Elektromotoren und Gertebau Barleben GmbH

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Monitoring relay for tap changers

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Table of contents

Item No. Heading Page

Firms history 3

Preface 3

1. Design features 4

2. Tests 5

3. Function 6

4. Type list 6

4.1. Type 12 6

4.2. Type 15 6

4.3. Possible switching system designs 7

5. Technical data 8

6. Special designs 9

7. Ordering data 10

8. Further devices 11

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Firms history Since its foundation the company has been passed through an eventful history with regard to ownership, affiliation and connected with these changes of firm names. 1863 Foundation of the company as sugar factory 1943 Establishment of SIEMENS Magdeburg 1948 VEB1 Elektromotorenwerk Barleben; VEM (state-owned firm) 1951 VEB1 Starkstromanlagenbau Magdeburg (state-owned firm) 1951 Start of manufacturing Buchholz relays at site in Barleben 1965 Start of manufacturing

Monitoring relays for tap changers at site in Barleben

1970 VEB1 Elektrotechnik und Gertebau Magdeburg; EGEM (state-owned firm) 1980 VEB1 Kombinat Elektromaschinenbau Dresden VEB1 Elektromotorenwerk Barleben; VEM; ELMO (state-owned firm) 1990 VEM Antriebstechnik AG Dresden Elektromotorenwerk Barleben GmbH; VEM; ELMO (public limited company) 1993 Elektromotoren und Gertebau Barleben GmbH; EMB (privately owned company)

Preface The monitoring relay for tap changers, also named protection relay for tap changers or oil flow relay, is a monitoring relay for oil-insulated tap changers. It protects the tap changer and the transformer from damage. On response the monitoring relay will generate a signal disconnecting immediately the tap changer and the transformer from the source of supply. The company has had for more than 40 years experience in producing monitoring relays and other protection devices for liquid-cooled appliances. It ranks among the most distinguished manufacturers of this kind of equipment. Experiences collected and profound know-how are the sound basis for a high product quality. References from reputed transformer and tap changer manufacturers as well as further users are proof of the high level of the products. The company is DIN EN ISO 9001/2000 certified. Our staff of highly qualified engineers and experienced skilled workers do their best to guarantee top quality high-precision products. The mechanical working of the casings is done on modern CNC-controlled machine tools. The final tests, where all the functions of the monitoring relays are checked, are done with each device by using special test equipment. Each device is delivered with a test certificate. Monitoring relays may be used in open-air or also in indoor equipment.

1 VEB = nationally owned firm

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1. Design features Casing components The casing is a casting of light alloy and is provided with a paint coat. To check the switching system for proper function, the casing is provided with inspection glasses arranged opposite each other, protected by hinged lids (1).

Figure 2: cover with dismantled cap

Switchgear components The switchgear has the following main components:

Switching system Carrier, frame components Mechanical testing device. The switching system consists of the following components:

damper (1) permanent magnet(s) (2) magnet contact tube(s) (3). Figure 3: switchgear The damper is retained in its normal and response positions by permanent magnets. Via a link the permanent magnet is firmly connected with the damper and initiates the contact-making process of the magnet contact tube at a certain oil flow.

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5

6

3

4

1 2

Cover components The cover is a casting of light alloy and is provided with a paint coat. Terminal box, test and reset button (1), covered by a cap nut as well as a bleeder screw (2) are arranged above the cover. The terminal box has an earthing contact (3) and the electrical connectors (4). By means of a removable cap (5) the terminal box is safe to touch and protected against pollution. The cable is to be brought in the terminal box through the cable gland (6).

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Figure 1: casing

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2. Tests To each monitoring relay a works-number is given mentioned in the test certificate and name plate. Furthermore the tests made with each monitoring relay are documented in the test certificate. - Dielectric strength test (AC 2000 V against casing) - Leakage test (acc. to EN 50216-2) - Functional test

(switching function) - Flow test (damper setting)

To each device we deliver in the agreed language: - operating instructions - test certificate. Monitoring relays are delivered in transport cardboards. Following information on name plate:

Figure 5: Flow test

Date of manufacture (week/year)

type specification/ damper setting

works-no. switching element

degree of protection

Figure 4: Functional and leakage test

S = normally-open = normally-closed W = change-over

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3. Function The monitoring relay has to be mounted into the pipe leading from the tap changer head to the oil conservator located as near as possible to the tap changer head. Due to the working method of the tap changer there is gas inside the gas collecting dome of the device. In case of oil flow the monitoring relay responds as follows: Fault: An incident generates an oil flow in the direction of the conservator. Response: The liquid flow reaches the damper arranged in the liquid flow. If the flow rate exceeds the operating threshold of the damper, the latter moves in flow direction. Due to this movement a switch contact is actuated. For that the tap changer and the transformer are disconnected. Figure 6: principle of working method of the damper 4. Type list Type

Works-design. Mode of

connection DN

of pipe (mm)

d1

Flange dimensions

(mm) d2 d3 d4 d5 f

Device dimensions

(mm) l h1 h2

weight (kg)

12 (RF 25/10)

Flange 4-holes 25 115 85 68 14 16 200 195 62 4,0

15 (RF 25)

Flange 4-holes 25 100 85 -- M 12 10 160 190 62 3,6

4.1. Type 12 4.2. Type 15

Oil

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4.3. Possible switching system designs As switching elements are used magnet contact tubes. There are normally-closed (NC), normally-open (NO) or change-over (CO) versions. For coding of the switching system version see point 7. ordering data, page 10. The magnet contact tube version is coded by the last figure of the ordering number.

...1 ...2 ...3 ...4 ...5 ...6 1 NO 1 NC 1 CO 2 NO 2 NC 1 NO and 1 NC

...7 ...8 ...9 2 CO 1 NO and 1 CO 1 NC and 1 CO

Explanation of symbols: Example: coding ... 3

switching system version (1CO)

---

---

Graphical symbol withterminal marking Terminal assignment in terminal box

A plate showing the connection diagram and the terminal assignment is arranged inside the cover of each monitoring relay for tap changers delivered by EMB.

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21

22 12

11

14

14

11

1224

23

14

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1222

21

13

14

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12

13

14 24

23 11

12 22

21

13

14 12

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4

1

2

1 1 change-over (CO)

4

1

2

Note: The switching systems is shown in its normal position, i.e. with the Buchholz relay filled completely with insulating liquid corresponding to trouble-free operation of the device to be monitored.

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5. Technical data The technical data listed in table 1 are valid for all monitoring relays for tap changers manufactured by EMB. More options are mentioned in table 2 on page 10. These additional special designs should be coded with the relevant identification number when ordering Buchholz relays. Parameter

Data

Notes

Nominal voltage

AC 230 V DC 230 V

12 V to 250 V 12 V to 250 V

Nominal current AC 2 A DC 2 A

0.05 A to 2 A 0.05 A to 2 A

Contact voltage capacity AC 1000 V -- Insulation voltage capacity AC 2000 V Contact against casing Temperature range: - ambient temperature

- working range * temperature of the insulation liquid * viscosity of the insulation liquid

-40C to +55C -40F to +131F -40C to +115C -40F to +239F 1 mm2/s to 1100 mm2/s

Climate acc. to DIN EN 60068-2-78:2002-09 Others on request Others on request

Switching system: - Number of switching contacts per switching system - Switching contact - damper Response time of damper Response values of the damper

1 magnet contact tube hold by magnets < 0.1 s 0.9 m/s +/- 15% 1.0 m/s +/- 15% 1.2 m/s +/- 15% 1.5 m/s +/- 15% 2.0 m/s +/- 15% 2.5 m/s +/- 15% 3.0 m/s +/- 15% 4.0 m/s +/- 15%

More on request -- -- Others on request

Resistance to pressure 0.25 MPa -- Resistance to vacuum < 2.5 kPa -- Cable gland M 20x1.5 Others on request Degree of protection IP 54 Others on request Nominal installation position t 2 o ascending towards

expansion vessel 2 to 4

Table 1: Technical data

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6. Special designs Explanation

Identif.no.

Climatic version (extreme frigid open-air climate below -40C) 34 Climatic version (sea climate) 36 Degree of protection IP 56 38 Degree of protection IP 66 39 Special design approved by RWE, Germany 24 Casing colour RAL 7001 (silver-grey) 41 Casing colour RAL 7012 (basalt-grey) 42 Casing colour RAL 7022 (umber-grey) 43 Casing colour RAL 7033 (cement-grey) 44 Casing colour RAL 7038 (agate-grey) 45 Casing colour RAL 7035 (light-grey) 46 Casing colour RAL 7016 (anthracite-grey) 47 Casing colour RAL 9002 (grey-white) 48 Casing colour RAL 7032 (siliceous-grey) 49 Switching system equipped with two magnet contact tubes 25 Customer request on the basis of conditions agreed with the manufacturer 29 Table 2: special designs Casing colour: two-component polyurethane-based structural coating

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7. Ordering data / type specification For placing orders, please, use the following key:

Important remark: NO = normally-open contact NC = normally-closed contact CO = change-over contact Ordering example: You need a monitoring relay for tap changers that means RF 25/10. The damper setting should have a velocity of 2.0 m/s. The switching system should be equipped with 2 magnet contact tubes. One contact should be normally-closed the other on normally-open. The device should be deliverd in colour RAL 7033. This information refers to type specification also called ordering data: type specification 12-25.44.-56 Explanation: 12 = RF 25/10 25 = switching system equipped with 2 magnet contact tubes 44 = colour RAL 7033 5 = damper setting of 2.0 m/s +/- 15%

6 = contact setting of the switching system: 1 NO-contact and 1 NC-contact

Contact setting of switching system

1 = one NO-contact 2 = one NC-contact 3 = one CO- contact 4 = two NO-contacts 5 = two NC-contacts 6 = one NO-contact and one NC-contact 7 = two CO-contacts 8 = one NO-contact and one CO-contact 9 = one NC-contact and one CO-contact

Damper setting (m/s)

1 = 0.9 +/- 15% 2 = 1.0 +/- 15% 3 = 1.2 +/- 15% 4 = 1.5 +/- 15% 5 = 2.0 +/- 15% 6 = 2.5 +/- 15% 7 = 3.0 +/- 15% 8 = 4.0 +/- 15% 9 = special agreement with customer

Special design (see table 2)

Type (see para. 4)

XX X. . . . XX XX X

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8. Further products Elektromotoren und Gertebau Barleben GmbH may supply also products for protection and supervision of liquid-insulated transformers and choke coils. Please, ask for our separate catalogues. Designation

Description

Buchholz Relay NEW

Buchholz relays Transformer protection relays (Buchholz principle) NM series - Buchholz relays with analog measurement of the gas volume

ZG 1.2. Gas sampling device The device is mounted at the transformer and connected to the Buchholz relay by means of a pipe. It allows to sample the relay gas at normal operating level. The device can be delivered with a lockable box.

ZG 3.1. Gas testing device The device serves to analyze the relay gas by means of two test fluids. It can be mounted directly on the Buchholz relay as well as on the gas sampling device ZG 1.2.

ZG 4.1. Reflux lock The device prevents that the insulation liquid gets into the gas testing device.

ZG 5.1. ZG 5.2.

Test pump The device serves to check the upper switching system by means of air. - manual-actuated

- foot-actuated

ZG 6.1. Oil sampling device The device is connected to the Buchholz relay by means of a pipe and serves to take oil samples (can be used for Buchholz relays with oil drain plug).

BGS Buchholz gas sampler The Buchholz gas sampler can be connected to the Buchholz relay or to the gas sampling device. It serves to sample and to transport safe the gas.

BGT Buchholz gas tester The Buchholz gas tester serves to analyze the Buchholz gas regarding the hydrogen concentration.

SG 25 SF 25

Oil flow indicator - with thread connection - with flange connection

Elektromotoren und Gertebau Barleben GmbH

Due to technical improvement of our products, the information contained in this brochure may be subjected to change without notice. We would like to apologize for possible printing mistakes which have not been found despite of intensive proof-reading. Edition: Catalogue monitoring relays K 07/01/09/02 English

Bahnhofstrae 27/28 39179 Barleben / Germany Phone: +49 39203 790 Telefax: +49 39203 5330 Telefax: +49 39203 5450 E-mail: info@emb-online.de Internet: http://www.emb-online.de