EN ISO 16315:2016

SLOVENSKI STANDARD
01-junij-2016
0DODSORYLOD(OHNWULþQLSRJRQVNLVLVWHPL,62
Small craft - Electric propulsion system (ISO 16315:2016)
Kleine Wasserfahrzeuge - Elektrische Antriebssysteme (ISO 16315:2016)
Petits navires - Système de propulsion électrique (ISO 16315:2016)
Ta slovenski standard je istoveten z: EN ISO 16315:2016
ICS:
47.020.60 (OHNWULþQDRSUHPDODGLMLQ Electrical equipment of ships
NRQVWUXNFLMQDPRUMX and of marine structures
47.080 ýROQL Small craft
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 16315
EUROPEAN STANDARD
NORME EUROPÉENNE
April 2016
EUROPÄISCHE NORM
ICS 47.080
English Version
Small craft - Electric propulsion system (ISO 16315:2016)
Petits navires - Système de propulsion électrique (ISO Kleine Wasserfahrzeuge - Elektrische Antriebssysteme
16315:2016) (ISO 16315:2016)
This European Standard was approved by CEN on 20 February 2016.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2016 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 16315:2016 E
worldwide for CEN national Members.

Contents Page
European foreword . 3
Annex ZA (informative) Relationship between this European Standard and the Essential
Requirements of Directive 2013/53/EU . 4
European foreword
This document (EN ISO 16315:2016) has been prepared by Technical Committee ISO/TC 188 "Small
craft"
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by October 2016, and conflicting national standards shall
be withdrawn at the latest by October 2016.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent
rights.
This document has been prepared under a mandate given to CEN by the European Commission and the
European Free Trade Association, and supports essential requirements of EU Directive(s).
For relationship with EU Directive(s), see informative Annex ZA, which is an integral part of this
document.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,
Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,
Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.
Endorsement notice
The text of ISO 16315:2016 has been approved by CEN as EN ISO 16315:2016 without any modification.
Annex ZA
(informative)
Relationship between this European Standard and the Essential
Requirements of Directive 2013/53/EU
This European Standard has been prepared under a mandate given to CEN by the European
Commission to provide one means of conforming to Essential Requirements of the New Approach
Directive 2013/53/EU.
Once this standard is cited in the Official Journal of the European Union under that Directive and has
been implemented as a national standard in at least one member state, compliance with the normative
clauses of this standard given in Table ZA.1 confers, within the limits of the scope of this standard, a
presumption of conformity with the relevant Essential Requirements of that Directive and associated
EFTA regulations.
Table ZA.1 — Correspondence between this European Standard and EU Directives
Clauses/sub-clauses of this Corresponding annexes/ Comments
European Standard paragraphs of Directive
2013/53/EU
Annex 1, Clause 5.3 – Electrical
System
2, 4, 5, 8, 9, 10 Electrical systems shall be designed The normative references in
and installed so as to ensure proper Clause 2 of this standard are
operation of the watercraft under indispensable for its
normal conditions of use application
4.1, 4.13, 6, 8.5, 8.6 Electrical systems shall be designed
and installed so as to minimise risk of
fire and electric shock
4, 7 All electrical circuits, except engine
starting circuits supplied from
batteries, shall remain safe when
exposed to overload
4, 9, 10 Electric propulsion circuits shall not
interact with other circuits in such a
way that either would fail to operate
as intended
4.1, 8.5, Annex B(a) Ventilation shall be provided to
prevent the accumulation of
explosive gases which might be
emitted from batteries
8.1 Batteries shall be firmly secured and
protected from ingress of water
4.14, 5, Annex A Annex I, Clause 2.5 – Owner’s Clause 4.14, Figure 1 gives
Manual enclosure hazard markings
Clause 5 provides information
on system alerts and alarms to
be included in the owner’s
manual
Annex A provides information
necessary for safe use of the
product drawing particular
attention to set up,
maintenance, regular
operation, the prevention of
risks and risk management
WARNING — Other requirements and other EU Directives may be applicable to the product(s) falling
within the scope of this standard.

INTERNATIONAL ISO
STANDARD 16315
First edition
2016-03-15
Small craft — Electric propulsion
system
Petits navires — Système de propulsion électrique
Reference number
ISO 16315:2016(E)
©
ISO 2016
ISO 16315:2016(E)
© ISO 2016, Published in Switzerland
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
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Tel. +41 22 749 01 11
Fax +41 22 749 09 47
copyright@iso.org
www.iso.org
ii © ISO 2016 – All rights reserved

ISO 16315:2016(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 General requirements . 5
4.1 General . 5
4.2 Components of an electric propulsion system . 6
4.3 Electric propulsion systems. 6
4.4 Arrangements for other electrical equipment and circuits on-board a small
craft connected to a common energy source for both propulsion and general
electrical installation . 8
4.4.1 DC systems . 8
4.4.2 AC systems. 8
4.5 Environmental factors . 9
4.6 Electrical ratings . 9
4.7 Equipment .10
4.7.1 Transformers .10
4.7.2 Converters .10
4.7.3 Motors .10
4.8 Enclosures .10
4.9 Identification of equipment and conductors .10
4.10 Segregation of DC and AC systems .11
4.11 Steering and throttle controls .11
4.12 Electromagnetic compatibility (EMC).11
4.13 Electrical equipment in the vicinity of battery banks .11
4.14 Hazardous areas .11
5 Controls, monitoring, system alerts and trips alarms .12
5.1 Electrical/electronic controls for electric propulsion systems .12
5.1.1 Controls .12
5.1.2 Emergency stop .13
5.1.3 Fault trip reset.13
5.1.4 “Get you home” mode .13
5.2 Instruments, alerts and trip alarms .13
5.2.1 General.13
5.2.2 Operating mode and status .13
5.2.3 System alerts .14
5.2.4 Fault trip alarms .14
6 Protection against electric shock .14
6.1 Protection against direct contact .14
6.2 Automatic disconnection of supply to the electric propulsion system under fault-
to-earth conditions (earthed two wire DC systems and earthed neutral AC systems) .14
6.3 Fault-to-earth monitoring and tripping arrangements for DC fully insulated
systems, DC 3-wire systems .15
6.4 Fault-to-earth tripping in AC non-neutral earthed systems (IT-type system) .16
7 Protection against over-current .16
7.1 General .16
7.2 Characteristics of protective devices .16
7.3 Overcurrent devices in the outgoing circuit(s) from a battery .17
8 Battery monitoring and installation .17
8.1 General arrangements .17
ISO 16315:2016(E)
8.2 Isolation of battery packs or battery banks .17
8.3 Operational switching of battery pack(s) or battery bank(s) .18
8.4 Permanently energized circuits .18
8.5 Ventilation .19
8.6 Electrical apparatus for explosive gas atmospheres .19
9 Electrical installation .19
9.1 General .19
9.2 Segregation of electrical propulsion system cables .19
10 Testing .20
10.1 General .20
10.2 Earthing and bonding.20
10.3 Insulation resistance .20
10.3.1 General.20
10.3.2 DC electrical propulsion systems .20
10.3.3 AC electrical propulsion systems .20
10.3.4 Switchboards, panel boards and distribution boards .20
10.3.5 Power and lighting final circuits.21
10.3.6 Generators and motors.21
10.3.7 Transformers .21
10.4 Electrical/electronic controls systems for propulsion motor control .21
10.5 On load test and inspection of electrical propulsion systems, and associated switch
gear and control gear .21
10.6 Voltage drop .21
Annex A (normative) Information and instructions to be included in the owner’s manual .22
Annex B (normative) Installation documentation .23
Bibliography .24
iv © ISO 2016 – All rights reserved

ISO 16315:2016(E)
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 on the meaning of ISO specific terms and expressions related to conformity
assessment, as well as information about ISO’s adherence to the WTO principles in the Technical
Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information
The committee responsible for this document is ISO/TC 188, Small craft, together with CEN/BT/WG 69,
Small craft and IEC/TC 18, Electrical installations of ships and of mobile and fixed offshore units.
ISO 16315:2016(E)
Introduction
Electrical propulsion systems are becoming more common in recreational craft and other small craft
and propulsion system voltages of up to AC 1 000 V and DC 1 500 V are possible together with variable
speed drives operating at frequencies which differ from 50/60 Hz or DC.
Electric propulsion systems for small craft are generally designed and constructed from a number of
component parts many of which can be of proprietary origin and all of the electrical and control items
are interconnected by cables and operated as a system.
There are a significant number of electrical propulsion system architectures for small craft and the
main types are the following.
— DC sourced. The main power source is a propulsion battery which is either recharged from on-
board DC generators, or on-board AC generators/an AC shore supply through battery chargers. The
electric propulsion system(s) may be variable speed through a DC motor controller or AC through a
Variable Frequency Drive (VFD) or be fixed speed with a variable pitch propeller or other mechanical
means of providing thrust. The electric propulsion system may be electrically separate from other
electrical systems on board (e.g. be fully insulated via the motor controller, or be an AC IT system via
a VFD or motor starter). Or the electrical propulsion system may be integrated with the whole craft
DC electrical system using converters DC/DC, DC/AC to provide for different services/consumers.
— AC sourced. The main power source is AC generator(s) generally configured as TT, TN-C or TN-S.
The electric propulsion system(s) may be DC variable speed through a AC/DC converter and DC
motor controller, or AC through a VFD, or be fixed speed with a variable pitch propeller or other
mechanical means of providing thrust. The electric propulsion system may be DC fully insulated
system or be an AC IT system via a galvanically isolated VFD or via an isolating transformer. A DC
propulsion system(s) may be supported by propulsion battery.
— Also possible are hybrid systems similar to the types being introduced for road vehicles where the
source is an internal combustion engine providing, for example, energy to a relatively lightweight
energy storage system with power take-off via converters to propulsion motor(s) and other electrical
consumers.
It is essential that the electric propulsion system designer/installer be competent with all aspects
of the equipment included in the design of a particular system such that the component parts of the
propulsion system are integrated in a coherent and safe manner.
Current electrical standards for small craft of less than 24 m LH are the following:
a) ISO 10133 which is limited to recommendation for the design, construction and installation of
direct current systems that operate at a voltage of DC 50 V or less; and
b) ISO 13297 which is limited to single phase alternating current electrical systems less than AC 250 V.
Neither of these standards includes requirements for electrical propulsion systems.
c) IEC 60092-507 is applicable to small craft up to 50 m/500 GT and includes requirements for three-
phase systems not exceeding AC 500 V and single-phase systems not exceeding AC 250 V and for
DC systems and sub-systems not exceeding DC 50 V nominal, and includes a section on electric
propulsion systems.
vi © ISO 2016 – All rights reserved

INTERNATIONAL STANDARD ISO 16315:2016(E)
Small craft — Electric propulsion system
1 Scope
This International Standard addresses the design and installation of alternating current (AC) and direct
current (DC) electrical systems used for the purpose of electrical propulsion and/or electrical hybrid
(system with both a rechargeable battery and a fuelled power source) propulsion.
This International Standard applies to electrical propulsion systems operated in the following ranges
either individually or in combination:
— direct current of less than 1 500 V DC;
— single-phase alternating current up to AC 1 000 V;
— three-phase alternating current up to AC 1 000 V.
This International Standard applies to electrical propulsion systems installed in small craft up to 24 m
length of the hull (L according to ISO 8666).
H
This International Standard also lists in Annex A additional information to be included in the owner’s
manual as well as Annex B additional information to be provided to the installer.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 8846, Small craft — Electrical devices — Protection against ignition of surrounding flammable gases
ISO 9094, Small craft — Fire protection
ISO 10133:2012, Small craft — Electrical systems — Extra-low-voltage d.c. installations
ISO 10239, Small craft — Liquefied petroleum gas (LPG) systems
ISO 10240, Small craft — Owner’s manual
ISO 11105, Small craft — Ventilation of petrol engine and/or petrol tank compartments
ISO 13297:2014, Small craft — Electrical systems — Alternating current installations
ISO 25197:2012, Small craft — Electrical/electronic control systems for steering, shift and throttle
IEC 60079-series, Electrical apparatus for explosive gas atmospheres
IEC 60092-202:1994/Amd 1:1996, Electrical installation in ships — Part 202: System design — Protection
IEC 60092-303, Electrical installation in ships — Part 303: Equipment — Transformers for power and
lighting
IEC 60092-352, Electrical installation in ships — Part 352: Choice and installation of electrical cables
IEC 60092-507:2014, Electrical installations in ships — Part 507: Small vessels
IEC 60898-1, Electrical accessories — Circuit-breakers for overcurrent protection for household and similar
installations — Part 1: Circuit-breakers for a.c. operation
ISO 16315:2016(E)
IEC 60945, Maritime navigation and radiocommunication equipment and systems — General requirements
— Methods of testing and required test results
IEC 60947-2, Low voltage switchgear and control gear — Part 2: Circuit breakers
IEC 61558-2-4, Safety of transformers, reactors, power supply units and similar products for supply voltages
up to 1100 V — Part 2-4: Particular requirements and tests for isolating transformers and power supply
units incorporating isolating transformers
IEC 61558-2-6, Safety of transformers, reactors, power supply units and similar products for supply voltages
up to 1 100 V — Part 2-6: Particular requirements and tests for safety isolating transformers and power
supply units incorporating safety isolating transformers
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
safety voltage
voltage which does not exceed AC 50 V r.m.s. between conductors, or between any conductor and
earth, in a circuit isolated from the supply by means such as a safety isolating transformer, or converter
with separate winding
voltage which does not exceed 50 DC V between conductors, or between any conductor and earth,
in a circuit which is isolated from higher voltage circuits
Note 1 to entry: Consideration should be given to the reduction of the limit of 50 V under certain conditions, such
as wet surroundings or exposure to heavy seas or where direct contact with live parts is involved.
Note 2 to entry: The voltage limit should not be exceeded either at full load or no load, but it is assumed, for the
purpose of this definition, that any transformer or converter is operated at its rated supply voltage.
[SOURCE: IEC 60092-101:1994, 1.3.19]
3.2
rated voltage
U
nominal AC r.m.s. line voltage to earth
nominal AC r.m.s. voltage between line conductor and neutral conductor
nominal DC voltage between poles
[SOURCE: IEC 60092-507:2014, 3.1.4]
3.3
live part
conductor or conductive part intended to be energized in normal operation including a neutral
conductor, but by convention not a PEN conductor (a conductor combining the functions of both a
protective conductor and a neutral conductor)
Note 1 to entry: This term does not necessarily imply risk of electric shock.
[SOURCE: IEC 60050-195:1998, 195-02-19, modified as follows: The text “or a PEM conductor or PEL
conductor” has been deleted. The text in brackets has been added]
2 © ISO 2016 – All rights reserved

ISO 16315:2016(E)
3.4
earthed
grounded, en US
connected to the general mass of the hull of the craft in such a manner as will ensure at all times an
immediate discharge of electrical energy without danger
[SOURCE: IEC 60092-101:1994, 1.3.9, modified as Note 1 to entry has been deleted]
3.5
readily accessible
capable of being reached quickly and safely for effective use without the use of tools
[SOURCE: ISO 13297:2014, 3.17]
3.6
final circuit
portion of a wiring system extending beyond the final overcurrent protection device for that circuit
[SOURCE: IEC 60092-101:1994, 1.3.17, modified – The words “overcurrent protective device of a board”
have been replaced with “overcurrent protection device for that circuit”]
3.7
overcurrent protection device
device provided to interrupt an electric circuit in case the conductor current in the electric circuit
exceeds a predetermined value for a specified duration
3.8
fuse
device that by the fusing of one or more of its specifically 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
Note 1 to entry: The fuse comprises all the parts that form the complete device.
[SOURCE: IEC 60050-441:1984, 441-18-01, modified]
3.9
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 a short circuit
[SOURCE: IEC 60050-441:1984, 441-14-20]
3.10
residual current device
RCD
mechanical switching device designed to make, carry and break currents under normal service
conditions and to cause the opening of the contacts when the residual current attains a given value
under specified conditions
[SOURCE: IEC 60050-442:1994, 442-05-02, modified as Note has been omitted]
3.11
protective conductor
PE (identification)
conductor provided for purposes of safety, for example, protection against electric shock
Note 1 to entry: In an electrical installation, the conductor identified PE is normally also considered as protective
earthing conductor.
[SOURCE: IEC 60050-195:1998, 195-02-09]
ISO 16315:2016(E)
3.12
bond
connection of non-current-carrying parts to ensure continuity of electrical connection, or to equalize
the potential between parts comprising, for example, the armour or lead sheath of adjacent length of
cable, the bulkhead, etc.
[SOURCE: IEC 60092-101:1994, 1.3.7, modified – Last part concerning “cables in a radio-receiving room”
has been deleted.]
3.13
conductor
conductive part intended to carry a specified electric current
[SOURCE: IEC 60050-195:1998, 195-01-07]
3.14
neutral conductor
conductor electrically connected to the neutral point and capable of contributing to the distribution of
electrical energy
[SOURCE: IEC 60050-195:1998, 195-02-06]
3.15
line conductor
phase conductor (in AC systems) (deprecated) pole conductor (in DC systems) (deprecated)
conductor which is energized in normal operation and capable of contributing to the transmission or
distribution of electric energy but which is not a neutral conductor
[SOURCE: IEC 60050-195:1998, 195-02-08]
3.16
transformer
energy converter with isolating separation between the input and output windings and the protective
conductor
3.17
switch
mechanical switching device capable of making, carrying and breaking currents under normal circuit
conditions which may include specified operating overload conditions and also carrying for a specified
time currents under specified abnormal circuit conditions such as those of short circuit
Note 1 to entry: A switch may be capable of making but not breaking short-circuit currents.
3.18
panel board
assembly of devices, such as circuit breakers, fuses, switches, instruments and indicators, for the
purpose of controlling and/or distributing electrical power
Note 1 to entry: Examples of devices include circuit breakers, fuses, switches, instruments and indicators.
3.19
disconnector
mechanical switching device which provides, in the open position, an isolating distance in accordance
with specified requirements
[SOURCE: IEC 60050-441:1994, 441-14-05]
4 © ISO 2016 – All rights reserved

ISO 16315:2016(E)
3.20
battery pack
mechanical assembly comprising battery cells and retaining frames or trays and possibly components
for battery management
Note 1 to entry: Note1 to entry: Typical battery packs will be a single assembly, voltage and connection in an
enclosure.
Note 2 to entry: Several connected battery packs form a battery bank.
[SOURCE: ISO 12405-2:2012, 3.2, modified by additional Note 1 and 2 to entry]
4 General requirements
4.1 General
Electric propulsion systems for small craft are generally designed and constructed from a number of
component parts many of which can be of proprietary origin and all of the electrical and control items
are interconnected by cables and operated as a system.
It is essential that the propulsion system designer/installer shall be competent with all aspects of the
equipment included in the design of a particular system such that the component parts of the propulsion
system are integrated in a coherent and safe manner.
The rated power output of each electric propulsion system at the motor shaft shall be designed to match
the propeller characteristics and the required rotational speed range or thrust range of variable pitch
propellers/thrusters.
The electric propulsion system may be electrically separate from other electrical systems on board a
small craft.
Different types of AC electrical system include four-wire with neutral earthed, but without hull return
(TN-C), five-wire with neutral earthed, but without hull return (TN-S), and IT systems with their
particular requirements for earth leakage current monitoring, alarm and tripping systems.
DC systems may be either earthed, or be fully insulated with particular requirements for insulation
resistance monitoring, alarm and tripping systems. For DC propulsion systems operating at voltages
greater than safety voltage, a three-wire system (e.g. DC +48 V/0/−48V) may be considered with the
mid-point conductor earthed to limit prospective touch voltage.
For DC electric propulsion systems and other electrical systems with rated nominal voltages in excess
of safety voltage, the precautions against the risk of electric shock shall be observed.
DC electric propulsion systems may have large capacity battery bank(s) or pack(s) as the main power
source, and particular attention is required for the following:
a) ventilation requirements necessary for battery bank or battery pack compartments;
b) requirements for an overcurrent device and an isolation switch for each propulsion battery bank or
battery pack;
c) circuit protection requirements for permanently energised circuits supplied from a battery bank
or battery pack.
Electric propulsion circuits shall be designed to protect against the following:
— fire by the use of overcurrent protection, grounding/earthing, terminal protection and conductor
type and size;
— shock by the use of enclosures, conductor and terminal insulation, automatic disconnection and
grounding/earthing system protection as appropriate.
ISO 16315:2016(E)
Electric propulsion circuits shall not interact with other circuits in such a way that circuits would fail to
operate as intended.
4.2 Components of an electric propulsion system
The electric propulsion system may include several sub-systems and components including, but not
limited to, the following:
— batteries;
— battery management systems;
— AC or DC generators;
— AC/DC, DC/DC, DC/AC, AC/AC converters, Variable Frequency Drives;
— electric propulsion motors;
— propulsion panel board;
— propulsion motor controls, monitoring, system alerts and trip alarms;
— transformers;
— conductors and cables;
— isolation switches (disconnectors), circuit breakers, contactors, fuses.
Each of these propulsion system components shall conform to the relevant ISO/IEC standard.
4.3 Electric propulsion systems
4.3.1 An electrical propulsion system may be
a) DC, sourced from battery(s) or DC generator(s) or AC/DC converters from an AC source, or
b) AC, sourced from alternator(s) or a DC/AC converter from a DC source [e.g. battery(s)].
The energy source(s) of an electric propulsion system may be reserved for this purpose and be
electrically separate from other electrical systems on board a craft, or all electrical systems on board
a craft may be directly connected to a common source but propulsion system(s) may have specific
requirements for electrical separation, earthing/bonding, conductor installation, etc. from the other
items of electrical equipment and circuits included in the overall design.
The rated voltage of an electric propulsion may be different from other electrical systems on-board a
craft and uses either AC or DC systems.
— For an AC propulsion system, it may be at variable frequency.
— For a DC propulsion system sourced from an AC system, the DC electrical propulsion system may
be obtained from an AC/DC converter with galvanic separation between input and output and
appropriate arrangements made at the output for fully insulated or negative earth propulsion
systems. Similarly, an earthed two wires propulsion system may be supplied from an insulated two
wires source via a DC/DC converter with galvanic separation and vice versa.
— For a DC propulsion system sourced from a DC system, the source shall have the same characteristics.
Systems may require attention to the treatment of the neutral earth, and also have specific
requirements in respect of earthing and bonding relative to the requirements of other electrical
systems on-board a craft.
6 © ISO 2016 – All rights reserved

ISO 16315:2016(E)
4.3.2 A DC electrical propulsion system may be configured as
a) fully insulated two-wire system (IT) or
b) two-wire system with negative earth/bonded (TN-S, TN-C, TN-C-S).
4.3.3 A single-phase AC electrical propulsion system may be configured as
a) single-phase two wire insulated (IT), or
b) single-phase two-wire with earthed neutral (TT or TN-C without hull return); or TT (when shore
connected), or
c) single-phase three-wire with mid-point earthed, both neutral and protective conductor (PE)
earthed at the energy source without hull return (TN-S).
4.3.4 A three-phase electrical propulsion system may be configured as
a) three-phase three-wire insulated (IT), or
b) three-phase four-wire with earthed neutral (TT or TN-C without hull return); or TT (when shore
connected), or
c) three-phase five-wire with mid-point earthed, both neutral and protective conductor (PE) earthed
at the energy source without hull return (TN-S).
If the AC propulsion system is required to be an IT from a TN source (or vice-versa), then an isolation
transformer conforming to IEC 61558-2-4 (U up to AC 1 100 V, maximum rated output 25 kVA for
single phase, 40 kVA for three-phase) may be used providing galvanic separation between primary and
secondary windings with appropriate arrangements
...