Railway applications - Fixed installations - D.C. switchgear -- Part 7-1: Measurement, control and protection devices for specific use in d.c. traction systems - Application guide

Supersedes ENV 50123-7-1:1998

Bahnanwendungen - Ortsfeste Anlagen - Gleichstrom-Schalteinrichtungen -- Teil 7-1: Mess-, Steuer- und Schutzeinrichtungen in Gleichstrom-Bahnanlagen - Anwendungsleitfaden

Diese Europäische Norm stellt Unterstützung, Anleitung und Anforderungen für die Auslegung von Schutz-, Steuer- und Messsystemen in Gleichstromanlagen zur Bahnenergieversorgung bereit. Der vorliegende Anwendungsleit¬faden kennzeichnet die Merkmale und Parameter von Einrichtungen, die zur Messung, Steuerung und dem Schutz in Gleichstrom-Bahnnetzen eingesetzt werden. Es wird Hilfestellung für die richtige Verwendung von Schutzeinrichtungen gegeben.

Applications ferroviaires - Installations fixes - Appareillage à courant continu -- Partie 7-1: Appareils de mesure, de commande et de protection pour usage spécifique dans les systèmes de traction à courant continu - Guide d'application

La présente Norme européenne fournit une aide, les lignes directrices et les prescriptions de conception pour les systèmes de protection, de commandes et de mesures utilisés dans les installations d'alimentation des réseaux de traction en courant continu. Le présent guide d'application identifie les caractéristiques et les paramètres des matériels de mesure, de commande et de protection des systèmes de traction en courant continu. Les lignes directrices s'applique plus particulièrement aux systèmes de protection électrique.

Železniške naprave – Stabilne naprave električne vleke – Stikalne naprave za enosmerni tok – 7-1. del: Merilne, krmilne in zaščitne naprave za specifično uporabo v vlečnih sistemih za enosmerni tok – Navodila za uporabo

General Information

Status
Published
Publication Date
30-Apr-2003
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-May-2003
Due Date
01-May-2003
Completion Date
01-May-2003

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SLOVENSKI STANDARD
SIST EN 50123-7-1:2003
01-maj-2003
1DGRPHãþD
SIST ENV 50123-7-1:1998
äHOH]QLãNHQDSUDYH±6WDELOQHQDSUDYHHOHNWULþQHYOHNH±6WLNDOQHQDSUDYH]D
HQRVPHUQLWRN±GHO0HULOQHNUPLOQHLQ]DãþLWQHQDSUDYH]DVSHFLILþQR
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Railway applications - Fixed installations - D.C. switchgear -- Part 7-1: Measurement,

control and protection devices for specific use in d.c. traction systems - Application guide

Bahnanwendungen - Ortsfeste Anlagen - Gleichstrom-Schalteinrichtungen -- Teil 7-1:

Mess-, Steuer- und Schutzeinrichtungen in Gleichstrom-Bahnanlagen -
Anwendungsleitfaden

Applications ferroviaires - Installations fixes - Appareillage à courant continu -- Partie 7-1:

Appareils de mesure, de commande et de protection pour usage spécifique dans les
systèmes de traction à courant continu - Guide d'application
Ta slovenski standard je istoveten z: EN 50123-7-1:2003
ICS:
29.130.99 Druge stikalne in krmilne Other switchgear and
naprave controlgear
29.280 (OHNWULþQDYOHþQDRSUHPD Electric traction equipment
SIST EN 50123-7-1:2003 en

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

---------------------- Page: 1 ----------------------
SIST EN 50123-7-1:2003
---------------------- Page: 2 ----------------------
SIST EN 50123-7-1:2003
EUROPEAN STANDARD EN 50123-7-1
NORME EUROPÉENNE
EUROPÄISCHE NORM February 2003
ICS 29.130.99;29.280 Supersedes ENV 50123-7-1:1998
English version
Railway applications –
Fixed installations – D.C. switchgear
Part 7-1: Measurement, control and protection devices
for specific use in d.c. traction systems –
Application guide
Applications ferroviaires – Bahnanwendungen –
Installations fixes – Ortsfeste Anlagen –
Appareillage à courant continu Gleichstrom-Schalteinrichtungen
Partie 7-1: Appareils de mesure, Teil 7-1: Mess-, Steuer- und
de commande et de protection Schutzeinrichtungen in Gleichstrom-
pour usage spécifique dans Bahnanlagen –
les systèmes de traction Anwendungsleitfaden
à courant continu –
Guide d'application

This European Standard was approved by CENELEC on 2002-09-01. CENELEC members are bound to

comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European

Standard the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on

application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other

language made by translation under the responsibility of a CENELEC member into its own language and

notified to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Czech Republic,

Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta,

Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels

© CENELEC -2003 All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.

Ref. No. EN 50123-7-1:2003 E
---------------------- Page: 3 ----------------------
SIST EN 50123-7-1:2003
EN 50123-7-1:2003 – 2 –
Foreword

This European Standard was prepared by SC 9XC, Electric supply and earthing systems for

public transport equipment and ancillary apparatus (fixed installations), of the Technical

Committee CENELEC TC 9X, Electrical and electronic applications for railways.

The text of the draft was submitted to the Unique Acceptance Procedure and was approved by

CENELEC as EN 50123-7-1 on 2002-09-01.
This European Standard supersedes ENV 50123-7-1:1998.
The following dates were fixed:
- latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement (dop) 2003-09-01
- latest date by which the national standards conflicting
with the EN have to be withdrawn (dow) 2005-09-01
This Part 7-1 is to be used in conjunction with EN 50123-1:2003.
Annexes designated “informative” are given for information only.
In this standard, annexes A, B and C are informative.
_____________
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SIST EN 50123-7-1:2003
– 3 – EN 50123-7-1:2003
Contents
Page

1 Scope........................................................................................................................................ 4

2 Normative references.............................................................................................................. 4

3 Definitions................................................................................................................................ 4

4 Measurement........................................................................................................................... 4

4.1 General............................................................................................................................ 4

4.2 Current............................................................................................................................. 4

4.3 Voltage dividers.............................................................................................................. 7

5 Control systems....................................................................................................................... 7

5.1 General............................................................................................................................ 7

5.2 Anti-pumping.................................................................................................................. 7

5.3 Auto-reclose with variable reclose time and final lock out............................................. 7

5.4 Line test device................................................................................................................ 8

5.5 Undervoltage close inhibit .............................................................................................. 9

6 Protection systems................................................................................................................. 10

6.1 General.......................................................................................................................... 10

6.2 Protection system for line circuit breakers (L) .............................................................. 10

6.3 Protection system for rectifier circuit breaker (R)......................................................... 11

6.4 Direct acting (series trip)............................................................................................... 12

6.5 Indirect acting................................................................................................................ 15

Annex A (informative) Electronic protection relay features ................................................... 20

A.1 Scope................................................................................................................................ 20

A.2 Failures............................................................................................................................. 20

Annex B (informative) Rate of rise and ΔI relay Examples for fault characteristic and

setting parameter selection .................................................................................................. 22

B.1 Scope................................................................................................................................ 22

B.2 Rate of rise detection........................................................................................................ 22

B.3 ∆I Protection .................................................................................................................... 23

B.4 Combined di/dt and ΔI protection.................................................................................... 24

Annex C (informative) Bibliography on relays in use.............................................................. 25

Figure 1 – Example of a split form hall effect sensor .....................................................................6

Figure 2 – Basic circuit for line test device.....................................................................................8

Figure 3 – Typical impedance device (electromagnetic) - Characteristics and setting .................14

Figure 4 – Frame fault protection systems ....................................................................................18

Figure B.1 – Example of rate of rise and ΔI relay discrimination.................................................23

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SIST EN 50123-7-1:2003
EN 50123-7-1:2003 – 4 –
1 Scope

This European Standard provides assistance, guidance and requirements for the design of

protection, control and measuring systems in d.c. installations intended to provide a power

supply to traction systems. This application guide identifies the characteristics and parameters of

equipment used in the measurement, control and protection of d.c. traction systems.

Guidance is given concerning the appropriate application of electrical protection systems.

2 Normative references
This European Standard makes reference to other parts of the EN 50123 series.
3 Definitions

For the purposes of this European standard the terms and definitions given in EN 50123-1. apply.

4 Measurement
4.1 General
Two types of measurements are made on traction systems:

a) measurements of current and voltage for connections to instruments and metering;

b) current and voltage signals used for operating protection devices.

NOTE 1 It is necessary to take care that inductive circuits can alter the inherent di/dt response.

NOTE 2 In traction systems with trains supplying regenerative energy and in double end fed line sections, the

current measurement device should be capable of measuring forward and reverse currents.

4.2 Current
4.2.1 d.c. shunt

A shunt is usually used for measurement purposes, but, when used for protection where accuracy

of response is required, the device is preferably of the non-inductive type.

Use of an isolating transducer permits operation of secondary devices at lower voltage and with

lower rated insulation. This is preferable to taking full mains voltage into what may otherwise be

low voltage compartments.

It should be noted that shunts can run very hot when carrying their rated normal current, with one

terminal hotter than the other, dependant on the direction of current flow. Where they are used

inside switchgear assemblies, then temperature rise tests of the assemblies should take this fact

into account.
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SIST EN 50123-7-1:2003
– 5 – EN 50123-7-1:2003
4.2.2 Isolating transducer
See EN 50123-7-2 and EN 50123-7-3.

This device requires an auxiliary power supply which should be derived from a guaranteed

source whose loss of supply should initiate an alarm.

The output signal is usually not of the same level as the input and is dependant on the

requirements of the secondary device.
4.2.3 Hall effect sensor

This device requires an auxiliary power supply which should be derived from a guaranteed

source whose loss of supply should initiate an alarm.

This device provides an isolated output. The primary insulation is generally provided by

encapsulation of the iron circuit and sensors. The device is sometimes constructed in a split form

for ease of fitting to a main conductor. See Figure 1 for typical example of a split form of Hall

effect sensor.

The output signal from the device is proportional to the current in the main conductor. This

signal is very low in magnitude and usually requires amplification to provide a suitable input to

the secondary device. Thus an auxiliary power supply is required.

Reliability and overall accuracy can be improved by using an average value obtained from

multiple devices. Placing devices at different locations around a conductor can reduce proximity

effects.
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SIST EN 50123-7-1:2003
EN 50123-7-1:2003 – 6 –
Figure 1 – Example of a split form hall effect sensor
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SIST EN 50123-7-1:2003
– 7 – EN 50123-7-1:2003
4.3 Voltage dividers

Dividers have the same insulation voltage requirements as the main circuit. Isolating transducers

should be employed if the secondary device can not withstand the main circuit insulation level.

NOTE Failure to open circuit of the footing resistor will result in approximately full mains voltage appearing on the

output side of the divider. A voltage limiter connected in parallel to the footing resistor may be employed for

protection against overvoltages
5 Control systems
5.1 General

Control systems are usually only those which involve the electrical closing of switchgear devices.

Their effect is to permit or inhibit a closure depending on the status of the system and the

compliance with specified requirements.
5.2 Anti-pumping

This system permits the closing device to effect a single attempt while the signal to close is

maintained. If the device fails to complete a satisfactory close operation whilst the close signal is

maintained, then attempts at further reclosing (pumping) are inhibited.

Anti-pumping can be achieved in the closing control circuit in various ways, either by using

mechanism auxiliary switches or a timing relay. It only allows a single closing pulse to the

closing device, which resets when the initial closing signal is released.

Anti-pumping should be explicitly requested by the purchaser and may be applied to all types of

switchgear closing device.
5.3 Auto-reclose with variable reclose time and final lock out

Auto-reclose is only applied to the line circuit breaker L. Its purpose is to reclose the line circuit

breaker automatically after an overcurrent release operation.

On traction systems especially light-rail or trolleybus systems, overcurrent release operations of

line circuit breakers are often due to overcurrents at simultaneous accelerations of vehicles or due

to temporary short circuits. An auto-reclose system can enhance the reliability of the system.

Auto-reclose is usually associated with a timing device which initiates several attempts at

reclosing with varying adjustable intervals of circuit dead time. After a prescribed number of

unsuccessful recloses, then a lock out of the reclosing circuit is instigated. This lock out is either

electrically or manually resettable.
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SIST EN 50123-7-1:2003
EN 50123-7-1:2003 – 8 –

The purchaser should specify the need for an auto-reclose device and provide the following

information:
a) number of recloses: e.g. 2 recloses then lock out;

b) time interval between each attempt: e.g. 15 s, followed by 60 s, followed by 180 s;

c) lock out reset: i.e. local or remote.
5.4 Line test device

This system is used on line circuit breakers L before closing, to prevent the line circuit breaker

closing onto an overload or a short circuit condition. A typical basic line test device circuit is

shown in Figure 2.
Figure 2 – Basic circuit for line test device

This is achieved by inserting a resistor by means of a suitably rated contactor between the

switchboard busbars and the contact line. An auxiliary supply is alternatively used as the test

voltage. The load impedance acts as a footing resistance to the inserted resistor and, by

measuring the voltage between feeder and return circuit, it can allow/inhibit a close signal.

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SIST EN 50123-7-1:2003
– 9 – EN 50123-7-1:2003

When the measured voltage is below a prescribed level, then there is an overload on the line and

the close is inhibited. When this voltage is above a prescribed level, a close is permitted.

Line test device systems may be either of the low resistance or the high resistance type. The

problem with line testing measurements is the effect of the negative voltage drop which can

appear on the return circuit, due to currents in the return circuit from loads external to the line

test device zone, which can give misleading interpretation of the line testing measurements.

Where negative voltage drop in the return circuit can give this effect, it can be minimised by

resorting to the low resistance system which tends to swamp out this effect.

The line test device can be coupled with auto-reclose schemes, thereby inhibiting a reclose if the

original trip was due to a fault which had not cleared itself in the dead time.

The line test device can be by-passed if the line is already live from the line circuit breaker at the

remote end.

The purchaser should specify the need for a Line test device system and provide the following

information:

a) high or low value of the resistor: i.e. involving a current value to be chosen from 1 A to

400 A;
b) whether line test device is combined with auto-reclose.
5.5 Undervoltage close inhibit

Operation of undervoltage close inhibit is usually achieved by the fitting of an undervoltage

release to the circuit breaker. Alternatively undervoltage relays with accurate pick up and drop

off voltage levels, operating on to shunt trip devices and close inhibits, can achieve similar

effects.

When fitted to a rectifier circuit breaker, this device has the effect that the circuit breaker cannot

be closed unless the rectifier is live. The voltage source is the output of the rectifier.

When fitted to a line circuit breaker, the voltage source is that of the busbar. Unless the busbar is

live the circuit breaker cannot be closed.

The purchaser should specify the requirements for undervoltage close inhibit and provide the

following information:
a) direct acting undervoltage trip relay;
b) indirect acting via undervoltage relay;
c) minimum pick up voltage (V);
d) maximum drop off voltage (V).
NOTE Direct acting devices require a very wide operating voltage range.
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SIST EN 50123-7-1:2003
EN 50123-7-1:2003 – 10 –
6 Protection systems
6.1 General
The protection scheme should address the following requirements:
a) operate for all intended line feeding arrangements:
• feeding only from one source;
• feeding from rectifiers in parallel at the substation;

• dual end feeding (effectively the rectifier(s) and the rectifier(s) in adjacent substations

are operating in parallel);
• feeding from the remote end with an intermediate substation out of service;
b) discriminate between traction currents and fault currents;
c) provide operation in the shortest time;
d) provide discrimination between primary and back-up protection.

The protection scheme comprises devices fitted directly onto the circuit breaker operating

mechanism and separate protection relays.
The electrical faults that require appropriate means of detection are

• positive pole to negative pole, low resistance, short circuit (bolted), in practice only

encountered on the track,

• positive pole to earth fault within the substation, for example, on switchgear, rectifiers, etc.,

• positive and negative pole to earth fault (for systems with both poles insulated to earth).

Consideration should also be given to detection of high resistance (arcing) faults between

positive and negative poles, usually on the track.
6.2 Protection system for line circuit breakers (L)

Protection systems for line circuit breakers may incorporate several characteristics to enable them

to detect correctly all types of line faults for the various severities encountered in the system but

avoiding false tripping.
The basic protection function is the direct acting overcurrent tripping system.
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SIST EN 50123-7-1:2003
– 11 – EN 50123-7-1:2003

Depending on the train characteristics and the line impedances, the load current of a line section

can be greater than that of a distant fault or a distant arcing fault and the instantaneous

overcurrent level protection cannot achieve the discrimination between service currents and

distant fault currents. In this case the line circuit breaker should be equipped with protection

devices using some or all of the following additional protection functions:
• protection examining the waveshape of the current (di/dt, ΔI);
• inverse time overcurrent protection;
• inverse time overcurrent protection with thermal imaging;
• undervoltage protection;
• falling voltage impedance protection.

In light-rail systems with overhead contact lines, special attention should be paid to the

requirements for protection against indirect contact as specified in 4.2 of EN 50122-1. In these

systems the maximum expected load current of a line section should be lower than the distant

fault current in the section. The line circuit breakers should be equipped with direct overcurrent

releases; additional protection functions as listed above can be useful for fault detection in

extreme cases as e.g. distant arcing faults.

If shielded feeder cables are used, a cable protection device in accordance with 6.3.4 of

EN 50122-1 should be added.

In practice unidirectional protection is applied only for currents in the overload range.

Bidirectional protection is applied in principle for direct acting short circuit protection (for faults

close to the circuit breaker) at each end of the contact line section, because there can never be a

high reverse short circuit fed from the remote end of the line.

The circuit breaker would then be specified as a U (see 5.2 d) of EN 50123-2). If the remote

end substation is close enough to supply the line circuit breaker with sufficient current to operate

its high set protection in the reverse direction, then the circuit breaker should be a type U .

NOTE Line circuit breakers are not normally specified as a type B because of the additional test requirements of

this category. Type B is only specified when the circuit breaker has to switch short circuits and load currents in both

directions such as an interconnector I circuit breaker.
6.3 Protection system for rectifier circuit breaker (R)

Where the rectifier circuit breaker R is used in series with the line circuit breaker L, the

protection system has to discriminate the operation of the line circuit breaker for a line fault.

Usual feeding arrangements may not make it practicable to utilise the rectifier circuit breaker as

back-up to the line circuit breaker for line faults. In both cases the rectifier circuit breaker is only

fitted with unidirectional protection acting on the reverse current flow to detect faults on the

rectifier.

Since both line and rectifier circuit breakers are of the series trip type, they will not discriminate

for high fault currents. For this reason rectifier circuit breakers are not fitted with forward direct

acting tripping. The circuit breaker would be specified as a type U (see 5.2 d of EN 50123-2).

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SIST EN 50123-7-1:2003
EN 50123-7-1:2003 – 12 –

The rectifier circuit breaker should have a short time current rating at least equal to the rating of

the rectifier, for a minimum time equal to or greater than the fault clearance time of the

a.c. circuit breaker acting as back-up protection to the line circuit breaker on a close up line fault.

6.4 Direct acting (series trip)

This protection system uses the main circuit current to act directly, through the mechanical

linkage and/or magnetic circuit, on the circuit breaker mechanism. This arrangement provides

overcurrent and/or overload protection.

NOTE In H and S circuit breakers, typical forms of this device may have an attracted armature iron circuit on a

current carrying conductor which responds to the magnetic field produced by the current. The armature is restrained

by a calibration spring. The armature moves to trip the circuit breaker when the magnetic field from the current

opposes the restraining force. The movement of the armature is independent of the direction of the current and is

therefore inherently bi-directional in its operation. When a polarising coil is fitted to the iron circuit and is

permanently energised to restrain the armature, the movement of the armature reacts to the current which opposes the

restraint, making the device unidirectional.

Another form of this device is an electrically held armature energised permanently by a polarising coil which

opposes a pull off calibration spring. The armature is released to trip the circuit breaker when the magnetic field

from the current opposes the holding force. This device is inherently unidirectional and will trip the circuit breaker

on loss of polarising coil voltage, making it also suitable for undervoltage tripping.

6.4.1 Instantaneous direct acting with adjustable setting range

The device is fitted on line L and interconnector I circuit breakers to provide high speed

operation on high line fault currents near the circuit breaker. It is bi-directional for I and is

type B. For L circuit breaker the trip device is also bi-directional, even if it cannot operate in the

reverse direction because insufficient current is available from the remote end and is type U (see

6.2).

Both H and S circuit breakers (see EN 50123-2) require this device. V circuit breakers have an

equivalent device.
The purchaser should specify the range of setting: e.g. from 150 % to 200 %.
6.4.2 Instantaneous low set reverse current protection

This device is fitted on rectifier circuit breakers R type U to provide protection in the event of

faults on the rectifier. It usually has a fixed setting of 50 % for semiconductor rectifiers, as

against 10 % used in the past for mercury arc rectifiers. The higher is this setting, then the higher

is the stability factor against tripping in the forward direction.
The purchaser should specify the reverse setting: e.g. 50 %.
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SIST EN 50123-7-1:2003
– 13 – EN 50123-7-1:2003
6.4.3 Undervoltage trip

Loss of busbar voltage would give automatic tripping of all line circuit breakers connected

thereto.

The effect is usually achieved by the fitting of an undervoltage release to the circuit breaker.

Alternatively undervoltage relays with accurate pick-up and drop-off voltage levels, operating on

to shunt trip devices and close inhibits, can achieve similar effects.

Nuisance tripping due to momentary drop in voltage can be prevented by the device having an

associated time delay response. This time delay will be of short duration for direct acting devices,

not longer than 0,1 s. Longer delays to prevent undue tripping may be achieved with

undervoltage relays fitted with time delay elements.
The purchaser should specify
a) the voltage rating of the device,
b) the minimum pick up voltage,
c) the maximum drop off voltage,
d) the minimum drop off time delay.
6.4.4 Shunt trip

This device, attached to the operating mechanism of a mechanically latched circuit breaker, is

used for electrical tripping either by the control system or through the protection relay system.

The device is operated from an auxiliary supply via contacts in the operating devices.

The purchaser should specify the voltage of the auxiliary supply and its operating range.

The supplier should specify:

a) the normal operating time of the device, including the circuit breaker, i.e. the no-load

opening time;

b) the power / current required to operate the device at its nominal voltage and duration.

6.4.5 Instantaneous direct acting falling voltage impedance trip

This device is a variant of that described in 6.4 as the electrically held version, but has current

settings that vary with the system voltage with the latter used to energise the polarising coil.

Figure 3 illustrates a typical set of impedance characteristics and settings.

The setting of the device is chosen to be the highest impedance which will not trip for train

starting currents but shall trip for a low resistance (bolted) distant fault. Preferably it should trip

for some degree of distant high resistance (arcing) fault as shown in Figure 3.
---------------------- Page: 15 ----------------------
SIST EN 50123-7-1:2003
EN 50123-7-1:2003 – 14 –

The current reduces proportionally with the reduction in the voltage, to give approximately a

constant U/I, hence its impedance characteristics. Because a voltage coil which is supplied from

the track system, is used, the device is inherently unidirectional with an undervoltage trip feature.

This device is used on line circuit breakers L making them inherently type U .

NOTE This device is favoured on railway systems which utilise switching stations situated between rectifier

substations. Because, for faults near the switching station, the line voltage is forced down to become much lower

than at the adjacent rectifier stations, the trip then has an apparently lower current trip setting, allowing it to

discriminate with the rectifier station. Its unidirectional feature allows only the line circuit bre

...

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