Siemens Aktiengesellschaft Alle Rechte vorbehalten.. © Siemens AG • 03/2010

Surge Arrester Type 3EL2

Operating instructions Order-No.: 928 00047 401 c

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2 © Siemens AG • 03/2010

Contents

Contents ________________________________________________________________________2 Technical data 4 Description 5 Design 5 Mode of operation 5 Transportation and storage 6 Screwed joints 7

Installation ______________________________________________________________________8 Accessories 8 Place of installation 8 Mounting the components 8 Installing of the arrester 9 Grounding 12 Terminal 12

Exploded view __________________________________________________________________14

Maintenance ____________________________________________________________________16 Disposal arrester and arrester accessories 16

© Siemens AG • 03/2010 3

The manufacturer of this surge arrester

Siemens AG

Energy Sector · Power Transmission High Voltage

has introduced and applies a quality system in accordance with

DIN ISO 9001 / EN 29 001

Quality systems: Model for quality assurance This system was first demonstrated in 1989 to the

DQS (German Association for the Certification of Quality Systems). The electrical testing laboratories and the materials technology laboratories of the manufacturer have been certified since 1992 by the German Accreditation Body in accordance with DIN EN 45 001.

If you require further copies of the operating instructions, please order them from the appropriate Siemens office,

indicating the title and order number shown on the title page.

Published by: In case of request: Siemens AG Telephone switchboard +49 / 30 / 386 1 E T HP AR Sales department: +49 / 30 / 386 33222 D-13623 Berlin Fax: +49 / 30 / 386 26721 e-mail: mailto:Arrester@Siemens.de Subject to change.

Note

The equipment covered by these instructions should be installed and serviced only by competent personnel familiar with good safety practices. This instruction is written for such personnel and is not intended as a substitute for adequate training an experience in safe procedures.

This information is intended for the correct installation of this product. Siemens has no control over the condition of the network, which can be greatly affected by the installation of a product. It is the responsibility of the user to chose the appropriate method of installation. Under no circumstance is Siemens liable for any direct or indirect damage caused by the use or misuse of this product.

4 © Siemens AG • 03/2010

The 3EL2 surge arrester serves to protect the insulation of a system (or of one of its components) from undue stresses resulting from overvoltages.

Technical data

The standard model is suitable for an installation altitude of up to 6000 ft above sea-level and for a rated frequency between 48 Hz and 62 Hz.

Fig. 1. Surge arrester type 3EL2

The surge arrester meets the following standards: Standard Classification VDE 0675-4

10 kA

IEC 60099-4

10 kA, Heavy duty

IEEE Std C62.11

Station valve arrester

The rating plate [Fig. 2.] will be found on the lowest flange (in some cases this has a special design in accordance with customer requirements).

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1 Order number 6 Pressure relief class 2 Rated voltage 7 Year of manufacture 3 Continuous voltage 8 Works serial no. 4 Rated discharge current 9 Unit no. of upper arrester unit 10 Unit no. of lower arrester unit

Fig. 2. Rating plate

In the case of arresters in several sections, each module will also be provided with a unit plate [Fig. 3.]:

1 Unit number 3 Year of manufacture 2 Rated voltage 4 Warehouse number

Fig. 3. Module plate

Description

Design The active components of the arrester are metal oxide resistors. They are arranged in a stack and hermetically protected against environmental influences by means of a directly mounted silicon enclo-sure. The mechanical strength is attained by glass-fibre-reinforced polymer rods which tightly enclose and compress the resistor stack. Thanks to its hydrophobic properties, the silicon enclosure minimises electrical discharges on the enclosure surface and thus ensures particularly good operating character-istics, even under conditions of heavy pollution. The flanges are made of a lightweight metal alloy suitable for use outdoors and directly connected with the silicon enclosure. The MO resistors are tightly enclosed by the GRP rods (as if in a cage). In the event of resistor over-load – an extremely unlikely case, but which cannot entirely be ruled out – the resultant arc produces no overpressure, since the resistors are not enclosed by a sealed, mechanically rigid casing. The arc escapes immediately through the silicon enclosure, without any abrupt rupturing of the mechanical load bearing enclosing structure. At the same time the MO resistors are held largely in place by a con-siderable number of GRP rods. The risk of parts flying off is therefore minimised. The arresters are, where necessary, equipped with control fittings and / or shields.

Mode of operation Metal oxide resistors are markedly non-linear - in other words, they have a strongly curved current-voltage characteristic, which means that with the continuous voltage obtaining under normal circum-stances only the so-called leakage current of just a few milliamps will be flowing. In the case of overvoltages due to lightning or to switching operations, the resistors become conduc-tive (ohm range) thereby allowing a discharge current to flow to ground and the overvoltage to be re-duced to the value of the voltage drop at the arrester (“discharge voltage”). Here the discharge cur-rents may range up to 2 kA in the case of switching surges and 1 - 10 - 20 kA in the case of lightning surges.

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1 Polymeric composite housing 2 Non-linear metal-oxide resistor 3 Insulating rods 4 Flange

Fig. 4. Sectional view of a modular unit

Transportation and storage

The units of the surge arrester are packed in boxes or crates in the factory in accordance not only with the stresses and climatic conditions they will encounter during shipping. but also with the requirements of the customer. The packaging will have the appropriate transportation and storage labelling as well as instructions on proper handling. The consignment should be inspected immediately after receipt for signs of damage. If damage is found the carrier should be informed without delay. Loose parts packed with the consignment should be checked against the dispatch note to make sure none is missing. This means that all shipping con-tainers will need to be opened. If the items are to be stored for extended periods, we recommend to leave the units and accessories in their shipping containers. All screws, terminals and supplementary equipment (tell-tale spark gap, surge counter) required for assembly and installation are supplied in an accessory pack.

Note:

To avoid damaging of insulators, do not remove the assembly and shipping protector until assembly and installation has been completed.

© Siemens AG • 03/2010 7

1 Polymeric composite housing 2 Protective packing for installation/transport

Fig. 5. Protective packing for installation/transport

Screwed joints

For mounting the arrester use only the bolts supplied. Grease the bolt threads with Molykote Longterm 2 plus.

Attention

Unchecked tightening can result in damage to or loosing of bolt joints Use torque wrench for assembly.

Necessary torque for screwed joints:

M 8: 13 ± 1.5 ft lb M 10: 25 ± 4 ft lb M 12: 43 ± 4 ft lb M 16: 65 ± 7 ft lb M 20: 75 ± 7 ft lb

8 © Siemens AG • 03/2010

Installation

Important note: Note the following before installing:

Warning

Before any work starts: switch off and isolate secure against reclosing verify that equipment is dead earth and short circuit the equipment cover or fence off nearby live parts

Death, severe injury and considerable damage to property and environmental damage may result if the safety instructions are not followed.

Confirm that these safety measures have been carried out.

Accessories With the standard model, the following accessories are included in the scope of supply: Grading ring and struts (as applicable)

Possibilities for isolated installing: 3-hole mounting insulated Ø7.87 … 10.87 mm [Fig. 10.] 4-hole mounting insulated 7.87 inch × 7.87 inch with screws M16 x 5.11 inch [Fig. 11.] 4-hole mounting insulated 12.2 inch × 12.2 inch with screws M20 x 5.51 inch [Fig. 12.].

Possibilities for the terminals: terminal bolt, corrosion-resistant steel [Fig. 14.], flat terminal, DIN, all hot-galvanised steel, [Fig. 15.], flat terminal, NEMA, all hot-galvanised steel, [Fig. 16.].

Place of installation The range of protection offered by the arresters is restricted, which is why the surge arrester should be installed as close as possible to that part of the system being protected. The distance between grounded or live components and adjacent arresters or their control components should be selected on the basis of the relevant regulations.

Note

The arresters must be installed or suspended vertically. If they need to be installed in a non-vertical position, you should first contact the manufacturer.

Mounting the components The individual components for mounting are shown in the drawing in [=> on page 15].

© Siemens AG • 03/2010 9

Installing of the arrester

Attention

Danger of damage to the interior of the arrester Do not lean a ladder against the surge arrester.

The contact faces of the flanges of the arresters must be cleaned with a steel brush, if necessary. With arresters consisting of several units the units must be placed one on top of the other in the se-quence of their numbers marked on the rating plate [Fig. 2., Fig. 3., Fig. 6.].

Attention

Danger of damage to the interior of the arrester The contact faces [4/Fig. 6.] shall be cleaned before installation.

1 lower unit 2 upper unit 3 Rating plate for unit 4 contact faces

Fig. 6. Surge arrester units

Attention

Shim plates between the individual arrester units are not allowed.

Before the top unit is located in place, it is advisable to fit the outer grading ring struts [3/Fig. 17.], [4/Fig. 17.] and the terminal plate [10/Fig. 17.] to the upper flange.

10 © Siemens AG • 03/2010

Fig. 7. Lifting gear

Fig. 8. Drilling plan / direct mounting

standing installation The arrester must be placed and mounted with four rag bolts M10 on a concrete foundation or with four bolts M10 on the support [Fig. 9.] by means of appropriate lifting gear (crane, tackle) comprising slings and lifting lugs [Fig. 7.].

Fig. 9. unisolated 4-hole mounting

Basic plate for isolated installation, 3 hole mounting ø 7.87 … ø 10.87 mm 3× M12 (standing installa-tion)

Attention

Do not remove the insulating tube from the bolts M12 × 5.51.

Put according to the drilling plan the three lower insulating sockets [Fig. 10.] to the holes of the sup-port. The base plate and the upper insulating sockets can be mounted with three bolts M12 × 5.51 on

© Siemens AG • 03/2010 11

the lower insulating sockets. The arrester must be placed and mounted with four bolts M10 × 1.97 on the base plate by means of appropriate lifting gear (crane, tackle) comprising slings and lifting lugs [Fig. 7.].

Fig. 10. Basic plate for isolated installation, 3 hole mounting Ø 7.87 … 10.87 mm 3× M12

Basic plate for isolated installation, 4 hole mounting 7.87 inch × 7.87 inch 4× M16

Attention

Do not remove the insulating tube from the bolts M 16 x 5.11.

Put according to the drilling plan the four lower insulating sockets [2/Fig. 11.] to the holes of the sup-port [1]. The base plate [3] and the upper insulating [4] sockets can be mounted with four bolts M16 × 5.11 on the lower insulating sockets. The arrester [5] must be placed and mounted with four bolts M10 × 1.06 on the base plate by means of appropriate lifting gear (crane, tackle) comprising slings and lifting lugs [Fig. 7.].

1 Support 2 Lower insulating socket 3 Base plate 4 upper insulating socket 5 Arrester

Fig. 11. Basic plate for isolated installation, 4-hole mounting M16, 200×200 mm²

Basic plate for isolated installation, 4 hole mounting 12.2 inch × 12.2 inch 4× M20 (standing installa-tion)

Attention

Do not remove the insulating tube from the bolts M 20 x 4.33.

Put according to the drilling plan the four lower insulating sockets [2 [2/Fig. 12.] to the holes of the support [1]. The base plate [3] and the upper insulating [4] sockets can be mounted with four bolts

12 © Siemens AG • 03/2010

M20 × 4.33 on the lower insulating sockets. The arrester [5] must be placed and mounted with four bolts M10 × 1.96 on the base plate by means of appropriate lifting gear (crane, tackle) comprising slings and lifting lugs [Fig. 7.].

1 Support 2 Lower insulating socket 3 Base plate 4 upper insulating socket 5 Arrester

Fig. 12. Basic plate for isolated installation, 4-hole mounting 12.2 inch × 12.2 inch 4× M20

suspended installation The top and bottom plates may have to be exchanged together with their associated bolts and insulat-ing parts to make it into a hanging version [Fig. 1.], [Fig. 17.]. In other respects, the arrester must be installed at site in accordance with local conditions.

Grounding The protective effect of surge arresters will be negatively affected with increasing length of the ground wire, since a voltage drop occurs along the ground wire during a surge event. Thus, the ground wire should connect the ground terminal of the arrester to the substation grounding system using the short-est and most direct path. The length of the ground wire, if possible, should not exceed 1 m for medium voltage surge arresters and 2 m for high voltage surge arresters. Because of the low currents in op-eration (mA range) or the short duration of the currents (ms range) in a surge event, we recommend a cross section of 35 mm² , but at least 16 mm² for the ground wire. Even if the arrester is monitored by devices connected in series with the ground wire, e.g. by control spark gap 3EX6 040 or surge counter 3EX5 030/050, the ground wire should be as short as possible and loops should be avoided. If monitoring devices are to be installed at a larger distance from the arrester, it is recommended to use devices with separate sensors and display units, such as the surge monitor with sensor unit 3EX5 060 and display unit 3EX5 062. If monitoring devices are connected to the ground wire, the conductor between the earth terminal of the monitoring device and the grounding system of the substation must protected against contact. For installation of ground wire and monitoring devices the requirements of the corresponding national or international standards are to be applied. The scope of delivery of the arresters and monitoring devices contains no ground wire.

Standing or suspended installation: Bolt the ground wire to one of the four M10 base flanges in accordance with [13a. Fig. 17.].

Isolated installation Bolt the ground wire to the M12 ground bolt in accordance with [14, Fig. 17.].

Terminal

Attention!

High-voltage connections with tube conductors should be flexible in order to prevent exertion of any inadmissible mechanical forces on the surge arrester.

© Siemens AG • 03/2010 13

Pay attention to the electro-chemical compatibility of the materials utilised.

Terminal with cable eye The terminal must be mounted with a cable eye according to [Fig. 13.].

Fig. 13. Terminal with cable eye

Bolt terminal, DIN-flat terminal or NEMA-flat terminal If the terminal is mounted by means of a bolt terminal [Fig. 14.] or a flat terminal [Fig. 15.], [Fig. 16.], the necessary accessories are already installed by the manufacturer.

Fig. 14. Bolt terminal

Fig. 15. Flat terminal DIN

Fig. 16. Flat terminal NEMA

14 © Siemens AG • 03/2010

Exploded view

Item Qty Designation 1a, 1b

4 8 4

Screw M10 × 1.37 Washer .41 Nut M10

1c 4 7 3

Screw M10 × 1.37 Washer .41 Nut M10

3 0/4 Strut 4 0/1 Grading ring 5 0/4

0/4 0/4

Screw M10 × .98 Washer .41 Nut M10

6 1/2 Polymeric composite housing 7 0/4

0/8 0/4

Screw M10 × 1.97 Washer .41 Nut M10

8 1 Rating plate 9 0/2 Rating plate for unit 10a 1 Plate 10b 1 Flat terminal DIN / NEMA 10c 1 Bolt terminal with plate 11a 1 Plate 11b 1 Basic plate for isolated installation 3× ø7.87…10.87

mm 11c 1 Basic plate for isolated installation 4× 7.87 × 7.87 mm 11d 1 Basic plate for isolated installation 4× 12.2 × 12.2 mm 12b 4

4 4

Screw M10 × 1.97 Washer .41 Nut M10

12c, 12d

4 8 4

Screw M10 × 1.77 Washer .41 Nut M10

13a 4 8 4 4

Screw M10 × 2.16 Washer .41 Spring washer B .39 Nut M10

13b 3 6 3 6 3 3

Screw M12 × 5.51 Washer .59 Insulating tube B .47 × 0,8 Insulating socket Spring washer B .47 Nut M12

13c 4 8 4 8 4 4

Screw M16 × 5.12 Washer .67 Insulating tube B .63 × .04 Insulating socket Spring washer B .63 Nut M16

13d 4 8 4 8 4 4

Screw M20 × 4.33 Washer .82 Insulating tube B .79 × .05 Insulating socket Spring washer B .79 Nut M20

14b 1 1 1 1

Screw M12 × 1.18 Spring washer B .47 Washer .51 Nut M12

14c, 14d

1 1 1

Screw M12 × 1.18 Spring washer B .47 Washer .51

© Siemens AG • 03/2010 15

Fig. 17. Überspannungsableiter 3EL2

16 © Siemens AG • 03/2010

Maintenance

Warning

Before any work starts: switch off and isolate secure against reclosing verify that equipment is dead earth and short circuit the equipment cover or fence off nearby live parts

Death, severe injury and considerable damage to property and environmental damage may result if the safety instructions are not followed.

Confirm that these safety measures have been carried out. For technical reasons the silicone sheds do not need cleaning. Should they nonetheless be cleaned, only use clear or soapy water and a soft cloth or sponge.

Important

Do not use solvents or abrasive or scratching materials.

Regular maintenance of the arresters is not necessary. The only monitoring required is to: – Read the operations counter – Check the tell-tale spark gap – Check the arrester for any overloads (blackening or traces of burning at the blow-out aperture of

the flange). In such a case you will need to replace the arrester

Disposal arrester and arrester accessories

Surge arresters and the accessories are an environmentally compatible product. Environmentally acceptable disposal of the surge arresters and the accessories is possible in line with current legisla-tion. The following materials have been used to make up the device: Steel, aluminium, glass-fibre-reinforced plastics, electronic components and silicon rubber (VMQ), ceramics (metal oxide). According to current waste disposal techniques, arresters type 3EL2 cannot be used for neither mate-rial nor thermal purposes.. Seeing as the arresters do not contain any dangerous substances, they can be disposed of along with household waste. In as-supplied-by-Siemens state, the device incorporates no hazardous substances in the sense of the pertinent regulations in Germany. If the device is to be operated outside Germany, the locally ap-plicable laws and regulations must be followed. Local customer support offices will be able to answer any questions concerning disposal.