EN 15624:2021

Railway applications - Braking - Empty-loaded changeover devices

This document is applicable to empty-loaded changeover devices. The purpose of such devices is the generation of a load-related signal which causes the brake performance to be adjusted to the current vehicle mass.
The manually operated empty-loaded changeover devices change their output signal according to the position of the handles which together with the associated changeover plates serve as interfaces. The changeover plates read the required information for the operation of the empty-loaded changeover devices, i.e. brake weights for each position and the relevant changeover mass of the vehicle.
Automatic empty-loaded changeover devices sense a certain load threshold of the vehicle to automatically adjust the output signal when the mass of a vehicle reaches a defined value. This threshold is the changeover mass. Below this mass the vehicle’s brake system provides a reduced brake force. For the changeover mass or more the high brake force applies.
This document specifies the requirements for the design, testing and quality assurance of empty-loaded changeover devices.

Bahnanwendungen - Bremse - Leer-Beladen-Umstellvorrichtungen

Dieses Dokument ist für Leer-Beladen-Umstellvorrichtungen anzuwenden. Der Zweck solcher Vorrichtungen ist die Erzeugung eines lastabhängigen Signals, das die Anpassung des Bremsvermögens an die jeweilige Fahrzeugmasse bewirkt.
Die handbetätigten Leer-Beladen-Umstellvorrichtungen ändern ihr Ausgangssignal je nach Stellung der Handgriffe, die zusammen mit den zugehörigen Schildlagern als Schnittstellen dienen. Die Schildlager lesen die für die Betätigung der Leer-Beladen-Umstellvorrichtungen erforderlichen Informationen, d. h. Bremsgewichte für jede Stellung und die entsprechende Umstellmasse des Fahrzeugs.
Automatische Leer-Beladen-Umstellvorrichtungen tasten einen bestimmten Schwellenwert der Fahrzeuglast ab, um das Ausgangssignal automatisch anzupassen, wenn die Fahrzeugmasse einen festgelegten Wert erreicht. Dieser Schwellenwert ist die Umstellmasse. Unterhalb dieser Masse stellt das Bremssystem des Fahrzeugs eine reduzierte Bremskraft bereit. Bei der Umstellmasse oder höheren Massen wird die hohe Bremskraft angewendet.
Dieses Dokument legt die Anforderungen an die Konstruktion, die Prüfung und die Qualitätssicherung von Leer-Beladen-Umstellvorrichtungen fest.

Applications ferroviaires - Freinage - Dispositifs de changement de régime vide-chargé

Le présent document s’applique aux dispositifs de changement de régime « Vide-Chargé ». La finalité de ces dispositifs est la production d’un signal dépendant de la charge qui permet l’ajustement des performances de freinage à la masse effective du véhicule.
Les dispositifs de changement de régime « Vide-Chargé » à commande manuelle modifient leur signal de sortie selon la position des poignées qui, avec les plaques de commutation associées, servent d’interfaces. Les plaques de commutation indiquent les valeurs nécessaires lors de l’exploitation des dispositifs de changement de régime « Vide-Chargé », c’est-à-dire les masses freinées pour chaque position et la masse de changement de régime correspondante du véhicule.
Les dispositifs de changement de régime Vide-Chargé automatiques détectent un certain seuil de charge du véhicule afin d’ajuster automatiquement le signal de sortie lorsque la masse du véhicule atteint une valeur déterminée. Ce seuil est la masse de changement de régime. En dessous de cette masse, le système de freinage du véhicule fournit un effort de freinage réduit. Pour la masse de changement de régime ou pour une masse supérieure, l’effort de freinage élevé est appliqué.
Le présent document spécifie les exigences relatives à la conception, aux essais et à l’assurance qualité des dispositifs de changement de régime « Vide-Chargé ».

Železniške naprave - Zavore - Avtomatsko menjalo "naloženo-prazno"

General Information

• Status: Published
• Publication Date: 09-Feb-2021
• Withdrawal Date: 30-Aug-2021
• ICS: 45.040 - Materials and components for railway engineering
• Technical Committee: CEN/TC 256 - Railway applications
• Drafting Committee: CEN/TC 256/SC 3/WG 47 - Braking
• Current Stage: 6060 - Definitive text made available (DAV) - Publishing
• Start Date: 10-Feb-2021
• Due Date: 18-Dec-2020
• Completion Date: 10-Feb-2021
• Directive: 2008/57/EC - Directive 2008/57/EC of the European Parliament and of the Council of 17 June 2008 on the interoperability of the rail system within the Community (Recast)
• Directive: 2016/797/EU - Directive (EU) 2016/797 of the European Parliament and of the Council of 11 May 2016 on the interoperability of the rail system within the European Union (Text with EEA relevance)
• Mandate: M/483 - Mandate for programming and standardisation addressed to the European standardisation bodies under directive 2008/57/EC in the field of the interoperability of the rail system within the European Union
• Mandate: M/591 - Standardisation request to the European Committee for Standardisation and the European Committee for Electrotechnical Standardisation as regards railway products in support of Directive (EU) 2016/797
• Ref Project: SIST EN 15624:2021 - Railway applications - Braking - Empty-loaded changeover devices

Relations

• Replaces: EN 15624:2008+A1:2010 - Railway applications - Braking - Empty-loaded changeover devices
• Effective Date: 17-Feb-2021
• Amended By: EN 15624:2021/prA1 - Railway applications - Braking - Empty-loaded changeover devices
• Effective Date: 01-Dec-2021

Standards Content (Sample)

SLOVENSKI STANDARD
SIST EN 15624:2021
01-april-2021
Nadomešča:
SIST EN 15624:2009+A1:2010
Železniške naprave - Zavore - Avtomatsko menjalo "naloženo-prazno"
Railway applications - Braking - Empty-loaded changeover devices
Bahnanwendungen- Bremse - Leer-Beladen-Umstellvorrichtungen

Applications ferroviaires - Freinage - Dispositifs de changement de régime Vide-Chargé

Ta slovenski standard je istoveten z: EN 15624:2021
ICS:
45.040 Materiali in deli za železniško Materials and components
tehniko for railway engineering
SIST EN 15624:2021 en,fr,de

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

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SIST EN 15624:2021
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SIST EN 15624:2021
EN 15624
EUROPEAN STANDARD
NORME EUROPÉENNE
February 2021
EUROPÄISCHE NORM
ICS 45.040 Supersedes EN 15624:2008+A1:2010
English Version
Railway applications - Braking - Empty-loaded changeover
devices

Applications ferroviaires - Freinage - Dispositifs de Bahnanwendungen - Bremse - Leer-Beladen-

changement de régime vide-chargé Umstellvorrichtungen
This European Standard was approved by CEN on 20 December 2020.

CEN 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 CEN-CENELEC Management Centre or to any CEN

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 CEN member into its own language and notified to the CEN-CENELEC Management

Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,

Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,

Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and

United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2021 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 15624:2021 E

worldwide for CEN national Members.
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SIST EN 15624:2021
EN 15624:2021 (E)
Contents Page

European foreword ....................................................................................................................................................... 4

1 Scope .................................................................................................................................................................... 5

2 Normative references .................................................................................................................................... 5

3 Terms and definitions ................................................................................................................................... 6

4 Design and manufacture ............................................................................................................................... 7

4.1 General ................................................................................................................................................................ 7

4.2 Functional requirements.............................................................................................................................. 7

4.2.1 General ................................................................................................................................................................ 7

4.2.2 Automatic empty-loaded changeover device ........................................................................................ 8

4.2.3 Pneumatic device characteristics.............................................................................................................. 9

4.2.4 Automatic hydraulic to pneumatic converter.................................................................................... 10

4.2.5 Automatic elastomeric to pneumatic converter ............................................................................... 10

4.2.6 Components for operation of the manual empty-loaded changeover device ........................ 10

4.3 Shock and vibration .................................................................................................................................... 11

4.4 Environmental conditions ........................................................................................................................ 11

4.4.1 General ............................................................................................................................................................. 11

4.4.2 Ambient temperature ................................................................................................................................. 11

4.4.3 Altitude ............................................................................................................................................................ 11

4.4.4 Humidity .......................................................................................................................................................... 11

4.4.5 Rain ................................................................................................................................................................... 12

4.4.6 Snow, ice and hail ......................................................................................................................................... 12

4.4.7 Solar radiation .............................................................................................................................................. 12

4.4.8 Pollution .......................................................................................................................................................... 12

4.5 Design requirements regarding pressure stress .............................................................................. 12

4.6 Tightness ......................................................................................................................................................... 12

4.7 Service life ....................................................................................................................................................... 13

4.8 Compressed air quality .............................................................................................................................. 13

4.9 Fire behaviour ............................................................................................................................................... 13

4.10 External appearance ................................................................................................................................... 13

4.11 Pneumatic interfaces .................................................................................................................................. 13

5 Type tests ........................................................................................................................................................ 13

5.1 General ............................................................................................................................................................. 13

5.2 Individual automatic empty-loaded changeover device type tests ........................................... 14

5.2.1 Test bench for individual automatic empty-loaded changeover device type tests .............. 14

5.2.2 Sampling for type tests ............................................................................................................................... 14

5.2.3 Test requirements ....................................................................................................................................... 14

5.2.4 Check of physical and geometrical characteristics .......................................................................... 15

5.2.5 Tightness ......................................................................................................................................................... 15

5.2.6 Changeover operation – empty to loaded ........................................................................................... 16

5.2.7 Changeover operation – loaded to empty ........................................................................................... 17

5.2.8 Response time – empty to loaded ........................................................................................................... 17

5.2.9 Response time – loaded to empty ........................................................................................................... 18

5.2.10 Shock and vibration tests .......................................................................................................................... 18

5.2.11 Operation at extreme temperatures ..................................................................................................... 18

6 In-service assessment................................................................................................................................. 19

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SIST EN 15624:2021
EN 15624:2021 (E)

7 Designation ..................................................................................................................................................... 20

8 Identification and marking ....................................................................................................................... 20

8.1 Identification .................................................................................................................................................. 20

8.2 Changeover plate for the manual empty-loaded changeover device ......................................... 20

Annex A (informative) Assessment of an empty-loaded changeover device when fitted to a

vehicle ............................................................................................................................................................... 21

A.1 General ............................................................................................................................................................. 21

A.2 Design acceptance testing set-up ............................................................................................................ 21

A.3 Static testing ................................................................................................................................................... 21

A.3.1 Vehicle requirements .................................................................................................................................. 21

A.3.2 Test procedures ............................................................................................................................................ 21

A.3.2.1 Changeover setting of automatic empty-loaded changeover devices ....................................... 21

A.3.2.1.1 Procedure ................................................................................................................................................ 21

A.3.2.1.2 Pass/fail criteria ................................................................................................................................... 21

A.3.2.2 Effects on brake characteristics .............................................................................................................. 22

A.3.2.2.1 General ..................................................................................................................................................... 22

A.3.2.2.2 Procedure ................................................................................................................................................ 22

A.3.2.2.3 Pass/fail criteria ................................................................................................................................... 22

A.4 Running tests .................................................................................................................................................. 22

A.4.1 General ............................................................................................................................................................. 22

A.4.2 Pneumatic empty-loaded changeover device – Air consumption ............................................... 22

A.4.2.1 Procedure ........................................................................................................................................................ 22

A.4.2.2 Pass/fail criteria ........................................................................................................................................... 22

A.4.3 Pneumatic empty-loaded changeover device – Impact of vibrations on the output

signal ................................................................................................................................................................. 23

A.4.3.1 Procedure ........................................................................................................................................................ 23

A.4.3.2 Pass/fail criteria ........................................................................................................................................... 23

Annex B (informative) Examples of manual empty-loaded changeover device handles and

changeover plates ......................................................................................................................................... 24

Annex C (informative) Test bench diagram ..................................................................................................... 26

Annex D (normative) In-service assessment ................................................................................................... 27

Annex ZA (informative) Relationship between this European Standard and the Essential

Requirements of EU Directive 2016/797/EU aimed to be covered............................................ 28

Bibliography ................................................................................................................................................................. 30

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SIST EN 15624:2021
EN 15624:2021 (E)
European foreword

This document (EN 15624:2021) has been prepared by Technical Committee CEN/TC 256 “Railway

applications”, the secretariat of which is held by DIN.

This European Standard shall be given the status of a national standard, either by publication of an

identical text or by endorsement, at the latest by August 2021, and conflicting national standards shall be

withdrawn at the latest by August 2021.

Attention is drawn to the possibility that some of the elements of this document may be the subject of

patent rights. CEN shall not be held responsible for identifying any or all such patent rights.

This document supersedes EN 15624:2008+A1:2010.
The main changes compared to EN 15624:2008+A1:2010 are:
a) normative references have been updated;
b) terms and definitions have been revised;
c) requirements on design and manufacture have been revised;
d) requirements on materials have been removed;
e) requirements on type tests have been revised;
f) requirements on routine test and inspection have been removed;
g) requirements on type validation have been removed;
h) requirements on in-service assessment have been added;

i) requirements on installation validation and on documentation have been removed;

j) requirements on designation, identification and marking have been revised;
k) Annex ZA has been updated.

This document has been prepared under a standardization request given to CEN by the European

Commission and the European Free Trade Association, and supports essential requirements of

EU Directive 2016/797/EU.

For relationship with EU Directive 2016/797/EU, see informative Annex ZA, which is an integral part of

this document.

According to the CEN-CENELEC Internal Regulations, the national standards organisations of the

following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,

Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,

Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North

Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United

Kingdom.
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SIST EN 15624:2021
EN 15624:2021 (E)
1 Scope

This document is applicable to empty-loaded changeover devices. The purpose of such devices is the

generation of a load-related signal which causes the brake performance to be adjusted to the current

vehicle mass.

The manually operated empty-loaded changeover devices change their output signal according to the

position of the handles which together with the associated changeover plates serve as interfaces. The

changeover plates read the required information for the operation of the empty-loaded changeover

devices, i.e. brake weights for each position and the relevant changeover mass of the vehicle.

Automatic empty-loaded changeover devices sense a certain load threshold of the vehicle to

automatically adjust the output signal when the mass of a vehicle reaches a defined value. This threshold

is the changeover mass. Below this mass the vehicle’s brake system provides a reduced brake force. For

the changeover mass or more the high brake force applies.

This document specifies the requirements for the design, testing and quality assurance of empty-loaded

changeover devices.
2 Normative references

The following documents are referred to in the text in such a way that some or all of their content

constitutes requirements of this document. For dated references, only the edition cited applies. For

undated references, the latest edition of the referenced document (including any amendments) applies.

EN 14478:2017, Railway applications — Braking — Generic vocabulary

EN 15625:2021, Railway applications — Braking — Automatic variable load sensing devices

EN 15877-1:2012+A1:2018, Railway applications — Marking on railway vehicles — Part 1: Freight

wagons

EN 45545-2:2020, Railway applications — Fire protection on railway vehicles — Part 2: Requirements for

fire behavior of materials and components

EN 60721-3-5:1997, Classification of environmental conditions — Part 3: Classification of groups of

environmental parameters and their severities — Section 5: Ground vehicle installations

(IEC 60721-3-5:1997)

EN 61373:2010, Railway applications — Rolling stock equipment — Shock and vibration tests

(IEC 61373:2010)

EN ISO 228-1:2003, Pipe threads where pressure-tight joints are not made on the threads — Part 1:

Dimensions, tolerances and designation (ISO 228-1:2000)
ISO 8573-1:2010, Compressed air — Part 1: Contaminants and purity classes
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SIST EN 15624:2021
EN 15624:2021 (E)
3 Terms and definitions

For the purposes of this document, the terms and definitions given in EN 14478:2017, EN 15625:2021

and the following apply.

ISO and IEC maintain terminological databases for use in standardization at the following addresses:

— IEC Electropedia: available at http://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1
empty-loaded changeover device

device connected to the vehicle, which is either manually operated or responds automatically to a change

of vehicle load, thereby providing a load-related signal which changes at a certain vehicle mass threshold

(changeover mass) when the load is increased or when the load is decreased
3.2
positive load signal pressure device

empty-loaded changeover device that provides a positive output pressure in the loaded state

3.3
zero load signal pressure device

empty-loaded changeover device that exhausts the output pressure to nominally 0 bar in the loaded state

3.4
changeover mass

lowest value of vehicle mass at which it is deemed to be in the loaded state, thereby requiring the

adjustment of brake force to achieve the required brake performance
3.5
automatic variable load sensing device
weighing valve

device connected to the vehicle, which responds to the loading of that vehicle to provide a continuous

load proportional signal to the brake control device

Note 1 to entry: The load input is normally a share of the wagon’s mass because of the devices position in the

vehicle suspension system. The result is a pneumatic output signal pressure that can be any value between a

minimum at tare mass and a maximum at maximum mass. Most of the existing self-adjusting load-dependant brakes

generate the load signal using a weighing valve.
[SOURCE: EN 15625:2021, 3.1]
3.6
mechanically operated pneumatic device

device or mechanism which responds to a mechanical input by a change of the output pressure

[SOURCE: EN 15625:2021, 3.2]
3.7
hydraulic to pneumatic converter

device or mechanism which transforms a hydraulic pressure into a pneumatic pressure with a defined

transmission ratio
[SOURCE: EN 15625:2021, 3.3]
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SIST EN 15624:2021
EN 15624:2021 (E)
3.8
elastomeric to pneumatic converter

device or mechanism having both elastomeric and pneumatic components which transforms a pressure

in the elastomer into a pneumatic pressure with a defined transmission ratio
[SOURCE: EN 15625:2021, 3.4]
3.9
output signal pressure
load signal pressure
LSP

output pressure delivered by the empty-loaded changeover device, which signals the load state (either

empty or loaded) of the vehicle to the brake control device
3.10
supply pressure
input pressure to a pneumatic empty-loaded changeover device
3.11
normal litre

unit of amount of a gas equal to the amount of 1 l at a pressure of 1,0 bar and at a standard temperature,

at 20 °C
Note 1 to entry: Air flow is often stated in normal litres per minute (Nl/min).
4 Design and manufacture
4.1 General

The design and manufacture of the empty-loaded changeover device shall take the requirements of this

clause into account for all intended operating conditions.
4.2 Functional requirements
4.2.1 General

4.2.1.1 The empty-loaded changeover device shall supply a signal indicating the variation in vehicle

load (empty or loaded) to the braking control system; this shall be mechanical or pneumatic. The method

of producing the pneumatic signal shall be a mechanically operated pneumatic device, hydraulic to

pneumatic converter device or an elastomeric to pneumatic converter device.

4.2.1.2 The empty-loaded changeover device shall, in all cases, supply an output signal, which is a

function of the load.

4.2.1.3 The empty-loaded changeover device shall not alter any of the characteristics of the

distributor and/or any associated relay device, when fitted to a vehicle, thereby not altering the

characteristics of the brake system, other than to signal the load change and thereby cause the brake

cylinder pressure to change from one state to another.

4.2.1.4 The design of the empty-loaded changeover device shall either provide a positive output

pressure (positive load signal pressure device) or exhaust the output pressure to nominally 0 bar (zero

load signal pressure device) in the loaded state dependant on the applicable design requirements.

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SIST EN 15624:2021
EN 15624:2021 (E)

4.2.1.5 The air consumption of a pneumatic empty-loaded changeover device shall, during running

of the vehicle, be minimal and shall not interfere with the normal braking performance of that vehicle. A

test which can be used to confirm this is described in A.4.2.
4.2.2 Automatic empty-loaded changeover device
4.2.2.1 General

4.2.2.1.1 An automatic empty-loaded changeover device shall change from the empty to a loaded state

or vice versa, when the vehicle mass exceeds or falls below the changeover mass.

4.2.2.1.2 The automatic empty-loaded changeover device shall comply with the changeover values

specified in its technical specification.

Once fitted on the vehicle the changeover shall take place within ± 5 % of the defined changeover mass

of the vehicle.

For vehicles that operate only in empty or fully loaded states, this tolerance is in the range of ± 20 %.

NOTE A test which can be used to confirm this is described in A.3.2.1.

4.2.2.1.3 An automatic empty-loaded changeover device may have a damping facility within its

mechanism to prevent the effects of transient suspension movement from causing a change of the load

signal.

4.2.2.1.4 An automatic empty-loaded changeover device shall be designed to fit to a vehicle in a

position to sense the load change of that vehicle, causing a change of state/output signal of the changeover

device.
4.2.2.2 Changeover response

Where the empty-loaded changeover device does not include integral damping the response of the output

pressure shall be immediate, i.e. the pressure shall fall or increase dependent on the particular design of

the device, as soon as the device is moved from one state to another. Where the empty-loaded changeover

device has integral damping a delay in the LSP response shall be apparent.
4.2.2.3 Empty to loaded changeover

4.2.2.3.1 Integrally damped device supplied with air from the distributor auxiliary reservoir or

main reservoir pipe

Not earlier than 3 s after the operating mechanism was moved to the loaded position and remains there

the output pressure shall change to the loaded state for the particular design of the device as defined in

4.2.3. This shall be tested in accordance with 5.2.8.2.

When the operating mechanism is moved to the loaded position and kept there for less than 3 s the output

pressure shall not reach a value that causes a changeover to occur.
4.2.2.3.2 Device supplied with air from the distributor output pressure

When the operating mechanism is in the loaded position the output pressure shall remain in or change

to the loaded state during braking for the particular design of the device as defined in 4.2.3. This shall be

tested in accordance with 5.2.8.

When the brake is released there is no output pressure provided by the empty-loaded changeover device

regardless the position of the operating mechanism.
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SIST EN 15624:2021
EN 15624:2021 (E)
4.2.2.4 Loaded to empty changeover

4.2.2.4.1 Integrally damped device supplied with air from the auxiliary reservoir or main

reservoir pipe

Not earlier than 3 s after the operating mechanism was moved to the empty position and remains there

the output pressure shall change to the empty state for the particular design of the device as defined in

4.2.3. This shall be tested in accordance with 5.2.9.2.

When the operating mechanism is moved to the empty position and kept there for less than 3 s the output

pressure shall not reach a value that causes a changeover to occur.
4.2.2.4.2 Device supplied with air from the distributor output pressure

When the operating mechanism is in the empty position the output pressure shall remain in or change to

the empty state during braking for the particular design of the device as defined in 4.2.3. This shall be

tested in accordance with 5.2.9.

When the brake is released there is no output pressure provided by the empty-loaded changeover device

regardless the position of the operating mechanism.
4.2.3 Pneumatic device characteristics

4.2.3.1 The device shall be designed to accept a supply pressure directly from the vehicle’s auxiliary

reservoir or from the distributor output/brake cylinder pressure.

4.2.3.2 When the load signal is pneumatically transmitted to the brake control device, the changeover

device shall produce a step in LSP at a defined value of input signal representing the changeover mass

between the empty and loaded states.

4.2.3.3 Where the supply pressure to the empty-loaded changeover device is supplied from the

auxiliary reservoir the following shall apply.
a) For a positive load signal pressure device:

1) all values of the LSP of ≤ 0,5 bar shall indicate a vehicle load that is less than the changeover mass

with the purpose of causing the brake control device to output its lower ratio,

2) all values of the LSP of ≥ 3,0 bar shall indicate a vehicle load greater than the changeover mass

with the purpose of causing the brake control device to output its higher ratio. An LSP lower than

3,0 bar is acceptable to signal a vehicle load greater than the changeover mass, when an

automatic variable load sensing device is used as an automatic empty-loaded changeover device.

b) For a zero load signal pressure device:

1) all values of the LSP of ≥ 3,0 bar shall indicate a vehicle load that is less than the changeover mass

with the purpose of causing the brake control device to output its lower ratio,
2) all val
...