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1 Purpose

This technical specification covers Bane NOR's requirements to section insulators for use in Bane NOR's contact line system.

2 Scope

This technical specification is created for use in frame agreements. It shall be used as a guide to select appropriate types of section insulators for contact line projects performed by Bane NOR or other companies executing projects for Bane NOR. The specification covers the electrical and mechanical requirements that shall be fulfilled by the section insulators provided by the suppliers.

3 Function

Section insulator in contact line system serves to electrically insulate neighbouring contact line sections. Each contact line section is connected to electric supply circuit through a dedicated disconnector. During normal operation these disconnectors will be closed, and the respective contact line sections will be energized. When needed (for example for maintenance work), a contact line section can be de-energized by opening the disconnector. Insulation from energized neighbouring contact line sections will be provided by the section insulator.

4 Definitions

4.1 Section insulator

sectioning point formed by insulators inserted in a continuous run of a contact line, with skids or similar devices to maintain continuous electrical contact with the current collector

no: seksjonsisolator

[Source: IEC 60050-811:2017, 811-36-15]

4.2 Polymeric insulator

insulator whose insulating body consists of at least one organic based material

[Source: EN 62217:2013]

  • resin insulator

polymeric insulator whose insulating body consists of a solid shank and sheds protruding from the shank made from only one organic based housing material

  • composite insulator

insulator made of at least two insulating parts, namely a core and a housing equipped with end fittings

[Source: EN 62217:2013]

4.3 Specified tensile load (STL)

tensile load which can be withstood by the insulator when tested under the prescribed conditions

[SOURCE: IEC 61952:2008]

4.4 Creepage distance

shortest distance or the sum of the shortest distances along the surface on an insulator between two conductive parts which normally have the operating voltage between them

no: krypstrømsvei

Note 1 – The surface of cement or of any other non-insulating jointing material is not considered as forming part of the creepage distance.
Note 2 – If a high resistance coating is applied to parts of the insulating part of an insulator, such parts are considered to be effective insulating surfaces and the distance over those parts is included in the creepage distance.

[SOURCE: IEC 60050-471:2007, 471-01-04]

4.5 End fitting

integral component or formed part of an insulator, intended to connect it to a supporting structure, or to a conductor, or to an item of equipment, or to another insulator

no: endefeste

Note 1 – Where the end fitting is metallic, the term “metal fitting” is normally used.
Note 2 – This Note only applies to the French text.

[SOURCE: IEC 60050-471:2007, 471-01-06]

4.6 Overhead contact line (OCL)

contact line placed above or beside the upper limit of the vehicle gauge and supplying vehicles with electric energy through roof-mounted current collection equipment

[SOURCE: IEC 60050-811:2017, 811-33-02]

4.7 Overhead conductor rail (OCR)

rigid metallic conductor mounted on insulators intended to interface with a vehicles roof-mounted current collection equipment

[SOURCE: IEC 60050-811:2017, 811-34-01, modified – "vehicle mounted current collector" has been replaced with "vehicles roof-mounted current collection equipment"]

5 Requirements

5.1 General

The insulating components in the section insulator shall be of polymer (resin or composite type) insulator materials. Any of the polymer insulators to be used for the section insulator shall conform to EN 62217:2013. In addition, if the polymer insulator is of composite type it shall also conform to EN 62621:2016, and IEC 61952:2008. The section insulators shall have a design lifetime of at least 50 years. Steel parts in the section insulator shall be hot-dip galvanized in accordance with EN ISO 1461.

5.2 Environmental conditions

Environmental conditions shall be as specified in EN 62217:2013 and EN 62621:2016. Section insulators may be offered for the following three classes of installation conditions:

  1. For overhead contact line in open air
  2. For overhead contact line in tunnels,
  3. For overhead conductor rail in tunnels

5.3 Electrical requirements

5.3.1 General information

While the contact line on one side of the section insulator is grounded and the other side is fully energized (for example during maintenance works), the section insulator shall be able to provide the full line voltage insulation between two neighbouring sections. The minimum insulation voltage requirement for the section insulator is 15 kV ac 16.7 Hz.

5.3.2 Rated Voltage

The rated voltages of the section insulators shall at least be as listed in the table below.

Definition Symbol Voltage [kV] Standard reference
Nominal voltage Un 15 EN 50163:2004
Rated insulation voltage UNm 17.25 EN 50124-1:2017
Rated impulse voltage UNi - Refer to clause Minimum strike through (air gap) distance

5.3.3 Rated frequency (fr)

The actual frequency will be 16.7 Hz. But section insulators designed for 50 Hz system will be accepted.

5.3.4 Short circuit current

The minimum short circuit current for a section insulator shall be defined by short circuit class of the network in which it is to be installed. The network is defined with the following short circuit classes.

Area Class
Ik [kA] Ip [kA] tk = 0.1 s
Ik0.1 [kA]
Substation Oslo S 31.5 69.0 37.8
Inside Oslo area 25.0 54.8 30.0
Ofotbanen 20.0 43.8 24.0
Outer Oslo-area 16.0 35.0 19.2
The rest of Norway 12.5 27.4 15.0

Ik - Rated short time withstand current,

Ip - Rated peak withstand current, and

tk - Rated duration of short-circuit

5.3.5 Creepage distances

Creepage distances shall be dimensioned for the rated insulation voltages UNm in accordance with EN 62621:2016, for contact line voltage and return conductor voltage respectively. In day zones, creepage distances shall at least be dimensioned corresponding to "unfavourable operating conditions" in accordance with EN 62621:2016. For insulators without natural wash (inside tunnels and under bridges), higher creepage distances corresponding to "extremely unfavourable operating conditions" are appropriate.

5.3.6 Minimum strike through (air gap) distance

The minimum strike through distance between electrically conducting parts on the opposite sides of the section insulator is minimum 150 mm in accordance with Norwegian national regulations (FEF 2006).

5.3.7 Voltage difference during pantograph crossing

The section insulator equipped with arcing horns shall be able to withstand a voltage difference of 1200 V when traversed by a pantograph head in normal traffic conditions.

5.4 Mechanical requirements

The section insulators are normally exposed to tensile forces from the contact wires and from the catenary wires. In addition, contact force will be exerted on the bottom of the section insulator when the pantograph's collector strips cross the section insulator. If the section insulator is mounted in overhead conductor rails, the tensile force will be negligible. The number of contact wires to which the section insulator will be connected is one.

5.4.1 Width of the traversing pantograph

The width of pantograph heads (PHW) normally traversing the section insulator in normal traffic conditions is between 0.48 m and 0.65 m in accordance with EN 50206-1:2010 and EN 50367:2012. The width of contact strips (CW) is 0.035 m.

Pantograph width

5.4.2 Traffic speed requirement

The section insulators shall be given for two speed classes, which are:

  • 130 km/h
  • 250 km/h

Trains shall be able to drive up to the maximum allowed line speed without any limitation by the interaction of the pantograph head and the section insulator. This applies for trains driving in either of the two directions along the line. In other words, the electrical and mechanical requirements of the section insulator shall be fulfilled regardless of the direction in which the train (and hence the pantograph head) crosses the section insulator.

5.4.3 Maximum tensile force

The section insulators which are mounted in overhead contact lines are normally exposed to tensile forces from the contact wires and from the catenary wires. The maximum tensile forces both in the contact wire and catenary wire is 15 kN. The minimum breaking tensile loading shall be at least 3 time higher than the maximum working load.

5.4.4 Contact force requirements

The section insulator shall be designed as described in EN 50119:2009 clause which specifies the requirements of maximum contact force and increase in contact force regarding rigid components.

Note – The contact force requirements shall apply for train traffic in either direction of the rail track as bane NOR operates both single track and double track rail ways.

5.4.5 Interfaces

The supplier shall provide the necessary detailed instruction describing how the section insulator shall be assembled with the contact line. The type of tools to be used for the assembly shall be described in the instruction manual. For section insulators mounted in a section of the contact line with curvature, the instruction shall explain how the appropriate adjustment of tilting (with respect to the horizontal plane) will be done.

When mounted in OCR the section insulators interface shall be compatible with the conductor rails section shown in this Figure.

OCR Section

6 Identification and documentation

Section insulators shall be identified as specified in EN 62621:2016. In addition, the insulators shall be marked with the supplier's batch number. Documentation shall be delivered in accordance with EN 62621:2016. The supplier shall provide 3d model of the section insulator in STEP or STEP-XML file format in accordance with ISO 10303 to the customer (Bane NOR), intended for use in planning of the OCL. The model shall as a minimum include the outer physical dimensions and weight of the section insulator. Instructions for installation, maintenance and operation shall be available in Norwegian, other documentation can be in English.

7 References (Standards)

  • EN 62217:2013 Polymeric HV insulators for indoor and outdoor use - General definitions, test methods and acceptance criteria
  • EN 62621:2016 Railway applications - Fixed installations - Electric traction - Specific requirements for composite insulators used for overhead contact line systems
  • IEC 61952:2008 Insulators for overhead lines - Composite line post insulators for A.C. systems with a nominal voltage greater than 1 000 V - Definitions, test methods and acceptance criteria
  • IEC 60050-471:2007 International Electrotechnical Vocabulary (IEV) - Part 471: Insulators
  • EN 50163:2004 Railway applications - Supply voltages of traction systems
  • EN 50124-1:2017 Railway applications - Insulation coordination - Part 1: Basic requirements - Clearances and creepage distances for all electrical and electronic equipment
  • EN 50152-2:2012 Railway applications Fixed installations Particular requirements for alternating current switchgear - Part 2: Disconnectors, earthing switches and switches with nominal voltage above 1 kV
  • EN 50119:2009 Railway applications - Fixed installations - Electric traction overhead contact lines
  • EN 50206-1:2010 Railway applications - Rolling stock - Pantographs: Characteristics and tests - Part 1: Pantographs for main line vehicles
  • EN 50367:2012 Railway applications - Current collection systems - Technical criteria for the interaction between pantograph and overhead line (to achieve free access).
  • EN ISO 1461:2009 Hot dip galvanized coatings on fabricated iron and steel articles - Specifications and test methods
  • ISO 10303 (series) Industrial automation systems and integration — Product data representation and exchange