ISO 23285:2025

International
Standard
ISO 23285
First edition
Agricultural machinery, tractors, and
2025-02
earth-moving machinery — Safety of
electrical and electronic components
and systems operating at 32 V to 75
V DC and 21 V to 50 V AC
Matériel agricole, tracteurs et engins de terrassement —
Sécurité des composants et systèmes électriques et électroniques
fonctionnant sous 32 V à 75 V DC et 21 V à 50 V AC
Reference number
© ISO 2025
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Published in Switzerland
ii
Contents Page
Foreword .vi
Introduction .vii
1 Scope . 1
2 Normative references . 1
3 Terms, definitions and abbreviated terms . 2
3.1 Terms and definitions .2
3.2 Abbreviated terms .8
4 General requirements . 9
4.1 V-model . .9
4.2 Voltages .9
4.3 Environmental and operational requirements.9
4.4 Components and devices .10
5 Protection against electric shock hazards . 10
5.1 Overview .10
5.2 General .10
5.2.1 Fundamental requirements .10
5.2.2 Determination of shock protection requirements .10
5.3 Protective measures . .11
5.4 Basic protection . 12
5.4.1 General . 12
5.4.2 Basic insulation . 12
5.4.3 Enclosures or barriers . 12
5.4.4 Limitation of touch current or capacitive discharge energy . 13
5.4.5 Limitation of voltage . 13
5.5 Fault protection .14
5.5.1 General .14
5.5.2 PEPB . . 15
5.5.3 Automatic disconnection of power supply . 20
5.5.4 Supplementary insulation . 20
5.5.5 Basic protection between circuits . 20
5.6 Enhanced protection . 20
5.6.1 General . 20
5.6.2 Reinforced insulation and protective separation between circuit .21
5.6.3 Protection by means of protective impedance and limited capacitive discharge
energy .21
5.7 Equipment protective combinations . 22
5.8 Separation of VC-A2- and VC-B1-systems from VC-B2 (and higher) systems . 22
5.9 Protection against residual voltages . 23
5.9.1 Basic protection . 23
5.9.2 Protection by power supply disruption . 23
5.10 Connector human contact .24
5.10.1 General .24
5.10.2 Mated non-enclosed connectors .24
5.10.3 Non-mated, non-enclosed connectors .24
5.10.4 Enclosed connectors . 25
5.10.5 Tractor implement plug/socket combinations (or similar mobile machinery
implement and attachment combinations) . 25
5.11 Water depth . 25
6 Wiring practices .26
6.1 Conductor and cable runs . 26
6.2 Colour . 26
6.3 Cable protection inside an enclosure . 26
6.4 Power supply voltage differences . 26

iii
7 Overcurrent protection (OCP) .27
7.1 Overview .27
7.2 General .27
7.2.1 Transformers .27
7.2.2 Power converters .27
7.2.3 OCP implementation .27
7.2.4 Rating and setting of OCP . 28
7.2.5 Placement of OCP. 28
7.2.6 Protection via engine shutoff . 28
7.3 Chassis faults/residual currents . 28
8 Disconnection and connection .28
8.1 General disconnecting devices . 28
8.2 Specifics of disconnecting . 28
8.2.1 VC-B1 . 28
8.2.2 Power converter disconnects . 29
8.2.3 Manually actuated disconnecting devices. 29
8.2.4 Disconnecting multiple power supplies. 30
8.3 Prevention of unintended start-up . 30
8.4 Charging power supplies and recuperation . 30
8.4.1 Electrical power supplies . 30
8.4.2 Powered interchangeable towed machinery and towed machines .31
8.4.3 PTO .31
8.5 Pre-charge protective measures .31
9 Connectors .32
9.1 General .32
9.2 Negative connectors and terminals .32
9.3 Connector mating . .32
9.3.1 Incompletely mated connectors .32
9.3.2 Connecting and disconnecting under load .32
9.4 Power cable connections . 33
9.5 Terminals for the PEPB cables . 33
9.6 Plug/socket combination . 33
10 Electric motors and generators .34
10.1 General . 34
10.2 Enclosures. 34
10.3 Mounting and compartments . 35
10.4 Overheating protection . . 35
10.5 Overspeed protection . . 35
10.6 Towing and coasting . 35
10.7 Bonding . 35
10.7.1 Motors and generators . 35
10.7.2 Exempted from marking requirement . 36
11 Non-motor loads (components) .36
11.1 General . 36
11.2 Accessories . 36
12 Insulation coordination .36
12.1 General . 36
12.2 Cable insulation .37
12.2.1 Temperature and loading .37
12.2.2 Inspection .37
12.2.3 Shielding .37
12.2.4 Different voltages .37
13 Verification and validation .38
13.1 General . 38
14 Information for use .38

iv
14.1 General . 38
14.2 Markings . 38
14.2.1 First responder information . 38
14.2.2 Shock hazard symbols . 38
14.2.3 Operating voltage . 38
14.2.4 Live parts accessible during installation and maintenance . 38
14.2.5 Bonding . 38
14.2.6 Residual voltage . 39
14.2.7 Power supply disruption . 39
14.2.8 Disconnected plug/socket combinations . 39
14.2.9 Maximum water depth . 39
14.2.10 Connection markings . 39
14.2.11 Conductor and cable colour markings . 39
14.2.12 Bolted joints . 39
14.2.13 Disconnection of electrical power supplies . 39
14.2.14 Multiple disconnects . 40
14.2.15 Unintended start-up . 40
14.2.16 External charging . 40
14.2.17 Towing . 40
14.2.18 Connecting and disconnecting under load . 40
14.2.19 Phase cable connections . 40
14.2.20 Bonding of motors and generators EPB . 40
14.2.21 Shipping, dealer setup and transport . 40
14.2.22 Electrical ratings . 40
14.2.23 Protection systems .41
14.2.24 General purpose socket-outlets .41
14.2.25 Magnetic hazard symbols .41
14.3 Manuals and technical documentation .41
14.3.1 General .41
14.3.2 Operator’s manual . .42
14.3.3 Service manuals .43
Annex A (informative) List of significant hazards .45
Annex B (informative) V-Model .46
Annex C (informative) Shock protection requirements . 47
Annex D (informative) Protection classes .49
Annex E (informative) Documentation . 51
Bibliography .53

v
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
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related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 23, Tractors and machinery for agriculture
and forestry, Subcommittee SC 19, Agricultural electronics, in collaboration with ISO/TC 127, Earth-moving
machinery, Subcommittee SC 3, Machine characteristics, electrical and electronic systems, operation and
maintenance.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

vi
Introduction
Electrification technology can provide increased flexibility in mobile machinery configuration. It offers
efficiency gains and enhanced power delivery options, which are not possible with current mechanical and
hydraulic systems.
Traditional agricultural and earth-moving machinery electrical systems operate in VC-A1, 0 V DC to 32 V DC
and 0 V AC to 21 V AC. VC-B2 mobile machinery operate in the 75 V DC to 1 500 V DC and 50 V AC to 1 000 V AC
and are covered by ISO 16230-1 for agricultural machines and ISO 14990 series for earth-moving machines.
This document covers mobile machinery with systems operating in VC-A2 and VC-B1 (see Table 1). Some of
the content of this document is based on IEC 60204-1 and IEC 62477-1, adapted to the specific application
of agricultural and earth-moving machinery. Non-electrical hazards are addressed by ISO 4254 series for
agricultural machinery, ISO 26322 series for tractors used in agriculture and forestry, and ISO 20474 series
for earth-moving machinery.
Even though this document addresses most hazards associated with the use of electrical systems within
the voltage ranges in the scope of this document, owing to the possible presence of additional electrical
hazards, conformance with it cannot be taken as an absolute guarantee of electrical safety. Areas of concern
are included in the list of significant hazards found in Annex A.
Having a background in the IEC approach to electrical system safety helps the user make better decisions
about the application of this document.
This document is a type-C standard as stated in ISO 12100.
This document is of relevance, in particular, for the following stakeholder groups representing the market
players with regard to machinery safety:
— machine manufacturers (small, medium and large enterprises); and
— health and safety bodies (regulators, accident prevention organisations, market surveillance, etc.)
Others can be affected by the level of machinery safety achieved with the means of the document by the
above-mentioned stakeholder groups:
— machine users/employers (small, medium and large enterprises);
— machine users/employees (e.g. trade unions, organizations for people with special needs);
— service providers, (e.g. for maintenance, small, medium and large enterprises);
— consumers (in case of machinery intended for use by consumers).
The above-mentioned stakeholder groups have been given the possibility to participate at the drafting
process of this document. The machinery concerned and the extent to which hazards, hazardous situations
or hazardous events are covered are indicated in the Scope of this document.
When requirements of this type-C standard are different from those which are stated in type-A or type-B
standards, the requirements of this type-C standard take precedence over the requirements of the other
standards for machines that have been designed and built according to the requirements of this type-C
standard.
vii
International Standard ISO 23285:2025(en)
Agricultural machinery, tractors, and earth-moving
machinery — Safety of electrical and electronic components
and systems operating at 32 V to 75 V DC and 21 V to 50 V AC
1 Scope
This document primarily specifies both general design requirements and guidelines for protection of
operators and bystanders against electric shock and electrically induced fire, for voltage classes A2 (32 V DC
to 60 V DC and 21 V AC to 30 V AC) and B1 (60 V DC to 75 V DC and 30 V AC to 50 V AC), including waveforms
synthesized by power electronic converters. This document is limited to addressing hazards that are not as
commonly found in 12 V DC and 24 V DC systems, including those related to higher power converters and
drive motors.
NOTE 1 Although protection against electrically induced fire hazards is addressed sparingly, conformance to
content of this document has the impact of reducing the occurrence and hazards associated with fire.
This document is applicable to electric systems used on:
— tractors, self-propelled ride-on machines, interchangeable towed machinery, semi-mounted implements,
and mounted implements used in or with agriculture and forestry; and
— earth-moving machinery (EMM) as defined in ISO 6165 and attachments.
For mobile machinery with multiple rated voltages, with at least one system rated greater than VC-B1, this
document addresses the risks associated with the interactions between VC-A2 and VC-B1 systems and those
systems which are nearby and rated greater than VC-B1.
NOTE 2 Electrical safety requirements for greater than VC-B1 are described in ISO 16230-1 for agricultural
machines and ISO 14990 series for earth-moving machines.
NOTE 3 Although 12 V DC and 24 V DC systems are generally below the limits of this document, meeting appropriate
requirements of this document ensures that proper protection exists between the covered systems and lower voltage
systems.
This document is applicable to mobile machinery that are either externally powered or self-powered or both.
Alternative safety requirements can be necessary for special equipment or components such as underground
mining equipment. This document does not address the additional risks for mobile machinery operating in
potentially explosive atmospheres.
This document deals with all significant hazards, hazardous situations, or hazardous events relevant within
its scope (see Annex A), when the mobile machinery is used as intended and under conditions of misuse
which are reasonably foreseeable by the manufacturer. It specifies appropriate technical measures for
eliminating or reducing risks arising from significant hazards, hazardous situations, or hazardous events
during commissioning, operation, and maintenance.
This document is not applicable to mobile machinery manufactured before the date of its publication.
2 Normative references
The following documents are referred to in the text in such a way that some or all 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.

ISO 6405-1:2017, Earth-moving machinery — Symbols for operator controls and other displays — Part 1:
Common symbols
1)
ISO 7010 , Graphical symbols — Safety colours and safety signs — Registered safety signs
ISO 12100:2010, Safety of machinery — General principles for design — Risk assessment and risk reduction
ISO 13857:2019, Safety of machinery — Safety distances to prevent hazard zones being reached by upper and
lower limbs
ISO 14990-1:2016, Earth-moving machinery — Electrical safety of machines utilizing electric drives and related
components and systems — Part 1: General requirements
ISO 14990-2, Earth-moving machinery — Electrical safety of machines utilizing electric drives and related
components and systems — Part 2: Particular requirements for externally-powered machines
ISO 14990-3, Earth-moving machinery — Electrical safety of machines utilizing electric drives and related
components and systems — Part 3: Particular requirements for self-powered machines
ISO 15003, Agricultural engineering — Electrical and electronic equipment — Testing resistance to
environmental conditions
ISO 16230-1:2015, Agricultural machinery and tractors — Safety of higher voltage electrical and electronic
components and systems — Part 1: General requirements
ISO 19014-3, Earth-moving machinery — Functional safety — Part 3: Environmental performance and test
requirements of electronic and electrical components used in safety-related parts of the control system
IEC 60034-1, Rotating electrical machines — Part 1: Rating and performance
IEC 60204-1:2016, Safety of machinery — Electrical equipment of machines — Part 1: General requirements
IEC 60309-1, Plugs, socket-outlets, and couplers for industrial purposes — Part 1: General requirements
IEC 60364-5-54:2011/AMD1:2021, Low-voltage electrical installations — Part 5-54: Selection and erection of
electrical equipment — Earthing arrangements and protective conductors
1)
IEC 60417 , Graphical symbols for use on equipment
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 60664 (all parts), Insulation coordination for equipment within low-voltage systems
IEC 60990:2016, Methods of measurement of touch current and protective conductor current
IEC 61140:2016, Protection against electric shock — Common aspects for installations and equipment
IEC 61984, Connectors — Safety requirements and tests
IEC 62477-1:2022, Safety requirements for power electronic converter systems and equipment — Part 1: General
SAE J1614, Wiring Distribution Systems for Off-Road, Self-Propelled Work Machines
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 12100 and the following apply.
1) The graphical symbol collections of ISO 7010 and IEC 60417 can be previewed and purchased on the Online Browsing
Platform (OBP), www .iso .org/ obp.

ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1.1
access system
(machine) access system
system provided on a machine for ascending from the ground or descending to the ground or for moving
from one area on the machine to another area
[SOURCE: ISO 2867:2011, 3.2.1]
3.1.2
accessible conductive part
accessible part having a conductive surface that is bare or covered by an insulating layer that does not
comply with the requirements of basic insulation
Note 1 to entry: An accessible conductive part is considered to be a hazardous live part if not separated from live parts
by at least basic insulation.
3.1.3
accessible part
part which, as installed, can be touched by means of the jointed test finger in IEC 60529
[SOURCE: IEC 60050-442:1998, 442-01-15, modified — definition has been changed to be more specific
about finger accessibility]
3.1.4
basic insulation
insulation of live parts providing protection against direct contact
Note 1 to entry: Basic insulation does not include insulation used exclusively for a functional purpose.
Note 2 to entry: The use of winding wire coatings as basic, supplementary, or reinforced insulation is restricted in
some VC-B2 (and higher) standards. However, VC-A and VC-B1 are not subject to such restrictions.
[SOURCE: IEC 60050-195:2021, 195-06-06, modified — definition has been clarified and better reflect the
voltage range covered by this document.]
3.1.5
basic protection
Protection against electrical shock under fault-free conditions
[SOURCE: IEC 60050-195:1998, 195-06-01]
3.1.6
conductive part
part of the machine that is capable of conducting electric current
[SOURCE: IEC 60050-195:2021, 195-01-06, modified — definition has been made clearer]
3.1.7
converter
electric energy converter
device for changing one or more characteristics associated with electric energy
Note 1 to entry: In informal usage, it is common to use the term "inverter" to mean converter, rectifier, or AC/DC or
AC/AC converter. The informal meanings of "inverter" are not used in this document.
[SOURCE: IEC 60050-151:2001, 151-13-36, modified — Note has been removed and replaced by a new Note.]

3.1.8
double insulation
insulation comprised of both basic and supplementary insulation types
[SOURCE: IEC 60050-195:2021, 195-06-08, modified — definition has been made clearer]
3.1.9
earth
local earth
ground, US
local ground, US
part of the Earth which is in electric contact with an earth electrode and whose electric potential is not
necessarily equal to zero
[SOURCE: IEC 60050-195:2021, 195-01-03]
3.1.10
electric chassis
chassis
conductive parts of a machine that are electrically connected and whose potential is taken as reference
[SOURCE: ISO 6469-4:2
...