IEC TS 62257-7-3:2018

IEC TS 62257-7-3 ®
Edition 2.0 2018-03
TECHNICAL
SPECIFICATION
Recommendations for renewable energy and hybrid systems for rural
electrification –
Part 7-3: Generator set – Selection of generator sets for rural electrification
systems
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IEC TS 62257-7-3 ®
Edition 2.0 2018-03
TECHNICAL
SPECIFICATION
Recommendations for renewable energy and hybrid systems for rural

electrification –
Part 7-3: Generator set – Selection of generator sets for rural electrification

systems
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 27.160 ISBN 978-2-8322-5455-4

– 2 – IEC TS 62257-7-3:2018 © IEC 2018
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 10
3 Terms and definitions . 11
4 Introduction to generator sets . 14
4.1 Generator set system . 14
4.2 Generator set application in rural electrification systems . 14
4.2.1 General. 14
4.2.2 Single generator set (micropower plant Type A) . 14
4.2.3 Multiple generator sets (micropower plant Type B) . 14
4.2.4 Single generator set with a power conditioning sub-system (micropower
plant Type C). 15
4.2.5 Multiple generator sets with multiple power conditioning sub-systems
(micropower plant Type D) . 15
4.3 Resource assessment . 16
5 Selection and erection . 16
5.1 General . 16
5.2 Selection requirements . 17
5.2.1 Power quality. 17
5.2.2 Generator set sizing . 17
5.2.3 Generator set type . 18
5.2.4 Derating factors . 19
5.2.5 Starting system . 19
5.2.6 Control systems . 20
5.2.7 Noise issues . 20
5.2.8 Environmental issues . 20
5.3 Erection . 21
5.3.1 Shipping . 21
5.3.2 Design of the erection site . 21
5.3.3 Installation requirements. 23
6 Safety. 25
6.1 General . 25
6.2 Electrical issues . 25
6.2.1 General requirements . 25
6.2.2 Connection system to the application . 25
6.2.3 Power cables . 26
6.2.4 Neutral system . 26
6.2.5 Earthing . 26
6.2.6 Overcurrent protection . 27
6.2.7 Residual Current Protection Device (RCD) . 27
6.2.8 Isolating devices . 27
6.3 Mechanical issues . 27
6.3.1 Vibration . 27
6.3.2 Protection from mechanical damage . 27
6.3.3 Protection from moving parts . 28
6.4 Thermal issues . 28

6.5 Fire risk . 28
7 Acceptance . 28
7.1 General . 28
7.2 Conformity of the generator set to the identification file . 28
7.3 Conformity of the generator set system to the generator set specification
(GS) . 28
7.4 Acceptance process . 28
7.4.1 Preparation of the generator set for commissioning . 28
7.4.2 Commissioning inspection of the generator set system . 29
7.4.3 Commissioning tests of the generator set system . 29
7.4.4 Test file . 30
8 Operation and maintenance . 30
8.1 Access to the generator set . 30
8.2 Operation process . 30
8.3 Monitoring . 31
8.4 Maintenance schedule. 31
9 Replacement . 31
10 Marking . 32
10.1 General . 32
10.2 Generator set . 32
10.3 Engine . 32
10.4 Alternator . 33
10.5 Shutdown apparatus . 33
11 Documentation . 33
11.1 General . 33
11.2 Installation . 33
11.3 Operation. 34
11.4 Inspection and maintenance . 34
Annex A (informative) Generator set classification criteria . 35
A.1 General . 35
A.2 Functioning mode . 35
A.3 Services provided . 35
A.4 Application classes . 35
A.5 Lifespan . 36
A.6 Generator set components design . 36
A.6.1 Engine . 36
A.6.2 Alternator . 37
A.6.3 Starting systems . 37
A.7 Configuration types . 37
A.8 Installation modes. 38
Annex B (informative) Identification file . 39
B.1 General . 39
B.2 Electrical construction characteristics . 39
B.3 Mechanical construction characteristics . 39
Annex C (informative) Maintenance schedule . 40
Annex D (informative) Example of commissioning records sheet. 41

Figure 1 – General functional configuration of micropower plant in micropower system . 9

– 4 – IEC TS 62257-7-3:2018 © IEC 2018
Figure 2 – Micropower plant Type A: single generator set . 14
Figure 3 – Micropower plant Type B: multiple generator sets in micropower plant . 15
Figure 4 – Micropower plant Type C: single generato
...