Buchholz Relay

BUCHHOLZ RELAYSTR | FI | ES | MA | GM | MK | TN | EG | AZ | IQ |SY | SA | AE | YE | MZ

BUCHHOLZ RELAYSOrderin System

1

Purchase orders should be given in accordancewith the following chart.

COLOR DESCRIPTION

RAL 1016

RAL 7001

RAL 7012

RAL 7016

01

02

03

04

RAL 7022

RAL 7032

RAL 7033

RAL 7035

05

06

07

08

RAL 7037

RAL 7038

RAL 9002

09

10

11

Example:AMBR25-F50: 751. 1. 1. 2. 01- (01) BUCHHOLZ RELAY FOR CONTACT CONNECTION DETAILS 9 or 10 See page

TYPE

ABR25-V50 (DG-25)

ABR25-F50 (DR-25)

ABR50-F100 (DR-50)

ABR80-F100 (DR-80)

741

751

761

771

UPPER CONTACT SYSTEM

Standart Reed Switch Normally Open (R-NO)

Standart Reed Switch Normally Closed (R-NC)

Changeover Reed Switch (W)

Without Contact (0)

1

2

3

0

LOWER CONTACT SYSTEM

Standart Reed Switch Normally Open (R-NO)

Standart Reed Switch Normally Closed (R-NC)

Changeover Reed Switch (W)

1

2

3

OIL FLOW SPEED SETTING

1,00 m/s

1,50 m/s

2

3

2 Normally Open Contact 03

2

BUCHHOLZ RELAYSAN-50216-2

MATERIALBuchholz Relay casing, cover, terminal box cover, glass frame coverare produced from aluminum material and coated with electrostaticpowder paint. The glasses on the relay are produced from temperedglass to make them stronger against breakage. Markings andgraduations on the glass are written with special firing technique.

MOUNTING THE BUCHHOLZ RELAY TO THE TRANSFORMERBuchholz Relay is intended to work in a horizontal positions. it isconnected with a 5° positive angle to the horizontal axis with thearrow mark on the relay pointing to the oil conservator.Buchholz Relays are manufactured to allow both thread and flangeconnections. Thread connections types for flange connections are also shownin (Table 1).

WORKING PRESSUREBuchholz Relay is tested for an inner pressure of 50 kPA. In additionto that, it is tested with an extreme pressure of 250 kPA for 2 minutes.

MAGNETIC FIELD RESISTANCEBuchholz Relays operate perfectly up to 25m T magnetic fieldsAdditionally, they are resistant to any d.c. field value at any dşrectionand polarization.

WORKING CURRENTSThe working current is 2A. r.m.s and 30ms, The short circuit currentis 10A. r.m.s.

TERMINAL BOXIn the terminal box, there is 1 earthing terminal and depending on thenumber of contacts there are 4 to 10 electric terminals.These electric terminals allow connection of cables with 1,5 and 4mm 2cross sections. PG16 or M20X1,5 cable gland can be used for cableentry. Connection diagram of the electric terminals is shown on theelectric terminal cover.

OIL TUBE CONNECTION

INNER DIAMETER mm

25

STEADY OILFLOW FOR THE

RELAY TO WORK m/s

1

TOLERANCE

±15

50

80

1

1-1,5

±15

±15

VOLTAGE

48V-127V d.c

CURRENT

2A

SEPARATION CAPACITY

L/R <40ms

2A Cos c >0.5

250W

400VA

SEPARATION AND CLOSING CAPACITY

Table1 - STEADY OIL FLOW FOR THE RELAY TO WORK m/s

230V a.c

INTENDED USE OF BUCHHOLZ RELAYOn power and distribution transformers with oil conversator,protection relays manıfactured by Buchholz principle are mountedbetween transformer tank and oil conservator and protects thetransformer against the following conditions:1-Against gas accumulations in the transformer,2-Against potential oil leakages in the transformer,3-Against oil surge which can occur during overheatingsituations caused by failures in transformers.

1-AGAINST GAS ACCUMULATIONS IN THE TRANSFORMERTwo float systems exist in the Buchholz Relay. These two floatsystems activate dry type Reed switches connected to them. Thefloat system which is at the Buchholz Relay’s upper sideactivates the alarm reed switch. In case between 100 cm3 and300 cm3 or 400 cm3 amounts accumulate in the Buchholz Relay,or in case of an oil leakage with these amounts, the alarm switch isactivated and sends a signal. As this alarm reed switch can be usedas one normal open or two normal open, one switch can be usedas changeover as well.

3-OIL SURGE WHICH CAN OCCUR DURINGOVERHEATING SITUATIONS CAUSEDBY TRANSFORMER FAILURESIn case of overhating situations caused by transformer failures,if the oil flow rate (table-1) in the Buchholz Relay exceeds thespecified values, the lower float system described in item two isactivated and sends a signal. This signal (trip) is also used to deactivate the transformer.

2-AGAINST POTENTIAL OIL LEAKAGESIN THE TRANSFORMERAs mentioned in item 1, when oil leakages that occur in thetransformer are more than 100 cm3, 300 cm3 and 400 cm3 thecontact system connected to upper float activates, the reed switchconnected to the second float system in the Buchholz Relayactivates and sends a signal. This signal means that the oil leakage in the transformer reached to critical level and there isnot enounh oil in the oil conservator to protect the transformer.Therefore this contact is called the “trip contact”.This is the contact used to deactivate the transformer.Thiscontact working in connection to the lower float can be used asone or two or can be preferred as changeover reed switch as well.

SAMPLE TAPThere is the sample tap over the Buchholz Relay. This tap allowstaking oil from within the transformer and degassing the gassesaccumulated in the relay as well. The tap is manufactured withglob valve principle in order to prevent gas leakage.

CONTROL-TEST BUTTONUsed to test if the contacts are working properly by moving theupper and lower floats in the Buchholz Relay up and down.Additionally, when the lower float is activated because of the oilflow rate, the signal doesn’t disappear from the system unless thesystem is reset by the test button.The systems are reset and the signal disappears when the test button is pressed.

3

Figure B: casing with thread connectionFigure A: casing with flange connection

Thread (B) and flange (A) connection types.

Inspection sight glass cover.

Strong and speciallygradualed inspection glass.

Terminal box

Sample tap

Control-test button

Product label area

Earthing screw

Electric terminal

Electric terminal connection scheme

Terminal box cover

Cable coupling(PG16 or M20x1,5)

Blind plug

BUCHHOLZ RELAYSAN 50216-2

Connection Hanger

Lower Float

Upper FloatUpper Reed Switch

Lower Reed Switch

Control-Test Button

Flow Speed Control Element

4


2812

5

18

185

6788

65

223

G1½

A

91 178.5

351

166

R92Ø25

Type NoDIN CODE

Type NoDIN CODE

ConnectionNom.Pipesize

(mm.) D1Weight(kg.)

TransformerPowerClass

741ABR25-V50

(DG-25)(AN50216-2)

ScrewedG 1½A

25 3,9 �5000 KVA

5


Type NoDIN CODE

Type NoDIN CODE


(mm.) D1Weight(kg.)


751ABR25-F50

(DR-25)(AN50216-2)

FLANGED 25 4,7 �5000 KVA

Ø11

5

Ø68

200

178.5

R92Ø85

Ø25

Ø14

166

351

16

88 223

67

91

65

2812

5

6


Type NoDIN CODE

Type NoDIN CODE


(mm.) D1Weight(kg.)


761ABR50-F100

(DR-50)(AN50216-2)


195

Ø10

2

Ø16

5

Ø18

351

90°

166

75.

5

R92Ø50

Ø125

68

18

28

178.5

112.

5

91

226

82.5

�5000 KVA

7


Type NoDIN CODE

Type NoDIN CODE


(mm.) D1Weight(kg.)


771ABR80-F100

(DR-80)(DIN 42566)


195

Ø13

8

Ø20

0

Ø18

351

Ø80

166

R92

Ø160

178.5

60.5

65

18

2897

.5

229

100

M16

8


Lower

Yellow11 12

Lower

Yellow14 11 12

Lower

Yellow11 12

Upper

Red21 22

Lower

Yellow14 11 12

Upper

Red24 21 22

Lower

Yellow11 12

Lower

Blue31 32

Upper

Red21 22

Upper

Green41 42

Lower

Yellow11 12

Lower

Blue31 32

Upper

Red24 21 22

Upper

Green34 31 32

(Lover float)(Single Contact)

1 Normally Open Contact

01(Lover float)

(Single Contact)1 Changeover Contact

(2 Normally Open Contact)1 Normally Open Contact Lower1 Normally Open Contact Upper

(2 Changeover Open Contact)1 Changeover Open Contact Lower1 Changeover Open Contact Upper

(4 Normally Open Contact)2 Normally Open Contact Lower2 Normally Open Contact Upper

(4 Changeover Open Contact)2 Normally Open Contact Lower

2 Changeover Open Contact Upper

NORMALLY OPEN CONTACT

02 03 04

05 06

9


NORMALLY CLOSED CONTACT

07

Lower

Yellow11 12

(Lover float)(Single Contact)

1 Normally Closed Contact

(2 Normally Closed Contact)1 Normally Closed Contact Lower1 Normally Closed Contact Upper

Lower

Yellow11 12

Upper

Red21 22

08

(4 Normally Closed Contact)2 Normally Closed Contact Lower2 Normally Closed Contact Upper

Lower

Yellow11 12

Lower

Blue31 32

Upper

Red21 22

Upper

Green41 42

09

Upper

Red24 21 22 34

Lower

Yellow11 12

Lower

Blue31 32

Upper

Green31 32

(4 Contact)2 Normally Closed Contact Lower

2 Changeover Closed Contact Upper

10

10


Buchholz Relay Sectional Views

Sample Tap

Control-Test Button

Oil Speed Control Element

Float Seating

Control - Test Button

Contact Locking Magnet

11


DATAPARAMETER NOTES

AC 230VDC 230V

Nominal voltage 12 V to 250 V12 V to 250 V

Nominal current

AC 1000 VContact voltage capacity -

AC 2000 VInsulation voltage capacity Contact against casing

AC 230VDC 230V

12 V to 250 V12 V to 250 V

TECHNICAL DATA

Temperature range:

(-40°C to +55°C)-(40°F to +131°F)-ambient temperature Climate acc. to DIN EN 60068-2-78:2002-09

-working range:

(-40°C to +155°C)-(-40°F to +239°F)(*temperature of the insulation fluid) Others on request

<1100 mm²/s(*viscosity of the insulation fluid)

class 4M6Shock resistance

2g(peak value) frequency range 2Hz to 200 Hz-Earthquake / Vibration -

25g/shocl duration 11 ms-Impact -

0.25 MPaResistance to pressure -

<2.5 kPaResistance to vacuum -

25mTInsensitivity to magnetic fields -

-Flow of insulation fluid

1.00 m/s+15%nominal diamenter (DN) 25 mm -

1.00 m/s+15%nominal diamenter (DN) 50 mm -

1.00 m/s+15% or 1.50 m/s+15% or 2.00 m/s+15%nominal diamenter (DN) 80 mm -

M20x1.5Cable gland Others on request

1° accending towards expansion vesselNominal installation position 0° to 5°

IP54Degree of protection Others on request

Switching system:

1-Number or switching contacts per switching system More on request

magnet contact tube-Switching contact -

hold by magnets-Flow speed control element -

<0.1s-Response time of speed control element -

Response of switching system in case of:

200 cm³ to 300 cm³-Gas accumulation -

Buchholz Relay

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