IEC 60092-503:2021

Electrical installations in ships - Part 503: Special features - AC supply systems with voltages in the range of above 1 kV up to and including 36 kV

IEC 60092-503:2021(E) is applicable to AC supply systems with voltages from 1 kV up to and including 36 kV. The requirements contained in other parts of the IEC 60092 series apply where appropriate, subject to the exceptions stated in the clauses of this document.

General Information

• Status: Published
• Publication Date: 26-Oct-2021
• ICS: 47.020.60 - Electrical equipment of ships and of marine structures
• Technical Committee: TC 18 - Electrical installations of ships and of mobile and fixed offshore units
• Drafting Committee: MT 6 - TC 18/MT 6
• Current Stage: PPUB - Publication issued
• Start Date: 27-Oct-2021
• Completion Date: 19-Nov-2021

Relations

• Revises: IEC 60092-503:2007 - Electrical installations in ships - Part 503: Special features - AC supply systems with voltages in the range of above 1 kV up to and including 15 kV
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60092-503 ®
Edition 3.0 2021-10
INTERNATIONAL
STANDARD
Electrical installations in ships –
Part 503: Special features – AC supply systems with voltages in the range of
above 1 kV up to and including 36 kV
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IEC 60092-503 ®
Edition 3.0 2021-10
INTERNATIONAL
STANDARD
Electrical installations in ships –

Part 503: Special features – AC supply systems with voltages in the range of

above 1 kV up to and including 36 kV

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 47.020.60 ISBN 978-2-8322-1039-2

– 2 – IEC 60092-503:2021 © IEC 2021
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms and definitions . 8
4 General requirements . 9
4.1 Environmental conditions . 9
4.2 System design . 9
4.3 Personnel safety . 9
4.4 Operational safety . 9
4.5 Integrity of external power supply. 9
4.6 Electrical and mechanical interlockings . 10
4.7 Selection criteria for distribution systems . 10
4.8 Distribution systems network earthing . 10
4.9 Divided system . 11
5 Insulation . 11
5.1 Selection of insulation level. 11
5.1.1 General . 11
5.1.2 Lightning impulse withstand voltage . 11
5.1.3 Consideration of rated withstand voltages . 11
5.2 Verification of clearance and creepage distances . 11
5.2.1 Clearance distance . 11
5.2.2 Creepage distance . 12
5.3 Voltage and frequency . 12
6 Electrical protection . 13
6.1 General . 13
6.2 Voltage-transformer protection . 13
6.3 Overvoltage protection . 13
6.4 Earth-fault monitoring . 14
7 High voltage equipment . 14
7.1 General . 14
7.1.1 Ingress protection . 14
7.1.2 Earthing of current and voltage transformers . 14
7.1.3 Safe earthing measures . 14
7.1.4 Accumulation of moisture and condensation . 15
7.1.5 Liquid cooling . 15
7.1.6 Terminals . 15
7.2 Switchgear and controlgear assemblies . 15
7.2.1 Design and construction . 15
7.2.2 Handrails . 16
7.2.3 Door opening . 16
7.2.4 Encapsulation . 16
7.2.5 Internal arc classification . 16
7.2.6 Continuous (common) busbar compartment . 16
7.2.7 Busbars of main switchboards . 17
7.2.8 Generator circuits . 17

7.2.9 Outgoing circuits . 17
7.2.10 Power-transformer circuits . 17
7.2.11 Shore-connection circuits . 17
7.2.12 Earthing switches . 17
7.2.13 Earthing of equipment . 18
7.2.14 Auxiliary circuits . 18
7.3 Generators and motors . 18
7.3.1 General . 18
7.3.2 Installation . 18
7.3.3 Encapsulation . 18
7.3.4 Temperature monitoring . 18
7.3.5 Stator winding circuit arrangement . 18
7.3.6 De-excitation . 18
7.4 Transformers and reactors . 19
7.4.1 General . 19
7.4.2 Enclosures and installation . 19
7.4.3 Encapsulation . 19
7.4.4 Temperature monitoring . 19
7.5 Converters . 19
7.5.1 General . 19
7.5.2 Encapsulation . 19
7.6 Cables . 20
7.6.1 General . 20
7.6.2 Installation . 20
7.6.3 Conductors and terminations . 20
7.6.4 Testing . 20
7.7 System test . 21
8 Installation requirements for high voltage equipment . 21
8.1 Access . 21
8.2 Identification and marking . 21
8.2.1 General . 21
8.2.2 Labelling . 21
8.2.3 Information plates and warning plates . 22
8.2.4 Installations with incorporated capacitors. 22
Bibliography . 23

Table 1 – Minimum clearance . 12
Table 2 – AC three-phase systems having a nominal voltage above 1 kV and up to
and including 36 kV . 13
Table 3 – Minimum IP ratings . 14

– 4 – IEC 60092-503:2021 © IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL INSTALLATIONS IN SHIPS –

Part 503: Special features –
AC supply systems with voltages in the range
of above 1 kV up to and including 36 kV

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
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9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
IEC 60092-503 has been prepared by IEC technical committee 18: Electrical installations of
ships and of mobile and fixed offshore units. It is an International Standard.
This third edition cancels and replaces the second edition published in 2007. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) modified the scope, increasing the voltage from 15 kV to 36 kV;
b) reference to IEC 61936-1 added:
c) included relevant parts of the IEC 62271 series;
d) removed low-impedance earthed neutral systems;
e) updated 7.7 on system test;

f) added requirements for switchgear and switchboards.
The text of this International Standard is based on the following documents:
Draft Report on voting
18/1734/FDIS 18/1742/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
A list of all parts in the IEC 60092 series, published under the general title Electrical installations
in ships, can be found on the IEC website.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – IEC 60092-503:2021 © IEC 2021
INTRODUCTION
IEC 60092 (all parts) forms a series of International Standards for electrical installations in sea-
going ships, incorporating good practice and coordinating, as far as possible, existing rules.
These standards form a code of practical interpretation and amplification of the requirements
of the International Convention on Safety of Life at Sea, a guide for future regulations which
may be prepared and a statement of practice for use by shipowners, shipbuilders and
appropriate organizations.
ELECTRICAL INSTALLATIONS IN SHIPS –

Part 503: Special features –
AC supply systems with voltages in the range
of above 1 kV up to and including 36 kV

1 Scope
This part of IEC 60092 is applicable to AC supply systems with voltages from 1 kV up to and
including 36 kV. The requirements contained in other parts of the IEC 60092 series apply where
appropriate, subject to the exceptions stated in the clauses of this document.
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.
IEC 60034 (all parts), Rotating electrical machines
IEC 60038, IEC standard voltages
IEC 60060-1, High-voltage test techniques – Part 1: General definitions and test requirements
IEC 60071-1, Insulation co-ordination – Part 1: Definitions, principles and rules
IEC 60076 (all parts), Power transformers
IEC 60092-101, Electrical installations in ships – Part 101: Definitions and general requirements
IEC 60092-201, Electrical installations in ships – Part 201: System design – General
IEC 60092-202, Electrical installations in ships – Part 202: System design – Protection
IEC 60092-303, Electrical installations in ships – Part 303: Equipment – Transformers for power
and lighting
IEC 60092-304, Electrical installations in ships – Part 304: Equipment – Semiconductor
convertors
IEC 60092-350, Electrical installations in ships – Part 350: General construction and test
methods of power, control and instrumentation cables for shipboard and offshore applications
IEC 60092-353, Electrical installations in ships – Part 353: Power cables for rated voltages 1 kV
and 3 kV
IEC 60092-354, Electrical installations in ships – Part 354: Single- and three-core power cables
with extruded solid insulation for rated voltages 6 kV (U = 7,2 kV) up to 30 kV (U = 36 kV)
m m
IEC 60282-1, High-voltage fuses – Part 1: Current-limiting fuses

– 8 – IEC 60092-503:2021 © IEC 2021
IEC 60282-2, High-voltage fuses – Part 2: Expulsion fuses
IEC 60502 (all parts), Power cables with extruded insulation and their accessories for rated
voltages from 1 kV (U = 1,2 kV) up to 30 kV (U = 36 kV)
m m
IEC 60502-1, Power cables with extruded insulation and their accessories for rated voltages
from 1 kV (U = 1,2 kV) up to 30 kV (U = 36 kV) – Part 1: Cables for rated voltages of 1 kV
m m
(U = 1,2 kV) up to 3 kV (U = 3,6 kV)
m m
IEC 60502-2, Power cables with extruded insulation and their accessories for rated voltages
from 1 kV (U = 1,2 kV) up to 30 kV (U = 36 kV) – Part 2: Cables for rated voltages from
m m
6 kV (U = 7,2 kV) up to 30 kV (U = 36 kV)
m m
IEC TS 60815-1, Selection and dimensioning of high-voltage insulators intended for use in
polluted conditions – Part 1: Definitions, information and general principles
IEC TS 60815-2, Selection and dimensioning of high-voltage insulators intended for use in
polluted conditions – Part 2: Ceramic and glass insulators for a.c. systems
IEC TS 60815-3, Selection and dimensioning of high-voltage insulators intended for use in
polluted conditions – Part 3: Polymer insulators for a.c. systems
IEC 62271-100, High-voltage switchgear and controlgear – Part 100: Alternating-current circuit-
breakers
IEC 62271-102, High-voltage switchgear and controlgear – Part 102: Alternating current
disconnectors and earthing switches
IEC 62271-106, High-voltage switchgear and controlgear – Part 106: Alternating current
contactors, contactor-based controllers and motor-starters
IEC 62271-200:2021, High-voltage switchgear and controlgear – Part 200: AC metal-enclosed
switchgear and controlgear for rated voltages above 1 kV and up to and including 52 kV
IEC 62271-201, High-voltage switchgear and controlgear – Part 201: AC solid-insulation
enclosed switchgear and controlgear for rated voltages above 1 kV and up to and including
52 kV
IEC/IEEE 80005-1, Utility connections in port – Part 1: High voltage shore connection (HVSC)
systems – 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:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1
high-impedance earthed neutral
IT system where the neutral is earthed through an impedance with numerical value equal to, or
higher than, the capacitive reactance between phase and earth

3.2
category A machinery space
spaces and trunks which contain:
1) internal combustion machinery used for main propulsion; or
2) internal combustion machinery used for purposes other than main propulsion where such
machinery with an accumulated total power output of not less than 375 kW; or
3) any oil-fired boiler or oil fuel unit.
[SOURCE: SOLAS, Chapter II-1, Part A, regulation 3.17]
3.3
main circuit
all the conductive parts of an assembly included in a circuit which is intended to transmit
electrical energy
[SOURCE: IEC 60050-441:1984, 441-13-02]
4 General requirements
4.1 Environmental conditions
Environmental conditions shall be in accordance with relevant requirements of IEC 60092-101.
4.2 System design
System design shall be in accordance with relevant requirements of IEC 60092-201.
4.3 Personnel safety
Particular attention shall be given to the safety of personnel during the installation, operation
and maintenance of equipment. This shall include
– manuals and instructions for transport, storage, installation, operation and maintenance,
– special tools required for operation, maintenance and testing,
– safe working procedures developed for specific locations, and
– safe earthing measures.
High voltage equipment shall be designed to limit the risk of arcing faults and contain possible
arcing faults in such a way that the risk for operators is reduced to a level acceptable to the
appropriate authority during internal fault conditions.
4.4 Operational safety
Control and protection systems shall take into account that continuous power supply is essential
to ship’s safety. The design shall be such that unnecessary tripping or de-energisation is
avoided.
4.5 Integrity of external power supply
If the power supply is divided into more than one switchboard, in order to provide power supply
availability in case of a single point failure (typically under fire condition), it shall be designed
and protected such that any single point failure does not jeopardize overall functionality of the
other switchboards.
– 10 – IEC 60092-503:2021 © IEC 2021
4.6 Electrical and mechanical interlockings
Interlocks between different components of the equipment are provided for reasons of safety
and for convenience of operations. The following provisions are mandatory for main circuits.
Apparatus installed in main circuits, the incorrect operation of which can cause damage, or
which are used for assuring isolating distances during maintenance work, shall be provided with
locking facilities (for example provision for padlocks).
Access to operation of a circuit-breaker, switch or contactor in the switchboard shall be limited
by a "safety system" which co-ordinates other apparatus involved such as motors, transformers,
generators, switchboards, etc. Back-feeding through transformers and shut off of starting air
and oil to engines shall be taken into consideration.
Earthing switches having a short-circuit making capacity less than the rated peak withstand
current of the circuit shall be interlocked with the associated disconnectors.
NOTE According to 7.2.1, the requirements of IEC 62271-200 are applicable. See IEC 62271-200:2021, 6.12 a), for
removable parts of assemblies, and IEC 62271-200:2021, 6.12 b), for other parts of assemblies.
4.7 Selection criteria for distribution systems
The neutral earthing method shall be carefully selected, considering the following:
– selection of insulation level;
– characteristics of overvoltage – limiting devices – such as spark gaps or surge arresters;
– selection of protective relays;
– design of earthing system.
NOTE 1 The method of neutral earthing strongly influences the fault current level and the fault current duration.
NOTE 2 The choice of the type of neutral earthing is normally based on the following criteria:
– continuity of supply required for the network;
– limitation of damage to equipment caused by earth faults;
– selective elimination of faulty sections of the network;
– detection of fault location;
– touch and step voltages;
– operation and maintenance aspects.
A
...