KA 01-01-12-02 Catalogue Buchholz Relay-PRINCIPLES

Transformer Protection Relays(Buchholz Principle)

Elektromotoren und Gerätebau Barleben GmbH

2


Table of contentsPage

Company history 3

1. Preface 4

2. Design features 5

3. Function 73.1. Gas accumulation 73.2. Insulating liquid loss 83.3. Insulatingliquidflow 8

4. Tests 9

5. Typelistofsingle-floatBuchholzrelays 105.1. Single-floatBuchholzrelayswiththreadedconnection 105.2. Single-floatBuchholzrelayswithflangedconnection 10

6. Switchingsystemdesignoptionsforsingle-floatBuchholzrelays 11

7. Typelistofdouble-floatBuchholzrelays 127.1. Double-floatBuchholzrelayswiththreadedconnection 127.2. Double-floatBuchholzrelayswithflangedconnection(round) 137.3. Double-floatBuchholzrelayswithflangedconnection(square) 157.4. Double-floatBuchholzrelayswithgeometricalflangedimensions according to Chinese norm 157.5. Double-floatBuchholzrelayswithgeometricalflangedimensions according to former French norm 167.6. Double-floatBuchholzrelayswithgeometricalflangedimensions accordingtoformerBritishstandard 17

8. Switchingsystemdesignoptionsfordouble-floatBuchholzrelays 18

9. Technical data 22

10. Specialdesigns 2310.1. Explanationstocodes23or24 2410.2. Explanationstocode32 25

11. Explanationstocode60-Buchholz relay NM series 2611.1. DesignfeaturesofBuchholzrelayNMseries 2611.2. ExtrafunctionofBuchholzrelayNMseries 2611.3. Analogue measuring unit - Analogue measurement of gas volume 27

12. Ordering data/Type code 2812.1. Single-floatBuchholzrelays 2812.2. Double-floatBuchholzrelays 28

13. AdditionaldevicesforBuchholzrelays 3013.1. GassamplingdeviceZG1.2. 3013.2. OtheradditionaldevicesforBuchholzrelays 33

14. Other protection devices 35

3

Company historySinceitsfoundationthecompanyhaspassedthroughaneventfulhistorywithregardtoownership,affiliationandchangeofnameassociatedwithsuchdevelopment.

1921 DevelopmentofBuchholzrelaybyMaxBuchholz

1943 BranchofSIEMENSMagdeburg

1948 VEBElektromotorenwerkBarleben;VEM (state-ownedfirm)

1951 VEBStarkstromanlagenbauMagdeburg (state-ownedfirm)

1951 StartofmanufactureofBuchholzrelaysinBarleben

1965 StartofmanufactureofmonitoringrelaysfortapchangersinBarleben

1970 VEBElektrotechnikundGerätebauMagdeburg;EGEM (state-ownedfirm)

1980 VEBKombinatElektromaschinenbauDresden VEBElektromotorenwerkBarleben;VEM;ELMO (state-ownedfirm)

1990 VEMAntriebstechnikAGDresden ElektromotorenwerkBarlebenGmbH;VEM;ELMO (publiclimitedcompany)

1993 ElektromotorenundGerätebauBarlebenGmbH;EMB (privatelyownedcompany)

2005 StartofmanufactureofBuchholzrelaysNMseries

2009 NewpremisesinBarleben

Figure1-EMBcompanybuilding

4


1. Preface

TheBuchholzrelaywasdevelopedin1921byMaxBuchholz,Oberrat(seniorcouncillor)atPreußi-scheElektrizitäts-AG(Prussianelectricitysupplycompany)inKassel.Sincethattimeithasbeenanimportantprotectionandmonitoringdeviceforinsulatingliquid-filledtransformerswithconservatorsandchokecoils.Italsoallowsseparatemonitoringofoil-filledbushingsorcableterminalboxes.Itis mounted in the cooling cycle of the appliance to be protected and responds to faults such as gas generation,lossofinsulatingliquidandexcessivelyhighflowratesofthelatter.

Fortransformerswithhermeticalclosurebymeansofamembrane(rubbersack)intheconservatorBuchholzrelayscanbeusedalsoasindicatingdevices(“aircellfailurerelay”)ofthismembrane.

TheBuchholzrelayissuitableforopen-airaswellasindoorinstallations.

Buchholzrelaysareavailableinanumberoftypeswhichcomplywithnormsandstandardsandmeet special customer requirements. The type of relay to be used depends on the nominal rating and construction features of the appliance to be protected. Our range of products permits optimum flexibility.

ElektromotorenundGerätebauGmbH(EMBGmbH)providesmorethan60yearsexperienceinproducingBuchholzrelaysandotherprotectiondevicesforliquid-cooledandliquid-insulatedappli-ances.Itranksamongthemostdistinguishedmanufacturersofthistypeofequipment.EMBBuch-holzrelayscomplywithDINEN50216-2andareknownfortheireasyoperation,highreliabilityandextremelylonglife.

Figure2-DINENISO9001/2008certificate

Ourstaffofhighlyqualifiedengineersandexperiencedskilledworkersdotheirbesttoguarantee top quality high-precision products. ThecasingsaremachinedonmodernCNC-controlled machine tools. All products are subjectedtofinalinspectionwhenallfunctionsarecheckedusingspecialtestequipment.

Profoundexperienceandexpertiseareasound basis for high product quality. Extensivereferencesfromreputedtransformermanufacturersaswellasotherusersareproofof the high qualitative level of the products.

ThecompanyiscertifiedtoDINENISO9001/2008.

Sony

Underline

đặt trên vòng tuần hoàn làm mát của thiết bị

5

2. Design features

Casing

Thecasingismadeofweather-resistantcastaluminiumalloyprovidedwithapaintcoat.Itissuppliedeitherwithscrewedorflangedconnection(1).Thedifferentcasingdesignsavailableareshowninsection5forsingle-floatBuchholzrelaysandsection7fordouble-floatBuchholzrelays,othersareavailableonrequest.

Tochecktheswitchingsystemforproperfunction,thecasingisprovidedwithsightglas-ses(2).Thesightglassesprovidedwithscalespermit reading of collected gas volume.

Therelayscanbeprovidedwithhingedlids(3)to protect the sightglasses.

Cover

The upper section of the cover accommodates theterminalbox(1).Thetestvalve(2)andthetestkeycoveredbyacapnut(3)aswellasaplatewithinstructionsforactuatingthetestkey(4)arearrangedinfrontofthecover.Theterminalbox(1)accommodatestheearthterminal(5)anduptoeightbushings(6)forthe terminals provided in the base of the cover. The number of these bushings determines the designoftheswitchingsystemsintermsoftype and quantity of the magnet contact tubes.

Theterminalbox(1)issealedbyanaluminiumcap(7)sothatitissafetotouchandprotectedagainst pollution. If the cap is opened the gra-phicsymbolandtheconnectiondiagram(8)areshown.Thecablecanbeinsertedthroughthecablegland(9).

Figure5-Coverwithcapremoved

2

1

Figure4-Casingwiththreadedconnection

1

3

Figure3-Casingwithflangedconnection

7

8

6

95

1

23

4

6


Switchgearofasingle-floatBuchholzrelay:

- Float -Permanentmagnet(s)-Magnetcontacttube(s)- Damper

The damper is held in its normal position by a magnet.

Switchgearofadouble-floatBuchholzrelay:

-Upperfloat-Lowerfloat-Permanentmagnet(s)forupperfloat-Permanentmagnet(s)forlowerfloat-Magnetcontacttube(s)forupperswitchingsystem-Magnetcontacttube(s)forlowerswitchingsystem- Damper

The damper is held in its normal position by a magnet andactsonthelowerswitchingsystem.

Switchgear

Theswitchgearhasthefollowingmaincomponents:

-Switchingsystem- Frame-Mechanicaltestingunit.

Whereasthesingle-floatBuchholzrelayhasonlyoneswitchingsystem,thedouble-floatBuchholzrelayhasanupperandalowerswitchingsystem.Permanentmagnetandfloatarerigidlylinkedforminganintegratedwholethatismovablyfittedtotheframetogetherwiththemechanicaltes-tingunitandthemagnetcontacttube(s).

Figure6-Single-floatBuchholzrelay

Figure7-Double-floatBuchholzrelay

7

3. Function

TheBuchholzrelayisinstalledinthepipebetweenthetankofthedevicetobeprotected(trans-former,reactor)andtheconservator.Duringnormaloperationitisfilledcompletelywithinsulatingliquid.

Duetobuoyancythefloatofthesingle-floatrelayandbothfloatsofthedouble-floatrelayareattheir top position.

Theupperandlowerswitchingsystemsformafunctionalunitinthesingle-floatBuchholzrelaysothatintheeventofafaultthetransformerisimmediatelydisconnectedfromthepowersystem.

InthefollowingthefunctionofaBuchholzrelayisexplainedusingtheexampleofadouble-floatBuchholzrelay.Ifafaultoccursinsidethetransformer,theBuchholzrelayrespondsasfollows:

3.1. Gas accumulation

Fault: Free gas is available in the insulating liquid.

Response:Thegasintheliquidmovesupwards,accumulatesintheBuchholzrelayanddisplacesthe insulating liquid level.

Themovingfloatactuatesaswitchcontact(magnetcontacttube).Analarmsignalistripped.

Thelowerfloatisnotaffectedasfromacertaingasvolumethegasflowsthroughapipingtotheconservator.

Gas

Öl

Figure 8 - Gas accumulation

Oil

Gas

Sony

Underline

n.sự nổi,sức nổi

8


3.3. Insulatingliquidflow

Fault:Aspontaneousincidentgeneratesapressurewavemovinginthedirectionoftheconservator.

Response:Theliquidflowreachesthedamperarrangedintheliquidflow.Iftheflowrateexceedstheoperatingvalueofthedamper,thelattermovesinflowdirection.

Duetothismovementaswitchcontactisactuatedsothatthetransformerisdisconnected.

Afterreleaseofthepressurewavethelowerswitchingsystemreturnstoitsstartingposition.

BuchholzrelaysmanufacturedbyEMBareequippedwithadamperheldbyapermanentmagnet.

Öl

Figure10-Insulatingliquidflow

3.2. Insulating liquid loss

Fault:Insulatingliquidlossduetoleakage.

Response:Astheliquidlevelfallsthetopfloatmovesdownwards.Analarmistripped.Iftheliquidlosscontinues,conservatorandpipingaswellastheBuchholzrelaywillbeemptied.

Astheliquidlevelfalls,thelowerfloatmovesdownwards.Themovingfloatactuatesaswitchcon-tact so that the transformer is disconnected.

Luft

Öl

Figure 9 - Insulating liquid loss

Oil

Oil

Air

Sony

Underline

adj.tự nguyện,tự phát

9

4. Tests

EachBuchholzrelayisprovidedwithaworks-numberthatisspecifiedonthetestcertificateandthenameplate.ThetestscarriedoutontheBuchholzrelayarerecordedinthetestcertificate.

- Dielectric strength test -Leakagetest - Functional test -Flowtest.

Buchholzrelaysaredeliveredincardboardboxes.Foreachrelaydeliveredthefollowingdocumentsinthelanguageagreedareproviced:

- Operating instructions -Testcertificate.

Thenameplatecoversthefollowinginformation:

Figure12-FlowtestFigure11-Functionalandleakagetest

works-no.6 digits

switchingelementS = normally-openÖ = normally-closedW = changed-over

IP code

type code

date of manufacture(week/year)Type

10


5. Typelistofsingle-floatBuchholzrelays

TypeInternal descriptionDINdescription

Type of connection

Pipe diameterDN(mm)

Flange dimensions(mm)

Device dimensions(mm) Weight

(kg)

Suited fortransformerratings of

d1 d2 d3 d4 d5 f l h1 h2

01(AG 25)(CG 25)

ThreadedconnectionG1½“

25 - - - - 16 185 170 62 3,1 ≤1600KVA

Figure13-Dimensionaldrawing,type01


Type of connection

Pipe diameterDN(mm)



(kg)


d1 d2 d3 d4 d5 f l h1 h2

02(AF 25/6)

(-)

Flange4-hole 25 100 75 60 12 12 185 195 62 3,6 ≤1600KVA

03(AF 25/10)

(-)

Flange4-hole 25 115 85 68 14 16 200 205 62 4,0 ≤1600KVA

25(AF 25)

(-)

Flange4-hole 25 100 75 - 12 10 160 195 62 3,3 ≤1600KVA

5.2. Single-floatBuchholzrelayswithflangedconnection

Figure14-Dimensionaldrawing,type02,03,25

5.1. Single-floatBuchholzrelayswiththreadedconnection

250

300350

cm3

80

d1

d4

d3

d2

h2

h1

fl

170

R80d5

250

300350

cm3

80h2

170

d1

G11/2"

h1

l

R80

f

11

...1 ...2 ...3 ...4 ...5 ...6

1NO 1NC 2NO 2NC 1NOand1NC 1 CO

13

14

11

12

13

14 24

23 11

12 22

21 13

14 12

11

4

1

2

...7 ...8 ...92 CO 1NOand1CO 1NCand1CO

24

21

22 12

11

14 14

11

1224

23

14

11

1222

21

6. Switchingsystemdesignoptionsforsingle-floatBuchholzrelays

Magnetcontacttubesareusedasswitchingelements.Thesearenormally-open(NO),normally-closed(NC)andchange-over(CO)contacts.Themagnetcontacttubedesigncanbederivedfromthelastdigitofthetypecode.Forcoding,seeOrderingdata/TypecodeunderSection 12.1. on page 28.

Explanation of symbols: Example:coding„... 6“Magnetcontacttube(s)design

4

1

2 1 CO

Graphicsymbolwithterminalmarking

Connectiondiagraminterminalbox

The inner side of the cap accommodates a plate with the graphic symbol and the connection diagram. The schemes show the switching systems in their neutral position. The neutral positionistheoperatingconditionwhentheBuchholzrelayisfilledwithinsulatingliquidupthe required level and the device to be protected operates without any fault.

12



Type of connection

Pipe diameterDN(mm)



(kg)


d1 d2 d3 d4 d5 f l h1 h2 h3

04(BG 25)(DG 25)


25 - - - - 16 185 235 90 - 4,2 ≤5000KVA

21(BG 25 S)

(-)


25 - - - - 16 185 235 90 - 3,6 ≤5000KVA

7.1. Double-floatBuchholzrelayswiththreadedconnection



7. Typelistofdouble-floatBuchholzrelays

250

300350

cm3

80h2

h1

l

f

R143

170

d1

G11/2"

250

300350

cm3

80h2

h1

l

f

150

d1

G11/2"

13


Type of connection

Pipe diameterDN(mm)



(kg)


d1 d2 d3 d4 d5 f l h1 h2

05(BF 25/6)

(-)

Flange4-hole 25 100 75 60 12 12 185 235 90 4,4 ≤5000KVA

06(BF 25/10)

(DR 25)

Flange4-hole 25 115 85 68 14 18 200 235 90 4,8 ≤5000KVA

23(BF 25/10 S)

(-)

Flange4-hole 25 115 85 68 14 18 200 235 90 4,4 ≤5000KVA

07(BF 50/6)

(-)

Flange4-hole 50 140 110 90 14 12 185 235 80 4,6 ≥5000KVA

≤10000KVA

08(BF 50/10)

(DR 50)

Flange4-hole 50 165 125 102 18 16 195 250 80 5,9 ≥5000KVA

≤10000KVA

09(BF 80/10)

(-)

Flange4-hole 80 200 160 138 18 15 195 265 80 6,2 ≥10000KVA

09-26.(BF80/10/8)

(DR 80)

Flange8-hole 80 200 160 138 18

M16 15 195 265 80 6,2 ≥10000KVA

24(BF 80/6)

(-)

Flange4-hole 80 190 150 130 18 15 195 260 80 6,0 ≥10000KVA

7.2. Double-floatBuchholzrelayswithflangedconnection(round)

14


Figure17-Dimensionaldrawing,type05,06,07,08,09,24


Figure19-Dimensionaldrawing,type09-26.

250

300350

cm3

80

lf

h2

h1 R143

d5

170

M16

d1

d4

d3

d2

250

300350

cm3

80h2

fl

h1

d1d4d3d2

d5

150

250

300350

cm3

80

d1

d3

h2

fl

h1

170

143

d4

d2

d5

15


Type of connection

Pipe diameterDN(mm)



(kg)


d1 b d3 d4 d5 f l h1 h2

10(BF 80/Q)(DQ 80)

Flangesquare4-hole

80 125 132 - 18 20 200 235 80 5,0 ≥10000KVA


Type of connection

Pipe diameterDN(mm)



(kg)


d1 b d3 d4 d5 f l h1 h2

63(BC 80)(QJ 80)

Flangesquare4-hole

80 160 160 - 18 15 185 245 80 5,0 ≥10000KVA



7.3. Double-floatBuchholzrelayswithflangedconnection(square)

7.4. Double-floatBuchholzrelayswithgeometricalflangedimensions according to Chinese norm

SuitableforconnectiontoChinesebutterflyvalves(squareflange).Othertypesonrequest.

250

300350

cm3

80h2h1

l

f

R143

d3

d5

b

d1

b

170

250

300350

cm3

fl

80h2

h1

R143

b

b

d1

d5

170

d3

16



Type of connection

Pipe diameterDN(mm)



(kg)


d1 d2 d3 d4 d5 f l h1 h2

41(NF 25)

(-)

Flange4-hole 25 115 85 - 14 8 240 235 90 4,2 ≤5000KVA

42(NF 50)

(-)

Flange4-hole 50 165 125 - 18 11 240 250 80 5,1 ≥5000KVA

≤10000KVA

43(NF 80)

(-)

Flange4-hole 80 200 160 - 18 11 240 265 80 5,5 ≥10000KVA

7.5. Double-floatBuchholzrelayswithgeometricalflangedimensions according to former French norm

Figure22-Dimensionaldrawing,type41,42,43

250

300350

cm3

d5

90°

l

80h2

h1

d1

d3

150

b

b

17


Type of connection

Pipe diameterDN(mm)



(kg)


d1 d2 d3 d4 d5 f l h1 h2

51(BS 25)

(-)

Flangesquare4-hole

25 --

722,83

--

M10M10

--

1275

2359,25

903,54 3,7 ≤5000KVA

52(BS 50)

(-)

Flange6-hole 50 140

5,511104,33

--

120,47

120,47

1857,28

2359,25

803,15 4,8 ≥5000KVA

≤10000KVA

53(BS 80)

(-)

Flange6-hole 80 160

6,301305,12

--

120,47

130,51

1857,28

2409,45

803,15 5,0 ≥10000KVA


Figure24-Dimensionaldrawing,type52,53

7.6. Double-floatBuchholzrelayswithgeometricalflangedimensions according to former British standard

250

300350

cm3

170

d1

d3

d5

h1

f

l

d2

R143

80h2

250

300350

cm3

d5

90°

l

80h2

d1

d3

150

b

b

h1

18


8. Switchingsystemdesignoptionsfordouble-floatBuchholzrelays

Magnetcontacttubesareusedasswitchingelements.Thesearenormally-open(NO),normally-closed(NC)andchange-over(CO)contacts.Themagnetcontacttubedesigncanbederivedfromthelasttwodigitsofthetypecode.Forcoding,seeOrderingdata/TypecodeunderSection 12.2. on page 2.

...11 BS 25...11 ...12 ...13 ...14 ...15Alarm Alarm Alarm Alarm Alarm Alarm1NO 1NO 1NO 1NO 1NO 1NO

13

14

13

14

13

14

13

14

13

14

13

14

Disconnection Disconnection Disconnection Disconnection Disconnection Disconnection

1NO 1NO 1NC 2NO 2NC 1NOand1NC

23

24

23

24

11

12

23

24 34

33 11

12 22

21 23

24 12

11

...16 ...17 ...19 ...21Alarm Alarm Alarm Alarm1NO 1NO 1NO 1NC

23

24

13

14

13

14

11

12

Disconnection Disconnection Disconnection Disconnection

1 CO 2 CO 3NO 1NO

14

11

1224

21

22 32

31

34

23

24 34

33

44

4313

14

19

...22 ...23 ...24 ...25 ...26 ...27Alarm Alarm Alarm Alarm Alarm Alarm1NC 1NC 1NC 1NC 1NC 1NC

11

12

11

12

11

12

11

12

21

22

11

12


1NC 2NO 2NC 1NOand1NC 1 CO 2 CO

21

22

13

14 24

23 21

22 32

31 13

14 22

21

14

11

12 24

21

22 32

31

34

...31 ...32 ...33 ...34 ...35 ...36Alarm Alarm Alarm Alarm Alarm Alarm1 CO 1 CO 1 CO 1 CO 1 CO 1 CO

24

21

22 24

21

22 24

21

22 24

21

22 24

21

22 24

21

22



13

14

11

12

33

34 44

43 31

32 42

41 13

14 12

11

14

11

12

20


...41 ...42 ...43 ...44 ...45 ...46Alarm Alarm Alarm Alarm Alarm Alarm2NO 2NO 2NO 2NO 2NO 2NO

13

14 24

23 13

14 24

23 13

14 24

23 13

14 24

23 13

14 24

23 23

24 34

33



33

34

11

12

33

34 44

43 11

12 22

21 33

34 12

11

14

11

12

14 34 3313

...51 ...52 ...53 ...54 ...55 ...56Alarm Alarm Alarm Alarm Alarm Alarm

1NCand1NO

1NCand1NO

1NCand1NO

1NCand1NO

1NCand1NO

1NCand1NO

11

12 14

13 11

12 14

13 11

12 14

13 11

12 14

13 11

12 14

13 21

22 24

23


1NO 1NC 2NO 2NC 1NCand1NO 1 CO

23

24

21

22

23

24 34

33 21

22 32

31 21

22 24

23

14

11

12

21

The inner side of the cap accommodates a plate with the graphic symbol and the connection diagram. The schemes show the switching systems in their neutral position. The neutral positionistheoperatingconditionwhentheBuchholzrelayisfilledwithinsulatingliquidupthe required level and the device to be protected operates without any fault.

Explanation of symbols: Example:coding„...1 2“Magnetcontacttube(s)designUpperswitchingsystem-AlarmLowerswitchingsystem-Disconnection

13

14

11

12

Alarm1NO

Disconnection1NC

Graphicsymbolwithterminalmarking

Connectiondiagraminterminalbox

22


9. Technical data

Parameter Data NotesVoltage AC12V-max.250V

DC12V-max.250VCurrent AC0.01A-max.2A

DC0.01A-max.2Acosφ>0,5L/R<40ms

Switchingcapacity ACmax.400VADCmax.250W

Dielectric strength AC2500VAC2000V(normally-opencontact)AC1000V(change-overcontact)

betweenelectriccircuitandearthbetweenopencontacts

Temperaturerange:- Ambient temperature

- Operating range * Temperature of the insulating liquid

* Viscosity of the insulating liquid

-40°Cto+55°C-40°Fto+131°F

-40°Cto+115°C-40°Fto+239°F

1 mm2/sto1100mm2/s

Climatic testing acc. toDINEN60068-2-78:2002-09

Othersonrequest:extremefrigidopen-airconditionsbelow-40°Coroffshore

Resistanceagainstvibration Class4M6 Classificationacc.toDINEN60721-3-4

Resistancetopressure 0.25MPaResistancetovacuum <2.5kPaInsensitivitytomagneticfields 25 mT Staticmagneticfieldofany

direction and polaritySwitchingsystem:-Numberofswitchingcontacts-Switchingelement- Damper

Responsetimeofdamper

1MagnetcontacttubeHeldbymagnets

<0.1s

Moreonrequest

Responseofswitchingsystemincaseof:- Gas accumulation

-InsulatingliquidflowPipediameterDNof25mm,50mmor80mm

200cm3to300cm3

min.0.65tomax.3.00m/s+/-15%

For possible data see Ordering data/Type code under Section 12 on pages 28 and 29.

Cable gland M20x1.5;M25x1.5 Others on requestNominalinstallationposition 0°to5° AscendingtowardsconservatorIP code IP54;IP56;IP66 Others on request

Casing colour Two-componenttexturepaint On polyurethane basis

ThetechnicaldatalistedinTable1areapplicabletoallBuchholzrelaysmanufacturedbyEMB.EMBBuchholzrelaysareincompliancewithDINEN50216-2.OptionsavailablearespecifiedintablesofSection10onpage23.ThesespecialdesignsarecodedusingtherespectivecodewhenorderingBuchholzrelays.

23

10. Special designs

Climate-proofversion(extremefrigidopen-airconditionsbelow-40°C) 34Climate-proofversion(offshore) 36

Climate-proof version

Explanation CodeNMseries-Buchholzrelaywithanaloguemeasurementofthegasvolume(onlydouble-floatBuchholzrelays) 60

Buchholz relay NM series

Withoildrainplug(onlydouble-floatBuchholzrelays) 28WithpremountedHarting-Connector(Theoptionisindicatedbyaletterafterthecode.) 59

Casing

Upperswitchingsystemequippedwithtwomagnetcontacttubes 35Lowerswitchingsystemequippedwithtwomagnetcontacttubes 25Upperandlowerswitchingsystemeachequippedwithtwomagnetcontacttubes 33 Lowerswitchingsystemequippedwiththreemagnetcontacttubes 99Testingoftheswitchingsystemsbymeansofcompressed-airandtestkey(onlydouble-floatBuchholzrelays) 32 Damperheldinresponseposition(onlydouble-floatBuchholzrelays) 23SpecialdesignapprovedbyRWE,Germany(onlydouble-floatBuchholzrelays) 24

Switching system (fordesignoptionsseepage11orpages18-20)

Specialrequest(onspecialagreementwithcustomer) 29

Special request

CasingcolourRAL7001(silver-grey) 41 CasingcolourRAL7012(basalt-grey) 42 CasingcolourRAL7022(umber-grey) 43 CasingcolourRAL7033(cement-grey) 44 CasingcolourRAL7038(agate-grey) 45 CasingcolourRAL7035(light-grey) 46CasingcolourRAL7016(anthracite-grey) 47CasingcolourRAL9002(grey-white) 48CasingcolourRAL7032(siliceous-grey) 49

Casing colour

Insulating liquid silicone oil 20Insulating liquid based on esther 21

Insulating liquid

IP code IP 56 38IP code IP 66 39

IP code

24


10.1. Explanations to codes 23 or 24 Buchholzrelayswiththefeature„damperheldinresponseposition“aredesignedsuchthatthedamperafteritwasoperatedduetoanunacceptablehighflowrateoftheinsulatingliquidislockedinitspositionand,henceiskeptinthispositionevenaftertheflowratehasbeenreduced.This means that the signal generated is maintained.

Thedamperhastobeunlockedmanuallybyturningthetestkeyanticlockwise.Whenunlockingthedamper,alsochecktheinsulatingliquidlevelintheBuchholzrelay.BleedtheBuchholzrelay,if required.

Forengineeringreasonsthefollowingspecialdesignscannotbecombinedinthesamedevice:

Code combination Code combination Code combination60-32 32-23,24 33-23,2460-33 32 - 25 33 - 9960-34 32 - 3360-35 32 - 35 35-23,2460-36 32 - 99 35 - 9960-5960-99 99-23,24

25

10.2. Explanations to code 32

ForBuchholzrelaysprovidedadditionallywithanairnipple(code32),themechanicalfunctionofthetwoswitchingsystemscanbetestedbymeansoftestkey(1),andtheupperswitchingsystem(alarm)canbetestedbypumpinginairviathetestvalve(2)usingasuitabletestpump.Additi-onally,theswitchingsystemscanbetestedpneumatically.Tothisend,airissuppliedviaanairsupplynipple(3)providedwithacheckvalve.PerformthetestwhiletheBuchholzrelayisfilledwithinsulating liquid up to the required level.

Pneumatic test of the upper switching system (alarm) using compressed air:Air is introduced slowlyintotheBuchholzrelaythroughtheairsupplynippleandthepipeairuntilthealarmcontactismadewhentheupperfloatislowered.

Pneumatic test of the lower switching system (disconnection) using compressed air:Through the air supply nipple and the pipe air is applied suddenly to the damper. When the damper responds the disconnection contact is made. Afteranytestusingair,bleedtheBuchholzrelaythroughthetestvalve.

ThefunctionaltestusingcompressedairresultsfromBritishStandardB.E.B.S.T2of1966.

Figure25-Coverwithadditionalairsupplynipple

2 3 1

26


11.2. Extra function of Buchholz relay NM series

ThestandardBuchholzrelaydetectsundissolvedgasesintheinsulatingliquidandindicatestheirpresencewhenaspecifiedthresholdisexceeded,meaningthatuptoacertaingasvolume,nosignalisgenerated.Neitherisitpossibletogatherinformationaboutthelengthoftimeittakesforgas to accumulate.

The process of the generation of unsolved gases in the insulating liquid over time is a very im-portant criterion for the evaluation of the fault as the quantity and composition of the fault gases dependonthekindandquantityoftheenergyoftheunderlyingfault.Spontaneousandenergy-richfaultscauselargegasquantitieswithinashortperiodoftime,whilstsmallvolumesofgasaregenerated in the case of minor and insidious faults.

TheBuchholzrelayofNMseriesallowscontinuousandanaloguegasvolumemeasurementsothatgaseswhichhaveaccumulatedintherelayaredetectedatanearlystage,informationaboutthe generation of the gases obtained and the conditions provided for the analysis of the fault at an early stage.

11. Explanations to code 60 - Buchholz relay NM series

11.1. Design features of Buchholz relay NM series

TheprincipalconstructionoftheBuchholzrelaywithfloatsanddamperaswellastheirelectro-mechanical functions have been maintained.

TheBuchholzrelayofseriesNMisequippedadditionallywithacapacitivesensor.ThesensorisinstalledinthecoveroftheBuchholzrelay.Thecapoftheterminalboxaccommodatestheelec-tronicamplifierofthemeasuringunit.Sensorandamplifierareconnectedbyashieldedcableinthree-wiretechnologyof15mlengthwithacableconnector.Thiscableisusedforthesupplyvoltage and the output signal.

Figure26showsthearrangementofthemeasuringunitusingtheexampleofaBuchholzrelayBF80/10/8.Apartfromthedusthoodandthecapoftheterminalboxwhicharehigherbyapprox.30mm,theinstallationdimensionsoftherelayhavenotbeenchanged.Hence,relayswithanaloguemeasuringunitscanbeinstalledinexistingsystems.

Figure26-DimensionaldrawingBuchholzrelayNMseriestype09-26.(BF80/10/8)

109

80

291

19515

138

200

170

M16

18

80

160

R143

27

11.3. Analogue measuring unit - Analogue measurement of gas volume

The measured value is based on capacitance variation of the sensor caused by variation of the insulatingliquidlevelintheBuchholzrelay.

Analoguemeasurementofthegasvolumeispossiblebetween50cm3and300cm3.Lowergasvolumescannotbemeasuredreliablybecauseofhighinaccuracies.Measurementsbeyondthisrangearenotnecessaryasinthiscasetheupperswitchingsystemwillrespond.Besides,theconstructionoftheBuchholzrelay(largergasvolumesescapetowardstheconservator)doesnotallowsuchmeasurements.Theoperatingpointoftheupperswitchingsystem(upperfloat)isagasvolumeof200-300cm3.

Fault: Free gas is available in the insulating liquid.

Response:Thegasintheliquidmovesupwards,accumulatesintheBuchholzrelayanddisplacestheinsulatingliquid.Thisdecreasesthelevelofinsulatingliquid.Liquidlevelchangesleadtovaria-tion of the capacity of the sensor. This change is converted into an analogue current signal.

It should be noted that for design reasons the current value of the sensor remains relatively con-stantuptoagasvolumeofapprox.50cm3.Thefunctionequationwillprovidetheactualvolumeonlywhenthecurrentsignalbecomessmallerand,hencethecalculatedvolumenoticeablylarger.

TheextrafunctionoftheNMseriesrelaysisensuredbyacapacitivesensorandtheappropriateelectronic components. Supply voltage of this assembly is DC 24 V. This voltage must be made available by the user. The output signal of the measuring unit is a standard current signal of DC4to20mA.Itdependsontheuserhowandinwhatformthissignalisprocessed.

ExtrafunctionoftheBuchholz relayNMseries

Standard functionoftheBuchholzrelay

Monitoring-system

Conversion and processing

Disconnection Alarm

DC 24 V

DC4-20mA

DC12V-max.250VDC0,01A-max.2A

Figure27-ExtrafunctionofBuchholzrelayNMseries

28


12. Ordering data/Type code

Forplacingorders,please,usethefollowingkey:

For switching system design options for single-floatBuchholzrelays,seeSection6onpage11.

12.1. Single-floatBuchholzrelays

Type(seeSection5)

Special design(seeSection10)

0=notoccupied

Dampersetting(m/s)

01=0,65+/-15%02=1,00+/-15%03=1,50+/-15%

Contact setting ofswitchingsystem

1=oneNOcontact2=oneNCcontact3=twoNOcontacts4=twoNCcontacts5=oneNOandoneNCcontact 6 = one CO contact7=twoCOcontacts8=oneNOandoneCOcontact9=oneNCandoneCOcontact

XX XX. XX. X X0

Orderingexamplefordouble-floatBuchholzrelays:

YouneedaBuchholzrelayoftypeBF80/Q.Thedampershouldrespondataflowrateof1.50m/s.Theupperswitchingsystemshouldbeequippedwithoneswitchingelement(magnetcontacttube)andthelowerwithtwoswitchingelements(magnetcontacttubes).Theupperswitchingelementshouldbedesignedasonenormallyopencontact,andthelowerastwonormallyopencontacts.ThedeviceshouldbedeliveredincolourRAL7033andshouldhaveoneoildrainplug.

Basedonthedataonpage29therelayorderedhasthefollowing

Typecode: 10-25.28.44.-0313

Explanation: 10=Double-floatBuchholzrelaytype10(BF80/Q) 25=Lowerswitchingsystemequippedwith2magnetcontacttubes 28 = With oil drain plug 44=CasingcolourRAL7033(cement-grey) 03=Dampersetting:1.50m/s+/-15% 1=Contactsettingofupperswitchingsystem:1NO 3=Contactsettingoflowerswitchingsystem:2NO

Legend:NO=normally-opencontactNC=normally-closedcontact CO = change-over contact

12.2. Double-floatBuchholzrelays

29

Double-floatBuchholzrelays

Forswitchingsystemdesignoptionsfordouble-floatBuchholzrelays,seeSection8onpages18-20.

Type(seeSection7)

Special design(seeSection10)

Dampersetting(m/s)

01=0,65+/-15% 11=1,20+/-15%02=1,00+/-15% 12=1,25+/-15%03=1,50+/-15% 13=1,30+/-15%04=2,00+/-15% 14=1,40+/-15%05=2,50+/-15% 15=1,80+/-15%06=3,00+/-15%

Contact setting of lowerswitchingsystem(disconnection)

1=oneNOcontact2=oneNCcontact3=twoNOcontacts4=twoNCcontacts5=oneNOandoneNCcontact 6 = one CO contact7=twoCOcontacts

9=threeNOcontacts

Contact setting of upperswitchingsystem(alarm)

1=oneNOcontact2=oneNCcontact 3 = one CO contact4=twoNOcontacts5=oneNCandoneNOcontact

XX XX. XX. XX XX

Legend:NO=normally-opencontactNC=normally-closedcontact CO = change-over contact

30


13. Additional devices for Buchholz relays

13.1. Gas sampling device ZG 1.2.

ThegassamplingdeviceismountedonthetransformerandconnectedtotheBuchholzrelaybymeansofapipe.Itallowssamplingoftherelaygasatnormaloperatinglevel.

Thelengthofthepipecanbeselectedbythecustomer(please,seepage31).

Thedevicecanbedeliveredwithalockablebox.

Figure 28 - Gas sampling device ZG 1.2. Figure 29 - Gas sampling device ZG 1.2. inlockablebox

Figure30-PipeofgassamplingdeviceZG1.2. Figure 31 - Sightglass cover for gas sampling device ZG 1.2.

31

Parameter Data NotesGas outlet opening G1/8“ Others on requestOil outlet opening G1/8“ Others on requestTemperaturerange:- Ambient temperature

- Operating range * Temperature of the insulating liquid

* Viscosity of the insulating liquid

-40°Cto+55°C-40°Fto+131°F

-40°Cto+115°C-40°Fto+239°F

1 mm2/sto1100mm2/s

Othersonrequest:extremefrigidopen-airconditionsbelow-40°Coroffshore

Weightwithoutpiping 2,2kgDimensions of pipe Ø6x1copperLengthofpipe <20m As requested by customerCasing colour Two-componenttexturepaint On polyurethane basis

Technical data

Insulating liquid silicone oil 20Insulating liquid based on esther 21

Insulating liquid

Climate-proofversion(extremefrigidopen-airconditionsbelow-40°C) 34Climate-proofversion(offshore) 36

Climate-proof version

Explanation CodeCasingcolourRAL7001(silver-grey) 41 CasingcolourRAL7012(basalt-grey) 42 CasingcolourRAL7022(umber-grey) 43 CasingcolourRAL7033(cement-grey) 44 CasingcolourRAL7038(agate-grey) 45 CasingcolourRAL7035(light-grey) 46CasingcolourRAL7016(anthracite-grey) 47CasingcolourRAL9002(grey-white) 48CasingcolourRAL7032(siliceous-grey) 49

Colour

Specialrequest(onspecialagreementwithcustomer) 29

Special request

Special designs:

32


Figure32-Dimensionaldrawing,typeZG1.2.

90 XX. XX. X XX,XXm

Type for ZG 1.2.

Lengthofpipein meters

Special designs(seepage31)

0=withoutbox1=withbox

Ordering example of gas sampling device ZG 1.2.:

Typecode: 90-34.44.-0-10,50mExplanation: 90=GassamplingdeviceZG1.2. 34=Climate-proofversion(extremefrigidopen-airconditionsbelow-40°C) 44=CasingcolourRAL7033(cement-grey) 0=Withoutbox 10,50m=Lengthofpipe10,50m

Ordering data/Type code of gas sampling device ZG 1.2.

125

9

15

93

210

30

10

33

Gas testing device ZG 3.1.

ThegastestingdeviceisusedtotestthegasaccumulatedintheBuchholzrelay.ItcanbeinstalledeitherdirectlyonthetestvalveoftheBuchholzrelayoronthegasoutlettapofthegassamplingdevice.TheBuchholzgasflowsthroughtwodifferentchemicalsolutionsanditscolourreactionsindicatethenature of the fault.

Use of the gas testing device is no substitute for a gas chromatographic analysis.

RefluxlockZG4.1.

Thedevicepreventsinsulatingliquidfromflowingintothegastestingdevice.ThedeviceisinstalledbetweentheBuchholzrelayorgassamplingdeviceand the gas testing device.

Test pump ZG 5.1. and ZG 5.2.

Thetestpumpchecksthefunctioningoftheupperswitchingsystem(alarm)oftheBuchholzrelaybypumpinginair.Thetestcanbeperformeddirect-lyontheBuchholzrelay.Forthatpurpose,thetestpumpisconnectedtothetestvalveoftheBuchholzrelay.Whenthetestisperformedviathegassamplingdevice,thetestpumpisconnectedtothegasoutlettapofthegassampling device.

- ZG 5.1. manually operated- ZG 5.2. pedal-operated

Oil sampling device ZG 6.1.

TheoilsamplingdeviceisconnectedtotheBuchholzrelayviaapipeandisusedtotakeoilsamplesfromtheBuchholzrelay(suitableforusewithBuchholzrelayswithanoildrainplug).Thepipeissuppliedtothecustomer’sspecifications.

13.2. Other additional devices for Buchholz relays

34


Buchholz gas sampler BGS

TheBuchholzgassamplerprovidesasafemethodoftakingandtransportinggassamplesfromtheBuchholzrelayorthegassamplingdevice.Itscapacityis100ml.

Buchholz gas tester BGT

TheBuchholzgastesterisusedtomeasurethehydrogenconcentrationoftheBuchholzgases.Themeasurementcanbeperformeddirectlywherethesampleistaken.

Forothergastestingequipment,please,contactus.

35

MonitoringrelayfortapchangersÜRF25,ÜRF25/10,ÜRF25/10-26

Themonitoringrelayfortapchangers,alsoknownastheprotectionrelayfortapchangersoroilflowrelay,isamonitoringdeviceforinsulatingliquid-filledtapchangerswithconservator.Itprotectsthetapchangerandthetransfor-merfromdamage.Themonitoringrelayrespondstoexcessiveoilflowinthedirection of the conservator and generates a signal disconnecting the tap changer and the transformer immediately from voltage supply.

PipediameterDN:25mm(1“)Typeofconnection:threadedorflanged

Oilflowindicator SG25,SF25,SF25/10

Theoilflowindicatorisaprotectiverelaymonitoringthecirculatingoillubri-cation or circulating oil cooling of machines and equipment. It indicates faults incirculatingoilsystemsorshutsdownthemachineorequipment,thuspre-ventingdamage.Theflowindicatoroperatesataverylowservicepressure,soitcanbeinstalledinanoilreturnpipewheretheoilflowisensuredbythesloping pipe.

PipediameterDN:25mm(1“)Typeofconnection:threadedorflanged

14. Other protection devices

Forfurtherinformation,pleaseaskforspecialreferencematerial.

Duetotechnicalimprovementofourproducts,theinformationcontainedinthiscatalogueissubjecttochangewithoutnotice.Wewouldliketoapologizeforanyprintingerrorswhichhavenotbeenfounddespiteofintensiveproof-reading.

Edition:CatalogueBuchholzrelaysKA01/01/12/02English

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KA 01-01-12-02 Catalogue Buchholz Relay-PRINCIPLES