IEC 61892-1:2010

IEC 61892-1


®

Edition 2.0 2010-08



INTERNATIONAL



STANDARD





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




IEC 61892-1:2010(E)

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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
® Registered trademark of the International Electrotechnical Commission

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– 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

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61892-1 © IEC:2010(E) – 3 –


INTERNATIONAL ELECTROTECHNICAL COMMISSION

___________



MOBILE AND FIXED OFFSHORE UNITS –

ELECTRICAL INSTALLATIONS –



Part 1: General requirements and conditions





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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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
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3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
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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;

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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.

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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.

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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

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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".

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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]

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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.

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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
2
()Q
h
THD = ∑
2
h=2
()Q

1
where
Q represents either current or voltage;
Q is the r.m.s. value of the fundamental component;
1
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]

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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 conditions and requirements which are common to all equipment and in-

stallations in the IEC 61892 series.

Electrical installations in units shall be such that:
– essential services will be maintained under various emergency conditions;
– the safety of crew, contractors, visitors and unit will be ensured;
– the requirements with respect to safety in this standard are considered;
– the requirements of the International Convention for the Safety of Life at Sea (SOLAS) are
met as far as applicable;
– the requirements of the IMO MODU Code are met as far as applicable.
NOTE Emergency conditions are normally defined in the safety assessment of the installation.
4.2 Workmanship and material
Good workmanship and adequate material are essential requirements for compliance with
these standards.
4.3 Acceptance of substitutes or alternatives
Where in these standards any special type of equipment, construction, or arrangement is
specified, the use of any other equipment, construction or arrangement is admissible, provided
it is not less effective and reliable.
4.4 Additions and alterations
An addition or alteration, temporary or permanent, shall not be made to an existing installation
until it has been ascertained that the ratings and the condition of existing accessories,
conductors, switchgear, etc. affected, are adequate for the new situation.

Special attention is drawn to those factors affecting the existing system design such as current-
carrying capacity, short-circuit level, voltage drop, harmonics, stability and proper discri-
mination of the protective devices.
4.5 Environmental conditions
4.5.1 General
Electrical equipment shall operate satisfactorily under various environmental conditions.
Environmental conditions are characterised by a number of variables:
– one set including mainly climatic conditions, biological conditions, conditions dependent
upon chemically and mechanically active substances and mechanical conditions;
– another set dependent mainly upon locations in unit, operational patterns and transient
conditions.

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NOTE Further information regarding environmental conditions in conjunction with some selected locations,

operational patterns and transient conditions which are considered to be generally representative can be found in
IEC 60721-3-6.


4.5.2 Design parameters


4.5.2.1 General


Design parameters based on environmental conditions applicable to certain types of equipment
may be determined according to location. Where no data is available, the following tables give
recommended values.


NOTE In certain areas, e.g. arctic areas, lower temperatures than those given in the tables have to be taken into

consideration. In certain areas, also a higher temperature than given in the tables has to be taken into
consideration.
4.5.2.2 Temperature
In other parts of the IEC 61892 series, where no "high air temperature" has been specified as a
design parameter for equipment, a value of 45 ºC shall apply.
Where equipment is designed to operate with temperatures higher or lower than those stated in
Table 1, permissible temperature rises may be reduced or increased accordingly.
Table 1 – Operational design parameters – Ambient temperature
Type of equipment Value
º
C
High air temperature
Cables 45
Generators and motors 50
Switchgear 45
Transformers 45
Control and instrumentation 55
Other electrical equipment 45
Low air temperature
Control and instrumentation 5 (general)
Control and instrumentation –25 (open deck)
High water temperature
Generators and motors 35


NOTE 1 The lower design temperature will normally be specified in the product standard.
NOTE 2 For batteries see 10.1.1 and 10.7 of IEC 61892-6.
4.5.2.3 Humidity, relative
Design values for relative humidity are given in Table 2.
Table 2 – Design parameters – Humidity, relative
Value
o
% C
95 up to 45
70 above 45

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61892-1 © IEC:2010(E) – 13 –


4.6 Materials


In general, all electrical equipment shall be constructed of durable, flame-retardant, moisture-

resistant materials, which are not subject to deterioration in the atmosphere and at the

temperatures to which they are likely to be exposed.


Equipment enclosures located outdoor, in naturally ventilated and wash down areas shall be

made of proven seawater resistant materials.


NOTE 1 Such material may be seawater resistant aluminium, stainless steel or UV resistant plastic material.

NOTE 2 For further information regarding environmental conditions, refer to IEC 60721-3-6.

4.7 Power supply system characteristics
4.7.1 General
Unless otherwise stated in other parts of this standard, equipment shall fu
...