prEN 50374

Conductor carts

This document applies to conductor cars that are used to access overhead line conductors, shield wires or shield wires with integrated communication systems to undertake work involving rectification of defects and/or installing components and fittings. This document covers also bicycle type access equipment where it is applicable.

Leitungsfahrzeuge

Nacelles suspendues

Le présent document s'applique aux nacelles suspendues utilisées pour accéder aux conducteurs de lignes aériennes, aux câbles de garde ou aux câbles de garde avec systèmes de communication intégrés afin d’effectuer des travaux qui impliquent la correction de défauts et/ou l'installation de composants et d'accessoires. Le présent document couvre également les équipements d’accès de type bicyclette lorsqu’ils s’appliquent.

Vozički za delo na nadzemnih vodih

General Information

• Status: Not Published
• Technical Committee: CLC/TC 78 - Equipment and tools for live working
• Current Stage: 4099 - Decision to launch vote
• Due Date: 11-May-2022
• Completion Date: 11-May-2022
• Directive: 2006/42/EC - Directive 2006/42/EC of the European Parliament and of the Council of 17 May 2006 on machinery, and amending Directive 95/16/EC (recast)
• Mandate: M/396 - Mandate to CEN and Cenelec for standardisation in the field of machinery
• Ref Project: oSIST prEN 50374:2021 - Conductor carts

RELATIONS

• Revised: EN 50374:2004 - Conductor cars
• Effective Date: 10-Apr-2018

Standards Content (sample)

SLOVENSKI STANDARD
oSIST prEN 50374:2021
01-februar-2021
Nadomešča:
SIST EN 50374:2004
Vozički za delo na nadzemnih vodih
Conductor carts
Leitungsfahrzeuge
Nacelles suspendues
Ta slovenski standard je istoveten z: prEN 50374
ICS:
13.260 Varstvo pred električnim Protection against electric
udarom. Delo pod napetostjo shock. Live working
29.240.20 Daljnovodi Power transmission and
distribution lines
oSIST prEN 50374:2021 en,fr,de

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

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oSIST prEN 50374:2021
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oSIST prEN 50374:2021
EUROPEAN STANDARD DRAFT
prEN 50374
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2020
ICS Will supersede EN 50374:2004 and all of its
amendments and corrigenda (if any)
English Version
Conductor carts
Nacelles suspendues Leitungsfahrzeuge
This draft European Standard is submitted to CENELEC members for enquiry.
Deadline for CENELEC: 2021-03-12.
It has been drawn up by CLC/TC 78.

If this draft becomes a European Standard, 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.

This draft European Standard was established by CENELEC 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 CEN-CENELEC Management Centre has the same status as the official versions.

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

Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the

Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,

Turkey and the United Kingdom.

Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to

provide supporting documentation.

Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and

shall not be referred to as a European Standard.
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels

© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.

Project: 66985 Ref. No. prEN 50374 E
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oSIST prEN 50374:2021
prEN 50374:2020 (E)
Contents Page

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

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

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

3 Definitions .........................................................................................................................................5

4 List of significant hazards .................................................................................................................7

5 Requirements ................................................................................................................................ 10

5.1 Classification of conductor cars ........................................................................................... 10

5.2 Mechanical requirements .................................................................................................... 10

5.2.1 General ........................................................................................................................ 10

5.2.2 Load-bearing structure ................................................................................................ 10

5.2.3 Welded joints ............................................................................................................... 10

5.3 Prevention of the conductor car falling ................................................................................ 10

5.4 Braking system .................................................................................................................... 11

5.4.1 General ........................................................................................................................ 11

5.4.2 Drive brakes ................................................................................................................ 11

5.4.3 Locking brakes ............................................................................................................ 11

5.5 Floor covering ...................................................................................................................... 11

5.6 Fall from height protection of the operator .......................................................................... 11

5.6.1 Fall arrest attachment options ..................................................................................... 11

5.6.2 Side guards and Hand rails ......................................................................................... 11

5.6.3 Entanglement and entrapment points ......................................................................... 12

5.6.4 Operator environment ................................................................................................. 12

5.6.5 Warning signs .............................................................................................................. 12

5.7 Tow rope attachment point .................................................................................................. 13

5.8 Lifting points for raising and lowering .................................................................................. 13

5.9 Built in traction sources ....................................................................................................... 13

5.9.1 General ........................................................................................................................ 13

5.9.2 Hydraulic equipment .................................................................................................... 13

5.9.3 Electrical equipment .................................................................................................... 13

5.9.4 Batteries ...................................................................................................................... 13

5.9.5 Combustion engines .................................................................................................... 13

5.9.6 Operating controls ....................................................................................................... 14

5.9.7 Drive systems .............................................................................................................. 14

5.9.8 Disengaging mechanism in the event of a breakdown of the built-in-traction ............. 14

5.10 Equipotential bonding .......................................................................................................... 14

5.11 Safety net............................................................................................................................. 14

5.12 Identification plate ................................................................................................................ 14

5.13 Instructions for use .............................................................................................................. 15

5.14 Log-book .............................................................................................................................. 16

5.15 For a harmonized standard ................................................................................................. 16

6 Tests .............................................................................................................................................. 17

6.1 General ................................................................................................................................ 17

6.2 Test of the load bearing structure ........................................................................................ 18

6.3 Handling test ........................................................................................................................ 18

6.4 Visual inspection .................................................................................................................. 18

6.5 Prevention of the conductor car falling ................................................................................ 19

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6.6 Brake test............................................................................................................................. 19

6.6.1 General ........................................................................................................................ 19

6.6.2 Drive brake test ........................................................................................................... 19

6.6.3 Locking brake test ....................................................................................................... 19

6.7 Functional brake test ........................................................................................................... 20

6.8 Fall from height protection of the operator .......................................................................... 20

6.8.1 Testing of fall arrest attachment options ..................................................................... 20

6.8.2 Test of the side guards and hand rails ........................................................................ 20

6.9 Test of tow rope attachment point ....................................................................................... 20

6.10 Test of lifting points for raising and lowering ....................................................................... 20

6.11 Test of drive systems ........................................................................................................... 21

6.12 Test of operating controls .................................................................................................... 21

6.13 Test of entanglement and entrapment points ...................................................................... 21

6.14 Wipe test .............................................................................................................................. 21

6.15 Test of hydraulic equipment ................................................................................................ 21

6.16 Test of electrical equipment................................................................................................. 21

6.17 Functional hydraulic and/or electrical tests ......................................................................... 21

6.18 Test of disengaging the drive mechanism in the event of a breakdown of built-in-

traction ................................................................................................................................. 21

6.19 Test of safety net ................................................................................................................. 22

6.20 Test of the equipotential bonding ........................................................................................ 22

Bibliography ........................................................................................................................................... 26

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oSIST prEN 50374:2021
prEN 50374:2020 (E)
European foreword

This document (prEN 50374:2020) has been prepared by CLC/TC 78 “Equipment and tools for live

working”.
This document is currently submitted to the Enquiry.
The following dates are proposed:
• latest date by which the existence of this (doa) dor + 6 months
document has to be announced at national
level
• latest date by which this document has to be (dop) dor + 12 months
implemented at national level by publication of
an identical national standard or by
endorsement
• latest date by which the national standards (dow) dor + 36 months
conflicting with this document have to be (to be confirmed or
withdrawn modified when voting)

This document will supersede EN 50374:2004 and all of its amendments and corrigenda (if any).

This document has been prepared under a mandate given to CENELEC by the European Commission

and the European Free Trade Association, and supports essential requirements of EU Directive(s).

For the relationship with EU Directive(s) see informative Annex ZZ, which is an integral part of this

document.
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oSIST prEN 50374:2021
prEN 50374:2020 (E)
1 Scope

This document applies to conductor cars that are used to access overhead line conductors, shield wires

or shield wires with integrated communication systems to undertake work involving rectification of

defects and/or installing components and fittings. This document covers also bicycle type access

equipment where it is applicable.
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 1011-4:2000, Welding - Recommendations for welding of metallic materials - Part 4: Arc welding of

aluminium and aluminium alloys

EN 60204-1:2006, Safety of machinery - Electrical equipment of machines - Part 1: General

requirements (IEC 60204 1:2005, modified)

EN ISO 4413:2010, Hydraulic fluid power - General rules and safety requirements for systems and their

components (ISO 4413:2010)

EN ISO 10042:2018, Welding - Arc-welded joints in aluminium and its alloys - Quality levels for

imperfections (ISO 10042:2018)

EN ISO 12100:2010, Safety of machinery - General principles for design - Risk assessment and risk

reduction (ISO 12100:2010)
3 Definitions
For the purposes of this document, the following terms and definitions apply.

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

— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
3.1
conductor car

devices designed to be used as mobile working platforms while suspended from overhead line

conductors or shield wires

Note 1 to entry: The conductor cars can be moved either manually, pulled using a rope or by built in traction

source.
3.2
drive brake

used for slowing down and stopping the conductor car and holding the conductor car in position to carry

out work
3.3
locking brake

applied directly to the conductor and used for securing the car at a position on the conductor or shield

wire
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3.4
conductor

wire or combination of wires not insulated from one another, suitable for carrying an electric current

Note 1 to entry: The conductors are strung between two overhead line support structures.

Note 2 to entry: The conductor may be arranged as a single conductor or as a conductor bundle, consisting

of at least two conductors.
3.5 Tests
3.5.1
type test
conformity test made on one or more items representative of the production
[SOURCE: IEC 6050-151:2001, 151-16-16]
3.5.2
acceptance test

contractual test to prove to the customer that the item meets certain conditions if its specification

[SOURCE: IEC 6050-151:2001, 151-16-23]
3.5.3
periodical test

inspection/test carried out at set intervals by a trained competent individual to check the conformity and

functionality of the conductor car
3.6
operating control

components fitted to the conductor car that when operated controls the movement of the conductor car

by controlling the power source i.e. the flow, position of information, energy and/or material

3.7
load-bearing structure

main structure of the conductor car that has been designed to withstand the specified loads and which

can be made up of individual components mechanically bonded together
3.8
guide axle
comprised of swivel and locking mechanism, axles and guide roller (free running)
3.9
safety sling

secondary device used to prevent the conductor car from falling if the wheels or rollers become detached

from the conductor
3.10
fall arrest attachment options

suitable connection point for fall arrest equipment of the operator that is mechanically strong enough to

withstand the potential loads in event of a fall from height and which can either be connected to the

conductor or to the attachment option on the conductor car
3.11
lifting point

designated lifting point for use when the conductor car is being raised to or lowered from the overhead

line
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3.12
maximum angle of inclination of the conductor

maximum angle of the conductor cable specified by the manufacturer that the conductor car can safely

operate in reference to the angle of the conductor with respect to the horizontal plane

3.13
working load limit

maximum load the conductor car can be safely operated at, as specified by the manufacturer

3.14
safety net

optional attachment that provides protection against objects being dropped while working in the

conductor car
4 List of significant hazards

Table 1 contains a list of significant hazards associated with the conductor car and associated

equipment that could harm the operator/s during normal use of the conductor car and if it is used

incorrectly. By following this document during the design and manufacture process should help mitigate

the risk of the operator/s being harmed when the conductor car and associated equipment is being used.

NOTE 1 The significant hazards are based upon EN ISO 12100:2010.
Table 1 — List of significant hazards and associated requirements
Relevant clause(s)
Hazards in this
document/Comments
Mechanical hazards caused by mechanical equipment e.g.:
a) shape; 5.2
b) relative location; 5.3
1 c) mass and stability (potential energy of elements which
5.6
could move under the effect of gravity);
d) mass and velocity (kinetic energy of elements in
5.3, 5.7
controlled or uncontrolled motion);
e) inadequacy of mechanical strength. 5.2
1.1 Crushing hazard 5.6.3
1.2 Shearing hazard 5.6.3
1.3 Cutting or severing hazard 5.6.3
1.4 Entanglement hazard 5.6.3
1.5 Drawing-in or trapping hazard 5.6.3
1.6 Friction or abrasion hazard 5.6.4
1.7 High pressure fluid injection or ejection hazard 5.9.2
1.8 Slipping, tripping and falling 5.8, 5.7, 5.3
2 Electrical hazards due to:
2.1 Contact of persons with live parts (direct contact) 5.9.3
Contact of persons with parts which have become live under
2.2 5.9.3
faulty conditions (indirect contact)
2.3 Approach to live parts under high voltage 5.9.3, 5.10
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Relevant clause(s)
Hazards in this
document/Comments
2.4 Electrostatic phenomena 5.9.3, 5.10
3 Thermal hazards, resulting in:
Burns, scalds and other injuries by a possible contact of
persons with objects or materials with an extreme high or
3.1 5.9.5
low temperature, by flames or explosions and by the
radiation of heat sources
4 Hazards generated by noise, resulting in:
Hearing loss (deafness), other physiological disorders (e.g.
4.1 5.13
loss of balance, loss of awareness)
Interference with speech communication, acoustic signals
4.2 5.13
etc.
5 Hazards generated by vibration due to:
Whole body vibration, particularly when combined with poor
5.1 5.13
postures
Hazards generated by materials and substances (and
6 their constituent elements) processed or used by the
machinery due to:
Hazards from contact with or inhalation of harmful fluids,
6.1 5.9.5
gases, mists, fumes, and dusts
6.2 Fire or explosion hazard 5.9.4, 5.9.5
Hazards generated by neglecting ergonomic principles
in machinery design as, e.g. hazards from:
7.1 Inadequate consideration of hand-arm or foot-leg anatomy 5.9.6
7.2 Inadequate local lighting 5.13
7.3 Human error, human behaviour 5.4.2
Inadequate design, location or identification of manual
7.4 5.9.6
controls
Unexpected start-up, unexpected overrun/overspeed (or
any similar malfunction) from:
8.1 Failure/disorder of the control system 5.4.2, 5.4.3
8.2 Restoration of energy supply after an interruption 5.9.6
8.3 External influences on electrical equipment 5.10
Errors made by the operator (due to mismatch of machinery
8.4 5.4.2
with human characteristics and abilities, see 8.6)
8.5 Overspeed during operation 5.4.2, 5.4.3, 5.9.7
Impossibility of stopping the machine in the best possible
9 5.4.2, 5.4.3
conditions
10 Failure of the power supply 5.9.6, 5.9.2, 5.9.3
11 Failure of the control circuit 5.4.2, 5.4.3
12 Errors of fitting 5.2
13 Break-up during operation 5.13
14 Falling or ejected objects or fluids 5.5, 5.9.2
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Relevant clause(s)
Hazards in this
document/Comments
15 Slip, trip and fall of persons (related to machinery) 5.5, 5.6
Additional hazards, hazardous situations and hazardous events due to mobility
16 Relating to the travelling function:
16.1 Movement when starting the engine 5.9.6
16.2 Movement without a driver at the driving position 5.9.6
Insufficient ability of machinery to be slowed down, stopped
16.3 5.4.2, 5.4.3, 5.9.7
and immobilised
Linked to the work position (including driving station)
on the machine due to:
Fall of persons during access to (or at/from) the work
17.1 5.5, 5.6
position
17.2 Exhaust gases/lack of oxygen at the work position 5.9.5
17.3 Fire (flammability of the cab, lack of extinguishing means) 5.9.5
Mechanical hazards at the work position:
− contact with the wheels;
− rollover and overturning
− slipping during access;
17.4 5.6
− fall of objects, penetration by objects;
− break-up of parts rotating at high speed;
contact of persons with machine parts or tools (pedestrian
controlled machines).
17.5 Noise at the work position 5.13
17.6 Vibration at the work position 5.13
18 Due to the control system:
18.1 Inadequate location of manual controls 5.9.6
Inadequate design of manual controls and their mode of 5.9.6
18.2
operation
Due to the power source and to the transmission of
power:
19.1 Hazards from the engine and the batteries 5.9.4, 5.9.6
19.2 Hazards from coupling and towing 5.7
20 From/to third persons due to:
20.1 Lack or inadequacy of visual or acoustic warning means 5.6.5
21 Insufficient instructions for the driver/operator
Additional hazards, hazardous situations and hazardous events due to lifting
22 Mechanical hazards and hazardous events:
5.8
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5 Requirements
5.1 Classification of conductor cars
The conductor cars are classified in two classes:
Class I.: Conductor car used only on de-energized conductors.
Class II.: Conductor car used both on de-energized and energized conductors.
5.2 Mechanical requirements
5.2.1 General

The mechanical strength of the structure shall be proven by conducting a schedule of testing. The

destructive and non-destructive mechanical tests carried out on the material and the mechanical joints

should be recorded and certified. The mechanical tests performed should consider the environmental

effects (e.g. UV, chemical and mechanical degradation) on the material where applicable.

5.2.2 Load-bearing structure
5.2.2.1 General

The load-bearing structure of the conductor car should be calculated by using the applicable standard,

in relation to the material (e.g.: Eurocode 9: EN 1999-1-1:2007 for aluminium structures). If a standard

is not considered, the calculation shall be performed with traditional methods by considering:

5.2.2.2 Materials which have a characteristic value of the yield strength

Load-bearing parts and parts that serve a safety function shall be designed to include a safety factor of

at least 3:1 of the yield strength of the material using worst case scenario conditions.

5.2.2.3 Materials which do not have a characteristic value of the yield strength

Load-bearing parts and parts that serve a safety function shall be designed to include a safety factor of

at least 5:1 of the ultimate tensile strength of the material using worst case scenario conditions.

5.2.2.4 Parts of drive system

The drive shaft fatigue strength shall be provided especially for worst case scenario operations using a

safety factor of 1:1 based on the fatigue strength value for the respective materials used.

5.2.3 Welded joints

The design and configuration of the weld joints shall comply with the requirements of the relevant

standard depending on the material used to construct the conductor car. For conductor cars constructed

using aluminium and/or aluminium alloys all welded joints shall comply with EN 1011-4:2000. All welded

joints shall conform to Evaluation Group D (moderate) according to EN ISO 10042:2018 as a minimum.

Where different materials are used, or another jointing technology is used (e.g. adhesive) to construct a

conductor car it should be carried out in accordance with the applicable EN and/or ISO standard.

5.3 Prevention of the conductor car falling

The conductor car shall be equipped with a device (e.g. safety sling or frame design) that prevents the

conductor car from unintentional tilting or falling under all normal operating and emergency conditions.

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5.4 Braking system
5.4.1 General

Conductor cars shall be equipped with a drive brake and a locking brake / device that work independently

of each other.

The number of drive brakes and locking brakes required on the conductor car is related to the working

configuration of the car, in order to ensure that at least one of each of the brakes is always active during

the use.

Conductor cars connected to an external winch system can be provided without drive brakes if the

braking system is incorporated in the winch mechanism.

The braking system shall be designed in such a manner that the conductor will not be damaged during

normal use of the system.
5.4.2 Drive brakes

Drive brakes shall be capable of stopping the conductor car as quickly as possible.

Drive brakes shall be designed in such a manner that they will not lose effectiveness (single fault

security) in the event of a malfunction. For conductor cars with a built-in traction source the braking

system should comply with EN ISO 13849-2:2012.
5.4.3 Locking brakes

Locking brakes provide an additional braking function to the drive brake system. They shall be capable

of holding the conductor car at any position within the prescribed scope of application.

5.5 Floor covering

The floor covering selected for the conductor car shall be slip-resistant and shall have drainage holes

(width < 15 mm).
5.6 Fall from height protection of the operator
5.6.1 Fall arrest attachment options

The operator can use the conductor as a connection point for fall arrest, in such case the conductor car

should be constructed without a fall arrest connection point.

Where conductor cars are fitted with at least one fall arrest connection point they shall be clearly

identifiable with durable and legible markings. The fall arrest connection points shall be capable of

withstanding the anticipated loads.
5.6.2 Side guards and Hand rails
5.6.2.1 Conductor cars

Conductor cars shall be fitted with side guards to protect the operator or prevent objects falling from the

conductor car. Comparable protection shall also be available for the front and rear of the conductor car.

The drive axles/shafts and guide axles could provide this protection, if appropriate.

Side guards on the conductor car shall be designed in such a manner that they will withstand the loads

anticipated under normal working conditions.
Side guards should be comprised of:
— hand rails ≥ 1 m in height (floor panels to the upper edge);
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— mid-rails at a height, to prevent the operator/s falling through the side of the conductor car

(e.g. ≤ 0,55 m clearance between the skirting boards and the mid-rails, or between the mid-rails

and the hand rails);
— skirting boards at a height of ≥ 0,15 m.

The skirting boards shall rest on the floor without a clearance so that objects on the floor cannot fall out

of the conductor car.

Where the conductor car is used on conductor bundles of two or more conductors the conductor can

fulfil the fun
...