IEC 61892-5:2014

Mobile and fixed offshore units - Electrical installations - Part 5: Mobile units

IEC 61892-5:2014 specifies the characteristics for electrical installations in mobile units, for use during transfer from one location to another and for use during the exploration and exploitation of petroleum resources. It applies to all installations, whether permanent, temporary, transportable or hand-held, to AC installations up to and including 35 000 V and DC installations up to and including 1 500 V (AC and DC voltages are nominal values). This third edition includes the following significant technical change with respect to the previous edition: the requirement to protection against flooding has been rewritten.

Unités mobiles et fixes en mer - Installations électriques - Partie 5: Unités mobiles

L'IEC 61892-5:2014 spécifie les caractéristiques des installations électriques dans les unités mobiles, à utiliser lors du transfert d'un emplacement à un autre et à utiliser pendant l'exploration et l'exploitation des ressources pétrolières. Elle s'applique à toutes les installations, qu'elles soient permanentes ou provisoires, mobiles ou portatives, en courant alternatif jusqu'à 35 000 V inclus ou en courant continu jusqu'à 1 500 V inclus (les tensions alternatives et continues sont des valeurs nominales). Cette troisième édition inclut les modifications techniques majeures suivantes par rapport à l'édition précédente: l'exigence d'une protection contre les submersions a été réécrite.

General Information

• Status: Published
• Publication Date: 05-Nov-2014
• ICS: 29.240.20 - Power transmission and distribution lines
• ICS: 33.200 - Telecontrol. Telemetering
• 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 18 - TC 18/MT 18
• Current Stage: DELPUB - Deleted Publication
• Start Date: 09-Apr-2019
• Completion Date: 26-Oct-2025

Relations

• Revised: IEC 61892-5:2019 - Mobile and fixed offshore units - Electrical installations - Part 5: Mobile units
• Effective Date: 05-Sep-2023
• Revises: IEC 61892-5:2010 - Mobile and fixed offshore units - Electrical installations - Part 5: Mobile units
• Effective Date: 05-Sep-2023

Standards Content (Sample)

IEC 61892-5 ®
Edition 3.0 2014-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Mobile and fixed offshore units – Electrical installations –
Part 5: Mobile units
Unités mobiles et fixes en mer – Installations électriques –
Partie 5: Unités mobiles
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IEC 61892-5 ®
Edition 3.0 2014-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Mobile and fixed offshore units – Electrical installations –

Part 5: Mobile units
Unités mobiles et fixes en mer – Installations électriques –

Partie 5: Unités mobiles
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX W
ICS 47.020.60 ISBN 978-2-8322-1922-5

– 2 – IEC 61892-5:2014 © IEC 2014

CONTENTS
FOREWORD . 5

INTRODUCTION . 7

1 Scope . 8

2 Normative references . 8

3 Terms and definitions . 9

4 General requirements . 10

4.1 Protection against flooding . 10
4.2 Rotating machines . 10
4.3 Conductors, equipment and apparatus . 10
4.4 Main switchboards . 10
4.5 Axes of rotation . 11
5 Limits of inclination of the unit . 11
5.1 Authority requirement . 11
5.2 Machines, equipment and apparatus – General . 11
5.3 Propulsion machinery. 11
5.4 Emergency machinery . 11
5.5 Dynamic condition. 11
6 Bilge pumps. 12
6.1 Power supply . 12
6.2 Cables and cable connections. 12
6.3 Location of starting arrangement . 12
7 Navigation lights . 12
7.1 General . 12
7.2 Navigation lights when in operation . 12
7.3 Steaming lights . 12
7.4 Collision regulations. 12
7.5 Power supply and monitoring systems . 12
7.6 Special requirements for lights using LEDs . 13
8 Steering gear . 13
8.1 Power operated steering gear . 13
8.2 Motors . 14

8.3 Motor starters . 14
8.4 Power circuits supply . 14
8.5 Supply of control circuits and control systems . 14
8.6 Circuit protection . 15
8.7 Starting and stopping of motors for steering gear power units . 15
8.8 Steering gear control systems . 15
8.9 Alarms and indications . 16
8.10 Rudder angle indication . 16
8.11 Separation of circuits . 16
8.12 Communication between navigating bridge and steering gear compartment . 16
9 Electric propulsion . 16
9.1 General . 16
9.2 General requirements . 17
9.2.1 Torque and critical speeds . 17

9.2.2 Lubrication . 18

9.2.3 Prime movers . 18

9.3 Electromagnetic compatibility (EMC) and harmonic distortion . 19

9.3.1 General . 19

9.3.2 Total harmonic distortion, THD . 19

9.3.3 Radio frequency interference . 19

9.4 Harmonic filtering . 19

9.5 Generators, motors, semiconductor converters and electric slip-couplings . 20

9.5.1 Machine and equipment temperature and ventilation . 20

9.5.2 Accessibility and facilities for repair in situ . 20

9.5.3 Protection against moisture and condensate . 21
9.5.4 Sudden short circuits . 21
9.5.5 Overspeed of propulsion motors . 21
9.5.6 Exciter sets. 21
9.5.7 Semiconductor converter design data . 21
9.6 Protection against moisture and condensation . 22
9.7 Controlgear . 22
9.7.1 Location of manoeuvring controls . 22
9.7.2 Engine order systems . 22
9.7.3 Operation of manoeuvring controls . 22
9.7.4 Interlocking of the means of control . 23
9.8 Cables and wiring . 23
9.8.1 Conductors . 23
9.8.2 Internal wiring . 23
9.8.3 Bus-bars . 23
9.9 Main and control circuits . 24
9.9.1 Control . 24
9.9.2 Power management system . 24
9.9.3 Circuitry and components . 25
9.10 Protection of the system . 26
9.10.1 Protection . 26
9.10.2 Instrumentation . 27
9.11 Propulsion transformers . 28
9.12 Testing . 28
10 Dynamic positioning . 28

11 Ballast systems . 29
11.1 General . 29
11.2 Ballast pumps . 29
11.3 Control and indicating systems . 29
11.4 Internal communication . 30
11.5 Protection against flooding . 30
12 Jacking systems . 30
12.1 General . 30
12.2 Design . 31
12.3 Holding capacity . 31
12.4 Electric motor capacity . 31
12.5 Control and monitoring . 31
12.6 Jacking gear motors and motor controller. 32
12.6.1 General . 32

– 4 – IEC 61892-5:2014 © IEC 2014

12.6.2 Group installation . 32

12.6.3 Overcurrent protection . 32

12.6.4 Running protection . 32

12.6.5 Metering . 32

12.7 Testing on board . 32

13 Anchoring systems . 32

13.1 General . 32

13.2 Anchoring arrangements . 32

13.3 Control systems . 33

13.4 Thruster-assisted anchoring systems (TA) . 33
Annex A (informative) Enhanced system verification test (HIL test) for dynamic
positioned mobile units . 34
A.1 General . 34
A.2 Scope of HIL testing . 34
A.3 Schedule and work process . 35
A.4 Requirements to control systems manufacturer . 35
A.5 Documentation and approval . 35
Bibliography . 36

Figure 1 – Typical equipment (configuration) for unit with one or two propellers . 17
Figure 2 – Typical control configuration . 25

INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
MOBILE AND FIXED OFFSHORE UNITS –

ELECTRICAL INSTALLATIONS –
Part 5: Mobile units
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
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International Standard IEC 61892-5 has been prepared by IEC technical committee 18:
Electrical installations of ships and of mobile and fixed offshore units.
This third edition cancels and replaces the second edition published in 2010. This edition
constitutes a technical revision.
This third edition includes the following significant technical change with respect to the
previous edition:
The requirement to protection against flooding has been rewritten.

– 6 – IEC 61892-5:2014 © IEC 2014

The text of this standard is based on the following documents:

FDIS Report on voting
18/1424/FDIS 18/1439/RVD
Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

The requirements specified in this International Standard are based on the Code for the
Construction and Equipment of Mobile Offshore Drilling Units (1989 MODU CODE) published
by the International Maritime Organization (IMO), and might include additional provisions.
A list of all the parts in the IEC 61892 series, published under the general title Mobile and
fixed offshore units – Electrical installations, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the stability date indicated on the IEC web site under "http://webstore.iec.ch" in the data
related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
INTRODUCTION
IEC 61892 forms a series of International Standards intended to ensure safety in the design,

selection, installation, maintenance and use of electrical equipment for the generation,

storage, distribution and utilization of electrical energy for all purposes in offshore units used

for exploration or exploitation of petroleum resources.

This part of IEC 61892 also incorporates and co-ordinates, as far as possible, existing rules

and forms a code of interpretation, where applicable, of the requirements laid down by the

International Maritime Organization, and constitutes a guide for future regulations which may

be prepared and a statement of practice for offshore unit owners, constructors and

appropriate organizations. This standard is based on equipment and practices which are in
current use, but it is not intended in any way to impede development of new or improved
techniques.
The ultimate aim has been to produce a set of International Standards exclusively for the
offshore petroleum industry.
– 8 – IEC 61892-5:2014 © IEC 2014

MOBILE AND FIXED OFFSHORE UNITS –

ELECTRICAL INSTALLATIONS –
Part 5: Mobile units
1 Scope
This part of IEC 61892 specifies the characteristics for electrical installations in mobile units,
for use during transfer from one location to another and for use during the exploration and
exploitation of petroleum resources.
It applies to all installations, whether permanent, temporary, transportable or hand-held, to AC
installations up to and including 35 000 V and DC installations up to and including 1 500 V.
(AC and DC voltages are nominal values).
NOTE Attention is drawn to further requirements concerning electrical installations on such mobile offshore units
contained in the MODU CODE of the International Maritime Organization (IMO).
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.
IEC 60034-1, Rotating electrical machines – Part 1: Rating and performance
IEC 60076 (all parts), Power transformers
IEC 60092-501:2013, Electrical installations in ships – Part 501: Special features – Electric
propulsion plant
IEC 60092-504, Electrical installations in ships – Part 504: Special features – Control and
instrumentation
IEC 60332-1-2, Tests on electric and optical fibre cables under fire conditions – Part 1-2: Test
for vertical flame propagation for a single insulated wire or cable – Procedure for 1 kW pre-

mixed flame
IEC 60332-3-22, Tests on electric cables under fire conditions – Part 3-22: Test for vertical
flame spread of vertically-mounted bunched wires or cables – Category A
IEC 61000-6-2:2005, Electromagnetic compatibility (EMC) – Part 6-2: Generic standards –
Immunity for industrial environments
IEC 61378-1, Converter transformers – Part 1: Transformers for industrial applications
IEC 61892-1, Mobile and fixed offshore units – Electrical installations – Part 1: General
requirements and conditions
IEC 61892-2, Mobile and fixed offshore units – Electrical installations – Part 2: System design
IEC 61892-3, Mobile and fixed offshore units – Electrical installations – Part 3: Equipment

IEC 61892-6, Mobile and fixed offshore units – Electrical installations – Part 6: Installation

International Convention for the Safety of Life at Sea (SOLAS):1974, Consolidated edition

IALA, International Association of Marine Aids to Navigation and Lighthouse Authorities,

Recommendation O-1239 On The Marking of Man-Made Offshore Structures, 2008

IMO Guidelines for vessels with dynamic positioning systems – see IMO/MSC/Circ. 645,

Annex, International Maritime Organization

IMO 904E, Convention on the International Regulations for Preventing Collisions at Sea,
International Maritime Organization (COLREG)
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 61892-1,
IEC 61892-2, IEC 61892-3, IEC 61892-6, as well as the following apply.
3.1
auxiliary steering gear
equipment, other than any part of the main steering gear, necessary to steer the unit in the
event of failure of the main steering gear but not including the tiller, quadrant or components
serving the same purpose
3.2
dynamic positioning system
DP system
equipment necessary to provide means of controlling the position and heading of a mobile unit
within predetermined limits by means of resultant vectored thrust
Note 1 to entry: This note applies to the French language only.
3.3
electric steering gear
power operated steering gear where an electric motor applies torque to the rudder stock
through mechanical means only
3.4
electrohydraulic steering gear
power operated steering gear where a hydraulic pump, driven by an electric motor, applies

torque to the rudder stock through hydraulic and mechanical means
3.5
main steering gear
machinery, rudder actuators, steering gear power units and ancillary equipment and the
means of applying torque to the rudder stock (for example tiller or quadrant) necessary for
effecting movement of the rudder for the purpose of steering the unit under normal service
conditions
3.6
propulsion machine
rotating machine normally intended to provide propulsive power
3.7
redundancy
in an item, existence of more than one means for performing a required function

– 10 – IEC 61892-5:2014 © IEC 2014

[SOURCE IEC 60050-191:1990, 191-15-01]

3.8
semiconductor converter
electronic power converter with semiconductor valve devices

Note 1 to entry: Similar terms are used for converters in general or for specific kinds of converters and for

converters with other or specific electronic valve devices, e.g. thyristor converter, transistor inverter.

[SOURCE IEC 60050-551:1998, 551-12-42]

3.9
steering gear control system
equipment by which orders are transmitted from the navigating bridge to the steering gear
power units
Note 1 to entry: Steering gear control systems comprise transmitters, receivers, hydraulic control pumps and their
associated motors, motor controllers, piping and cables, etc.
3.10
steering gear power unit
electric motor and its associated electrical and/or hydraulic equipment used to operate the
steering gear
4 General requirements
4.1 Protection against flooding
In every mobile unit in which electric power is used for the services necessary for the safety
of the unit, the generators, switchgear, motors and associated controlgear for such services,
with the exception of machinery in the platform of semi-submersibles, shall be so situated or
arranged that they continue to operate in the event of partial flooding of the unit, within
inclination limits referred in Clause 5.
The essential services for safety of personnel and unit including generators, switchgear,
motors and associated controlgear for such services should be located above the worst
damage waterline and be readily accessible.
4.2 Rotating machines
Rotating machines shall be installed to minimise the effects of motion. The design of bearings
of all machines and the arrangement for their lubrication shall be adequate to withstand the

motions encountered in heavy weather and operation for prolonged periods at the list and trim
specified in Clause 5 without the spillage of oil.
4.3 Conductors, equipment and apparatus
Conductors, equipment and apparatus shall be placed at such a distance from each magnetic
compass or shall be so disposed that the interfering external magnetic field is negligible; that
is, the total singular deviation shall not exceed 30 min when any combination of circuits is
switched on and off.
4.4 Main switchboards
The main switchboard shall be subdivided into at least two parts. The subdivision may be
effected by removable links, circuit-breakers or other suitable means so that the main
generators and any supplies to duplicated services which are directly connected to the
busbars are, as far as is practicable, equally divided between the sections.

4.5 Axes of rotation
For units where the requirements to dynamic conditions, as specified in 5.5 apply, horizontal

rotation machines shall to the extent possible be installed preferably with the shaft in the fore-

and-aft direction. Where a machine is installed athwartship, it shall be ensured that the design

of the bearings and the arrangements for lubrication are satisfactory to withstand the rolling
specified in Clause 5. The manufacturer shall be informed when a machine for installation

athwartship is ordered.
5 Limits of inclination of the unit

5.1 Authority requirement
Dependent upon the outcome of all studies relevant to the intact and damaged stability of the
unit, the appropriate authority may require or permit deviations from the angles stated in 5.2,
5.3 and 5.4.
5.2 Machines, equipment and apparatus – General
All machines, equipment and apparatus shall operate satisfactorily under all conditions with
the unit upright and when inclined up to the following angles from the normal:
– for column stabilized units, 15° in any direction;
– for self-elevating units, 10° in any direction;
– for surface units, 15° either way in list and simultaneously trimmed 5° by the bow or stern.
5.3 Propulsion machinery
Main propulsion machinery and all auxiliary machinery essential to the propulsion and safety
of the mobile unit shall be capable of operating under the static conditions specified in 5.2 and
the following dynamic conditions:
– for column stabilized units, 22° 30′ in any direction;
– for self-elevating units, 15° in any direction;
– for surface units, 22° 30′ rolling and simultaneously pitching 7° 30′ by the bow or stern.
5.4 Emergency machinery
Emergency machines, equipment and apparatus fitted in accordance with requirements from
the appropriate authority for emergency plant shall operate satisfactorily under all conditions
with the unit upright and when inclined up to the following maximum angles from the normal:

– for column stabilized units, 25° in any direction;
– for self-elevating units, 15° in any direction;
– for surface units, 22° 30′ about the longitudinal axis and/or when inclined 10° about the
transverse axis.
5.5 Dynamic condition
Where required by the appropriate authority, dynamic condition limits shall apply as follows:
– rotation about fore-and-aft axis (rolling), ±22° 30′;
– rotation about athwartship (pitching), ±7° 30′ .
NOTE These motions can occur simultaneously.

– 12 – IEC 61892-5:2014 © IEC 2014

6 Bilge pumps
6.1 Power supply
Motors of permanently installed emergency bilge pumps, if any, shall be connected to an

emergency switchboard.
6.2 Cables and cable connections

Cables and their connections to submersible pumps shall be capable of operating under a

head of water equal to their distance below the worst damaged condition waterline. The
cables shall either be armoured or mechanically protected by other means and shall not be
installed within the assumed extent of damage. They shall be installed in continuous lengths
from above the worst damaged condition waterline to the motor terminals, entering the air-bell
from its underside.
6.3 Location of starting arrangement
Under all circumstances it shall be possible to start the motor of a permanently installed bilge
pump from a convenient point above the worst damaged condition waterline and in a space
not within the assumed extent of damage.
NOTE Information regarding the worst damaged condition waterline and the spaces within the assumed extent of
damage is given in IMO requirements, for example in the MODU Code.
7 Navigation lights
7.1 General
Except when a unit is stationary and engaged in operations, IMO 904E applies.
7.2 Navigation lights when in operation
When a unit is stationary and engaged in operations, attention is drawn to the requirements
for the safety of navigation of the coastal state in whose territorial sea or on whose
continental shelf the unit is operating.
Unless otherwise required for the obstruction lighting by national authorities, the lighting is to
be in accordance with IALA Recommendation O-1239.
7.3 Steaming lights
All units shall be provided with "steaming lights" which comprise masthead, side, stern,
anchor, not-under-command and, if applicable, special-purpose lights. The construction and
installation of navigation lights shall be to the satisfaction of the appropriate authority.
7.4 Collision regulations
Attention is drawn to the collision regulations in relation to the provision of primary and
alternative lanterns for each of the navigation lights.
7.5 Power supply and monitoring systems
The following electrical arrangements relate only to the navigation lights referred to in 7.3 and
7.4.
– Each light shall be connected by a separate cable to a distribution board reserved solely
for navigation lights, fitted in an accessible place under the control of watchkeeping
personnel.
– There shall be two separate power supply systems to the distribution board, one being

from the main switchboard and one from the emergency switchboard. Where a transitional

source of emergency power is required by the Safety of Life at Sea (SOLAS) Convention,

the arrangements shall enable the lights to be supplied from this source in addition to the

emergency switchboard. An alarm shall be activated in the event of failure of a power

supply to the distribution board.

– As far as practicable, the arrangements should be such that a fire, a fault or mechanical

damage at any one point will not render both systems inoperative. It is, however, accepted

that the systems must come together at some point where the changeover can be

performed. This should, preferably, be at or near to the distribution board.

– Each light shall be controlled and protected in each insulated pole by a switch and fuse or

by a circuit-breaker mounted in the distribution board.
– Each light shall be provided with an automatic indicator to give an acoustic and/or optical
alarm in the event of complete extinction of the light. If an optical signal is used, which is
connected in series with the steaming light, means to prevent failure of the indicator
extinguishing the steaming light shall be provided. If an acoustic device alone is used it
shall be connected to an independent source of supply, for example a battery, and
provision shall be made for testing this supply.
The use of junction boxes in navigation light circuits, other than those provided for connecting
the lanterns to the fixed wiring of the electrical installation, should be avoided. Cables for
different circuits should not use the same junction box.
7.6 Special requirements for lights using LEDs
The luminous intensity of LEDs gradually decreases while the electricity consumption remains
unchanged. The rate of decrease of luminous intensity depends on the output of LEDs and
temperatures of LEDs. To prevent shortage of luminous intensity of LEDs, one of the following
solutions shall be used:
• An alarm function shall be activated to notify the Officer of the Watch that the luminous
intensity of the light reduces below the level required by COLREGs; or
• LEDs shall only be used within the lifespan (practical term of validity) specified by the
manufacturer to maintain the necessary luminous intensity of LEDs. The lifespan of LEDs
should be determined and clearly notified by the manufacturer based on the appropriate
test results on the decrease of luminous intensity of the LEDs under various temperature
conditions and on the temperature condition of LEDs in the light during operation, taking
the appropriate margin into account.
The manufacturer of the navigation light should give information regarding detection of low
illumination intensity.
8 Steering gear
8.1 Power operated steering gear
8.1.1 Electric and/or electrohydraulic steering gear shall be used for the power-operated
main and auxiliary steering gear required by the appropriate authorities.
8.1.2 The electrical systems of the main steering gear and auxiliary steering gear shall be
so arranged that any failure in one of the steering gears will not render inoperative the
electrical systems of the other steering gear.
When an auxiliary steering gear is not required by the appropriate authorities and the main
steering gear comprises two or more power units, the electrical system for each power unit
shall be so arranged that the failure of one of them will not render the other units inoperative.

– 14 – IEC 61892-5:2014 © IEC 2014

8.2 Motors
8.2.1 To determine the required characteristics of the electric motors for power units, the

breakaway torque and maximum working torque of the steering gear under all operating

conditions shall be used. The ratio of pull-out torque to rated torque shall be at least 1,6.

8.2.2 The rating shall be determined on the basis of the steering gear characteristics of the

subject unit as specified in 8.2.3 and 8.2.4.

Motors for steering gear power units may be rated for intermittent power demand.

8.2.3 For motors of electric steering gear power units the rating shall be as follows:
S3 – 40 % in accordance with lEC 60034-1.
8.2.4 For motors of electrohydraulic steering gear power units and for converters, the
rating shall be as follows:
S6 – 25 % in accordance with IEC 60034-1.
8.3 Motor starters
Each electric motor of a main or auxiliary steering gear power unit shall be provided with its
own separate motor starter gear, either located within the steering gear compartment or in the
supply switchboard rooms (see 8.1.2).
8.4 Power circuits supply
8.4.1 Each electric or electrohydraulic steering gear comprising one or more power units
should, except as otherwise permitted by the appropriate authorities, be served by at least
two excl
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