static protective device

single-phase current measuring (IRI1-ER) aszero-current differential protection (restrictedearth fault 64 REF)

three-phase current measuring (IRI1-3ER) asphase-current differential protection

high stability by serial stabilizing resistor Rsr perphase

high sensitivity by low input burden of C.T.

extremely wide setting range with fine grading

wide range of operation of the supply voltage(AC/DC)

coding for the self-holding function or automaticreset of the LEDs and trip relays

frequency range 50/60 Hz

rated current 1A or 5A

output relay with 2 change-over contacts


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Fig. 4.2: Connection diagram IRI1-3ER

4.1.1 Analog inputs

At three-phase measuring, the analog input signals ofthe differential currents are fed to the protective devicevia terminals B1 to B6 (IRI1-3ER), respectively at singlephase measuring via terminals B1/B2 (IRI1-1ER).

L1 L2 L3

P1

S2P2 S2P2

S1P1

P2

S1P1 S1

S2

P1

S2P2 S2P2

S1P1

P2

S1P1S1

S2

50/60Hz

50/60Hz

50/60Hz

~

D9E9C9

L-/NL+/L

D1

C1

E1

D2

C2

E2

Rsr

Rsr

Rsr

B2

B3

B4

B5

B6

B1

Reset

TripID

ID

ID

PowerSupply

~

4. Design

4.1 Connections

Fig. 4.1: Connection diagram IRI1-ER

P1

P2

S1

S2

P1

S2P2 S2P2 S2

S1S1P1

P2

S1P1

L1 L2 L3 D9

D1

C1

E1

D2

C2

Rsr

50/60HzB2

B1

E2

Reset

Trip

ID

ID

E9C9

L-/NL+/L

PowerSupply

ID

~

4.1.2 Output relays

Both relay types are equipped with a trip relay with twochange-over contacts.

Tripping ID: D1, C1, E1

D2, C2, E2


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4.2 Front plate

Fig. 4.3: Front plate

The front plate of the IRI1-ERcomprises the followingoperation and indication elements:

1 set of DIP-switches for setting the tripping value

2 LEDs for indication of faults- and readyness foroperation

1 push button

4.2.1 LEDs

On the front plate of the IRI1-ER 2LEDs are installed,signalizing the following 2 service conditions:

LED ON (green): readyness for service

LED ID(red): tripping

4.2.2 DIP-switchesThe set of DIP switches on the front plate serves forsetting the tripping value for the differential current I

D.

4.2.3 -push button

The push but ton is used foracknowledgement and reset of the LED and the trippingrelay after tripping at the specifically preset value (see4.3).

4.3 Code jumper

Behind the front plate, two coding jumpers are installedat the bottom side for setting the LED-display, as wellas for the tripping function of the output relay.

Fig. 4.4: Code jumper

Code Function Position of Operating modejumper code jumper

3 Differential current OFF latching of the red LED ID

indication ON automatic reset of the red LED ID

4 Differential current OFF latching of the tripping relay tripping ON automatic reset of the tripping relay

Table 4.1 Code jumper

ID

ID ON

Code jumper

Code jumper ON

Front plate

3 4

Code jumper OFF

RESET

7.5%5102040

ON

ID

50000

ID

IRI1-3ER


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6. Operations and settings

6.1 Layout of the operating elements

The DIP-switch required for setting of parameters is

located on the front plate of the relay.

6.2. Setting of the pick-up value for the

differential current ID

The pick-up value of the differential current tripping ID

can be set by means of the DIP-switches set IDin the

range of 5% to 82.5% x INwith a grading of 2.5%.

The pick-up value is calculated by adding up the valuesof all DIP-switches.

5. Working principle

The protection relay IRI1-ER is connected to thedifferential circuit of the c.t.s as a current differentialprotection relay. When used as zero-current differentialprotection (restricted earth fault), the relay (IRI1-ER)isto be connected acc. figure 2.1. When used as highly

stabilized differential current relay, the relay (IRI1-3ER)is to be connected acc. figure 2.2.

The knee voltage UKn

is an important characteristic ofthe transformer. The transformer does not worklinearly anymore above this voltage. Two transformersof the same class still show the same behavior belowU

Knwithin the scope of their precision class. Above U

Kn

they can, however, show very different saturationbehavior.

Connected in a differential current circuit an apparentfault current can thus be measured at large primarycurrent intensity which really results only from thedifferent saturation of both transformers.

An additional stabilizing resistor RST

counteracts thiseffect. It attenuates the current flow through themeasuring device. This way the unsaturatedtransformer drives part of its current into the saturated

Fig. 5.1 Single line diagram IRI1-ER

transformer and minimizes the faulty differentialcurrent effect on secondary side. By small currents thestabilizing resistor effects however also the accuracy ofthe real fault current measurement. Because this effectlies in a linear range it can be taken into considerationmathmatically by adjusting the protection device.

(see para. 6.4).

For demonstrating the working principle, figure 5.1shows the single-line diagram of the IRI1-ER.

Protecting object

RS

IF

IR

US

ZZ

Z = 0RAt saturated C.T.

Rsr

RL RL

IF

RS

The harmonics existing during a transformer saturationand the DC-component are suppressed by a filter circuitlocated in the input circuit of the relay; the filter circuitis adjusted to the mains frequency (50/60Hz).

The IRI1-ER has a single-phase differential currentsupervision with an adjustable pick-up value. The

current measured in the differential circuit is constantlycompared with the set reference value.

Measuring principle IRI1-ER

The analog current signals are galvanically decoupledvia the input transformer and are led over a low passwith subsequent band-pass for suppression of theharmonics, then rectified and compared with the setreference value of a comparator. In case the currentmeasured exceeds the reference value, aninstantaneous tripping takes place (figure 4.1).

The IRI1-3ER has a three-phase differential currentsupervision with adjustable pick-up value. The currentsmeasured in the individual differential circuits areconstantly compared with the set reference value.

Measuring principle IRI1-3ER

The analog current signals are galvanically decoupledvia three input transformers and led over a low passwith subsequent band-pass for suppressing the

harmonics. Then rectified and compared with the setreference value of a comparator. In case one of thethree currents measured exceeds the reference value,an instantaneous tripping takes place (figure 4.2).


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Example:

A pick-up value of 30% of the rated current is required.

6.2.1 Indication of fault

The fault alarm is shown by the LED IDon the front

plate of the relay, which lights up red at tripping.

Depending on the coding by means of the code jumper(see chapter 6.3.2), the fault alarm extinguishes

automatically or after pressing the pushbutton, after the fault is eliminated.

6.3 Reset

6.3.1 Reset by pressing the -push-button

By pressing the push button, the trippingrelay is reset and the LED-signal extinguishes. Allcoding switches must be plugged out for this (seechapter 4.3).

6.3.2 Automatic reset

Code jumper 1

If no code jumper is plugged in at coding place 1, thered fault alarm LED I

Dis coded latching.

The fault signal can only be reset manually by pressingthe push button.

If the code jumper is plugged in at coding place 1, thered fault signal LED I

Dis automatically reset, after the

fault is eliminated.

Code jumper 2

The tripping relay is coded latching, if no code jumperis plugged in on coding place 2.

The tripping relay can only be reset manually bypressing the push button.

If the code jumper is plugged in on coding place 2, thetripping relay is automatically reset after elimination ofthe fault.

5

0

0

0

7.5%

5

10

20

40ID

ID= 5 + 5 + 20 = 30% x I

N

6.4 Calculation of the tripping currentand the stabilizing resistance

Prior to setting the relay, the stabilizing resistance Rsr, as

well as the tripping current Iset

must be calculated. Forthe correct setting, the knee-point voltage in themagnetizing circuit of the c.t. is of special importance.In order to obtain a sufficient differential current fortripping on account of internal faults, the knee-point

voltage Uknof the transformer should be twice as highas the maximum expected stabilizing voltage U

Sin case

of faults from outside the protection zone. From thisresults the following calculation:

UKn

= 2 US= 2 I

f,sek (R

S+ R

L)

Explanation:

Ukn

knee-point voltage of the magnetizing circuit ofthe transformer

Us

maximum stabilizing voltage in case of externalfaults

If,sek maximum expected fault current (secondary-side)in case of external faults

RS

secondary resistance of the transformer

RL

Resistance of the connection line between c.t. andrelay

The tripping current of the relay is then calculated, asfollows:

ID>

Explanation:

RSr

stabilizing resistance

The strength of the stabilizing resistance must beselected in a way to ensure that the tripping current iswithin the setting range (5% to 82.5% of I

N).

When the pick-up value is exceeded, nearly animmediate tripping is initiated. With 30 ms the trippingtime is approx. five times as high as the tripping value.In case of lower currents, the tripping time is slightlyhigher (about 100ms), in order to reach a stabilization

of the protective function against external faults (seealso chapter 5).

6.4.1 Sample calculation - alternator

An IRI1-ERprotection relay is used for the earth-faultprotection of an alternator. In the starpoint, thefollowing c.t. is provided:

transformation ratio : 100/1A

class : 5 P 10

output : 2.5 VA

secondary resistance

of the transformer :


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The individual resistance values are:

2 x RL= 150 m, at 20 m, 2.5 mm Cu

2 RL+ R

r+ R

S= 0.87

Therefore, the following is valid:

Rkreis

= = 62.5

Calculation of the stabilizing resistanceThe stabilizing resistance is calculated from aboveratios, as follows:

RS

= Sr circuit

- (2 RL+ R

r+ R

S)

= Rcircuit

- 0.87

= 61.6

In operational mode < ID, the output requirement P

Nis

as follows:

PN< I x R

sr= 0.2 A x 61.6 < 2.47 W

In this case, PNrepresents the minimum output required

(pure current-heat losses). A considerably increasedoutput P

Fis required in the event of a fault.

Example: The fault current is: IF,prim

= 13.1 kA

If one neglects the transformer saturation, the followingpeak voltage U

Poccurs:

Up= (R

Sr+ 2 R

L+ R

r+ R

S)

Up= (62.5) = 8187.5 V

If one considers the transformer saturation, a short-term peak voltage U

SSoccurs, as shown in the following

calculation:

USS

= 2(2UKn

(Up - U

Kn))+0.5 < 3 kV

USS

= 2(225 V (8187.5 V - 25 V))+0.5

= 1.28 kV

Pr = = 26.6 kW

The calculation of PNand P

Fmust be effected in any

case, in order to get the exact power range of thestabilizing resistor.

Take over of power by the resistor in the event of afault P

F

creates a short-term peak value.

6.4.2 Example calculation -transformer

An IRI1-ERprotection relay is used for the earth-faultprotection of a 1.6 MVA-transformer (11000/415 V,6%), see figure 2.1. The following c.t.s are used in therigidly earthed starpoint:

transformation ratio: 2 500/1A

class: X

resistance Rs: 8

knee-point voltage: 250 V

The relay is situated about 20m away from the c.t.sand is connected with a 2.5 mm2cable.Calculation of the stabilizing voltage

The primary-side fault-current IF,prim

is:

IF,prim

= = 37.1 kA

Line resistance RL(2.5 mm ~ 7.46 /km)

RL = 20 m X = 0.15

Additional resistance Rr(ca. 0.02 )

A primary-side fault current of 20% x IN shall be

recorded. The secondary current is used forcalculation.

Calculation of the knee-point voltage

If the knee-point voltage is not indicated by themanufacturer, as is the case in our example, theapproximate value can be calculated, as follows:

Ukn

= = 25V

Explanation:

S output of the c.t.

klu

overcurrent factor of the c.t.

IN

secondary-side rated current of the transformer

Calculation of the active resistances

The relevant resistances in the differential circuit addup to a total (circle-) resistance:

Rcircuit

= = RSr+ 2R

L+R

S+R

r

Explanation:

Rkreis

total resistance in the differential circuit

Rsr

stabilizing resistance

RL

resistance of the connection line between c.t. and

relay

Rs

secondary resistance of the transformer (


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IF,prim

n

37100 A 1

2500

From this results the stabilizing voltage for:

US= X (2 X R

L+ R

S+ R

r)

US= X (2 X 0.15+ 8+ 0.01)

=123.5

Up= X (8 + 2 X 0.15

+ 0.02+ 308.75) = 4.7 kV

USS

= 2 X (2 X 250 V X (4700 V X 250 V))+0.5

= 298

Since the requirement is met, the set values and the

resulting resistance values can be accepted.The calculation of the output requirement for thestabilizing resistance can be carried out similar to thecalculation of sample 6.4.1.

37.1 kA 1

2500

Since the knee-point voltage shall be Ukn

= 2x US(2 x

123.5V = 247 V), the above transformer with Ukn=250 V can be used.

Calculation of the set current and the stabilizingresistance (sample value)

The rating for the set current of 20% is calculated:

ID= 20 % x I

N= 0.2 x 1 A = 0.2 A

From this results the stabilizing resistance for:

Rcircuit

= ~ RSr => = 617.5

In the event of a fault, the stabilizing resistance mustwithstand a secondary-side false current of:

IF sek

= = 14.84 A

The calculation of the short-term peak voltagesprovides the following result:

US= X (8+ 2 X 0.15

+ 0.02+ 615) =9.25 kV

Thus, the ratio

USS

= 2 X (2 X UKn

X (Up - U

Kn))+0.5< 3 kV

USS

= 2X(2X250 V X(9250 V - 250V))+0.5

= 4.24 kV

is not reached and the calculation must be repeated

with a higher set current.Calculation of the set current and the stabilizingresistance (actual value)

The rating for the set current of 40% is calculatedagain:

ID= 40 % x I

N= 0.4 x 1 A = 0.4 A

From this results the stabilizing resistance for:

Rcircuit

= ~ RSr=>

= 308.75

Thus, the requirement of the short-term peak voltageis met.

1600000 VA

3 X 415 V X 6% X 2500

37.1 kA 1

2500

123.5 V

0.2 A

US

ID

US

ID

123.5 V

0.4 A

6.5 Application of IRI1-3ER relay asHigh Impedance Bus DifferentialProtection:

IRI-1ER or IRI1-3ER (a 3-phase version of IRI1-1ER)

relays also offers reliable Bus protection based on HighImpedance Differential Principle.

The figure below indicates a typical Single Bus systemusing IRI-ERrelay for Bus Protection. This sample systemincorporates two incoming and two outgoing bays.

In case of normal operation, following Kirchoff s law, thecurrents terminating on bus and going put adds up to Zerowith corresponding reproduction on CT secondary side ofrespective bays. As the vector summation of the currentsbalances each other out, the Relay does not operate.

In case of internal faults, as the fault currents will be fed

from all sources possible, the differential current willoperate the relay.

For External fault, though the amount of current flowinginto the fault will increase, the net summation of thecurrent again will zero and the relay will restrain.

Here, it is important to consider unequal saturationcharacteristics of the Current transformers involved. It isalso important to ascertain that the relay remains stablein presence of Harmonics and DC currents.

Fig. 6.1


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10

Especially for a Bus Differential relay, following factorsare vital:

Because of higher concentration of fault MVA, theRelay should operate very fast for heavy internalfaults.

The Relay should be reliably stable in presence ofHarmonics especially 2ndand 3rdharmonics andpresence of DC currents.

IRI1-ER relays ensure:

Operating time of less than 15 milliseconds at morethan 5 times of the setting.

2ndHarmonic rejection ratio of more than 4.

3rdHarmonic rejection ratio of more than 40.

Remains very stable against superimposed DC

currents.

Kpv

2.Rs

RL : = 0.5 Rct : = 6 Zr : = Zr = 0.125

Kpv : = Ifs . (Rct + 2.RL)

Kpv : = 186.667

Knee point required for the CT core should higher than,

KpvCT : = 2 . Kpv KpvCT = 373.333

Rs : = -Zr Rs = 466.542

Up : = Ifs . (Rs + 2.RL + Rct + Zr)

Up = 1.263 x 104 1.594 . 10000 = 1.594 x 104

Uss : = 2 . [2 . Kpv. (Up - Kpv]0.5

Uss = 4.311 x 103

=0.2

The use of Metrosil can be avoided as the relay canreliably withstand Uss up to 5 kV. For fault currentsexceeding this level, the Metrosils should be used.

[( ) ]KpvId

0.02

Id2

Rs : Stabilising Resistance in Ohms

Id : Differential Current Setting

Up : Peak Voltage neglecting Saturation

Uss : Short term peak Voltage considering Saturation

Ifs: Secondary value of Fault Current

Ifmax : 40000 kV : = 220 CTR : = 1500

MVAf : =3.kV.Ifmax MVAf = 1.524 x 107 Id : = 4

Ifs : = Ifs = 26.667Ifmax

CTR


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8.3.3 Checking the pick-up and trippingvalues ( IRI1-ER )

With the IRI1-ER, the analog input signal of thesinglephase testing AC must be supplied to the relay viathe terminals B1/B2 for checking the pick-up value I

D.

For testing the differential current pick-up value, firstthe injected current must be set below the set pick-up

value Id. Then the injected current is increasedgradually, until the relay trips. This is indicated by theLED I

D lighting up red, with the relay tripping at the

same time. Check that the value shown at the ammeterdoes not deviate by more than +/- 3% from the setpick-up value I

D.

The resetting value of the differential current pick-upvalue is determined, by slowly decreasing the testingAC, unti l the output re lay I

D trips. The LED I

D

extinguishes (supposed the respective coding waseffected).

Check that the resetting value is greater than 0.97

times the pick up value, i.e. the resetting ratio of thedifferential current supervision is below 1.

8.3.4 Checking the operating and

resetting values (IRI1-3ER)

With the IRI1-3ER, all analog input signals of thesingle-phase current must be supplied to the relay viathe terminals B1/B2; B3/B4; B5/B6 one after anotherfor checking the pick-up value I

Din similar manner as

indicated above in para 8.3.3.

8.4 Primary injection testPrincipally, a primary injection test (real-time test) of ac.t. can be carried out in the same way as a secondaryinjection test. Since the cost and potential hazards maybe very high for such tests, they should only be carriedout in exceptional cases, if absolutely necessary.

8.5 Maintenance

Maintenance testing is generally done on site at regularintervals.These intervals may vary among usersdepending on many factors: e.g. type of protectiverelays employed; type of application; operating safetyof the equipment to be protected; the users past

experience with the relay etc.For s tat ic re lays such as the IR I1-ER/-3ER ,maintenance testing once per year is sufficient.

8.3 Secondary injection test

8.3.1 Test equipment

ammeter

auxi l iary power supply wi th a vol tagecorresponding to the rated data on the type plate

single-phase AC-power supply (adjustable from 0

- 2.0 x IN) test leads and tools

potentiometer

Fig. 8.3.1 Test circuit IRI1-3ER

L+/LL-/N

~

D9E9C9

PowerSupply

50/60Hz

50/60Hz

50/60Hz

D1

C1E1

D2C2

E2

Reset

ID

Trip

ID

+

ID

2

A

3

1. Current source2. Amperemeter3. Relay under test4. Potentiometer adjust resistor5. Switching device6. Timer

Stop

Timer6

+Start

4

5

Current source

1

B6

B5

B4

B3

B2

B1

-

switching device

timer

8.3.2 Example of a test circuit for a

IRI1-3ER -relay

For testing the IRI1-3ER-relay, only power signals arerequired. Fig. 8.3.1 shows an example of a test circuitwith adjustable power supply. The phases are testedindividually one after the other.


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13

9. Technical Data

9.1 Measuring input

Rated data:

Nominal current IN

: 1A/5A

Nominal frequency fN

: 50/60 Hz

Power consumption :


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14

9.5 System data

Design standard : VDE 0435, part 303, IEC 255.4, BS 142

Specified ambient serviceTemperature range:for storage : - 40C to + 85C

for operating : - 20C to + 70C

Environmental protection

class F as per DIN 40040and per DIN IEC 68 2-3 : relative humidity 95 % at 40C for 56 days

Insulation test voltage, inputsand outputs between themselvesand to the relay frame as perVDE 0435, part 303 IEC 255-5 : 5 kV; 1.2/50 Hz; 1 min.

(except supply voltage inputs)

Impulse test voltage, inputsand outputs between themselvesand to the relay frame as perVDE 0435, part 303 IEC 255-5 : 5 kV; 1.2 / 50 s; 0.5 J

High frequency interferencetest voltage, inputs and outputsbetween themselves and to therelay frame as per DIN IEC 255-6 : 2.5 kV / 1MHz

Electrostatic discharge (ESD)test as per DIN VDE 0843, part 2IEC 801-2 : 8 kV

Electrostatic discharge (ESD)test as per DIN VDE 0843, part 4IEC 801-4 : 4 kV / 2.5 kHz, 15 ms

Radio interference suppressiontest as per EN 55011 : limit value class B

Radio interference fieldtest as per DIN DVE 0843, part 3IEC 801-4 : electrical field strength 10 V/m

Mechanical tests:Shock : class 1 acc. to DIN IEC 255-21-2

Vibration : class 1 acc. to DIN IEC 255-21-1

Degree of protection - front of relay : IP 54 by enclosure of the relay case and front panel(relay version D)

Weight : approx. 1.5 kg

Degree of pollution : 2 by using housing type A

3 by using housing type D

Overvoltage class : III

Influence variable values:Frequency influence : 40 Hz < f < 70 Hz:


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15

9.7 Dimensional drawing

Please note:

A distance of 50 mm is necessary when the units are mounted one below the other in order to allow easy openingof the front cover of the housing. The front cover opens downwards.

260

230

36

76

Cut Out DimensionsInstallation Depth : 275mmAll dimensions in : mm

68.7

136

.5

142

142

16

76

10. Order form

Stabilized earth-fault current relay IRI1-

Measuring of earth current 1 phase measuring 1ER3 phase measuring 3ER

Rated current in the earth-faul t phase 1 A 15A 5

Auxiliary voltage 24 V (16 to 60 V AC/16 to 80 V DC) L

110 V (50 to 270 V AC/70 to 360 V DC) H

Housing (12TE) 19 rack AFlush mounting D

Technical data subject to change without notice!


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11.example calculation -transformer

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