COMESA 287-3: Reciprocating internal combustion engine driven alternating current generating sets — Part 3: Alternating current generators for generating sets

2007·1.1 MB·English

by  Common Market for Eastern and Southern Africa (COMESA)

Common Market for Eastern
and Southern Africa
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COMESA 287-3 (2007) (English): Reciprocating
internal combustion engine driven alternating
current generating sets — Part 3: Alternating
current generators for generating sets

COMESA HARMONISED COMESA/FDHS
STANDARD 287-3:2007

Reciprocating internal combustion engine
driven alternating current generating sets —
Part 3: Alternating current generators for
generating sets

REFERENCE: FDHS 287-3:2007
Foreword

The Common Market for Eastern and Southern Africa (COMESA) was established in 1994 as a
regional economic grouping consisting of 20 member states after signing the co-operation Treaty.
In Chapter 15 of the COMESA Treaty, Member States agreed to co-operate on matters of
standardisation and Quality assurance with the aim of facilitating the faster movement of goods
and services within the region so as to enhance expansion of intra-COMESA trade and industrial
expansion.

Co-operation in standardisation is expected to result into having uniformly harmonised standards.
Harmonisation of standards within the region is expected to reduce Technical Barriers to Trade
that are normally encountered when goods and services are exchanged between COMESA
Member States due to differences in technical requirements. Harmonized COMESA Standards
are also expected to result into benefits such as greater industrial productivity and
competitiveness, increased agricultural production and food security, a more rational exploitation
of natural resources among others.

COMESA Standards are developed by the COMESA experts on standards representing the
National Standards Bodies and other stakeholders within the region in accordance with
international procedures and practices. Standards are approved by circulating Final Draft
Harmonized Standards (FDHS) to all member states for a one Month vote. The assumption is
that all contentious issues would have been resolved during the previous stages or that an
international or regional standard being adopted has been subjected through a development
process consistent with accepted international practice.

COMESA Standards are subject to review, to keep pace with technological advances. Users of
the COMESA Harmonized Standards are therefore expected to ensure that they always have the
latest version of the standards they are implementing.

This COMESA standard is technically identical to ISO 8528-3:2005, Reciprocating internal
combustion engine driven alternating current generating sets — Part 3: Alternating current
generators for generating sets

A COMESA Harmonized Standard does not purport to include all necessary provisions of a contract.
Users are responsible for its correct application.
INTERNATIONAL ISO

STANDARD 8528-3

Second edition
2005-07-01

Reciprocating internal combustion
engine driven alternating current
generating sets —
Part 3:
Alternating current generators for
generating sets
Groupes électrogènes à courant alternatif entraînés par moteurs
alternatifs à combustion interne —
Partie 3: Alternateurs pour groupes électrogènes

Reference number
ISO 8528-3:2005(E)
© ISO 2005
ISO 8528-3:2005(E)
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ii © ISO 2005 – All rights reserved
ISO 8528-3:2005(E)
Contents
Page
Foreword............................................................................................................................................................iv
1 Scope.....................................................................................................................................................1
2 Normative references...........................................................................................................................1
3 Symbols, terms and definitions..........................................................................................................2
4 Other requirements and additional regulations................................................................................6
5 Rating.....................................................................................................................................................6
5.1 General...................................................................................................................................................6
5.2 Basic continuous rating (BR)..............................................................................................................6
5.3 Peak continuous rating (PR)................................................................................................................6
6 Limits of temperature and temperature rise......................................................................................7
6.1 Basic continuous rating.......................................................................................................................7
6.2 Peak continuous rating........................................................................................................................7
7 Rated power and speed characteristics.............................................................................................7
8 Voltage characteristics.........................................................................................................................7
9 Parallel operation..................................................................................................................................7
10 Special load conditions........................................................................................................................8
10.1 General...................................................................................................................................................8
10.2 Unbalanced load current......................................................................................................................8
10.3 Sustained short-circuit current...........................................................................................................8
10.4 Occasional excess current capability.................................................................................................8
10.5 Telephone Harmonic Factor (THF)......................................................................................................8
10.6 Radio interference suppression (F)....................................................................................................9
11 Effect of electromechanical frequency of vibrations when sets operate in parallel.....................9
12 Asynchronous generators with excitation equipment......................................................................9
12.1 General...................................................................................................................................................9
12.2 Sustained short-circuit current...........................................................................................................9
12.3 Range of voltage setting......................................................................................................................9
12.4 Parallel operation..................................................................................................................................9
13 Operating limit values........................................................................................................................10
14 Rating plate.........................................................................................................................................10
Annex A (normative) Transient voltage characteristic of an a.c. generator following a sudden
change in load.....................................................................................................................................11

© ISO 2005 – All rights reserved iii
ISO 8528-3:2005(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies
(ISO member bodies). The work of preparing International Standards is normally carried out through ISO
technical committees. Each member body interested in a subject for which a technical committee has been
established has the right to be represented on that committee. International organizations, governmental and
non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the
International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 8528-3 was prepared by Technical Committee ISO/TC 70, Internal combustion engines.
This second edition cancels and replaces the first edition (ISO 8528-3:1993), which has been technically
revised.
ISO 8528 consists of the following parts, under the general title Reciprocating internal combustion engine
driven alternating current generating sets:
— Part 1: Application, ratings and performance
— Part 2: Engines
— Part 3: Alternating current generators for generating sets
— Part 4: Controlgear and switchgear
— Part 5: Generating sets
— Part 6: Test methods
— Part 7: Technical declarations for specification and design
— Part 8: Requirements and tests for low-power generating sets
— Part 9: Measurement and evaluation of mechanical vibrations
— Part 10: Measurement of airborne noise by the enveloping surface method
— Part 111): Rotary uninterruptible power supply systems — Performance requirements and test methods
— Part 12: Emergency power supplies to safety services

1) Part 11 will be published as ISO/IEC 88528-11.
iv © ISO 2005 – All rights reserved
INTERNATIONAL STANDARD ISO 8528-3:2005(E)

Reciprocating internal combustion engine driven alternating
current generating sets —
Part 3:
Alternating current generators for generating sets
1 Scope
This part of ISO 8528 specifies the principal characteristics of Alternating Current (a.c.) generators under the
control of their voltage regulators when used in generating set applications. It supplements the requirements
of IEC 60034-1.
NOTE At present no International Standard is available for asynchronous generators. When such an International
Standard is published, this part of ISO 8528 will be revised accordingly.
This part of ISO 8528 applies to a.c. generators used in a.c. generating sets driven by reciprocating internal
combustion (RIC) engines for land and marine use, excluding generating sets used on aircraft or to propel
land vehicles and locomotives.
For some specific applications (e.g. essential hospital supplies, high-rise buildings), supplementary
requirements may be necessary. The provisions of this part of ISO 8528 should be regarded as the basis for
establishing any supplementary requirements.
For a.c. generating sets driven by other reciprocating-type prime movers (e.g. steam engines) the provisions
of this part of ISO 8528 should be used as a basis for establishing these requirements.
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.
ISO 8528-12), Reciprocating internal combustion engine driven alternating current generating sets — Part 1:
Application, ratings and performance
IEC 60034-1, Rotating electrical machines — Part 1: Rating and performance
CISPR 14-1, Limits and methods of measurement of radio interference characteristics of household electrical
appliances, portable tools and similar electrical apparatus
CISPR 15, Limits and methods of measurement of radio interference characteristics of fluorescent lamps and
luminaires

2) To be published.
© ISO 2005 – All rights reserved 1
ISO 8528-3:2005(E)
3 Symbols, terms and definitions
For indications of technical data for electrical equipment, IEC uses the term “rated” and the subscript “N”. For
indications of technical data for mechanical equipment, ISO uses the term “declared” and the sub-script “r”.
Therefore, in this part of ISO 8528, the term “rated” is applied only to electrical items. Otherwise, the term
“declared” is used throughout.
An explanation of the symbols and abbreviations used in this International Standard are shown in Table 1.
Table 1 — Symbols, terms and definitions
Symbol Term Unit Definition
U Set voltage V Line-to-line voltage for defined operation
s
selected by adjustment.
U Maximum steady-state voltage deviation V
st,max
U Minimum steady-state voltage deviation V
st,min
U Rated voltage V Line-to-line voltage at the terminals of the
r
generator at the rated frequency and rated
output.
NOTE Rated voltage is the voltage
assigned by the manufacturer for operating and
performance characteristics.
U Recovery voltage V Maximum obtainable steady-state voltage for
rec
a specified load condition.
NOTE Recovery voltage is normally
expressed as a percentage of the rated voltage. It
normally lies within the steady-state voltage
tolerance band (∆U). For loads in excess of the
rated load, recovery voltage is limited by saturation
and exciter-regulator field forcing capability (see
Figure A.2.1).
U Downward adjustable voltage V
s,do
U Upward adjustable voltage V
s,up
U No-load voltage V Line-to-line voltage at the terminals of the
0
generator at rated frequency and no-load.
U Maximum upward transient voltage on load V
dyn,max
decrease
U Minimum downward transient voltage on V
dyn,min
load increase
∆U Steady-state voltage tolerance band V Agreed voltage band about the steady-state
voltage that the voltage reaches within a
given regulating period after a specified
sudden increase or decrease of load given
by:
U
∆U =2δU × r
st
100

2 © ISO 2005 – All rights reserved