Kontaktledning/Filterimpedanser


1 SCOPE

These specifications apply to the production and delivery of filter impedances to Norwegian National Railway Administration (NNRA).

2 FUNCTIONAL REQUIREMENTS

Usage of filter impedances:

  • To let the return current pass the insulated joints on sections with double insulated track fields, and in the transition between single and double isolated track fields
  • Collecting return current from the rails to the return feeder lines
  • Equipotential bonding between the rails and in connection with the earthing of larger conductive structures

2.1 Lifespan

2.1.1 Filter impedance

a) The lifespan of the filter impedances should be at least 50 years.

2.2 Electrical requirements

2.2.1 Interfaces

a) Filter impedances are connected to the rails, return feeder lines and/or signalling track field circuits by cables, depending on the application.

2.2.2 Amperage requirement (16.7 Hz) for filter impedances

a) Short term current load: These following currents shall not cause temperature rise of more than 50°C of the oil:

Type 1: 600 A Type 2: 800 A
800 A 2 hours 1000 A 2 hours
950 A 30 minutes 1200 A 30 minutes
1600 A 5 minutes 2000 A 5 minutes
3500 A 1 minute 4000 A 1 minute
20000 A 1 second 20000 A 1 second

2.2.3 Impedance

a) Measured between the terminations “A” and “B”:

  • Resistance at most 0.005 Ω measured with direct current
  • Impedance at least 16 Ω measured at 30 V / 95 Hz
  • Impedance at least 30 Ω measured at 6 V / 95 Hz

2.2.4 Electrical losses

a) The supplier shall state the non-load losses and load losses at 16.7 Hz for the different Ampere values specified above.

2.2.5 Insulation requirements

a) Insulation level: 1000 V
b) Impulse withstand voltage (referred to a surge of 1.2/50 μs): 170 kV

2.2.6 Saturation Limit

a) At 16.7 Hz the voltage saturation shall occur between 20 and 30 volts, however, 20 V 16.7 Hz superimposed on 10 V 95 Hz shall not cause saturation.

2.2.7 Calibration

a) The measured voltage drop and impedance between the terminations "A" and "0" shall be equal to the measured voltage drop and the impedance between the terminations "B" and "0".
b) Maximum asymmetry between the primary circuits at continuous current: [math]\frac{U_{A-0}}{U_{B-0}} = 1 \pm 0.1\% \quad i.e. \quad 0.999 \lt \frac{U_{A-0}}{U_{B-0}} = 1.001[/math]

2.3 Mechanical requirements

2.3.1 Interface

a) Mechanical interface for filter impedances is an angle steel profile in each corner of the tank and cable lugs for the terminations to "A", "B" and "0". See provided drawing.

2.3.2 Materials

a) Filter impedance case, bolts and the support for the warning pin shall be made of galvanized steel, with zinc coating that shall be at least 115 μm
b) Filter impedance circuits shall consist of copper
c) Insulated feed-through connections shall be according to drawing EK.707115 sheet 5
d) Oil quality should be according to NEK-240-1:2008 class II A, modified

2.3.3 Mechanical design and dimensions

a) Filter impedances shall be designed according to the drawings: EK.707115 sheets 1, 5, 6, and 7 and EK.705300

2.3.4 Casing

a) In the container’s four corners, the arrangement support a plate with holes corresponding to the holes in the vertical support irons
b) Fastenings (bolts, etc.) shall have standard metric dimensions
c) Impedance connections shall be totally enclosed water-proof and oil-cooled. Enclosures and associated parts shall be hot-dip galvanized both outside and inside
d) The enclosure shall consist of a container with a bolted lid. Container bottom and side walls made with 5 mm thick steel plate, lid and flange (side panels) with 6 mm steel plate
e) The seal (gasket) material between the flanges of container and cap should be in a good weather and oil resistant quality
f) Over the feed-trough connections there shall be provided a protective hinged cover (see EK.705300). Hinged bolts shall be of stainless steel
g) There shall be provided a threaded plug for controlling the oil level and replenishment of oil and for the extraction of oil samples and draining
h) The plug is to be performed with ½" (12.7 cm) pipe thread
i) The plug should represent the weakest point on filter impedance casing, i.e. in the event of pressure increase in the case and it shall be replaceable
j) The plug shall be fully sealed in normal operation
k) The impedances shall be constructed with handles/lifting eye bolts or similar for both manual and crane lifting
l) The distance between the inside of the tilting lid and feed-trough connections shall be built in a secure way to avoid all electrical hazards. See drawing EK.707115 Sheet 1

2.4 Tools

a) No special tools should be necessary for installation or connection.
b) For equipment that may need special tools for installation or connection the special tools shall be supplied with the order.

2.5 Environmental requirements

2.5.1 Temperature

a) The filter impedances should be able to meet all functional requirements for ambient temperatures between -40°C and +50°C.

2.5.2 Corrosion

a) Filter impedances shall be made of materials resistant to corrosion, according to [Fe / Zn Class A NS 1978].

2.5.3 Moisture and dust

a) Filter impedances should be able to meet all functional requirements at 100% humidity
b) The casing shall have protection IP67. (The feed-through insulators are only protected by lid/cover; see Casing g))
c) Filter impedances shall be able to satisfy all the performance requirements of pollution class III, as defined in NEK IEC/TR 60815

2.5.4 Snow and ice

a) The requirements for snow and ice load shall be at least equal to 1.5 kg/m² at +5°C

2.5.5 Vibration

a) The equipment shall withstand vibrations and shall be tested according to IEC 60068-2-6 test Fc. See appendix 1.

2.5.6 EMC

a) The equipment shall be able to operate in an industrial environment as defined in EN 61000-6-2 and be tested according to this specification
b) For electromagnetic radiation, the equipment shall comply with the requirements set to a common reference environment as identified in EN 61000-6-3 and tested according to this specification

2.6 Labelling

2.6.1 Labelling of filter impedances

a) The filter impedance’s feed-trough connections shall be marked with "A", "0" and "B"
b) A rating plate shall show: current, oil type, manufacturer, year of manufacture and serial number
c) The rating plate shall be placed on the underside of the protective lid
d) The protective lid shall be fitted with yellow and black stripes

2.7 Documentation

2.7.1 Drawings/documents

a) The supplier shall supply all necessary drawings / documents, i.e.:

  • Technical descriptions
  • Maintenance descriptions
  • Data Sheets according to NS 5820

2.8 Storage and transport

2.8.1 Transport of filter impedances

a) The filter impedances shall be delivered in wooden crates on pallets suitable for forklifting.

3 APPENDIX

Appendix 1: Mechanical and climatic environment, tables of parameters for tests.

Appendix 2: Drawings

EK.705055-000 Connection pad for filter impedance
EK.705295-000 Connection terminal for filter impedance
EK.705300-000 Supports for filter impedance
EK.707115-001 Casing with protection lid
EK.707115-005 Feed-trough connections for filter impedance
EK.707115-006 Coil and circuit diagram for filter impedance 600 A, type NNRA
EK.707115-007 Filter impedance, coil and circuit diagram. 600 A
EK.707455-000 Support for warning pin on filter impedance

4 REFERENCES

NEK IEC/TR 60815 IEC 60068-2-6, test Fc

NEK 240-1:2008, Isolerolje – Kvalitative krav, overvåkning og vedlikehold

NS 5820
EN 61000-6-2, Electromagnetic compatibility (emc) - Generic standards - Immunity for industrial environments
EN 61000-6-3, Electromagnetic compatibility (emc) - Part 6-3: Generic standards - Emission standard for residential, commercial and light-industrial environments
NS 1978 class A

5 CHECKLIST

The supplier shall sign out all points of the specification in the following checklist. Any deviation from these requirements shall be commented, which points a), b), c), etc., that are not met and what / why point is not fulfilled.

Description of requirement Compliant (Yes/No) Supplier’s references Supplier’s comments
2.1.1 Filter impedance

a)

2.2.1 Interface

a)

2.2.2 Amperage requirement (16.7 Hz) for filter impedances

a)

2.2.3 Impedance

a)

2.2.4 Electrical loss

a)

2.2.5 Insulation requirements

a)

b)

2.2.6 Saturation Limit

a)

2.2.7 Calibration

a)

b)

2.3.1 Interface

a)

2.3.2 Materials

a)

b)

c)

d)

2.3.3 Mechanical design and dimensions

a)

2.3.4 Casing

a)

b)

c)

d)

e)

f)

g)

h)

i)

j)

k)

l)

2.4 Tools

a)

b)

2.5.1 Temperature

a)

2.5.2 Corrosion

a)

2.5.3 Moisture and dust

a)

b)

c)

2.5.4 Snow and ice

a)

2.5.5 Vibration

a)

2.5.6 EMC

a)

b)

2.6.1 Labelling of filter impedances

a)

b)

c)

d)

2.7.1 Drawings

a)

2.8.1 Transport of filter impedances

a)

Filterimpedanser