Switching devices for overhead contact line
1 Purpose
This technical specification states Bane NOR's (hereinafter referred to as BN in this document) requirements to switching devices (disconnectors, switch-disconnectors, earthing switches) and associated equipment for application in the Norwegian national rail network.
2 Scope
This specification is created for use in frame agreements.
Switching devices for application in the overhead contact line network shall be manufactured, tested and delivered in accordance with this technical specification.
This technical specification covers delivery of:
- switching devices including operating mechanisms and operating devices,
- switching devices excluding operating mechanisms, for installation with existing operating mechanisms,
- operating mechanisms excluding switching devices, for installation with existing switching devices, and
- operating devices
The switching devices covered by this specification are:
- disconnectors,
- switch-disconnectors,
- earthing switches,
- two-position switching devices, and
- three-position switching devices
The operating mechanisms covered by this specification are:
- Manual operating mechanism
- Actuators (230 V AC)
The operating devices covered by this specification are:
- Rigid operating device (operating lever)
- Flexible operating device (remote control cable)
It is estimated that the main volume of deliveries will be switch-disconnectors and to some extent disconnectors, while the volume of earthing switches and two-position switches will be low. Three-position switches are currently not in use, but may be applicable at a later stage of the contract period.
Due to varying service conditions depending on installation sites, the Supplier may suggest to define classes of delivery facilitating various service conditions, for example: inside/outside tunnels; short circuit levels.
3 Function
The functions of a disconnector in the contact line system are:
- to provide sufficient current-carrying capability for load current and short-circuit current in the closed position, and
- to provide safe isolating distance in the open position.
The functions of a switch-disconnector in the contact line system are the functions of a disconnector and in addition:
- to interrupt load current,
- to provide the ability of disconnecting contact line sections from an energized state, and
- to provide the ability of energizing contact line sections including connected loads, taking into consideration:
- transformer inrush, and
- the possibility that a short circuit may have occurred on the contact line section to be energized.
The functions of an earthing switch in the contact line system are:
- to provide sufficient isolation in the open position,
- to sufficient current-carrying capability for short-circuit current in the closed position, and
- to provide the ability to close with energized primary side in accordance with the specified electrical endurance class of the earthing switch.
The functions of a two-position switching device and a three-position switching device in the contact line system are the combined function of a switch-disconnector and an earthing switch with the following positions:
- closed position,
- open position (three-position switches only), and
- open position with one side earthed
4 Requirements
The switching device and associated equipment shall be designed, manufactured and tested in accordance with EN 50152-2.
4.1 Terms and definitions
mechanical switching device which provides, in the open position, an isolating distance in accordance with specified requirements
no: skillebryter
[SOURCE: IEV-411-14-05]
Note 1 to entry: A disconnector is capable of opening and closing a circuit when either negligible current is broken or made, or when no significant change in the voltage across the terminals of each of the poles of the disconnector occurs. It is also capable of carrying currents under normal circuit conditions and carrying for a specified time currents under abnormal conditions such as those of short circuit.
switch which, in the open position, satisfies the isolating requirements specified for a disconnector
no: lastskillebryter
[SOURCE: IEV 411-14-12]
earthing switch in which the fixed and moving contacts of each pole are not supported by a common base or frame
no: jordingsbryter
[SOURCE: IEV 411-14-07]
Note 1 to entry: A typical example is the pantograph or semi-pantograph disconnector.
Note 2 to entry: This term applies to high-voltage disconnectors only.
value of the voltage by which the electrical installation or part of the electrical installation is designated and identified
[SOURCE: IEV 826-11-01]
Note 1 to entry: This value is also assigned to the switching device to show its useability in the supply system.
Note 2 to entry: An AT-System which is supplied with two phases, having a phase shift of 180 ° between them is commonly named 2 x Un according to the Un supplied to the contact line system.
the voltage assigned by the manufacturer for a specified operating condition of an accessory
[SOURCE: IEV 442-01-03]
Note 1 to entry: This value is also used to determine its dielectric characteristics and will be used instead of the rated insulation voltage (UNm) as defined in EN 50124-1:2001.
Note 2 to entry: The abbreviation Ur isn’t used for railway devices.
the test voltages, under specified conditions, that the insulation is designed to withstand
[SOURCE: IEV 421-09-02]
Note to entry: These test voltages can be for instance:
a) rated lightning impulse and short duration power frequency withstand voltages.
b) rated lightning and switching impulse withstand voltages (phase-to-earth).
the frequency at which the disconnector, switch-disconnector or earthing switch is designed to operate
[SOURCE: IEV 421-04-03]
Note to entry: The definition is modified from “the transformer or reactor is” to “the disconnector, switch-disconnector or earthing switch is” to be more suitable for this specification.
the current assigned by the manufacturer for a specified operating condition of the disconnector, switch-disconnector or earthing switch
[SOURCE: IEV 442-01-02]
Note to entry: The definition is modified from “an accessory” to “the disconnector, switch-disconnector or earthing switch is” to be more suitable for this specification.
current that a circuit or a switching device in the closed position can carry during a specified short time under prescribed conditions of use and behaviour
[SOURCE: IEV 441-17-17]
value of peak current that a circuit or a switching device in the closed position can withstand under prescribed conditions of use and behaviour
[SOURCE: IEV 441-17-18]
the time it takes before the protective gear switches of an accidental or intentional conductive path between two or more conductive parts forcing the electric potential differences between these conductive parts to be equal to or close to zero
[SOURCE: IEV 151-12-04]
Note to entry: The definition is modified with “the time it takes before the protective gear switches of an” to give the definition deeper sense in this context.
is the maximum peak current that a switch, circuit breaker, or switching device can safely close onto when a short circuit already exists, without suffering unacceptable mechanical damage
[SOURCE: Copilot]
Note to entry: Only applicable for switch-disconnectors.
microprocessor-based device used in SCADA (Supervisory Control and Data Acquisition) systems to monitor and control equipment at remote locations. It collects data from field devices such as sensors, meters, breakers, valves, and actuators, then communicates that information to a central control system. It can also receive commands from the control center and operate the connected equipment accordingly
no: fjernterminal
[SOURCE: Copilot]
a device that ensures immediate provision of electric energy from a secondary source when the normal provision of electrical energy fails
no: avbruddsfri strømforsyning
4.2 Requirements for switching devices for overhead contact line
The clauses 4.2.1 through 4.3.2 below specify parameters for the switching device in accordance with EN 50152-2:2012 clause 10.
4.2.1 System data
4.2.1.1 Nominal voltage
15 kV phase-neutral, as specified in EN 50163.
4.2.1.2 Nominal frequency
16.7 Hz, as specified in EN 50163.
4.2.1.3 Number of phases
- 1 for conventional system
- 2 for autotransformer system
4.2.2 Normal and special service conditions
Service conditions shall be in accordance with EN 62271-1:2017 Clause 2.1.2 (outdoors) with the following user specification:
- Minimum ambient air temperature outdoors: according to IEC 62271-1:2017, Clause 4.2.4, point b).
- Ice coating: at least 10 mm shall be considered.
- Solar radiation: are for Norwegian operational conditions 1050 W/m².
Special service conditions are:
- Wind speeds above the standardized level, up to 50 m/s (gust), this shall not cause permanent damage to the equipment.
- Optional altitude up to 1250 m shall be available on request.
- Vibration due to passing trains shall be considered, for switching devices mounted on contact line masts.
- Pressure/suction from passing trains, with train speed up to 250 km/h shall be considered.
- For equipment mounted at servicing level in free air 3 m to the side of the track centre, calculated pressure/suction in the track transverse direction is ±0.80 kN/m2.
Inside tunnels, service conditions are different. EN 50125-2 gives guidance on service conditions inside tunnels.
- Excessive dust may occur. Cleaning may be specified by the supplier; however, cleaning intervals are expected to be several years.
- No solar radiation, rain, or wind in the transverse direction.
- Ambient air temperature close to tunnel portals is equal to outside temperatures; inside the tunnel air temperature mainly varies in the range of 5–20 °C.
- Pressure and suction caused by passing trains, with train speed up to 250 km/h shall be considered.
- Calculated maximum pressure and suction in the tunnel longitudinal direction: ±2.5 kN/m2.
- Calculated maximum pressure and suction in the tunnel transverse direction: ±0.35 kN/m2.
4.2.3 Electrical characteristics of the switching device
4.2.3.1 Number of poles
1 pole and 2 poles shall be available.
For some earthing switches, 3 poles are also applicable.
4.2.3.2 Installation
Outdoor.
4.2.3.3 Rated voltage (UNe)
Default implementation
UNe = 17.25 kV phase-neutral in accordance with EN 50152-2.
Note: 2 x 17.25 kV phase-phase for multi-pole configuration.
Test facilities at service points
UNe = 27.5 kV phase-neutral in accordance with EN 50152-2.
4.2.3.4 Rated insulation level (UNi)
Minimum values for UNi are:
Default implementation
- 125 kV (common value)
- 145 kV (across isolating distance)
in accordance with EN 50152-2.
Test facilities at service points
- 200 kV (common value)
- 220 kV (across isolating distance)
in accordance with EN 50152-2
4.2.3.5 Rated frequency (fr)
Default implementation
fr = 16.7 Hz in accordance with EN 50152-2
Test facilities at service points
fr = 50 Hz in accordance with EN 50152-2
4.2.3.6 Rated normal current (Ir)
Minimum value for Ir is 1250 A
The supplier must be able to provide an alternative to be used in the Oslo area.
Minimum value for Ir is 2000 A
4.2.3.7 Rated short time withstand current (Ik), Rated peak withstand current (Ip), and Rated duration of short-circuit (tk)
The minimum short circuit current for a switching device shall be defined by the defined short circuit class of the network in which it is to be installed (to be defined when ordering).
The network is defined with the following short circuit classes.
| Class Ik kA |
Ip kA (p) | Ik0.1 kA tk = 0.1 s |
|---|---|---|
| 31.5 | 69.0 | 37.8 |
| 25 | 54.8 | 30.0 |
| 20 | 43.8 | 24.0 |
| 16.0 | 35.0 | 19.2 |
| 12.5 | 27.4 | 15.0 |
Substation protective devices guarantee clearance of high short circuit currents within 0.1 s. Ik0.1 is the calculated maximum thermal current for 0.1 s including transients. Much smaller short circuit currents may have a duration up to 0.3 s before being cleared.
It is estimated that only a limited number of the classes 31.5 kA and 20 kA devices will be needed.
4.2.3.8 Rated making current (Ima)
Only applicable for switch-disconnectors.
It shall be possible to use switch-disconnectors for energizing contact line sections with and without an autotransformer. This gives the following characteristic making currents:
- autotransformer inrush current, peak current up to 3 kA is expected to occur for a large proportion of making operations (estimated 10–50 %)
- making towards short circuit, making current equal to peak short circuit current Ip. This is expected to happen no more than 3 times during the lifetime of the device.
The Customer is aware that the requirement of making towards short circuit may be a cost driver, and that the requirement may lead to increased maintenance. This is not desired. The Supplier should propose alternative ways of handling this:
- The Supplier can propose an alternative offer with capability of making towards short circuit only for the lowest short circuit levels.
- The Supplier can propose a risk assessment approach instead of increasing Ima to the specified levels.
- The overall functional requirement will be that after making towards one short circut the switch shall stay closed and feed the short circuit so that the substation protective devices will trip.
- Operative and maintenance procedures after making towards a short circuit shall be specified by the Supplier.
4.2.3.9 Rated static and dynamic terminal loading
Not specified.
4.2.3.10 Use of rigid or flexible conductors
Not specified.
4.2.3.11 Mounting conditions and HV connections
Refer to Clause Mounting.
4.2.3.12 Requirements for the insulators
Shall be in accordance with EN 50124-1 for the rated voltage, with the following classes:
- Free air and tunnels: “extremely unfavourable conditions”
4.2.3.13 Type and classification of switching device
| Switching device | Classification |
|---|---|
| Disconnectors |
|
| Switch-disconnectors |
|
| Earthing switces |
|
| Two-position devices |
|
| Three-position devices |
|
4.2.4 Use of compressed gases
Not relevant.
4.2.5 Requirements regarding tests
Testing shall be done in accordance with EN 50152-2. Documentation from routine tests shall be part of each delivery. The customer shall be given the opportunity of witnessing routine tests of at least one unit.
4.2.6 Alternative solution, switching device mounted in a ground-mounted enclosure
The supplier of switching devices shall provide a ground-mounted enclosure solution for switching devices. The solution shall accommodate multiple switching devices installed side by side and shall allow each switching device to be operated independently.
4.3 Requirements for operating mechanisms
4.3.1 Manual operating mechanism
Manual operating mechanism is a device meant to be operated by hand to shift the switchgear from energised to deenergised position or vice versa usually by a lever.
4.3.2 Actuators for switching devices in OCL (230 V AC)
Actuators shall provide an operating safe and controlled operating of the switchgear in overhead contact lines.
4.3.2.1 Method of operation
Method of operation shall be electrical.
Standard interface:
- Rated voltage Ua: 230 V AC +10/-15 % (EN 62271-1)
- Rated frequency fa: 50 Hz
- Normal maximum current: 2.5 A
- Maximum current during heavy load (ice): A 4 A slow fuse shall not activate
Alternative interface: Electrical interface on 230 V 16.7 Hz fed from the contact line system may be requested for specific projects. In this case the following interface specification applies:
- The enclosure shall be equipped with a battery with storage capacity of at least 24 h with one switching operation in the start and one in the end of the period. Project specific adjustments to the battery storage capacity may be applicable.
- Voltage variation will be 230 V +10 / -35 % (depending on train traffic).
- A battery charger fed by 230 V AC 16.7 Hz shall be included. The system should be designed with a long charging time after each switching operation in order to limit the charging current.
- It shall be possible to connect external batteries and/or chargers from external power sources to the battery terminals.
- The enclosure shal be equipped with an operation counter indicating the cumulative number of switching operations.
4.3.2.2 Local operation
Local 3-position selector mounted inside the enclosure of the operating mechanism: Remote, Local, Off (Labelled in Norwegian: “Fjern”, “Lokal”, “Av”)
- Remote: The switching device can only be operated remotely, local operation is blocked.
- Local: The switching device can only be operated by local push-buttons, remote operation is blocked.
- Off: Electrical operation is blocked. Only manual operation is allowed.
Local electrical operation shall be facilitated by means of two push-buttons: Open and Close (Labelled in Norwegian: “Åpne”, “Lukk”)
Local manual operation shall be facilitated in accordance with EN 50152-2.
4.3.2.3 Number and type of auxiliary contacts for remote operation and auxiliary power
General
Remote control is realized by means of an external RTU (Remote Terminal Unit) which may control several switching devices and other pieces of equipment. There exist one normal set-up (1) and one alternative set-up (2). The alternative set-up (2) is an older set-up and is specified for backwards compatibility. The alternative set-up (2) is expected to be relevant only in very few cases.
In addition to these two set-ups the Customer is considering a revision of the interface for future projects, with the aim of reducing need for cables. Two possiblities are being considered (3 and 4). The Supplier should indicate whether these interfaces may be available if requested by the Customer.
All electrical connections for auxiliary supply and remote control shall be available on terminal blocks inside the enclosure.
1 – Normal set-up
Connection to RTU via one cable with 7 conductors.
Power supply and command contacts:
- Common neutral connection
- Power supply connection (always energized)
- Command “Open”
- Command “Close”
Command connections carry pulses of power supply voltage with a duration of 1–2 seconds. Alternative signalling voltages may be requested for specific projects.
Indication contacts:
- Indication Common
- Indication “Open”
- Indication “Close”
Potential-free contacts, 230 V AC or 24 V AC or DC. Load current: up to 0,5 A. The contacts shall be closed in the end position.
2 – Alternative setup
Connection to RTU via one cable with 6 conductors. It shall be possible for the customer to convert this unit to the ordinary set-up with 230 V AC power supply in a relatively simple manner, for example by means of jumpers or by disconnecting and removing apparatus.
Power supply and command contacts:
- Common neutral connection
- Command “Open”
- Command “Close”
A command will switch 230 V AC supply to the relevant command input, and switch 230 V AC supply off from the other command input. Power supply shall be delivered via the command inputs. Both supplies may be energized or de-energized in the mid-position (during switch-over). The command input will normally stay energized after the switching operation has succeeded.
Indication contacts – equal to set-up 1:
- Indication Common
- Indication “Open”
- Indication “Close”
Potential-free contacts, 230 V AC or 24 V AC or DC. Load current: up to 0,5 A. The contacts shall be closed in the end position.
3 – Remote control via communications cable (fiber optic or ethernet) on IEC 60870-5-104
Power supply contacts:
- Neutral connection
- Power supply connection (always energized)
Remote control connection for fibre cable or cat 5 ethernet cable with at least the following signals:
- Command “Open”
- Command “Close”
- Indication “Open”
- Indication “Close”
Additional communication or signals may be suggested by the supplier.
4 – Remote control on wireless link with GPRS via GSM-R system
Power supply contacts:
- Neutral connection
- Power supply connection (always energized)
Remote control on wireless link on GPRS
- Command “Open”
- Command “Close”
- Indication “Open”
- Indication “Close”
4.3.2.4 Enclosure
The enclosure shall be designed according to EN 50152-2.
The front door of the enclosure shall be hinged. It shall be possible to lock the front door with a padlock. It shall be possible to inspect the position of the operating mechanism without opening the front door, primarily by means of an inspection window.
The enclosure shall be protected against ingress of rain water. The opening for the operating link shall be water tight.
The enclosure shall be protected against condensation. If this is achieved by means of a heating element, the element shall be self-regulating with respect to humidity and temperature. Requirements to heating elements according to EN 62271-1 apply.
4.3.2.5 Earthing and bonding
When mounted to a metallic mast, the enclosure is bonded through the fixing.
All enclosures shall be equipped with an M12 bolt for connecting the enclosure to an external bonding, for use when mounted on non-metallic masts.
An insulated terminal for connecting the PE conductor of the incoming low voltage supply shall be fitted inside the enclosure.
4.4 Reqirements for operating devices
Operating devices shall be offered in two types as stated below.
- Rigid operating device (operating lever)
- Flexible operating device (remote control cable)
Rigid operating devices: shall be capable of reliable operation of the switching device at ambient air temperature according to IEC 62271-1:2017, Clause 4.2.4, point b). An ice coating of at least 10 mm shall not lead to malfunction in operating the switching device.
Flexible operating devices: shall be capable of reliable operation of the switching device at ambient air temperature according to IEC 62271-1:2017, Clause 4.2.4, point b). An ice coating of at least 10 mm shall not lead to malfunction in operating the switching device.
5 Interface between operating mechanism and switching device
Where the delivery is a combined switching device including operating mechanism, the Supplier is responsible for the interface and the compatibility between the switching device and the operating mechanism, including the operating link. EN 50152-2:2012 Clause 6.2 applies. The Customer prefers that a specification which is compatible with existing operating mechanisms be applied (see below), but will accept other values for the mechanical interface if the Supplier demonstrates a real (economical or practical) benefit.
Where the delivery is an operating mechanism for fitting with an existing switching device, the operating mechanism shall be compatible with the existing mehanical specification of the switching device.
Where the delivery is a switching device for fitting with an existing operating mechanism, the switching device shall be compatible with the existing mehanical specification of the operating mechanism.
If necessary, the operating link shall also be changed when changing either switching device or operating mechanism.
Mechanical specification of existing interface:
| Parameter | Specification |
|---|---|
| Nominal switching force (close/open) | 3 300 N |
| Minimum switching force at 15 % voltage drop (close/open) | 3 000 N |
| Maximum switching force at rated voltage (close/open) | 4 100 N |
| Vertical travelling distance | 120 mm fine-tuning shall be possible |
| Rotational angle, if applicable | 180° |
| Maximum operating time between end-positions | 2 seconds |
6 Mounting
Necessary brackets for mounting on masts are not part of the delivery. Drawings of standard brackets to which the switching devices are to be fitted, are listed below.
| Mast type | Mounting |
|---|---|
| Steel masts |
Typical fitting of a two-poled switching device: EH-011903-000.
|
| Wooden masts Concrete masts |
Standard brackets switching devices:
Standard bracket for operating mechanism:
|
7 Reference documents
| Standard | Specifications |
|---|---|
| EN 50124-1:2017 | Insulation coordination - Part 1: Basic requirements - Clearances and creepage distances for all electrical and electronic equipment |
| EN 50152-2:2012 | Fixed installations - Particular requirements for alternating current switchgear - Part 2: Disconnectors, earthing switches and switches with nominal voltage above 1 kV |
| EN 50163:2004 | Supply voltages of traction systems |
| IEC 60050 | Electropedia - International Electrotechnical Vocabulary (IEV) |
| EN 62271-1:2017 | High-voltage switchgear and controlgear - Part 1: Common specifications for alternating current switchgear and controlgear |
8 Documentation
Documentation shall be delivered in accordance with EN 50152-2.
Guidance concerning disassembly and end-of-life procedures as described in EN 62271-1:2008 Clause 12 shall be given in the instruction manual.
The operating instructions and the maintenance instructions shall be available in Norwegian (other parts of the documentation are accepted in English).
A 3d model of the switching device shall be part of the delivery. The file format shall be STEP or STEP-XML in accordance with ISO 10303. The model shall as a minimum include the outer physical dimensions and weight of the device.
Type test certificates shall be available on request.