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INTERNATIONAL
STANDARD

Flow battery energy systems for station ary appl ications -

Pa rt 2-2: Safety req u i rements

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 IEC 62932-2-2
Edition 1.0 2020-02

INTERNATIONAL
STANDARD

Flow battery energy syste ms for stationary appl ications -

Part 2-2: Safety req u i reme nts

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION

ICS 29.220.99 ISBN 978-2-8322-7854-3

Warning! Make sure that you obtained this p u b l i cation from an authorized distributor.

® Registered trademark of the International Electrotechnical Commission

 -2- IEC 62932-2-2:2020 © IEC 2020

CONTENTS

FOREWORD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
I N TROD UCTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
1 Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
2 Normative references . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3 Terms, definitions and abbreviated terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.1 Terms and definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2 Abbreviated terms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4 Procedure of the risk analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
5 Safety requirements and protective measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.2 Risk information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.3 Electrical hazards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.3.1 Electrical shock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
5. 3. 2 Short-circuits ................................................................................................. 10
5.3.3 Leakage currents ........................................................................................... 11
5.4 Hazards of gaseous emissions .................................................... .......................... 11
5.4.1 General .................................................... ..................................................... 11
5. 4. 2 Harmful gas ................................................................................................... 12
5. 4. 3 Ventilation ..................................................................................................... 13
5. 4. 4 Warning sign ................................................................................................. 13
5.4.5 Close vicinity to emissions ........................................... .................................. 14
5.5 Hazard posed by liquids .................... .................................................................... 14
5.5.1 General .................................................... ..................................................... 14
5.5.2 Detection of electrolyte leakage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
5.5.3 Protective measures against leakage ............................................................. 14
5.5.4 Specific information ....................................................................................... 14
5.5.5 Flow path identification ....................................................... ........................... 15
5.6 Hazards of mechanical cause ......................................................... ...................... 15
5. 7 Operational hazards and measures ............................................. .......................... 15
5.7.1 General .................................................... ..................................................... 15
5. 7.2 Start ......................................................... ..................................................... 15
5. 7.3 Remote monitoring and control systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
5.7.4 Protection ...................................................................................................... 16
5.7.5 Auxiliary power failure ................................................................................... 16
6 Instructions .................................................... ... .. . .. . ....................................................... 16
7 Identification labels or marking ..................................................... ................................. 16
7.1 Name plate information ......... ... ... .. . .. .. . .. . . . . . ........................................................... 16
7.2 Warning label information and location ................................................................. 17
8 Transport, storage, disposal and environmental aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
8.1 Packing and transport ......... .................................................................................. 17
8.2 Dismantling, disposal, and recycling ..................................................................... 17
9 Inspection ...................................................... ... .. . .. . ....................................................... 17
10 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
11 Verification tests for protective measures ...................................................................... 18
IEC 62932-2-2:2020 © IEC 2020 -3-

11.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
11. 1. 1 Tests ............................................................................................................. 18
11.1.2 Test object. .................................................................................................... 19
11.1.3 Test category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
11.2 Dielectric strength of the parts in contact with the fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
11.2.1 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
11.2.2 Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
11.2.3 Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
11.2.4 Test and acceptance criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
11.3 Operational sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
11.3.1 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
11.3.2 Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
11.3.3 Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
11.3.4 Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11.3.5 Acceptance criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11.4 Emergency stop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11.4.1 Requirement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11.4.2 Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11.4.3 Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11.4.4 Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11.4.5 Acceptance criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11.5 Protection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11.5.1 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
11.5.2 Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
11.5.3 Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
11.5.4 Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
11.5.5 Acceptance criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
11.6 Safety requirement for stacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Annex A (informative) Recommended structure of user manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
A.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
A.2 Table of contents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
A.3 Safety warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
A.4 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
A.5 Product description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
A.5.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
A.5.2 Technical specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A.5.3 System structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A.5.4 Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A.5.5 Operational sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A. 6 Site requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A.6.1 Location and load . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A.6.2 Access and clearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A.6.3 Precautionary measures for fluid containment.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
A.6.4 Ventilation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
A.6.5 Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
A. 7 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
A.7.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
A.7.2 Checks before operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
A.7.3 Energizing and de-energizing the system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
 -4 - IEC 62932-2-2:2020 © IEC 2020

A74 . . Valve status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

A.7.5 Specific operations ........................................................................................ 24
A.7. 6 Notices for operation ....... .............................................................................. 24
A8. Alarms and fault finding ........................................................................................ 25
A9. Maintenance .......... ............................................................................................... 25
A.10 Contact information ............................................................................................... 25
Annex B (normative) Safety requirements for stacks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
B.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
B2. External short-circuit of the stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
B21 . . Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
B22 . . Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
B23 . . Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
B24 . . Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
B.2.5 Acceptance criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
B.3 Heat shock strength . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
B.3.1 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
B.3.2 Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
B.3.3 Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
B.3.4 Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
B.3.5 Acceptance criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
B.4 Leakage of the stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
B.4.1 Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
B.4.2 Category . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
B.4.3 Number of samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
B.4.4 Test . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
B.4.5 Acceptance criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Bibliography . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Figure 1 - Flow battery energy system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Table 1- List of verification tests for protective measurements ............................................ 18

Table B.1 - List of verification tests for stacks for protective measurements . . . . . . . . . . . . . . . . . . . . . . . . . 26
IEC 62932-2-2:2020 © IEC 2020 -5-

INTERNATIONAL ELECTROTECHNICAL COMMISSION

FLOW BATTERY ENE RGY SYSTEMS FO R STATIONARY AP PLICATIONS -

P a rt 2-2: Safety req u i re m e n ts

FOREWORD

1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The objective of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
this end and in addition to other activities, IEC publishes International Standards, Technical Specifications,
Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as "IEC
Publication(s)"). Their preparation is entrusted to technical committees; any IEC National Committee interested
in the subject dealt with may participate in this preparatory work. International, governmental and non­
governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with
the International Organization for Standardization (ISO) in accordance with conditions determined by agreement
between the two organizations.
2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees. While all reasonable efforts are made to ensure that the technical content of IEC Publications is
accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any
end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence between
any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter.
5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
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 edition.
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 62932-2-2 has been prepared by IEC technical committee 21:
Secondary cells and batteries, in collaboration with IEC technical committee 105: Fuel cell
technologies.

The text of this International Standard is based on the following documents:

FDIS Report on voting

21/1029/FDIS 21/1035/RVD

Full information on the voting for the approval of this International Standard can be found in the
report on voting indicated in the above table.

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

A list of all parts in the IEC 62932 series, published under the general title Flow battery energy
systems for stationary applications, can be found on the IEC website.
 -6- IEC 62932-2-2:2020 © IEC 2020

The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be

• reconfirmed
• withdrawn
• replaced by a revised edition, or
• amended.
IEC 62932-2-2:2020 © IEC 2020 - 7 -

INTROD UCTION

A flow battery system (FBS) can be utilized in a flow battery energy system (FBES). Such an
FBES can consist of:

- a flow battery system,

- a power conversion system,
- other equipment and surroundings.

The FBES is connected to the external power input/output via a point of connection ( POC).

This document covers the domain of the FBES, as shown in Figure 1. Energy to the auxiliary
systems such as the battery management system (BMS), the battery support system (BSS),
and the power conversion system (PCS) may be supplied by one of the following:

a) direct connection to the external power source;

b) the internal power source of the FBES or FBS itself.

Filow bnllsry anargy .,.tam

-
PtMel" hput./Qul:put
J
"
.J
, Power conversion system I
?OC

Flow b911:ery (system) ' Power lnpufllUllUt

I BMS
I I BSS
I
I stadlt•)
I I Al.it! dn:ulaticn system
I

Fi g u re 1 - Flow battery energy system

 -8 - IEC 62932-2-2:2020 © IEC 2020

FLOW BATTERY ENE RGY SYSTEMS FO R STATIONARY AP PLICATIONS -

P a rt 2-2: Safety req u i re m e n ts

1 Scope

This part of IEC 62932 applies to flow battery systems for stationary applications and their
installations with a maximum voltage not exceeding 1 500 V DC in compliance with
IEC 62932-1.

This document defines the requirements and test methods for risk reduction and protection
measures against significant hazards relevant to flow battery systems, to persons, property and
the environment, or to a combination of them.

This document is applicable to stationary flow battery systems intended for indoor and outdoor
commercial and industrial use in non-hazardous (unclassified) areas.

This document covers significant hazards, hazardous situations and events, with the exception
of those associated with natural disaster, relevant to flow battery systems, when they are used
as intended and under the conditions foreseen by the manufacturer including reasonably
foreseeable misuse thereof.

The requirements described in this document are not intended to constrain innovations. When
considering fluids, materials, designs or constructions not specifically dealt with in this
document, these alternatives are evaluated as to their ability to yield levels of safety equivalent
to those specified in this document.

2 Normat i ve refe re n ces

The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements 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 60079-10-1, Explosive atmospheres - Part 1 0- 1 : Classification of areas - Explosive gas

atmospheres

IEC 60364-4-41, Low-voltage electrical installations - Part 4-4 1 : Protection for safety -
Protection against electric shock

IEC 60364-4-43, Low-voltage electrical installations - Part 4-43: Protection for safety -
Protection against overcurrent

IEC 60364-6, Low voltage electrical installations - Part 6: Verification

IEC 61936-1, Power installations exceeding 1 kV a.c. - Part 1 : Common rules

IEC 62485-2:2010, Safety requirements for secondary batteries and battery installations -
Part 2: Stationary batteries

IEC 62932-1, Flow battery energy systems for stationary applications - Part 1 : Terminology and
general aspects

ISO 7010, Graphical symbols - Safety colours and safety signs - Registered safety signs
IEC 62932-2-2:2020 © IEC 2020 -9-

3 Terms, defi n it i o ns a n d abbrevi ated terms

3.1 Terms and d efi n i t i ons

For the purposes of this document, the terms and definitions given in IEC 62932- 1 apply.

ISO and IEC maintain terminological databases for use in standardization at the following
ad dresses:

• IEC Electropedia: available at http://www.electropedia.org/

• ISO Online browsing platform: available at http://www.iso.org/obp

3.2 A b b re v i ated terms

BMS battery management system

BSS battery support system
EES electrical energy storage
FBES flow battery energy system
FBS flow battery system
FMEA failure mode and effects analysis
FTA fault tree analysis
GHS global harmonized system
HAZOP hazard and operability study
MSDS material safety data sheet
PCS power conversion system
POC point of connection
sos safety data sheet
U PS uninterruptible power system

4 P ro ce d u re of t h e r i s k a n a l ys i s

A written risk analysis shall be performed on an FBES to ensure that:

a) all reasonably foreseeable hazards and hazardous events, including reasonably

foreseeable misuse throughout the anticipated lifetime, have been identified;
b) the risk for each of these hazards has been estimated from the combination of its probability
of occurrence and of its foreseeable severity;
c) the two factors which determine each one of the estimated risks (probability and severity)
have been eliminated or reduced to a level not exceeding the acceptable risk level as far
as reasonably possible according to the following principles in the order given:
- eliminate hazards or reduce risks by inherent design measures,
- take necessary protective measures in relation to risks that cannot be reduced by
inherent design measures,
inform intended users and where appropriate other persons of the residual risks, indicate
whether any particular training is required and specify any need to use personal
protective equipment.

For example, failure mode and effects analysis (FMEA), fault tree analysis (FTA) methods,
hazard and operability study (HAZOP), and/or the following International Standards shall be
used as guidance:

• IEC 60812;
• IEC 61025.
 -10- IEC 62932-2-2:2020 © IEC 2020

5 Safety requ i re m e nts a n d protecti ve m e a s u res

5.1 Genera l

Each secondary battery has a different structure and therefore only the features critical or
specific to the flow battery shall be taken into consideration. The flow battery energy system as
shown in Figure 1 differs from other secondary batteries, in that a system for circulating the
electrolyte is present. The fluid circulating system consists of tanks, pumps, piping, sensors
and some safety-relevant devices.

From a chemical safety point of view, since fluid is contained in tanks, pipes and stacks, the
sealing is an important factor. There is also the possibility of hazardous gases being present,
requiring that appropriate countermeasures be implemented.

Clause 5 specifies the safety requirements and protective measures in consideration of the
above-mentioned aspects.

5.2 R i s k info r m a t i on

The manufacturer shall provide the user with risk information based on the risk analysis to
describe hazards and the appropriate measures taken or to be taken for mitigation purposes.

The information shall include a safety data sheet (SOS).

The information can be provided in the form of a user manual. See the recommended structure
for user manual in Annex A.

5.3 E l ectr i c a l hazards

5.3. 1 E l ectri ca l shock

The FBS is an electrical energy storage device and contains hazardous live parts of DC and/or
AC voltage which can cause a risk of electrical shock. Electrolyte is to be considered as carrying
dangerous voltages.

Batteries are sources of dangerous voltages and energy (current flow) also when they are not
connected to an external power circuit. In flow batteries the amount of residual energy is, when
no electrolyte circulates, limited to the charge stored in the electrolyte remaining in the stack
itself. In all cases protective measures according to IEC 60364-4-41 shall be implemented.

5.3.2 S h o rt-c ircu its

The electrical energy stored in an FBS can be released in an inadvertent and uncontrolled
manner due to short-circuiting the terminals. Because of its considerable level of energy and
subsequent high current, the heat generated can melt metal, produce sparks, cause explosion,
or vaporize fluid.

To avoid short-circuits, protective devices such as insulation shrouds, fuses and circuit breakers
shall be installed in a way that a short-circuit does not occur under any foreseeable conditions.
For the type of conductor arrangement of unprotected sections, IEC 60364-4-43 shall be taken
into consideration.

For protective measures, the FBS shall mitigate a short-circuit fault which occurs outside stacks
by:

stopping the supply of energy and fluids to the flow battery cells;
- stopping PCS and opening circuit breaker(s); and,
interrupting the short-circuit current path by using fuses between stacks.
IEC 62932-2-2:2020 © IEC 2020 - 11-

It is suggested that each stack has a fuse to break the short-circuit path. Specific location and
quantity of fuses and/or circuit breakers shall be agreed and decided between the manufacturer
and the system user in consideration of cell protection and system safety.

The intrinsic safety of the stack under short-circuit conditions shall be verified according to
Annex B.

5.3.3 Leakage c u rrents

In a system in which no point of the battery installation is directly connected to earth, ground
faults in the FBS are, due to the large amount of fluid in the fluid handling parts (pumps, pipes,
stacks, tanks), a particular problem, and system operators shall be well informed of this matter.
Ground faults can cause the following significant risks:

electrocution when a person accesses the fluid leaking from piping, cells and/or other
components of the fluid system;

NOTE 1 In this case a person's body becomes a part of the circuit of the leakage current.

arcs and fire when short-current is established by the fluid leaking from piping, cells and/or
other components of the fluid system.

NOTE 2 The criticality of arcs and fire depend on the electrical conductivity of the fluid. If the fluid has low electrical
conductivity, leakage current is small and severity of the risk is low. This also depends on the configuration of stacks.
Thus, the detection level is designed taking dangerous leakage current level into account.

The circuit of the FBS shall be properly insulated from other local conductive parts. The
minimum insulation resistance between the battery circuit and other local conductive parts shall
meet the requirements of IEC 62485-2:2010, 6.4. The minimum insulation resistance between
them shall be greater than 100 0 per volt of the nominal voltage of the FBS.

The insulation shall resist the environmental effects of temperature, dampness, dust, gases,
steam, and mechanical stress.

Before carrying out any test, the absence of hazardous voltage between the battery and the
associated rack or enclosure shall be verified.

The battery shall be isolated from the external circuit before an insulation-to-ground resistance
determination test is carried out.

The insulation shall be verified in accordance with the test method in 11.2.

Protective devices for detecting grounding faults shall be provided in the FBS or in the external
system, such as a power conversion system, in order to account for a malfunction in the
insulation.

5.4 Hazards of g a s e o u s e m is s i ons

5.4. 1 Genera l

Flow batteries can produce gases that can be explosive (hydrogen), toxic (bromine), or
corrosive, or that can affect the respiratory system. The quantities produced depend on the
operating conditions of the FBS and their release to the environment shall be managed with
adequate safety features (e.g. ventilation, absorption traps, scrubbers, voltage limits).

In general, gases are produced in the stacks and accumulated in the system. For example, in
the case of the FBS, gases are accumulated in the top portion of the tanks.

Since gas generation and accumulation depend on the characteristics and construction of
individual FBS, the gas hazard presents different levels of risk in individual FBS.
 -12 - IEC 62932-2-2:2020 © IEC 2020

When hydrogen is produced in an FBS, for example, the generation rate of hydrogen increases
as the FBS is charged above the rated voltage range. The correlation between the charging
voltage and the gas generation cannot be expressed by a common equation, however, because
the gas generation rate depends highly on the characteristics of cell components and fluids
which can vary between manufacturers.

The gas emission and its mitigation shall be considered in the flow battery design process. It is
suggested to install necessary gas monitoring equipment with alarms and appropriate interlocks.

5.4.2 Ha rmfu l g a s

5.4.2 .1 Exp l o s ive gas

The risk level of explosive gases increases if the following hazards coincide:

generation and accumulation of combustible gases,

their mixture with oxygen,
presence of ignition sources.

The FBS shall have protective measures against the above hazards, including but not limited
to:
reduction in the generation of combustible gases,
dilution of combustible gases,
prevention of diffusion of gases outside the volume where they are generated,
elimination of ignition sources,
prevention of external oxygen ingress.

5.4.2.2 T ox i c g a s

The risks caused by toxic gases increase if the following hazards coincide:

generation and accumulation of toxic gases,

human access to the vicinity of toxic gases.

The FBS shall have protective measures against the above hazards, including but not limited
to:

elimination of toxic gases,

dilution of toxic gases,
collection of toxic gases by a scrubber,
limitation of human access.

5.4.2.3 Co rros ive g a s

The risk level of corrosive gases increases if the following hazards coincide:

generation and accumulation of corrosive gases,

human access to the vicinity of corrosive gases.

The FBS shall have protective measures against the above hazards, including but not limited
to:
construction of the system with corrosion-resistant material,
elimination of corrosive gases,
dilution of corrosive gases,
collection of corrosive gases by a scrubber,
limitation of human access.
IEC 62932-2-2:2020 © IEC 2020 - 13-

5.4.2 .4 Gases affecting the res p i ratory system

There are cases where gases affecting the respiratory system are generated and accumulated.
The risks caused by gases increase if the following hazards coincide:

generation and accumulation of gases affecting the respiratory system,

human access to the vicinity of gases affecting the respiratory system.

The flow battery system shall have protective measures against the above hazards, including
but not limited to:

elimination of gases affecting the respiratory system,

dilution of gases affecting the respiratory system,
collection of gases affecting the respiratory system by a scrubber,
limitation of human access.

5.4.3 Venti l a t i on

5.4.3.1 G ene ra l

The manufacturer shall specify the ventilation requirements for the room where the FBS is
installed. This specification shall involve warning signs, operator access limitation, mitigation
of static discharges, numbers of air exchanges in m3/h, required air flow patterns and exhaust
direction. When the FBS is installed outdoors, the safety requirements and procedures for
approaching personnel shall be specified. The manufacturer shall provide data and a
measurement method used to determine the gas emission rating, and ventilation measures shall
be implemented based on IEC 60079-10- 1. Reference shall be made to the theoretical minimum
ventilation flow rate to dilute the gases, which is given in IEC 60079-10-1.

Ventilation is required to ensure that no combustible or harmful gases reach a critical

concentration level. The ventilation requirement shall be met by either one or a combination of
the following methods:

natural ventilation,
forced ventilation through the room or enclosure.

5.4.3.2 N at u ra l vent i l at i on

When natural ventilation is used, battery rooms or enclosures shall be equipped with an inlet
and an outlet for the air with a minimum free opening area which meets the ventilation
requirements.

5.4.3.3 Forced vent i l at i on

When forced ventilation is used, gases which are released from the FBS into the room or
enclosure shall be expelled to the atmosphere using a ventilation system, which may combine
an opening and fan. If forced ventilation is essential for the safe operation of the FBS, then an
appropriate interlock shall prevent its operation when the forced ventilation is not operating or
has failed.

5.4.4 Wa rning s i g n

Appropriate warning signs which prohibit sparks, smoking, open flame, and electrostatic
discharges shall be placed at the entrance of the hazardous area as determined in accordance
with IEC 60079-10-1.
 -14 - IEC 62932-2-2:2020 © IEC 2020

5.4.5 C l ose v i c i n i ty to e m i s s i ons

The dilution of gases is not always fully achieved in the close vicinity of the exhaust of released
gases or at the outlet of direct forced ventilation, therefore a safety distance from the outlet
shall be observed. The dispersion of gases depends on the gas emission rate and the type of
ventilation close to the source of emission.

5.5 Hazard posed by l i q u i d s

5.5.1 General

The impact of the fluid involved in the FBS leakage can be categorized in terms of toxicity,
corrosiveness, environmental impacts, and flammability.

Since the fluids are flowing through the fluid system, there is a possibility that a leakage will
continue unattended or unmitigated if the detection of the leakage and/or the protection against
the leakage are inappropriate. In addition, fluids supplied to the stacks are stored in the common
tank in a large volume. The following are the basic measures against such hazards and are
further described in 5.5.2 to 5.5.5:

ensuring the sealing performance of the fluid system,

incorporating corrosion resistance in the design and the material of the parts that come into
contact with the electrolyte,
detecting leakage and taking appropriate measures,
preventing leakage to the surroundings, and,
providing information and markings concerning the fluid.

5.5.2 Detect ion of e l ectrolyte l ea k a g e

Leakage shall be detected by appropriate protection measures such as a leakage sensor. The
detection and protective functions shall be verified appropriately in accordance with 11.5.

The detection of the fluid shall initiate the necessary countermeasures such as stopping the
pumps and closing the valves.

5.5.3 P rotect i ve m e a s u res a g a inst l e a ka g e

It is required that the flow battery energy system (FBES) has a collecting tray (also known as
collecting basin) under the tanks, which is stable to liquids and has a volume at least equal to
the largest tank size of the FBS. Refer to the local safety regulations for other or additional
protective measures.

5.5.4 S p e c ific info r m at i on

The manufacturer shall provide information relevant to the fluids which details:

- the primary emergency measures that shall be taken if there is:

a) exposure and/or contamination of persons by substances emitted from the FBS,
b) contamination of the environment by substances emitted from the FBS,
personal protective equipment:
A material safety data sheet (MSDS) shall indicate that the use of synthetic clothing which
can cause electrostatic discharge is not recommended in a hazardous area where explosive
gases are present and that personal protective equipment shall include flame retardant and
anti-static clothing.
IEC 62932-2-2:2020 © IEC 2020 -15-

The following four pieces of information shall be indicated on each tank:

content and international sign ( Global Harmonized System ( GHS)) if necessary depending
on the chemistry,
volume,
polarity,
warning label in case the tank contains hazardous liquids.

5.5.5 Flow p ath i dent ification

Most flow batteries operate with two distinct fluids in which the electrochemically active species
are dissolved, suspended or present as gases.

Each of the fluids may require particular attention and methods of containment in case of
spillage or maintenance.

To reduce the risk of hazards during intervention on the fluid system, the fluid pipes shall be
clearly identified with the name of positive fluid or negative fluid written in two distinct colours
on the tanks and pipes, together with an arrow indicating the flow direction in the relevant pipes.
Symbols such as"+"as positive and"-"as negative are also available for identification marking.

5.6 Hazards of m echan i c a l c a u se

The flow battery is a complex assembly of electricity and fluid-carrying components housing
large volumes of chemicals.

All these structural components shall be properly dimensioned and tested taking into
consideration temperature and pressure at specified conditions, material aging processes and
extreme conditions of temperature and pressure.

Particular attention shall also be given to the fact that the fluids are chemically aggressive and
can cause an accelerated loss of mechanical stability and cross-section loss.

5.7 O pe ratio na l hazards and m ea s u res

5.7 .1 G ene ra l

When the flow battery is designed to work with other equipment upstream and/or downstream,
such as a control centre upstream, a signal interface or other means shall be provided to enable
a coordinated operation, including start, stop, emergency shutdown, charge and discharge.
Improper integration can cause unintentional operation which potentially leads to a hazardous
situation.

Proper coordinated operation shall be confirmed by appropriate methods. The verification

method shall be in accordance with 11.3.

5.7.2 Start

The FBS shall be started only when the starting condition is achieved through ensuring that:

all safeguards are in place and are functional,

the safety conditions have been fulfilled for restart after a stop,
non-hazardous conditions are verified for intentional restarting actuation,
suitable interlocks are provided for correct sequential starting.
 -16- IEC 62932-2-2:2020 © IEC 2020

5.7.3 Rem ote m o n i t o ring and control syste m s

An FBS and/or FBES that can be operated remotely shall have a local, labelled switch or other
means to disconnect the system from remote signals that may be used while a local operator
performs inspection or maintenance. The implementation of a remote monitoring system shall
be considered in order to check if the system is operating safely. The data collected
automatically from the FBS or through an FBES inquiry can help to evaluate its state of health
and the remaining life of its components. Diagnosis is performed by monitoring the change of
capacity or changes in the measured parameters. These data can be transmitted through an
information network in a timely manner. Cyber security is important not only for remote
monitoring but also for the system connected to the Internet. Refer to IEC 62351 (all parts) for
additional guidance.

5.7.4 P rotect ion

The FBS and FBES shall be equipped with appropriate protective devices to detect abnormal
situations and initiate an emergency stop.

An optional test to verify such protective functions is provided in 1 1.5.

5.7.5 Auxi l i a ry powe r fa i l u re

In case of an auxiliary power failure, the FBES shall be designed in such a way to ensure:

- the detection of loss of power in the FBES,

- the trigger of an alarm informing on the situation at the designated terminal,
initiation of a proper designated shutdown including separation from the POC, and
- stopping of the pumps and closing of the designated valves.

As an example, this can be facilitated through integrating a U PS for supporting the BMS
operation and/or supplying power from a separate secure source.

6 Instruct i o n s

The battery and its subsystems shall be installed according to the manufacturer's instructions.

The instructions provided by the manufacturer shall cover the layout schematics, the required
building materials and the installation and start-up procedures to fulfil local/regional standards
and regulations.

7 Id e ntifi cati o n labe l s o r m a rk i n g

7.1 N a m e p l ate info rm a t i on

The name plate/label(s) shall include the following information:

a) manufacturer's name,
b) manufacturer's or supplier's type reference,
c) serial number (optional),
d) date of commissioning (optional),
e) maximum AC and/or DC voltage in operation (V),
f) maximum AC and/or DC current in operation (A)
g) rated AC and/or DC power in operation (kW),
h) rated energy capacity (kWh),
IEC 62932-2-2:2020 © IEC 2020 - 17 -

i) transport weight (kg) (optional),

j) chemical type of battery (active materials and solvent shall be indicated),
k) volume amount of hazardous material.

7.2 Warning l a b e l info rm a t i on and l oc a t i on

The warning labels shall be placed at such a position that they are visible from any direction of
approach to the FBES before entering the area where a particular piece of information is
desirable and/or hazards are present.

The labels/pictograms shall cover, according to ISO 7010, the appropriate ones for

safe conditions (green square),

- fire protection (red square),

and the appropriate mandatory ones for

must do (blue circle),

- warn of hazard (yellow triangle).

The meaning of each selected symbol and possibly associate information shall be explained
and/or included in the FBES instruction manual.

8 Tra n s po rt, stora g e, d i spos a l a n d e nv i ro n m e nt a l aspe cts

8.1 P a c k i n g and t rans p o rt

Various national and international regulations cover the packing and transport of the FBS and
the risks of accidental short-circuits, heavy mass and spillages of fluid.

For short-circuit protection, appropriate measures shall be taken, such as emptying the fluids
from the stack or discharging the battery to 0 V. Before transportation, the stack terminals shall
be properly insulated for short-circuit protection and proper measures for leakage protection
shall be considered. Conformity with regional and international transportation regulations shall
be ensured.

8.2 D i s m ant l i ng, d i s p o s a l , and recy c l ing

Dismantling and disposal of an FBS shall be undertaken by competent and trained personnel.
The relevant national and international regulations shall be followed.

9 Inspect i o n

A regular inspection o f the flow battery system and its operation environment i s required for
functional and safety reasons.

The inspection shall be conducted in accordance with the manufacturer's requirements, which
shall include a check of:

- the appearance of the equipment, for example any signs of physical damage such as dents
or corrosion,
leaks from stacks, pipes, valves, pumps or tanks,
abnormal noise, vibration and odour from the equipment, especially from power electronic
equipment and mechanical parts such as pumps and fans.
 -18- IEC 62932-2-2:2020 © IEC 2020

1O M a i nte n a n ce

A comprehensive maintenance plan shall be prepared owing to the fact that the FBS consists
of various equipment and components.

The maintenance plan shall clarify the items to be maintained, the required procedures and
maintenance intervals and shall cover items such as:

periodical maintenance, for example, daily, weekly, monthly and annual inspections,
replacement of parts,
overhaul of equipment.

During a maintenance operation personnel may work close to the battery system. The personnel
shall be competent to carry out such works, and shall have been trained in any special
necessary procedures. To minimize the risk of injury, the FBS shall be designed with battery
terminal covers which allow routine maintenance whilst minimizing exposure to live parts
through the following:

a minimum distance of 1,50 m between simultaneously touchable conductive live parts of

the battery having a potential exceeding 120 V DC (nominal voltage),
devices to sectionalize the FBS into groups of less than 1 500 V DC when operating
batteries with nominal voltages above 1 500 V DC,
fuse carriers which prevent contact with live parts.

All metallic personal objects shall be removed from the hands, wrists and neck before starting
work. For FBSs where the nominal voltage is more than 120 V DC, insulated protective clothing
and local insulated coverings shall be required to prevent personnel from making contact with
the floor or parts connected to earth or ground. Batteries shall be neither connected nor
disconnected when current is flowing.

NOTE Back feeds from chargers or parallel batteries can cause the accessible contacts to be live when the fuse is
removed. Where screw type fuses are used, the battery output terminals can be connected to the bottom contact.
Screw type fuses cannot be used where both terminals remain live after the fuse is removed, for example, within
parallel battery systems. Batteries can be equipped with flame arrestor vent plugs (see IEC 60050-482:2004,
482-05-11) to avoid internal explosions caused by an external naked flame or spark.

11 Ve rifi cati o n tests fo r protect i ve meas u res

1 1 .1 Genera l

1 1 .1 .1 Tests

Clause 11 specifies the methods and criteria of the tests which shall be applied to verify some
of the requirements in Clause 5. The requirements in Clause 5 shall be verified by conducting
the tests in accordance with the criteria in Clause 11. The tests are summarized in Table 1.

Table 1 - L i st of verifi c a t i on tests fo r p rotective m e a s u rements

Test Test category Test object Sample nu mber

Dielectric strength of fluid Routine test System Whole system

systems

Operational sequence Routine test System Whole system

Emergency stop Routine test System Whole system

Protection Routine test System Whole system

Stacks Refer to Annex B.

IEC 62932-2-2:2020 © IEC 2020 - 19-

1 1 . 1 .2 Test o bject

Possible test objects are:

component of the flow battery system,

sub-system,
- whole system.

1 1 . 1 .3 Test cate g o ry

The following categories apply:

- type test,
routine test.

1 1 .2 D i e l ectr i c strength of the p a rts in contact with t h e f l u i d

1 1 .2. 1 Req u i re m ents

Fluid circulation systems including tanks and stacks shall have adequate dielectric strength and
resistance to avoid grounding fault in the FBES where the DC circuit is not earthed.

1 1 .2.2 C ateg o ry

This test is classified as a routine test.

1 1 .2.3 N u m be r of s a m p les

Each system as a whole shall be tested.

1 1 .2.4 Test and acce ptance c r i t e r i a

For low-voltage FBESs, the insulation resistance test and w i thstand voltage test shall be
performed according to IEC 60364-6.

For FBESs exceeding 1 kV AC or 1,5 kV DC, the w i t h s t and voltage test shall be performed
according to IEC 61936-1.

1 1 .3 O p e ra t i o n a l seq u ence

1 1 .3.1 Req u i re m ents

The FBS shall be coordinated with the power conversion system to change its operation mode
safely between charging or discharging.

1 1 .3.2 Categ o ry

This test is classified as a routine test.

1 1 .3.3 N u m be r of s a m p les

Each system as a whole shall be tested.

 -20- IEC 62932-2-2:2020 © IEC 2020

1 1 .3.4 Test

This test shall be conducted under the following conditions whereby operating modes are
changed as below. Detail testing conditions shall be defined between the system supplier and
the user:

a) stop state to charge state and vice versa,

b) stop state to discharge state and vice versa,
c) charge state to discharge state and vice versa,
d) charge state to the end-of-charge,
e) discharge to the end-of-discharge.

It is recommended that charge and discharge in the procedure of d) and e) are terminated by
the charge termination condition or discharge termination condition, respectively. The end-of­
charge or end-of-discharge condition is system specific and has to be specified by the
manufacturer for a particular current, voltage or power setting.

1 1 .3.5 Acce ptance c r i t e r i a

The system shall be transferred between operation modes safely. Main components such as
circuit-breaker, pumps, valves, indicating lamp and metering shall work according to the design
specified between the system supplier and the user.

1 1 .4 E m e rg ency stop

1 1 .4.1 Req u i re m ent

The emergency stop shall work safely according to the system design.

1 1 .4.2 C ateg o ry

This test is classified as a routine test.

1 1 .4.3 N u m be r of s a m p les

All whole systems shall be subjected to this test.

1 1 .4.4 Test

This test shall be conducted under the following conditions:

a) the sample system is either charging or discharging,

b) the emergency stop is initiated.

1 1 .4.5 Acce ptance c r i t e r i a

The sample system shall immediately stop safely when the manual emergency stop is used.

1 1 .5 P rotect ion

1 1 .5.1 Req u i re m ents

Protection devices shall initiate the emergency shutdown procedure when fault conditions occur.

The FBS shall completely stop safely when fault conditions occur which initiate the emergency
shutdown procedure.
IEC 62932-2-2:2020 © IEC 2020 -21-

1 1 .5.2 Categ o ry

This test is classified as a routine test.

1 1 .5.3 N u m b e r of s a m p les

All whole systems shall be subjected to this test.

1 1 .5.4 Test

This test shall be conducted under the following conditions:

a) actual faults or simulated faults activate protection devices,

b) the following faults are used to trigger emergency shutdowns:
- grid faults such as overvoltage, undervoltage, overfrequency and underfrequency,
FBES system faults such as overvoltage, undervoltage, overcurrent, over-temperature,
under-temperature, overpressure, ground faults, fluid leak, control power down.

1 1 .5.5 Acce ptance c r i t e r i a

The FBS shall completely stop in a safe mode when the emergency shutdown procedure is
initiated by actual or simulated faults.

1 1 .6 S afety req u i re m ent fo r stacks

The tests of stacks described in Annex B shall be carried out in order to ensure safety.
 -22 - IEC 62932-2-2:2020 © IEC 2020

An n ex A
(i nfo rmative )
Reco m m e n d e d stru ctu re of u s e r m a n u a l

A.1 G e n e ra l

The user manual i s a n important document that i s designed t o provide the user with all relevant
information about the system.

Annex A recommends a structure for the user manual which can contain clauses (sections) that
address specifications, installation, site preparation, operating instructions, safety guidelines,
fault finding and emergency procedures. It is suggested that the manual be in a comprehensive
format that includes illustrations, pictures and references to engineering drawings where
appropriate.

Annex A is not intended to constrain alternative structures for user manuals. Annex A can be
used to check whether the proposed user manual includes those contents which are generally
regarded to be necessary.

Clauses A.2 to A.10 specify the recommended structure and contents.

A.2 Tabl e of c o ntents

Contents and page numbers are shown as the table of contents.

A.3 Safety warn i n g

The manufacturer provides a summary of potential safety risks for the flow battery so that the
users/operators have a good understanding of all safety instructions prior to operating the
system. This is one of the most important sections of the manual.

This clause includes precautionary statements about the restriction of access to the system,
such that only trained and qualified personnel may have access to the system.

Although safety warnings are comprehensively provided in this section, independent

precautions are also provided to remind users of specific safety matters in the corresponding
parts of the manual.

A.4 Introd u ct i o n

This clause provides a general introduction and a n overview of the manual. I t includes the
purpose and structure of the manual.

A.5 P ro d u ct d e s c ri pt i o n

A.5.1 Overv i ew

This subclause provides a general and brief description of the FBS to help in understanding the
user manual.
IEC 62932-2-2:2020 © IEC 2020 -23-

A.5.2 Tec h n ic a l s p e c i f i c at i o n s

This subclause includes details o f parameters and additionally the physical dimensions, and
weight, environmental transport and operating conditions, and control and monitoring features.

A.5.3 System struct u re

This subclause shows the configuration of the FBS with illustrations or drawings including
electrical diagrams, piping diagrams, and physical dimensions.

Relevant documents and drawings of each component can also be provided as attachments.

A.5.4 A p p l i ca t i o n s

This subclause describes applications of the FBS. It can include a summary of the control
principles of those applications.

A.5.5 O p e rat i o n a l s e q u e n ce

The operational sequence of both normal and abnormal operation (e.g. emergency shutdown)
is shown here. For example, it includes start, stop, charging or discharging operational
sequences.

The information provided clarifies conditions at each step of the operational sequence including
but not limited to, breaker ON/OFF, pump ON/OFF, erroneous conditions or other mandatory
conditions to proceed with the sequence further.

A.6 Site req u i re m e nts

A.6.1 Locati o n a n d l o a d

The floor loading requirements for the battery installation are stated in this subclause including
any additional loads that occur during installation, for example cranes or fork lift trucks.

Any requirements for the provision of slope conditions of floors, or secondary containment walls
are also included.

If necessary, descriptions and layout diagrams for positioning tanks and other equipment, and
requirements for mounting and fixing are stated.

The conditions for fixing and installing enclosures for stacks, pumps, pipework and tanks, if
applicable, are also included.

A.6.2 Access a n d c l e a r a n ce

Specific space requirements are suggested in this subclause to take into account safety and
installation, maintenance and cleaning.

A.6.3 P re c a u t i o n ary m ea s u res fo r fl u i d c o n t a i n m e n t

The manual provides instructions for protective measures against any potential leaks, spillage
caused by system failure or external events, taking into account the corrosive, toxic or caustic
nature of the fluids.
 -24 - IEC 62932-2-2:2020 © IEC 2020

A.6.4 Vent i l a t i o n

Flow batteries can generate gases (such a s hydrogen, chlorine) or vapour (such a s bromine)
or aerosols (fluid) during operation. Requirements for ventilation as a result of normal or
abnormal operation are provided in this subclause.

A.6.5 Tem pe ratu re

The safety, performance and life of flow batteries are temperature dependent. The suitable
temperature range for operation, transport and storage are stated here.

A. 7 Ope rat i o n

A.7.1 G e n e ra l

This clause provides full detailed instructions for system start up, shutdown, normal operations,
as well as how to deal with system alarms if applicable. It includes the following subclauses to
make it comprehensive.

A.7.2 C h ecks b efore o pe rat i o n

This subclause describes items to b e checked and confirmed before operation, such as
electrical power.

A.7.3 E n e rg iz i n g a n d de-e n e rg i z i n g t h e system

This subclause describes procedures of energizing and de-energizing the flow battery system
with relevant illustrations or diagrams for visual explanation.

The procedures include, but are not limited to, identification of circuit breakers to be switched
on or off, the order of switching on or off of the circuit breakers and indicator status such as
light on/off.

The flow battery system can consist of several sets of equipment, and the procedures provide
a clear and comprehensive order of energizing or de-energizing different components, such as
which one to be energized first.

A.7.4 Valve stat u s

The normal status of all the valves, such as open or closed, is shown in this subclause.

A.7.5 S p e c i f i c o p e rat i o n s

This subclause gives guidance to the user to start or stop specific operations such as scheduled
peak-cutting, stabilizing renewable energy.

The procedures include, but are not limited to, control of human machine interfaces, such as a
BMS or other equipment, as well as setting parameters and indicator status, in such a way that
a clear comprehensive sequence is provided.

The operating procedures for remotely-operated system or data acquisition system, if any, are
also provided here.

A.7.6 Noti ces for o p e rat i o n

Specific recommendations from the manufacturer such a s the effect o f depth o f discharge
versus lifetime, operations at low temperature or high temperature, if necessary, are provided
in this subclause.
IEC 62932-2-2:2020 © IEC 2020 -25-

A.8 Al arms a n d fa u l t fi n d i n g

This clause provides explanations and the actions/measures to be taken for all system alarms.

It can include corrective actions for each abnormal situation as well as protective measures to
be taken prior to any fault-finding activities.

A.9 M a i nte n a n ce

This clause describes the maintenance plan and procedures. Since the flow battery system
consists of various equipment and components, a dedicated clause is required for a
comprehensive maintenance plan.

The maintenance plan clarifies items to be covered, procedures and intervals, and can result in
such categories as:

periodical maintenance, for example, daily, weekly and monthly inspections,

replacement of parts,
overhaul of equipment.

A.1 O C o ntact i nfo rmat i o n

This clause provides the manufacturer's contact details including the company name, website,
hotline, service telephone number, fax and email to allow customers to receive information or
request help when needed. Supplementary information, such as declarations or descriptions of
licenses, patents and similar information is also included in this clause.
 -26 - IEC 62932-2-2:2020 © IEC 2020

An n ex B
(normative)
S afety req u i re m e nts f o r stacks

B.1 G e n e ra l

Annex B specifies methods and criteria of tests for stacks which shall be applied to verify some
of the requirements in Clause 5. Table B. 1 shows the list of the tests.

Table B.1 - L i st of ve rifi cat i o n tests fo r stacks for p rotective m e as u re m e n ts

Test Test category Te st object Sample nu mber

External short-circuit Type test Stack 1

Heat shock strength Type test Stack 1

Leakage Routine test Stack All stacks

B.2 Exte r n a l s h o rt-c i rc u i t o f t h e sta c k

B.2.1 Req u i re m e nts

An external short-circuit of the stack shall not cause fire, explosion or electrolyte leakage.

B.2.2 Cate g o ry

This test is classified as a type test.

B.2.3 N u m be r of s a m p les

One (1) sample shall be tested.

B.2.4 Test

This test shall be conducted as follows:

a) Keep ambient temperature in the range 20 ° C to 25 ° C,

b) Place the sample stack in the system designated for this test,
c) Charge battery fully and have the fluid circulation system active, i.e. electrolyte flow through
the stack,
d) Connect the positive and negative terminals of the sample stack with a resistive load having
a resistance of not more than 20 mo until 1) the battery is completely discharged, 2) the
integrated protective device has acted, or 3) the battery structure has failed, whichever
occurs first.

This test can be destructive and shall be carried out in an appropriate test facility under the
supervision of qualified person(s).

NOTE It is assumed that external short-circuit of a stack occurs when metal bars or wires touch a terminal of the
stack in the FSB. The electrical resistance of this short-circuit is assumed to be 20 mO.

B.2.5 Accepta nce c r i t e r i a

The test is passed if there is no fire, explosion or electrolyte leakage.

IEC 62932-2-2:2020 © IEC 2020 -27 -

B.3 H eat s h o c k stre n g t h

B.3.1 Req u i re m e nts

The stack shall withstand the thermal-induced mechanical stress when the fluid circulation
starts.

B.3.2 Cate g o ry

This test is classified as a type test.

B.3.3 N u m be r of s a m p les

One (1) sample of the stack or the sub-stack shall be tested.

B.3.4 Test

The temperature parameters used in B.3. 4 are defined as follows:

Tmax fluid manufacturer

: maximum fluid temperature specified by the manufacturer,

Tmin fluid manufacturer : minimum fluid temperature specified by the manufacturer,

Tmax ambient manufacturer : maximum ambient temperature of the stacks specified by the
manufacturer,

Tmin ambient manufacturer : minimum ambient temperature of the stacks specified by the
manufacturer
°
Tmax fluid = Tmax fluid manufacturer + 5 C

Tmin fluid = Tmin fluid manufacturer - 5 °C

°
Tmax ambient = Tmax ambient manufacturer + 5 C

Tmin ambient = Tmin ambient manufacturer - 5 °C

This test shall be conducted as follows:

a) expose the sample to whichever is the higher temperature of Tmax flu id or Tmax ambient•

b) circulate fluid which is used in the flow battery system with whichever is the lower
temperature of Tmin fluid or Tmin ambient to the sample for 1 h with the maximum inlet pressure
which the manufacturer specifies,
c) expose the sample to whichever is the lower temperature of Tmin flu id or Tmin ambient
continuously,
d) circulate fluid with whichever is the higher temperature of Tmax fluid or Tmax ambient to the
sample for 1 h with maximum inlet pressure which the manufacturer specifies,
e) repeat the procedures from a) to d) nine times.

NOTE The heat shock conditions are imposed 10 times in total.

B.3.5 Accepta nce c r i t e r i a

There shall be no visible fluid leakage.

B.4 L e a k a g e o f t h e stack

B.4.1 Req u i re m e nts

The intended use of the stack shall not cause leakage of the fluids.
 -28- IEC 62932-2-2:2020 © IEC 2020

B.4.2 Cate g o ry

This test is classified as a routine test.

Since this test is intended for all the stacks, it may be conducted either on individual stacks or
with a group of stacks.

B.4.3 N u m b e r of s a m p l e s

All the stacks shall be tested.

B.4.4 Test

This test shall be conducted as follows:

a) keep the ambient temperature within the manufacturer's specified temperature range,
b) circulate the fluids at the manufacturer's specified flow rate,
c) keep the fluids' temperatures within the manufacturer's specified range of the rated
temperature,
d) apply a fluid pressure of 1,2 times the maximum operating pressure to the inlet of the stack,
e) maintain the test pressure for at least 1 h, or longer, as necessary, to complete the leak
checks, while inspecting all external surfaces of the stack for any signs of leaks.

B.4.5 Accepta n c e crite r i a

There shall be no visible fluid leakage.

IEC 62932-2-2:2020 © IEC 2020 -29-

B i b l iography
IEC 60050-482, International Electrotechnical Vocabulary - Part 4 82: Primary and secondary
cells and batteries (available at http://www.electropedia.org)

IEC 60364-5-53, Low-voltage electrical installations - Part 5-53: Selection and erection of
electrical equipment - Devices for protection for safety, isolation, switching, control and
monitoring

IEC 60529, Degrees of protection provided by enclosures (IP Code)

IEC 60664-1, Insulation coordination for equipment within low-voltage systems - Part 1 :
Principles, requirements and tests

IEC 60721-3-2, Classification of environmental conditions - Part 3: Classification of groups of

environmental parameters and their severities - Section 2: Transportation and handling

IEC 60812, Failure modes and effects analysis (FMEA and FMECA)

IEC 60900, Live working - Hand tools for use up to 1 000 V A C and 1 500 V D C

IEC 61000 (all parts), Electromagnetic compatibility (EMC)

IEC 61025, Fault tree analysis (F TA)

IEC 61660-1, Short-circuit currents in d.c. auxiliary installations in power plants and substations
- Part 1 : Calculation of short-circuit currents

IEC 61660-2, Short-circuit currents in d.c. auxiliary installations in power plants and substations
- Part 2: Calculation of effects

IEC 61936-1, Power installations exceeding 1 kV a.c. - Part 1 : Common rules

IEC 62282-3-100, Fuel cell technologies - Part 3- 1 00: Stationary fuel cell power systems -
Safety

IEC 62282-3-300, Fuel cell technologies - Part 3-300: Stationary fuel cell power systems -
Installation

IEC 62351 (all parts), Power systems management and associated information exchange -
Data and communications security

IEC 62477-1, Safety requirements for power electronic converter systems and equipment -
Part 1 : General

IEC 62932-2-1, Flow battery energy systems for stationary applications - Part 2- 1 : Performance
general requirements and test methods

ISO 3864 (all parts), Graphical symbols - Safety colours and safety signs

ISO 7000, Graphic symbols for use on equipment - Index and synopsis (available from:
<http://www.graphical-symbols.info/equipment> )

ISO 13850, Safety o f machinery - Emergency stop function - Principles for design
 -30- IEC 62932-2-2:2020 © IEC 2020

CENELEC WORKSHOP AG REEMEN T, CWA 506 1 1, Flow batteries - Guidance on the

specification, installation and operation

United Nations, Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
(available at http://www.ghs-label.com/)
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