Siemens 3EL2 User manual

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© Siemens AG • 07/2003
Surge Arrester Type 3EL2
Operating instructions Order-No.: 928 00047 176
The copying, distribution and utilization of this document as well as the communication of its
contents to others without expressed authorization is prohibited. Offenders will be held liable
for the payment of damages. All rights reserved in the event of the grant of a patent, utility
model or ornamental design registration.

2© Siemens AG • 07/2003
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 • 07/2003 3
The manufacturer of this surge arrester
Siemens AG
Power Transmission and Distribution Group
High Voltage Division
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 exchange +49 / 30 / 386 1
PTD H 4 Sales department: +49 / 30 / 386 23061
D-13623 Berlin Fax: +49 / 30 / 386 26721
e-mail: mailto:[email protected]
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 condi-
tion 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 • 07/2003
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 1000 m 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, Teil 4/A2 : 2000-07 10 kA
IEC 60099-4, Ed. 1.2, 2001-12 10 kA, Heavy duty
ANSI C62.11-1999 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).
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 Module no. of upper arrester unit
5 Line discharge class 10 Module 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 module plate [Fig.
3]:

© Siemens AG • 07/2003 5
1 Order number 3 Year of manufacture
2 Rated voltage 4 Unit no.
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 consider-
able 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 conductive
(ohm range) thereby allowing a discharge current to flow to ground and the overvoltage to be reduced
to the value of the voltage drop at the arrester (“discharge voltage”). Here the discharge currents may
range up to 2 kA in the case of switching surges and 1 - 10 - 20 kA in the case of lightning surges.

6© Siemens AG • 07/2003
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 modules 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 require-
ments 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 you leave the modules and accesso-
ries in their shipping containers.
All of the 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 the insulators, do not remove the assembly and shipping protector
until assembly and installation has been completed.

© Siemens AG • 07/2003 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: 18 ± 2 Nm 13 ± 1.5 ft lb
M 10: 35 ± 5 Nm 25 ± 4 ft lb
M 12: 60 ± 5 Nm 43 ± 4 ft lb
M 16: 90 ± 10 Nm 65 ± 7 ft lb
M 20: 105 ± 10 Nm 75 ± 7 ft lb

8© Siemens AG • 07/2003
Installation
Important note: Note the following before installing:
Warning
Before any work starts:
Øswitch off and isolate
Øsecure against reclosing
Øverity that equipment is dead
Øearth and short circuit the equipment
Øcover 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.
ØConfirm that these safety measures have been carried out.
Accessories
With the standard model, the following accessories are included in the scope of supply:
ØGrading ring and struts (as applicable)
Possibilities for isolated installing:
Ø3-hole mounting insulated Ø200 … 276 mm [Fig. 10]
Ø4-hole mounting insulated 200 × 200 mm² with screws M16 x 130 [Fig. 11]
Ø4-hole mounting insulated 310 × 310 mm² with screws M20 x 140 [Fig. 12].
Possibilities for the terminals:
Øterminal bolt, corrosion-resistant steel [Fig. 14],
Øflat terminal, DIN, all hot-galvanised steel, [Fig. 15],
Øflat 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 • 07/2003 9
Installing of the arrester
Attention
Danger of damage to the interior of the arrester
ØDo 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 • 07/2003
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 ø200 … ø 276 mm 3× M12 (standing installation)
Attention
Do not remove the insulating tube from the bolts M12 × 140.
Put according to the drilling plan the three lower insulating sockets [Fig. 10] to the holes of the support.
The base plate and the upper insulating sockets can be mounted with three bolts M12 × 140 on the

© Siemens AG • 07/2003 11
lower insulating sockets. The arrester must be placed and mounted with four bolts M10 × 50 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 200 … 276 mm 3× M12
Basic plate for isolated installation, 4 hole mounting 200 × 200 mm² 4× M16
Attention
Do not remove the insulating tube from the bolts M 16 x 130.
Put according to the drilling plan the four lower insulating sockets [2/Fig. 11] to the holes of the support
[1]. The base plate [3] and the upper insulating [4] sockets can be mounted with four bolts M16 × 130
on the lower insulating sockets. The arrester [5] must be placed and mounted with four bolts M10 × 50
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
5Arrester
Fig. 11 Basic plate for isolated installation, 4-hole mounting M16, 200×200 mm²
Basic plate for isolated installation, 4 hole mounting 310 × 310 mm² 4× M20 (standing installation)
Attention
Do not remove the insulating tube from the bolts M 20 x 110.
Put according to the drilling plan the four lower insulating sockets [2 [2/Fig. 12] to the holes of the sup-
port [1]. The base plate [3] and the upper insulating [4] sockets can be mounted with four bolts
M20 × 110 on the lower insulating sockets. The arrester [5] must be placed and mounted with four
bolts M10 × 50 on the base plate by means of appropriate lifting gear (crane, tackle) comprising slings
and lifting lugs [Fig. 7].

12 © Siemens AG • 07/2003
1 Support
2 Lower insulating socket
3 Base plate
4 upper insulating socket
5Arrester
Fig. 12 Basic plate for isolated installation, 4-hole mounting 310 × 310 mm² 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 3 m for high voltage surge arresters. 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 moni-
toring devices are to be installed at a larger distance from the arrester, it is recommended to use de-
vices 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 be-
tween 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.
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.
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].

© Siemens AG • 07/2003 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 • 07/2003
Exploded view
Item Qty Designation
1a,
1b
4
8
4
Screw M10 × 35
Washer 10,5
Nut M10
1c 4
7
3
Screw M10 × 35
Washer 10,5
Nut M10
30/4 Strut
40/1 Grading ring
50/4
0/4
0/4
Screw M10 × 25
Washer 10,5
Nut M10
61/2 Polymeric composite housing
70/4
0/8
0/4
Screw M10 × 50
Washer 10,5
Nut M10
81 Rating plate
90/2 Rating plate for unit
10a 1Plate
10b 1 Flat terminal DIN / NEMA
10c 1 Bolt terminal with plate
11a 1Plate
11b 1 Basic plate for isolated installation 3× ø200…276 mm
11c 1 Basic plate for isolated installation 4× 200 × 200 mm
11d 1 Basic plate for isolated installation 4× 310 × 310 mm
12b 4
4
4
Screw M10 × 50
Washer 10,5
Nut M10
12c,
12d
4
8
4
Screw M10 × 45
Washer 10,5
Nut M10
13a 4
8
4
4
Screw M10 × 55
Washer 10,5
Spring washer B10
Nut M10
13b 3
6
3
6
3
3
Screw M12 × 140
Washer 15
Insulating tube B12 × 0,8
Insulating socket
Spring washer B12
Nut M12
13c 4
8
4
8
4
4
Screw M16 × 130
Washer 17
Insulating tube B16 × 1
Insulating socket
Spring washer B16
Nut M16
13d 4
8
4
8
4
4
Screw M20 × 110
Washer 21
Insulating tube B20 × 1,2
Insulating socket
Spring washer B20
Nut M20
14b 1
1
1
1
Screw M12 × 30
Spring washer B12
Washer 13
Nut M12
14c,
14d
1
1
1
Screw M12 × 30
Spring washer B12
Washer 13

© Siemens AG • 07/2003 15
Fig. 17 Überspannungsableiter 3EL2

16 © Siemens AG • 07/2003
Maintenance
Warning
Before any work starts:
Øswitch off and isolate
Øsecure against reclosing
Øverity that equipment is dead
Øearth and short circuit the equipment
Øcover 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.
ØConfirm 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 ac-
ceptable disposal of the surge arresters and the accessories is possible in line with current legislation.
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 applica-
ble laws and regulations must be followed.
Local customer support offices will be able to answer any questions concerning disposal.