IEC 61892-1:2010

Mobile and fixed offshore units - Electrical installations - Part 1: General requirements and conditions

IEC 61892-1:2010(E) contains provisions for electrical installations in mobile and fixed offshore units including pipeline, pumping or 'pigging' stations, compressor stations and exposed location single buoy moorings, used in the offshore petroleum industry for drilling, processing and storage purposes. It applies to all installations, whether permanent, temporary, transportable or hand-held, to a.c. installations up to and including 35 000 V and d.c. installations up to and including 1 500 V (a.c. and d.c. voltages are nominal values). It does not apply either to fixed equipment for medical purposes or to the electrical installations of tankers. This edition cancels and replaces the first edition published in 2001. This edition includes the following significant technical changes with respect to the previous edition:
a) the d.c.voltages given in Clause 1, have been updated in order to ensure uniform requirements for all parts of the standard;
b) the requirement to EMC has been rewritten to comply with the requirements of IEC 61000 2 4;
c) a clause regarding environmental impact has been added;
d) Annex A (Guidance on environmental conditions) has been deleted;
e) Annex B (Informative) regarding cold climate precautions has been added.

General Information

• Status: Published
• Publication Date: 18-Aug-2010
• 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: 13-Jul-2015
• Completion Date: 26-Oct-2025

Relations

• Revises: IEC 61892-1:2001 - Mobile and fixed offshore units - Electrical installations - Part 1: General requirements and conditions
• Effective Date: 05-Sep-2023
• Revised: IEC 61892-1:2015 - Mobile and fixed offshore units - Electrical installations - Part 1: General requirements and conditions
• Effective Date: 05-Sep-2023

Overview

IEC 61892-1:2010 - "Mobile and fixed offshore units - Electrical installations - Part 1: General requirements and conditions" is the foundational standard for electrical installations in the offshore petroleum industry. It applies to mobile and fixed offshore units (including pipeline/pumping stations, compressor stations and single-buoy moorings) for drilling, processing and storage. The standard covers a.c. systems up to 35 000 V and d.c. systems up to 1 500 V (nominal values). It does not apply to fixed medical equipment or tanker electrical installations. Key 2010 edition updates include revised d.c. voltage limits, revised EMC requirements (aligned with IEC 61000-2-4), a new environmental impact clause and added cold-climate guidance.

Key Topics and Technical Requirements

The standard sets general requirements and conditions that guide design, installation, testing and maintenance of offshore electrical systems. Important technical topics include:

• Power supply system characteristics - AC and DC distribution considerations and operational parameters.
• Protection against electric shock and insulation practices to ensure personnel safety.
• Earthing (grounding) practices tied to the unit structure and hull.
• Electromagnetic compatibility (EMC) requirements updated to comply with IEC 61000-2-4 for industrial environments.
• Environmental conditions and impact - design parameters for temperature, humidity and environmental protection; new clause addressing environmental impact.
• Degree of protection and enclosures - ingress protection, mechanical and thermal protection, and selection of enclosures for exposed locations.
• Precautions for explosive atmospheres - interface with hazardous-area requirements (see IEC 61892‑7 / IEC 60079).
• Cables, cable entries and mechanical protection - routing, sealing and resistance to vibration, shock, water, steam and oil.
• Maintenance, inspection and lifecycle considerations, including requirements for additions and alterations.
• Corrosion control - galvanic corrosion precautions for marine environments.
• Cold climate precautions (informative Annex B).

Applications and Who Uses It

IEC 61892-1 is used by:

• Offshore electrical designers and system engineers specifying power distribution for platforms, FPSOs, MODUs and single-buoy moorings.
• EPC contractors, equipment manufacturers and integrators supplying switchgear, transformers, generators and control systems.
• Classification societies, regulators and owners ensuring compliance with IMO SOLAS, MODU Code and national rules.
• Maintenance teams and inspectors developing test regimes, inspection schedules and modification plans.

Keywords: IEC 61892-1, offshore electrical installations, mobile and fixed offshore units, offshore petroleum industry, EMC, earthing, corrosion, cold climate precautions.

Related Standards

• IEC 61892-2 (System design)
• IEC 61892-7 (Hazardous areas)
• IEC 61000-2-4 (EMC industrial environment)
• IEC 60079 (Explosive atmospheres)
• IEC 60034 (Rotating machines)
• IEC 61140 (Protection against electric shock)
• IMO SOLAS and MODU Code (maritime safety requirements)

Standards Content (Sample)

IEC 61892-1 ®
Edition 2.0 2010-08
INTERNATIONAL
STANDARD
Mobile and fixed offshore units – Electrical installations –
Part 1: General requirements and conditions

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IEC 61892-1 ®
Edition 2.0 2010-08
INTERNATIONAL
STANDARD
Mobile and fixed offshore units – Electrical installations –
Part 1: General requirements and conditions

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
PRICE CODE
S
ICS 47.020.60 ISBN 978-2-88912-152-6
– 2 – 61892-1 © IEC:2010(E)
CONTENTS
FOREWORD.3

INTRODUCTION.5

1 Scope.6

2 Normative references.6

3 Terms and definitions .7

4 General requirements and conditions .11

4.1 General .11

4.2 Workmanship and material .11
4.3 Acceptance of substitutes or alternatives .11
4.4 Additions and alterations.11
4.5 Environmental conditions .11
4.5.1 General .11
4.5.2 Design parameters.12
4.6 Materials .13
4.7 Power supply system characteristics .13
4.7.1 General .13
4.7.2 AC distribution systems.13
4.7.3 DC distribution systems .14
4.8 Electrical apparatus for explosive gas atmospheres .15
4.9 Precautions against galvanic corrosion .15
4.10 Clearance and creepage distances .15
4.11 Insulation.15
4.12 Maintenance and inspection.15
4.13 Cable entries .15
4.14 Precautions against vibration and mechanical shock .15
4.15 Location of electrical equipment in units.16
4.16 Mechanical protection.16
4.17 Protection from heat, water, steam and oil .16
4.18 Protection against electrical shock .16
4.19 Enclosures .16
4.20 Environmental impact .17
Annex A (informative) Degree of protection .18
Annex B (Informative) Cold climate precautions.20

Bibliography .21

Table 1 – Operational design parameters – Ambient temperature .12
Table 2 – Design parameters – Humidity, relative .12
Table A.1 – Degrees of protection against foreign objects indicated by the first
characteristic numeral .18
Table A.2 – Degrees of protection against water indicated by the second characteristic
numeral .19

61892-1 © IEC:2010(E) – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION

___________
MOBILE AND FIXED OFFSHORE UNITS –

ELECTRICAL INSTALLATIONS –
Part 1: General requirements and conditions

FOREWORD
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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 61892-1 has been prepared by IEC technical committee 18:
Electrical installations of ships and of mobile and fixed offshore units.
This second edition cancels and replaces the first edition published in 2001. This edition
constitutes a technical revision.
This second edition includes the following significant technical changes with respect to the
previous edition:
a) the d.c.voltages given in Clause 1, have been updated in order to ensure uniform
requirements for all parts of the standard;
b) the requirement to EMC has been rewritten to comply with the requirements of
IEC 61000-2-4;
c) a clause regarding environmental impact has been added;
d) Annex A (Guidance on environmental conditions) has been deleted;

– 4 – 61892-1 © IEC:2010(E)
e) Annex B (Informative) regarding cold climate precautions has been added.

The text of this standard based on the following documents:

FDIS Report on voting
18/1166/FDIS 18/1176/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.

A list of all parts of the IEC 61892 series can be found, under the general title Mobile and fixed
offshore units – Electrical installations, 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.
A bilingual version of this publication may be issued at a later date.

61892-1 © IEC:2010(E) – 5 –
INTRODUCTION
The IEC 61892 series of International Standards is intended to enable 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 which are used

for the purpose of exploration or exploitation of petroleum resources.

This part of the IEC 61892 series incorporates and co-ordinates, as far as possible, existing

rules and forms a code of interpretation, where applicable, of the requirements of the

International Maritime Organization, 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.
– 6 – 61892-1 © IEC:2010(E)
MOBILE AND FIXED OFFSHORE UNITS –

ELECTRICAL INSTALLATIONS –
Part 1: General requirements and conditions

1 Scope
This part of IEC 61892 series contains provisions for electrical installations in mobile and fixed
offshore units including pipeline, pumping or 'pigging' stations, compressor stations and
exposed location single buoy moorings, used in the offshore petroleum industry for drilling,
processing and storage purposes.
This International Standard applies to all installations, whether permanent, temporary,
transportable or hand-held, to a.c. installations up to and including 35 000 V and d.c.
installations up to and including 1 500 V (a.c. and d.c. voltages are nominal values).
This standard does not apply either to fixed equipment for medical purposes or to the electrical
installations of tankers.
NOTE For medical rooms, see IEC 60364-7-710.
2 Normative references
The following referenced documents are indispensable for the application 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 60034-1:2010, Rotating electrical machines – Part 1: Rating and performance
IEC 60079 (all parts), Explosive atmospheres
IEC 61000-2-4:2002, Electromagnetic compatibility (EMC) – Part 2-4: Environment –
Compatibility levels in industrial plants for low-frequency conducted disturbances

IEC 61140, Protection against electric shock – Common aspects for installation and equipment
IEC 61892-2:2005, Mobile and fixed offshore units – Electrical installations – Part 2: System
design
IEC 61892-7, Mobile and fixed offshore units – Electrical installations – Part 7: Hazardous
areas
IMO-110E, IMO-111F and IMO 113S, International Convention for the Safety of Life at Sea
(SOLAS)
IMO MODU Code, Code for the construction and equipment of mobile offshore drilling units

61892-1 © IEC:2010(E) – 7 –
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.

NOTE The terms and definitions included in this part are those having general application in the IEC 61892 series.

Terms and definitions applying to particular apparatus or equipment are included in the other parts of IEC 61892.

3.1
appropriate authority
governmental body and/or classification society with whose rules a unit is required to comply

3.2
equipment
single apparatus or set of devices or apparatuses, or the set of main devices of an installation,
or all devices necessary to perform a specific task
NOTE Examples of equipment are a power transformer, measuring equipment.
[IEC 60050-151:2001, 151-11-25, modified]
3.3
apparatus
device or assembly of devices which can be used as an independent unit for specific functions
[IEC 60050-151:2001, 151-11-22, modified]
3.4
room with a controlled atmosphere
room where the temperature and humidity can be controlled within specified limits
3.5
degree of protection provided by enclosures (of electrical apparatus)
measures applied to the enclosures of electrical equipment and apparatus to provide for :
1) protection of persons against contact with or approach to live parts and against contact with
moving parts (other than smooth rotating shafts and the like) inside the enclosure and the
protection of the apparatus against ingress of solid foreign bodies
2) protection of the apparatus inside the enclosure against harmful ingress of water
[IEC 60050-426:2008, 426-04-02, modified]
NOTE 1 For further information regarding degree of protection, see IEC 60529.

NOTE 2 Explanation of the numerals used for classification of degree of protection is given in Tables A.1 and A.2.
3.6
distribution board
assembly containing different types of switchgear and controlgear associated with one or more
outgoing electric circuits fed from one or more incoming electric circuits, together with
terminals for the neutral and protective conductors, if required
[IEC 60050-826:2004, 826-16-08, modified]
3.7
earth
general mass of the metal structure or hull of the unit
NOTE In the U.S.A. and Canada "ground" is used instead of "earth".

– 8 – 61892-1 © IEC:2010(E)
3.8
earthed
connected to the general mass of the structure or hull of the unit in such a manner as will

ensure at all times an immediate discharge of electrical energy without danger

3.9
essential services
services essential for the navigation, steering or manoeuvring of the mobile unit, or for the

safety of human life, or for special characteristics of the unit (for example special services)

3.10
frequency
3.10.1
cyclic frequency variation
periodic deviation in frequency during normal operation such as might be caused by regularly
repeated loading
±( f - f ) × 100
max min
Cyclic frequency variation = %
2 f
nominal
3.10.2
frequency tolerance
maximum departure from nominal frequency during normal operation conditions excluding
transient and cyclic frequency variations
NOTE Frequency tolerance is a steady state tolerance and includes variations caused by loads and governor
characteristics. It also includes variations due to environmental conditions.
3.10.3
frequency transient
sudden change in frequency which goes outside the frequency tolerance limits and returns to
and remains inside these limits within a specified recovery time after initiation of the
disturbance (time range: seconds)
3.11
insulation
3.11.1
basic insulation
insulation of hazardous-live-parts which provides basic protection against electric shock
NOTE Basic insulation does not necessarily include insulation used exclusively for functional purposes.

[IEC 60050-195:1998, 195-06-06, modified]
3.11.2
supplementary insulation
independent insulation applied in addition to basic insulation, for fault protection in the event of
a failure of basic insulation
[IEC 60050-195:1998, 195-06-07, modified]
3.12
live part
conductor or conductive part intended to be energized in normal operation, including a neutral
conductor, but by convention not a PEN conductor or PEM conductor or PEL conductor
NOTE This concept does not necessarily imply a risk of electric shock.
[IEC 60050-195:1998, 195-02-19]

61892-1 © IEC:2010(E) – 9 –
3.13
PEN conductor
conductor combining the functions of both a protective earthing conductor and a neutral

conductor
[IEC 60050-195:1998, 195-02-12]

3.14
PEM conductor
conductor combining the functions of both a protective earthing conductor and a mid-point
conductor
[IEC 60050-195:1998, 195-02-13]
3.15
PEL conductor
conductor combining the functions of both a protective earthing conductor and a line conductor
[IEC 60050-195:1998, 195-02-14]
3.16
petroleum
complex mixture of hydrocarbons that occurs in the earth in liquid or gaseous forms
3.17
point (in wiring)
any termination of the fixed wiring intended for the attachment of a luminaire or for connecting
to the supply of a current-using appliance
3.18
spaces
3.18.1
accommodation spaces
spaces used for public spaces, corridors, lavatories, cabins, offices, crew quarters, hospitals,
game and hobby rooms, pantries containing no cooking appliances and similar spaces
3.18.2
machinery spaces
spaces containing propelling machinery, boilers, oil fuel units, steam and internal combustion
engines, hydrocarbon process equipment, water treatment and handling equipment, drilling and
associated equipment, generators and major electrical machinery, oil filling stations,
refrigerating, stabilizing, ventilation and air-conditioning machinery, and similar spaces and

trunks to such spaces
3.18.3
public spaces
portions of the accommodation used for halls, dining rooms, lounges, and similar permanently
enclosed spaces
3.19
voltages
3.19.1
voltage tolerance
maximum departure from nominal user voltage during normal operating conditions, excluding
transient and cyclic voltage variations
NOTE Voltage tolerance is a steady state tolerance and includes voltage drop in cables and voltage regulator
characteristics. It also includes variations due to environmental conditions.

– 10 – 61892-1 © IEC:2010(E)
3.19.2
voltage unbalance tolerance
difference between the highest and lowest phase to phase voltage

3.19.3
cyclic voltage variation
periodic voltage deviation (max. to min. r.m.s. values) of the nominal voltage, such as might be

caused by regularly repeated loading

±(U − U ) × 100
max min
Cyclic voltage variation = %
2 U
nominal
3.19.4
voltage transient
sudden change in voltage (excluding spikes) which goes outside the nominal voltage tolerance
limits and returns to and remains inside these limits within a specified recovery time after the
initiation of the disturbance (time range: seconds)
3.20
recovery time
3.20.1
voltage transient recovery time
time elapsed from exceeding the normal voltage tolerance until the voltage recovers and
remains within the normal tolerance limits
3.20.2
frequency transient recovery time
time elapsed from exceeding the normal frequency tolerance until the frequency recovers and
remains within the frequency tolerance limits
3.21
waveform
3.21.1
total harmonic distortion
THD
ratio of the r.m.s. value of the sum of all the harmonic components up to a specified order
(recommended notation “H”) to the r.m.s. value of the fundamental component
h=H
()Q
h
THD = ∑
h=2
()Q
where
Q represents either current or voltage;
Q is the r.m.s. value of the fundamental component;
h is the harmonic order;
Q is the r.m.s. value of the harmonic component of order h;
h
H is 50 for the purpose of the compatibility levels in this standard
NOTE THD takes account of harmonics only. For the case where interharmonics are to be included, reference is
made to A.3.1 of IEC 61000-2-4:2002.
[IEC 61000-2-4:2002, 3.2.7]
61892-1 © IEC:2010(E) – 11 –
3.21.2
single harmonic content
ratio of the effective r.m.s. value of that harmonic to the r.m.s. value of the fundamental

expressed in per cent
4 General requirements and conditions

4.1 General
This clause contains con
...