IEC 60092-302-2:2019

Electrical installations in ships - Part 302-2: Low voltage switchgear and controlgear assemblies - Marine power

IEC 60092-302-2:2019 defines the specific requirements of low voltage marine power switchgear and controlgear assemblies (MPSC-assemblies) as follows:
- stationary assemblies with enclosure for which the rated voltage does not exceed 1 000 V AC or 1500 V DC;
- assemblies intended for use in conjunction with the power generation, distribution and conversion of electric energy, and for the control of electric energy consuming equipment.
This document applies to all assemblies whether they are designed, manufactured and verified on a one-off basis or fully standardised and manufactured in quantity.
The manufacture and/or assembly can be carried out other than by the original manufacturer.
This document does not apply to individual devices and self-contained components, such as motor starters, fuse switches, electronic equipment, which comply with the relevant product standards.
This first edition cancels and replaces the fourth edition of IEC 60092-302 published in 1997. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous edition:
a) this document has been renumbered to fall in line with IEC 61439 (all parts);
b) this document has been restructured to fall in line with IEC 61439 (all parts);
c) the creepage distances have been modified;
d) the references to non type tested assemblies (NTTA) have been removed;
e) non-applicable tables have been removed;
f) the applicability of IEC 61439 (all parts) annexes have been identified.
g) specific requirements that were detailed in IEC 60092-302:1997, covered under 7.6.101 have partly been moved to 60092-201.

General Information

• Status: Published
• Publication Date: 15-Sep-2019
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• 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: 16-Sep-2019
• Completion Date: 19-Apr-2019

Relations

• Replaces: IEC 60092-302:1997 - Electrical installations in ships - Part 302: Low-voltage switchgear and controlgear assemblies
• Effective Date: 05-Sep-2023
• Revised: IEC 60092-302-2:2025 - Electrical installations in ships - Part 302-2: Low voltage switchgear and controlgear assemblies - Marine power
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 60092-302-2 ®
Edition 1.0 2019-09
INTERNATIONAL
STANDARD
Electrical installations in ships –
Part 302-2: Low voltage switchgear and controlgear assemblies – Marine power

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IEC 60092-302-2 ®
Edition 1.0 2019-09
INTERNATIONAL
STANDARD
Electrical installations in ships –

Part 302-2: Low voltage switchgear and controlgear assemblies – Marine power

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 47.020.60 ISBN 978-2-8322-6662-5

– 2 – IEC 60092-302-2:2019 © IEC 2019
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Symbols and abbreviations . 7
5 Interface characteristics. 7
6 Information . 8
7 Service conditions . 9
8 Constructional requirements . 9
9 Performance requirements. 12
10 Design verification . 13
11 Routine verification . 15
Annex AAA (informative) Items subject to agreement between the assembly
manufacturer and the user . 19
Bibliography . 24

Figure 201 – Relationship of standards . 5

Table 1 – Minimum clearances in air (8.3.2) . 15
Table 2 – Minimum creepage distances (8.3.3) . 16
Table 6 – Temperature rise limits (9.2). 17
Table AAA.1 – Items subject to agreement between the assembly manufacturer and
the user . 19

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRICAL INSTALLATIONS IN SHIPS –

Part 302-2: Low voltage switchgear and
controlgear assemblies – Marine power

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 co-operation on all questions concerning standardization in the electrical and electronic fields. To
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
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.
International Standard IEC 60092-302-2 has been prepared by IEC technical committee 18:
Electrical installations of ships and of mobile and fixed offshore units.
This first edition cancels and replaces the fourth edition of IEC 60092-302 published in 1997.
This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) this document has been renumbered to fall in line with IEC 61439 (all parts);
b) this document has been restructured to fall in line with IEC 61439 (all parts);
c) the creepage distances have been modified;
d) the references to non type tested assemblies (NTTA) have been removed;
e) non-applicable tables have been removed;

– 4 – IEC 60092-302-2:2019 © IEC 2019
f) the applicability of IEC 61439 (all parts) annexes have been identified.
g) specific requirements that were detailed in IEC 60092-302:1997, covered under 7.6.101
have partly been moved to 60092-201.
The text of this document is based on the following documents:
FDIS Report on voting
18/1656/FDIS 18/1668/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
This International Standard is to be used in conjunction with IEC 61439-1:2011 and
IEC 61439-2:2011.
This document supplements or modifies the corresponding clauses in IEC 61439-1:2011 and
IEC 61439-2:2011. Where this document states "addition", "deletion" or "replacement", the
relevant text of IEC 61439-1:2011 and IEC 61439-2:2011 is adapted accordingly.
Clauses and subclauses which are additional to those of IEC 61439-1:2011 and
IEC 61439-2:2011 are numbered starting from 201. Additional annexes are numbered starting
from AAA.
In this document, terms written in small capitals are defined in Clause 3.
Where the abbreviated term PSC-assembly is used in applicable clauses of IEC 61439-2:2011,
this refer to MPSC-assembly.
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 "http://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.
A bilingual version of this publication may be issued at a later date.

INTRODUCTION
This part of IEC 60092 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 for the Safety of Life at Sea, a guide for future regulations
which may be prepared and a statement of practice for use by ship owners, shipbuilders and
appropriate organizations.
IEC 61439 (all parts) identifies the requirements for land based low voltage switchgear and
controlgear assemblies. IEC 60092-302 (all parts) has been developed in-line with Figure 201,
which shows the future intention to develop appropriate marine standards for final distribution
boards to be operated by ordinary persons; and busbar trunking systems.
IEC 60092 (all parts) remains the lead standard series for electrical installations in ships, and
the applicable standards are applied accordingly. Wherever there are differences between
IEC 61439 (all parts) and IEC 60092 (all parts), IEC 60092 (all parts) takes precedence.
IEC 61439-1
IEC 61439-2 IEC 61439-3 IEC 61439-4 IEC 61439-5 IEC 61439-6
IEC IEC IEC
a a
60092-302-2 60092-302-3 60092-302-6
IEC 60092
SSereriieses
IEC
Key
a
Under consideration.
NOTE At the time of publication, IEC 60092-302-3 and IEC 60092-302-6 are not developed. The figure shows that
these standards are potential future projects to align with the IEC 61439 series.
Figure 201 – Relationship of standards

– 6 – IEC 60092-302-2:2019 © IEC 2019
ELECTRICAL INSTALLATIONS IN SHIPS –

Part 302-2: Low voltage switchgear and
controlgear assemblies – Marine power

1 Scope
This part of IEC 60092 defines the specific requirements of low voltage marine power
switchgear and controlgear assemblies (MPSC-assemblies) as follows:
• stationary assemblies with enclosure for which the rated voltage does not exceed
1 000 V AC or 1500 V DC;
• assemblies intended for use in conjunction with the power generation, distribution and
conversion of electric energy, and for the control of electric energy consuming equipment.
This document applies to all assemblies whether they are designed, manufactured and
verified on a one-off basis or fully standardised and manufactured in quantity.
The manufacture and/or assembly can be carried out other than by the original manufacturer.
This document does not apply to individual devices and self-contained components, such as
motor starters, fuse switches, electronic equipment, which comply with the relevant product
standards.
NOTE Individual devices and components include those that are covered by the IEC 60947 series.
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 60092-101:2018, Electrical installations in ships – Part 101: Definitions and general
requirements
IEC 60092-201:2019, Electrical installations in ships – Part 201: System design – General
IEC 60533, Electrical and electronic installations in ships – Electromagnetic compatibility
(EMC) – Ships with a metallic hull
IEC 61439-1:2011, Low-voltage switchgear and controlgear assemblies – Part 1: General
rules
IEC 61439-2:2011, Low-voltage switchgear and controlgear assemblies – Part 2: Power
switchgear and controlgear assemblies
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
Clause 3 of IEC 61439-2:2011 is applicable except as follows.
3.1 General terms
Additional terms and definitions:
3.1.201
MARINE POWER SWITCHGEAR AND CONTROLGEAR ASSEMBLY
MPSC-assembly
low-voltage switchgear and controlgear assembly used to distribute and control energy for all
types of loads, intended for marine applications specifically, in ships, operated by skilled or
instructed persons only
Note 1 to entry: It is not excluded for a MPSC-assembly to be located in an area accessible to ordinary persons.
3.1.202
MAIN SWITCHBOARD
MPSC-assembly which is directly supplied by the main source of electrical power and is
intended to control and distribute electrical energy to the ships services
3.1.203
MOTOR CONTROL CENTRE
MCC
MPSC-assembly which is supplied by main or emergency switchboards and is intended to
control and distribute electrical energy
Note 1 to entry: It is possible for the MCC to be a section or sections of the main switchboard.
3.1.204
EMERGENCY SWITCHBOARD
MPSC-assembly which is normally supplied by the main switchboard, but in the event of failure
of the main electrical power system is directly supplied by the emergency source of electrical
power and is intended to control and distribute electrical energy to the emergency services
3.1.205
DISTRIBUTION BOARD
MPSC-assembly which is supplied by a main or emergency switchboard, or distribution boards
and is used to distribute and control energy to other distribution boards, final distribution
boards or final sub circuits
Note 1 to entry: The definition of "section board" as defined in previous versions of IEC 60092-302 has been
replaced by the one of "distribution board".
4 Symbols and abbreviations
Clause 4 of IEC 61439-2:2011 is applicable.
5 Interface characteristics
Clause 5 of IEC 61439-2:2011 is applicable except as follows.

– 8 – IEC 60092-302-2:2019 © IEC 2019
5.2 Voltage ratings
5.2.3 Rated insulation voltage (U ) (of a circuit of an assembly)
i
Replacement of 5.2.3 of IEC 61439-1:2011:
The rated insulation voltage of a circuit of an assembly is the voltage value to which dielectric
test voltages and creepage distances are referred.
Due to the potential effects of the marine environment on creepage distances, the rated
insulation voltage of a circuit shall be 1,5 times higher than the values stated for U and for
n
U for the same circuit up to a final maximum of U 1 000 V AC or 1 250 V DC. Any DC
e i
application requiring U exceeding 1 250 V DC shall need to have special consideration.
i
For single-phase circuits derived from IT systems (see IEC 60364-5-52), the rated insulation
voltage should be at least equal to the voltage between phases of the supply.
While it is advisable to use the above safety factor for all internal components and devices;
those that have been tested in accordance with their own product standard need not have this
safety factor applied.
5.6 Other characteristics
Replacement of item g) of IEC 61439-1:2011:
g) operated by skilled and instructed persons only;
6 Information
Clause 6 of IEC 61439-2:2011 is applicable except as follows.
6.1 Assembly designation marking
Replacement of item d):
d) IEC 60092-302-2;
Addition of item e):
e) ambient air temperature (see 7.1.1.1 and 7.1.1.2).
6.3 Device and/or component identification
Addition:
Individual circuits and their devices shall have the following durable and permanent markings
and meet the requirements of IEC 60092-201:2019, 5.3.
a) The rated current of the circuit I and assigned settings of adjustable protective devices
nc
(see 6.2.2 of IEC 61439-1:2011 for documentation of settings requirements).
b) When, for fuse systems above 500 V, the fuseholders permit the insertion of fuse links for
lower rated voltage, special warning labels or symbols, for example "Caution 690 V fuse
links only".
c) Arranging warning labels where polarized circuit-breakers are installed in DC systems so
as to guard against the possibility of incorrect connections during maintenance or
replacement.
d) Withdrawable and/or removable parts along with relevant fixed parts of an assembly shall
be provided with permanent markings in order to identify where the parts can be correctly
reassembled.
Compliance is checked according to the test of 10.2.7 of IEC 61439-1 2011 and by inspection.
7 Service conditions
Clause 7 of IEC 61439-1:2011 is applicable except as follows.
7.1.1.1 Ambient air temperature for indoor installations
Replacement:
The ambient air temperature does not exceed +45 °C, and its average over a period of 24 h
does not exceed +40 °C.
The lower limit of the ambient air temperature is 5 °C.
NOTE Where the ambient air temperature of the assembly is different, details of calculation methods are given in
10.10.3.201.
7.1.1.2 Ambient air temperature for outdoor installations
Replacement:
The ambient air temperature does not exceed +45 °C, and its average over a period of 24 h
does not exceed +40 °C.
The lower limit of the ambient air temperature is –25 °C.
NOTE Where the ambient air temperature of the assembly is different, details of calculation methods are given in
10.10.3.201.
7.1.2.1 Humidity conditions for indoor installations
Replacement:
In other parts of the IEC 60092 series, where no "high air temperature" has been specified as
a design parameter for equipment, the relative humidity of the air does not exceed 95 % at a
maximum temperature of +45 °C.
Moderate condensation should be borne in mind which can occasionally occur due to
variations in temperature.
Additional subclauses:
7.1.201 Vibration
MPSC-assemblies shall be unaffected by vibration likely to occur under normal service. Design
parameters are detailed in 4.6.3.5 of IEC 60092-101:2018.
7.1.202 Angular deviation and motion
MPSC-assemblies shall be unaffected by movement of the ship likely to occur under normal
service. Design parameters are detailed in 4.6.3.4 of IEC 60092-101:2018.
8 Constructional requirements
Clause 8 of IEC 61439-2:2011 is applicable except as follows.

– 10 – IEC 60092-302-2:2019 © IEC 2019
8.2.2 Protection against contact with live parts, ingress of solid foreign bodies and
water
Deletion of Note 1 in 8.2.2 of IEC 61439-1:2011.
8.3.2 Clearances
Deletion of the note in 8.3.2 of IEC 61439-1:2011.
8.3.3 Creepage distances
Replacement of the third paragraph in 8.3.3 of IEC 61439-1:2011:
Creepage distances shall correspond to a pollution degree as specified in 7.1.3 and to the
corresponding material group at the rated insulation voltage given in Table 2. Devices that
have been tested in accordance with their own product standard need not have this safety
factor applied.
Deletion of Note 2 in 8.3.3 of IEC 61439-1:2011.
8.4.3 Fault protection
8.4.3 of IEC 61439-1:2011 is applicable except as follows.
Additional paragraph:
8.4.3.201 Protection against electric shock for accessibility maintenance
If earth bars (protective conductor) are installed in main and emergency switchboards, MCCs
and distribution boards shall be installed and located to ensure their easy access and access
to their terminations, during and after installation.
8.4.6 Operating and servicing conditions
8.4.6 of IEC 61439-1:2011 is applicable except as follows.
8.4.6.2.3 Requirements related to accessibility for maintenance
Addition:
It shall be possible to replace or maintain all devices used for isolation of the main source of
electrical power without complete blackout of the main source of electrical power.
Where polarized circuit breakers are installed in DC systems, and in all other similar cases,
warning labels shall be arranged so as to guard against the possibility of incorrect connection
during maintenance.
8.5 Incorporation of switching devices and components
8.5 of IEC 61439-1:2011 is applicable except as follows.
8.5.4 Installation of switching devices and components
Addition:
Wherever possible, components of main circuits with different nominal voltages shall be
installed separate from each other.

8.6 Internal electrical circuits and connections
8.6 of IEC 61439-1:2011 is applicable except as follows.
8.6.2 Auxillary circuits
Addition:
Wiring shall comply with the relevant requirements given in the cable standards within the
IEC 60092 series.
8.6.3 Bare and insulated conductors
Addition:
Cables shall comply with the relevant requirements given in the cable standards within the
IEC 60092 series.
Additional subclauses:
8.6.3.201 Busbars
8.6.3.201.1 General
Busbars shall be of a composition suited for operation in a salt-laden atmosphere.
EXAMPLE Electrolytic copper or copper-clad aluminium.
8.6.3.201.2 Sub-division of main switchboard main busbar
The MPSC-assembly shall meet the specific requirement of the system as detailed in
IEC 60092-201:2019, Clause 8.
Where there is a functional requirement for more than one incoming device within the
assembly, the main busbars of the assembly shall be subdivided into at least two isolated
parts; this is to be done by a multipole switch or circuit breaker.
8.6.3.201.3 Busbar phase or polarity arrangements
Where practicable, a standard pattern of busbar phase and polarity arrangements shall be
used. Examples for such a pattern as viewed from the front of the assembly are as follows:
a) for AC MPSC-assemblies – busbar L1, L2, L3. counting from front to rear, top to bottom or
left to right (when viewed from the front of the switchgear assembly);
b) polarities on DC switchgear and controlgear busbars and connections to be: positive,
neutral, negative, counting from front to rear, top to bottom or left to right.
8.8 Terminals for external conductors
Deletion of Note 1 of IEC 61439-1:2011.
8.101 Internal separation of PSC-assemblies
8.101 of IEC 61439-2
...