oSIST prEN ISO 13297-1:2026
(Main)Small craft - Alternating and direct current installations of electrical systems - Part 1: Single-phase AC, Craft low voltage DC (ISO/DIS 13297-1:2026)
- Abstract
This document specifies the requirements for the design, construction and installation of the following types of DC and AC electrical systems, installed on small craft either individually or in combination:
a) extra-low-voltage direct current (DC) electrical systems that operate at nominal potentials of 50 V DC or less;
b) single-phase alternating current (AC) systems that operate at a nominal voltage not exceeding AC 250 V.
This document does not cover the following:
— electrical propulsion systems of direct current less than 1 500 V DC, single-phase alternating current up to 1 000 V AC, and three-phase alternating current up to 1 000 V AC, which are addressed by ISO 16315;
— any conductor that is part of an outboard engine assembly and that does not extend beyond the outboard engine manufacturers supplied cowling;
— three-phase AC installations that operate at a nominal voltage not exceeding 500 V AC, which are addressed by IEC 60092-507.
- Status
- Not Published
- Public Enquiry End Date
- 14-Sep-2026
- Technical Committee
- I13 - Imaginarni 13
- Current Stage
- 4020 - Public enquire (PE) (Adopted Project)
- Start Date
- 15-Jul-2026
- Due Date
- 02-Dec-2026
- Completion Date
- 15-Sep-2026
oSIST prEN ISO 13297-1:2026 is a draft CEN/ISO standard for small craft electrical systems. It specifies requirements for the design, construction and installation of craft low voltage DC systems and single-phase AC systems on small craft, for builders, installers, equipment suppliers and surveyors who need a common basis for safe marine electrical installations.
What does oSIST prEN ISO 13297-1:2026 specify?
oSIST prEN ISO 13297-1:2026 covers the design, construction and installation of DC and AC electrical systems on small craft, used individually or in combination, across normal operating states and environmental locations. It focuses on craft low voltage DC systems with a highest voltage not exceeding 60 V DC and single-phase AC systems up to 250 V AC.
The document excludes propulsion systems, high-voltage DC craft systems, three-phase AC installations, conductor parts that stay within outboard engine or factory-built assemblies, general shore power connection hardware for power supply and battery charging, EMC test methods and requirements, and lithium-ion batteries.
| Annex | What it covers |
|---|---|
| Annex A | Conductor requirements, current ratings, derating and voltage-drop calculations |
| Annex B | Instructions to include in the owner's manual |
| Annex C | Typical AC system diagrams |
| Annex D | DC overcurrent protection location detail |
| Annex E | DC earthing and grounding systems |
| Annex F | Craft low voltage terminology and voltage categories |
| Annex G | Protective equipotential bonding and corrosion |
| Annex H | Shore power earth separation device |
| Annex I | Local earth and the interconnection of AC protective equipotential, DC chassis ground and functional equipotential systems |
| Annex J | Guarding of energized parts and protective means |
The main clauses run from general requirements through DC systems, AC systems, identification, batteries, battery switch, power source options, inverters, overcurrent protection, earth-leakage protection, panelboards, conductors, wiring, sockets, ignition protection, earthing, power distribution assemblies, documented information and test procedures.
What are the key requirements of oSIST prEN ISO 13297-1:2026?
oSIST prEN ISO 13297-1:2026 is built around safe separation, fault protection, controlled earthing and clear installation practice. The most important requirements shape how the whole system is laid out, how faults are cleared and how the craft is documented and tested.
DC systems
Clause 5 allows craft low voltage DC systems to be fully chassis isolated two-wire systems, chassis negative two-wire systems, or combinations of the two. Where a main earthing bus is installed, the document requires a single-point connection, and fully isolated DC systems need a DC functional equipotential bonding system.
This matters because the DC return path affects fault current, shock risk and how equipment cases are bonded. The standard also requires overcurrent protection at each source of power, and the DC equipment must operate safely over the battery terminal voltage range expected in service.
Clause 5 also limits voltage drop to 10 % of nominal voltage, with 3 % for equipment vital to safety such as navigation lights, bilge pumps, bilge blowers and marine communication radios. In practice, that means conductor size is not just a mechanical choice - it affects whether critical equipment works properly at the end of a long cable run.
AC systems
Clause 6 limits AC systems to single-phase neutral-earthed arrangements with protective earth (PE), either two-wire or three-wire. AC and DC distribution must be separate and identified, and energized parts must be guarded by one or more protective means such as enclosures, barriers, insulation, obstacles or safety symbols.
This matters because AC and DC faults behave differently and need different wiring discipline. For polarized systems, the neutral conductor is earthed only at the AC origin of power, while unpolarized systems need double-pole circuit protection and switching.
Clause 6 also requires that a circuit cannot be energized by more than one power source at a time unless the changeover arrangement opens all live conductors before closing the alternate source. That prevents back-feeding, unwanted parallel sources and arc-over during transfer between shore power, generator and inverter.
Protection, batteries and switching
Clause 14 requires earth-leakage protection on all AC origin-of-power supply circuits, including shore power, inverter, transformer and generator supply circuits. The protection uses double-pole residual current devices (RCDs) with a maximum trip sensitivity of 30 mA and a maximum trip time of 100 ms, and the RCD must be trip-free with a manual test function.
For DC systems, Clauses 8 and 9 set out battery installation and the craft battery switch. Batteries must be secured against movement, installed above anticipated bilge water, protected against mechanical damage and accidental contact with terminals, and ventilated. The battery switch must be close to the battery source, readily accessible, correctly rated for cranking and continuous duty, and still be provided even if a battery management system (BMS) includes a disconnect device.
In practice, these rules reduce fire risk, shock risk and service problems. They also make sure the user can isolate the battery source without having to search through the craft.
Conductors, wiring and installation practice
Clauses 17 to 20 require conductor sizing to follow Annex A, which takes account of load, temperature, bundling and allowable voltage drop. DC distribution uses insulated stranded copper or tinned copper conductors with fire-retardant insulation and a minimum 60 V rating, while AC distribution uses similar conductors with a minimum 300 V / 500 V rating.
The wiring rules also control how cables are supported, separated and protected. AC and DC circuits cannot share the same wiring system unless the document’s separation methods are used, and conductors that could be damaged by heat, water or physical contact must be routed and protected accordingly.
Clause 20 also sets connection-quality rules: terminals must maintain mechanical and electrical integrity, twist-on connectors are not permitted, and exposed terminal parts need shorting protection. That matters in practice because many marine faults come from vibration, corrosion and poor terminations rather than from the equipment itself.
Earthing, bonding and corrosion control
Clause 23 links electrical safety with earthing and corrosion management. The craft must have an effective craft earth for specified AC and DC arrangements, and the earthing method may use an earthing plate, a metallic hull or an immersed chassis ground, depending on the system type.
The document also distinguishes protective equipotential systems from functional equipotential systems, and it treats the marine RF counterpoise separately from craft earth. This is important because the same bond can improve shock protection while also influencing galvanic corrosion, so the standard keeps the functions distinct.
Documentation and testing
Clause 25 requires an owner’s manual, wiring diagrams, source data, maintenance instructions and the instructions listed in Annex B. Clause 26 requires completion tests such as RCD testing, polarity checks, earth resistance testing and insulation resistance testing for isolated DC systems.
That means the standard is not only about installation. It also defines what the craft owner and installer need to receive, what must be checked after installation or modification, and what evidence supports a compliant handover.
What terms does oSIST prEN ISO 13297-1:2026 define?
Craft earth is the onboard earthing terminal connection that provides both protective and functional equipotential bonding through the surrounding water.
Earthing plate is a conductive device immersed in water to achieve craft earth.
Shore power is off-board AC power from shore, delivered to the craft through the shore power cable, inlet and connector arrangement.
Protective-equipotential-bonding is equipotential bonding used for electrical safety, such as the AC protective conductor system.
Functional-equipotential-bonding is equipotential bonding used for reasons other than electrical safety, such as equalizing potentials between DC device cases and the DC main negative bus or main earthing bus.
Protective equipotential bonding system (PEBS) is the bonding system that provides protective-equipotential-bonding.
Functional equipotential bonding system (FEBS) is the bonding system that provides functional-equipotential-bonding.
Polarized system is an AC system where the nominal voltage is between line and neutral, with line and neutral connected in the same relation at all terminals in the circuit.
Who uses oSIST prEN ISO 13297-1:2026?
Boatbuilders use oSIST prEN ISO 13297-1:2026 when designing and installing onboard AC and DC electrical systems. Marine electricians use it for conductor sizing, protection devices, earthing, socket selection, inverter installation and final testing.
Equipment suppliers use it to design panelboards, power distribution assemblies, inverters, battery switches, sockets, breakers and enclosures for small craft. Quality managers and surveyors use it when checking installation drawings, documentation, markings and test results.
It is also useful for buyers, owners and maintenance technicians who want to understand what a compliant small craft electrical installation should include and what information should be handed over with the craft.
What changed in oSIST prEN ISO 13297-1:2026 from the previous edition?
The foreword states that this fifth edition cancels and replaces ISO 13297:2014 and ISO 10133:2012. The main change identified in the document is the combination of the alternating current standard and the direct current standard into a single marine electrical standard.
Which standards are used with oSIST prEN ISO 13297-1:2026?
- ISO 7010 - provides the registered safety signs and graphical symbols used for warnings and marking.
- ISO 8666 - supplies principal craft data used in the technical context of small craft.
- ISO 8846 - covers ignition protection for equipment exposed to flammable gases.
- ISO 16750-2 - provides electrical load tests for critical systems and components.
- ISO 19642-1 - gives vocabulary and design guidelines for automotive cables used as a cable reference.
- ISO 23625 - covers lithium-ion batteries, which are addressed separately.
- IEC 60038 - gives standard voltages.
- IEC 60287-1-1 - supports cable current rating calculations.
- IEC 60309-2 - covers industrial plugs and socket-outlets referenced for shore power connection.
- IEC 60529 - provides IP Code enclosure protection levels.
- IEC 60695-11-10 - provides flame test methods for fire-hazard evaluation.
- IEC 60934 and IEC/EN IEC 60947-2 - support circuit-breaker requirements.
- EN IEC 60079-0:2018/A11 - gives general requirements for equipment in explosive atmospheres.
- IEC 60364-5-54, IEC 60227-1, IEC 60364-1 and IEC 60332-1-2 - support earthing, cable requirements, basic low-voltage installation principles and fire testing of cables.
- ISO 10240 - supports the owner’s manual.
- ISO 10088, ISO 10239, ISO 11105 and ISO 9094 - support fuel systems, LPG systems, ventilation and fire protection references used around ignition-risk installations.
- EN IEC 61439-2 and EN IEC 60255-1 - support power distribution assemblies and protection equipment.
What does the oSIST prEN ISO 13297-1:2026 document contain?
oSIST prEN ISO 13297-1:2026 contains conductor rating tables, derating factors and a voltage-drop formula in Annex A, plus owner’s manual instructions in Annex B. It also includes typical AC system diagrams, DC overcurrent location diagrams, earthing and grounding sketches, and explanatory annexes on craft low voltage, bonding and corrosion, shore power earth separation, local earth interconnection and guarding.
The body of the document gives installation methods, protection rules, earthing arrangements, marking requirements, battery installation rules, wiring separation rules, socket requirements, ignition-protection rules, power distribution assembly requirements and a completion test procedure. In practice, that makes the standard useful for design review, installation work, final inspection, conformity checks and maintenance documentation.
Relations
- Effective Date
- 19-Jun-2024
- Effective Date
- 19-Jun-2024
- Effective Date
- 19-Jun-2024
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Frequently Asked Questions
oSIST prEN ISO 13297-1:2026 is a draft published by the Slovenian Institute for Standardization (SIST). Its full title is "Small craft - Alternating and direct current installations of electrical systems - Part 1: Single-phase AC, Craft low voltage DC (ISO/DIS 13297-1:2026)". This standard covers: This document specifies the requirements for the design, construction and installation of the following types of DC and AC electrical systems, installed on small craft either individually or in combination: a) extra-low-voltage direct current (DC) electrical systems that operate at nominal potentials of 50 V DC or less; b) single-phase alternating current (AC) systems that operate at a nominal voltage not exceeding AC 250 V. This document does not cover the following: — electrical propulsion systems of direct current less than 1 500 V DC, single-phase alternating current up to 1 000 V AC, and three-phase alternating current up to 1 000 V AC, which are addressed by ISO 16315; — any conductor that is part of an outboard engine assembly and that does not extend beyond the outboard engine manufacturers supplied cowling; — three-phase AC installations that operate at a nominal voltage not exceeding 500 V AC, which are addressed by IEC 60092-507.
This document specifies the requirements for the design, construction and installation of the following types of DC and AC electrical systems, installed on small craft either individually or in combination: a) extra-low-voltage direct current (DC) electrical systems that operate at nominal potentials of 50 V DC or less; b) single-phase alternating current (AC) systems that operate at a nominal voltage not exceeding AC 250 V. This document does not cover the following: — electrical propulsion systems of direct current less than 1 500 V DC, single-phase alternating current up to 1 000 V AC, and three-phase alternating current up to 1 000 V AC, which are addressed by ISO 16315; — any conductor that is part of an outboard engine assembly and that does not extend beyond the outboard engine manufacturers supplied cowling; — three-phase AC installations that operate at a nominal voltage not exceeding 500 V AC, which are addressed by IEC 60092-507.
oSIST prEN ISO 13297-1:2026 is classified under the following ICS (International Classification for Standards) categories: 47.020.60 - Electrical equipment of ships and of marine structures; 47.080 - Small craft. The ICS classification helps identify the subject area and facilitates finding related standards.
oSIST prEN ISO 13297-1:2026 has the following relationships with other standards: It is inter standard links to SIST EN ISO 13297:2021, SIST EN ISO 13297:2021/A11:2023, SIST EN ISO 13297:2021/A1:2022. Understanding these relationships helps ensure you are using the most current and applicable version of the standard.
oSIST prEN ISO 13297-1:2026 is associated with the following European legislation: EU Directives/Regulations: 2013/53/EU; Standardization Mandates: M/542. When a standard is cited in the Official Journal of the European Union, products manufactured in conformity with it benefit from a presumption of conformity with the essential requirements of the corresponding EU directive or regulation.
oSIST prEN ISO 13297-1:2026 is available in PDF format for immediate download after purchase. The document can be added to your cart and obtained through the secure checkout process. Digital delivery ensures instant access to the complete standard document.
Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2026
Mala plovila - Inštalacije električnih sistemov za izmenični in enosmerni tok - 1.
del: Enofazni izmenični tok (AC), nizkonapetostni enosmerni tok (DC) na plovilih
(ISO/DIS 13297-1:2026)
Small craft - Alternating and direct current installations of electrical systems - Part 1:
Single-phase AC, Craft low voltage DC (ISO/DIS 13297-1:2026)
Kleine Wasserfahrzeuge - Wechselstrom- und Gleichstromanlagen von elektrischen
Systemen - Teil 1: Niederspannung (ISO/DIS 13297-1:2026)
Petits navires - Installations à courant alternatif et continu des circuits électriques - Partie
1: Courant alternatif monophasé, courant continu à basse tension du bateau (ISO/DIS
13297-1:2026)
Ta slovenski standard je istoveten z: prEN ISO 13297-1
ICS:
47.020.60 Električna oprema ladij in Electrical equipment of ships
konstrukcij na morju and of marine structures
47.080 Čolni Small craft
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
DRAFT
International
Standard
ISO/DIS 13297-1
ISO/TC 188
Small craft — Alternating and direct
Secretariat: SIS
current installations of electrical
Voting begins on:
systems —
2026-06-30
Part 1:
Voting terminates on:
2026-09-22
Single-phase AC, Craft low voltage
DC
ICS: 47.080; 47.020.60
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
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.
Reference number
ISO/DIS 13297-1:2026(en)
DRAFT
ISO/DIS 13297-1:2026(en)
International
Standard
ISO/DIS 13297-1
ISO/TC 188
Small craft — Alternating and direct
Secretariat: SIS
current installations of electrical
Voting begins on:
systems —
Part 1:
Voting terminates on:
Single-phase AC, Craft low voltage
DC
ICS: 47.080; 47.020.60
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: +41 22 749 01 11
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 13297-1:2026(en)
ii
ISO/DIS 13297-1:2026(en)
Contents Page
Foreword .v
1 Scope . 1
2 Normative references . 2
3 Terms and definitions . 2
4 General requirements, DC and AC systems. 17
5 General requirements, DC systems .18
6 General requirements, AC systems .21
7 Identification of equipment and systems .24
7.1 General .24
7.2 Marking, DC systems .24
7.3 Marking, AC systems .24
8 Batteries, DC systems .25
9 Craft battery switch, DC systems .28
9.1 Installation . 28
9.2 Unswitched Circuits . 28
9.3 Ampacity Rating . . 29
9.4 Remote control . 29
10 Power source options, AC systems .29
11 Inverters and inverter/chargers .30
12 Overcurrent protection, DC systems .31
12.1 General .31
12.2 Source of power .32
12.3 Charging system .32
12.4 Battery bank interconnections .32
12.5 Battery bank source of power . . 33
12.6 BMS disconnect device . 33
12.7 Amperage Interrupting Capacity (AIC) . 33
12.8 Solar photovoltaic (PV) systems . 33
13 Overcurrent protection, AC systems .33
13.1 General . 33
13.2 Supply circuits . 34
13.3 Branch circuits . 34
14 Ground-fault protection/earth-leakage protection, AC systems .35
15 Panelboards, General Requirements .35
16 Panelboards, AC systems.35
17 Conductors, DC and AC systems .36
18 Conductors, DC systems .37
19 Conductors, AC systems .38
20 System wiring, DC and AC systems .38
21 Sockets, DC and AC systems. 41
21.1 General .41
21.2 Sockets, DC systems .41
21.3 Sockets, AC systems .41
22 Ignition protection, DC and AC systems .42
23 Earthing, Chassis Negative and Equipotential Systems .42
iii
ISO/DIS 13297-1:2026(en)
23.1 Craft earth .42
23.2 Earthing methods .43
23.3 Equipotential systems .43
23.3.1 Main earthing bus . 44
23.4 Conductive Hulls . 44
23.5 Marine RF counterpoise . 44
24 Power distribution assemblies .44
24.1 General Requirements . 44
24.2 Operation . 44
24.3 Installation . 44
24.4 Overcurrent protection . 44
24.5 Solid state overcurrent protection .45
25 Documented information .45
25.1 Owner’s manual .45
25.2 Wiring diagrams .45
25.3 Power distribution assembly literature . 46
26 Test procedures .46
Annex A (normative) Conductor requirements .48
Annex B (normative) Instructions to be included with owner's manual .50
Annex C (informative) Typical AC system diagrams . 51
Annex D (informative) DC overcurrent protection location detail .59
Annex E (informative) DC Earthing and Grounding Systems .62
Annex F (informative) Craft Low Voltage .65
Annex G (informative) Protective Equipotential Bonding and Corrosion . 67
Annex H (informative) Shore Power Earth Separation Device .71
Annex I (informative) Local Earth and the Innerconnection of AC Protective Equipotential, DC
Chassis Ground and Functional Equipotential Systems .72
Annex J (informative) Guarding of energized parts protective means .73
Annex ZA (informative) .75
Bibliography .78
iv
ISO/DIS 13297-1:2026(en)
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 documents 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).
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent
rights identified during the development of the document will be in the Introduction and/or on the ISO list of
patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
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 188, Small craft, in collaboration with the
European Committee for Standardization (CEN) Technical Committee CEN/TC 464, Small craft, in accordance
with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement).
This fifth edition of ISO 13297 cancels and replaces ISO 13297:2014 and ISO 10133:2012, which have been
technically revised.
The main changes compared to the previous editions are as follows:
— combined the standard for alternating current (ISO 13297:2014) and the standard for direct current
(ISO 10133:2012) into a single marine electrical standard.
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.
v
DRAFT International Standard ISO/DIS 13297-1:2026(en)
Small craft — Alternating and direct current installations of
electrical systems —
Part 1:
Single-phase AC, Craft low voltage DC
NOTE — The colours represented in the electronic file of this document can be neither viewed on
screen nor printed as true representations. For the purposes of colour matching, see ISO 3864-4,
which provides colorimetric and photometric properties together with, as a guideline, references
from colour order systems.
1 Scope
This document specifies the requirements for the design, construction and installation of the following
types of DC and AC electrical systems, installed either individually or in combination, for all small craft
operational states and environmental locations:
a) craft low voltage direct current (DC) electrical systems where the highest voltage of a system does not
exceed 60 V DC;
b) single-phase alternating current (AC) systems that operate at an RMS voltage not exceeding 250 V AC.
NOTE In Europe, 230 V AC single-phase systems are either polarized and unpolarized.
In North America, 120/240 V AC split-phase systems are a variation of a 3-wire single-phase system. The 120 V AC
systems are wired polarized while the 240 V AC systems are wired unpolarized.
Regarding this standard, 250 V AC is rounded up to ensure variations in 240 V AC are included.
This document does not cover the following:
— electrical propulsion systems of direct current less than 1 500 V DC, single-phase alternating current up
[1]
to 1 000 V AC, and three-phase alternating current up to 1 000 V AC, which are addressed by ISO 16315 .
— any conductor that is part of a factory-built assembly and that does not extend beyond the assembly such
as network cables, engines and engine management systems.
— three-phase AC installations that operate at a nominal voltage not exceeding 500 V AC, which are
[2]
addressed byIEC 60092-507 .
— craft-high voltage direct current (DC) systems where the highest voltage of a systems exceeds 60 V DC
and does not exceed 1 500 V DC.
— shore power connection for general power supply and battery charging, which are not addressed by
[3]
IEC 60309-2 .
— electromagnetic compatibility (EMC) test methods and requirements.
[4]
— lithium-ion batteries which are addressed by ISO 23625
ISO/DIS 13297-1:2026(en)
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.
ISO 7010, Graphical symbols — Safety colours and safety signs — Registered safety signs
ISO 8666, Small craft — Principal data
ISO 8846, Small craft — Electrical devices — Protection against ignition of surrounding flammable gases
ISO 16750-2, Road vehicles — Environmental conditions and testing for electrical and electronic equipment —
Part 2: Electrical loads
ISO 19642-1, Road vehicles — Automotive cables — Part 1: Vocabulary and design guidelines
ISO 23625, Small craft — Lithium-ion batteries
IEC 60038, IEC standard voltages
IEC 60287-1-1, Electric cables - Calculation of the current rating - Part 1-1: Current rating equations (100 % load
factor) and calculation of losses - General
IEC 60309-2, Plugs, fixed or portable socket-outlets and appliance inlets for industrial purposes - Part 2:
Dimensional compatibility requirements for pin and contact-tube accessories
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 60695-11-10, Fire hazard testing - Part 11-10: Test flames - 50 W horizontal and vertical flame test methods
IEC 60934, Circuit breakers for equipment (CBE)
IEC 60947-2, Low-voltage switchgear and controlgear - Part 2: Circuit-breakers
EN IEC 60079-0:2018/A11, Explosive atmospheres - Part 0: Equipment - General requirements
3 Terms and 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
craft earth
craft ground
earthing terminal (3.7) connection onboard the craft (3.63) which provides both protective-equipotential-
bonding (3.8) and functional-equipotential-bonding (3.19) to achieve an intentional connection to earth (3.5)
via the water in which the craft (3.63) is immersed
ISO/DIS 13297-1:2026(en)
3.2
earthing plate
ground plate
conductive device of a specific surface area affixed to the craft (3.63) which is immersed in the surrounding
water to achieve craft earth (3.1)
EXAMPLE A conductive metal plate mounted externally on the hull below the waterline. It provides a low-
resistance electrical path to the surrounding water, serving as a earthing (3.6) point for the craft (3.63) AC electrical
systems and which may include lightning protection, radio grounding, EMC management, and bonding of metallic
components to manage galvanic corrosion.
3.3
shore earth
shore ground
earthing terminal (3.7) connection onboard the craft (3.63) which provides protective-equipotential-bonding
(3.8) to the shore earth electrode
Note 1 to entry: The shore earth (3.3) /ground (3.5) is active only when the shore power (3.23) is connected to the craft
(3.63) by a cable (3.32).
3.4
local earth
ground
part of the Earth that is in electric contact with an earth electrode and that has an electric potential not
necessarily equal to zero
[SOURCE: IEV 195-01-03]
3.5
earth
ground
to make an electric connection between a conductive part and a local earth (3.4)
Note 1 to entry: The connection to local earth (3.4) can be:
— intentional, or
— unintentional or accidental
and can be permanent or temporary.
[SOURCE: IEV 195-01-08, added note 1]
3.6
earthing
DC grounding
electric connections between conductive parts and local earth (3.4)
[SOURCE: IEV 195-01-24]
3.7
earthing terminal
grounding terminal, US
terminal provided on equipment and intended for the electric connection with the earthing (3.6) arrangement
[SOURCE: IEV 195-02-31]
3.8
protective-equipotential-bonding
equipotential bonding for the purposes of electrical safety
EXAMPLE The green or green with yellow stripe insulated conductor (3.33) connecting AC equipment and circuits
to the craft earth (3.1).
ISO/DIS 13297-1:2026(en)
Note 1 to entry: Utilized for craft AC circuits and craft HV DC circuits for managing the risk of harm caused by
electricity. Where designed, it may serve as a redundant means of managing fault currents.
[SOURCE: IEV 195-01-15, added note 1 and example]
3.9
protective equipotential bonding system
PEBS
equipotential bonding system providing protective-equipotential-bonding (3.8)
[SOURCE: IEV 195-02-23]
3.10
protective bonding conductor
protective conductor (3.27) provided for protective-equipotential-bonding (3.8)
[SOURCE: IEV 195-02-10]
3.11
protective bonding terminal
equipotential bonding terminal (3.22) intended for protective-equipotential-bonding (3.8)
[SOURCE: IEV 195-02-42]
3.12
common equipotential bonding system
common bonding network (CBN)
equipotential bonding system providing both protective-equipotential-bonding (3.8) and functional-
equipotential-bonding (3.19)
[SOURCE: IEV 195-02-25]
3.13
radio earthing plate
communication ground plate
low impedance conductive device of a high surface area affixed to the craft (3.63) which is immersed in the
surrounding water to for high frequency communication systems
3.14
radio counterpoise
network of conductive wires or cables oriented horizontally to earths surface utilized as a radio earth which
is not in contact with the water surrounding the craft (3.63) and not in contact with other craft earthing
circuits
3.15
main earthing bus
main grounding bus
defined point for the interconnection of the DC main negative bus (3.16), AC protective equipotential bonding
system (3.9), functional equipotential bonding system (3.20) and craft earth (3.1)
Note 1 to entry: The connection to earth (3.5) for a craft (3.63) is either intentional or accidental. An intentional
connection to earth ground is dependent upon the installed system type.
3.16
DC main negative bus
in a DC chassis (3.44) negative system, a portion of the craft's negative circuit to which all DC negative
voltage potential is referenced, and which provides for the interconnection of DC sources of power, loads,
and the main earthing bus (3.15)
Note 1 to entry: Commonly consisting of bus (3.17) bar(s), conductor(s) (3.33), battery terminal(s) and/or engine
negative terminal(s) (3.18).
ISO/DIS 13297-1:2026(en)
3.17
bus
single circuit consisting of conductors (3.33) (cables, bus bar and interconnected bus bars) used as a
connection point to distribute electrical current from multiple circuits
Note 1 to entry: Commonly capable of the maximum current and voltage drop requirements of the electrical system.
3.18
engine negative terminal
terminal on the engine, starter or solenoid to which the negative battery cable is connected
3.19
functional-equipotential-bonding
equipotential bonding for reasons other than electrical safety
EXAMPLE The green or green with yellow stripe insulated conductor (3.33) connecting conductive cases of DC
electrical devices which contain live conductors or extraneous conductive parts to either the DC main negative bus
(3.16) or main earthing bus (3.15).
Note 1 to entry: Utilized for all other equipotential circuits not associated with electrical shock. Where designed, it
may serve as a redundant means of managing fault currents.
[SOURCE: IEV 195-01-16, added note 1 and example]
3.20
functional equipotential bonding system
FEBS
equipotential bonding system providing functional-equipotential-bonding (3.19)
[SOURCE: IEV 195-02-24]
3.21
functional bonding conductor
conductor (3.33) provided for functional-equipotential-bonding (3.19)
Note 1 to entry: normally non-current-carrying conductor (3.33) used to put various exposed conductive parts of
direct current electrical devices and extraneous conductive parts at a substantially equal potential
[SOURCE: IEV 195-02-16, note 1 added]
3.22
equipotential bonding terminal
terminal provided on equipment and intended for the electric connection with an equipotential bonding
system
[SOURCE: IEV 195-02-32]
3.23
shore power
off-board power connection mode 1
transmission of an earthed AC source of power (3.64) originating from shore, external to the craft (3.63),
which includes an electrical connection consisting of a cable plug, mating inlet fitting and conductor
termination
EXAMPLE Terms used include: AC shore power, shore power inlet, shore power cable, shore power connection or
shore appliance inlet.
Note 1 to entry: An "off-board power connection mode 1" is considered a those found in IEC 60309-2.
3.24
polarization transformer
transformer that automatically orientates the neutral and line conductor (3.28) in the system in the same
polarity orientation as the polarized system (3.40) of the craft (3.63)
ISO/DIS 13297-1:2026(en)
3.25
isolation transformer
transformer installed in the shore power (3.23) supply circuit on a craft (3.63) to electrically isolate all the
normally live conductors (3.29) and the protective conductor (3.27) on the craft (3.63) from the AC system
conductors of the shore power (3.23) supply
3.26
neutral conductor
conductor (3.33) intentionally maintained at earth (3.5) potential and capable of contributing to the
transmission of electrical energy
Note 1 to entry: IEV 195-02-06 states that a neutral conductor (3.26) is electrically connected to the neutral point and
capable of contributing to the distribution of electric energy which applies to AC 3-phase systems.
3.27
protective conductor
protective grounding conductor
conductor (3.33), not normally carrying current, used for some measure of protection against electric shock
(3.87), for electrically connecting any of the following parts of electrical equipment to the craft's ground/
earth and to the shore AC grounding conductor (3.33) through the shore power cable:
a) exposed conductive parts of electrical equipment;
b) extraneous conductive parts;
c) the main grounding point or Craft earth/ground;
d) earth electrode(s);
e) the earth point of a source, or an artificial neutral
EXAMPLE See protective bonding conductor (3.10) definition.
3.28
line conductor
conductor (3.33) intended to be energized and capable of contributing to the transmission or distribution of
electric energy but which is not a AC neutral conductor (3.26) or mid-point conductor (3.33), or a DC negative
ground conductor
EXAMPLE DC Chassis Two-Wire Negative Systems:
— L+ = Positive DC Line/Live Conductor (DC+, POS)
— L- = Negative DC Live Conductor (DC-, NEG)
DC Fully Chassis Isolated Two-Wire Isolated Systems:
— L+ = Positive DC Line/Live Conductor (DC+, POS)
— L- = Negative DC Line/Live Conductor (DC-, NEG)
AC Systems (TN-S)
— L1 = Active (Phase) AC Line/Live Conductor
— N = Neutral AC Live Conductor
— PE = Protective Earth Conductor
[SOURCE: IEV 195-02-08, modified - added example, added DC term to definition]
ISO/DIS 13297-1:2026(en)
3.29
live conductor
line conductor (3.28) or other conductor (3.33) which is energized in normal use, including an AC neutral
conductor (3.26) or DC negative conductor (3.33) for both chassis (3.44) negative and isolated DC systems
3.30
live
qualifies a conductive part intended to be energized in normal operation
Note 1 to entry: A live part may be temporarily dead when it is not energized. A neutral conductor (3.26) is considered
as live (3.30) but earthing (3.6) conductors are not.
[SOURCE: IEV: 151-15-60]
3.31
wire
flexible cylindrical conductor (3.33) the length, with or without an insulating covering, the length of which is
large with respect to its cross-sectional dimensions
EXAMPLE Used in craft (3.63) to define DC system types and cross-sectional dimensions of conductors.
Note 1 to entry: The cross-section of a wire (3.31) may have any shape, but the term "wire" is not generally used for
ribbons or tapes.
[SOURCE: IEV 151-12-28, clarifying example]
3.32
cable
assembly of one or more conductors and/or optical fibres, with a protective covering and possibly filling,
insulating and protective material
[SOURCE: IEV 151-13-38]
3.33
conductor
conductive part intended to carry electric current
EXAMPLE 1 Craft conductors without an insulating covering include: busbars, engine blocks, power posts and
terminals.
EXAMPLE 2 Craft conductors with an insulating covering include: battery cables, stranded copper conductors,
bonding conductors, and protective conductors.
Note 1 to entry: [SOURCE: IEV 151-12-05, element intended to carry electric current, Note 1 – The term "conductor
(3.33)" is often used for an element the length of which is large with respect to the cross-sectional dimensions, e.g.
conductors of a line or of a cable (3.32).]
[SOURCE: IEV 195-01-07]
3.34
plain conductor
metal cable (3.32)conductor (3.33) in which the wire (3.31) or wires are not coated with an additional metal
[SOURCE: IEV 461-01-02]
3.35
tinned conductor
metal-coated conductor (3.33) in which the metal coating is of tin
[SOURCE: IEV 461-01-04]
ISO/DIS 13297-1:2026(en)
3.36
stranded conductor
conductor (3.33) consisting of a number of individual wires or strands all or some of which generally have a
helical form
EXAMPLE Bunched conductor or multiple-stranded conductor
[SOURCE: IEV 461-01-07]
3.37
solid conductor
conductor (3.33) consisting of a single wire (3.31)
Note 1 to entry: The solid conductor (3.37) may be circular or shaped.
[SOURCE: IEV 461-01-06]
3.38
ignition-protected
equipment designed and constructed to give protection against ignition of surrounding flammable gases
[5]
[SOURCE: The protection against ignition of surrounding flammable gases is covered in ISO 8846 ]
3.39
panelboard
switchboard
assembly of devices for the purpose of controlling and/or distributing electrical power
Note 1 to entry: It can include devices such as circuit breakers, fuses, switches, instruments, and indicators.
3.40
polarized system
system where the nominal system voltage (3.82) is between the line conductor (3.28) and neutral conductor
(3.26), and the live conductors (3.29) (line and neutral) are connected in the same relation to all terminals on
devices or receptacles (socket outlets) in a circuit
3.41
unpolarized system
system where the nominal system voltage (3.82) is between the line conductors, and all live conductor (3.29)
are line conductors with no neutral conductor (3.26)
3.42
chassis negative two-wire DC system
two-wire DC system with negative ground
system in which the DC negative live conductor (3.29) has continuity to the chassis (3.44)
Note 1 to entry: In addition to continuity the chassis (3.44) maybe a conductor (3.33) within the DC system e.g. Engine
block.
Note 2 to entry: The chassis (3.44) may establish an effective or accidental conducting connection with the earth (3.5).
The equipotential difference between the water and the chassis (3.44) is incidental and does not affect functionality of
fault current paths.
3.43
fully chassis isolated two-wire DC system
DC IT wired system
fully insulated two-wire DC system
system in which DC positive and negative line conductors are intentionally isolated from the chassis (3.44)
Note 1 to entry: Systems utilizing a momentary chassis (3.44) negative connection for engine starting and stopping
purposes, which returns to an isolated state are considered fully isolated two-wire DC systems.
Note 2 to entry: DC live conductor (3.29) include both the positive and negative poles of a two-wire DC system.
ISO/DIS 13297-1:2026(en)
Note 3 to entry: Isolated systems are not connected to the water through a metallic hull (3.101), the propulsion system
or earthed through the craft earth (3.1) or AC protective conductor (3.27).
3.44
chassis
mechanical structure designed to support associated electric and electronic components
EXAMPLE 1 In many cases, the chassis (3.44) is made of conductive material and has also an electric function, e.g.
Craft earth.
EXAMPLE 2 Consisting of the conductive engine block, conductive drive train and DC main negative bus (3.16)
which are conductors.
Note 1 to entry: The chassis (3.44) may establish an effective or accidental conducting connection with the earth (3.5).
The equipotential difference between the water and the chassis (3.44) is incidental and does not affect functionality of
fault current paths.
[SOURCE: IEV 151-13-06, added marine detail to example 1, added marine example 2 and note 1]
3.45
self-limiting
device whose maximum output is restricted to a specified value by its magnetic or electrical characteristics
3.46
fuse
device that by the fusing of one or more of its specially designed and proportioned components, opens the
circuit in which it is inserted by breaking the current when this exceeds a given value for a sufficient time.
The fuse comprises all the parts that form the complete device
Note 1 to entry: A trip-free (3.47)overcurrent protection device (3.50) that interrupts the circuit irreversibly.
[SOURCE: IEV 441-18-01, added note to entry]
3.47
trip-free
which is designed so that the resetting means cannot be manually held in place to override the current-
interrupting mechanism
[SOURCE: IEV 442-01-45, modified definition of trip-free mechanism "a mechanism designed so that
disconnection can neither be prevented nor inhibited by a reset mechanism, and so that the contacts
can neither be prevented from opening nor be maintained closed against a continuation of the excess
temperature or current"]
3.48
circuit breaker
mechanical switching device capable of making, carrying and breaking currents under normal circuit
conditions and also making, carrying for a specified time and breaking currents under specified abnormal
circuit conditions such as those of overload (3.54) or short circuit, and which is trip-free (3.47)
EXAMPLE A circuit breaker (3.48) contains the function of a fuse (3.46).
[SOURCE: IEV 441-14-20, added "overload" and "and which is trip-free".]
3.49
power distribution assembly
factory-built assembly (3.98) module in a digital control and monitoring system, connected to a network cable
(3.32), with channels for transferring data, for controlling, switching and/or distributing electrical power
Note 1 to entry: Power Distribution Assemblies may include devices such as solid state overcurrent protection devices,
circuit breakers, fuses and LED indicators.
Note 2 to entry: Power Distribution Assemblies are often associated with a touchscreen user interface, which may be a
multifunction display (MFD), and which is connected via the communications network.
ISO/DIS 13297-1:2026(en)
3.50
overcurrent protection device
device intended to interrupt an electrical circuit when the conductor (3.33) current exceeds a predetermined
value for a specified duration which is trip-free (3.47)
EXAMPLE A fuse (3.46) or circuit breaker (3.48) or solid state device.
[SOURCE: IEV 826-14-14, added example]
3.51
double-pole device
de
...