ISO 22734-2:2011

INTERNATIONAL  ISO
STANDARD 22734-2
First edition
2011-11-15
Hydrogen generators using water
electrolysis process —
Part 2:
Residential applications
Générateurs d’hydrogène utilisant le procédé d’électrolyse de l’eau —
Partie 2: Applications résidentielles
Reference number
ISO 22734-2:2011(E)
©
 ISO 2011

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ISO 22734-2:2011(E)
COPYRIGHT PROTECTED DOCUMENT
©  ISO 2011
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means,
electronic or mechanical, including photocopying and microfilm, without permission in writing from either ISO at the address below or ISO’s
member body in the country of the requester.
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Published in Switzerland
ii © ISO 2011 – All rights reserved

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ISO 22734-2:2011(E)
Contents Page
Foreword . v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 5
4 Operating conditions . 6
4.1 Energy consumption . 6
4.2 Feed water specifications . 6
4.3 Ambient environment . 7
4.4 Purge gas . 7
4.5 Oxygen venting . 7
4.6 Hydrogen venting . 7
4.7 Delivery of hydrogen . 8
5 Mechanical equipment . 8
5.1 General requirements . 8
5.2 General materials requirements . 9
5.3 Enclosures . 9
5.4 Pressure-bearing components . 11
5.5 Fans and ventilators .13
5.6 Pumps .13
5.7 Heat transfer system .13
5.8 Connection to potable water .14
6 Electrical equipment, wiring and ventilation .14
6.1 Fire and explosion hazard protection requirements .14
6.2 Electrical equipment .16
7 Control systems .18
7.1 General .18
7.2 Control function in the event of failure.19
7.3 Programmable electronic equipment .19
7.4 Start .19
7.5 Emergency stop .19
7.6 Stop .20
7.7 Self-correctable conditions .20
7.8 Interconnected installations .20
7.9 Safety components .20
7.10 Remote control systems .21
7.11 Alarms .21
7.12 Purge gas quantity .21
7.13 Reset .21
7.14 Suspension of safeguards .21
8 Ion transport medium .21
8.1 Electrolyte .21
8.2 Membrane .22
9 Protection of service personnel .22
10 Test methods .23
10.1 Type (qualification) tests .23
10.2 Routine tests .33
11 Marking and labelling .34
11.1 General requirements .34
11.2 Hydrogen generator marking .34
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ISO 22734-2:2011(E)
11.3 Marking of components .35
11.4 Warning signs.35
12 Documentation accompanying the hydrogen generator .35
12.1 General .35
12.2 Hydrogen generator ratings .36
12.3 Hydrogen generator installation .36
12.4 Hydrogen generator operation .38
12.5 Hydrogen generator maintenance .39
Annex A (informative) Hydrogen-assisted corrosion .40
Annex B (informative) Flammability limits of hydrogen .41
Bibliography .42
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ISO 22734-2:2011(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 22734-2 was prepared by Technical Committee ISO/TC 197, Hydrogen technologies.
ISO 22734 consists of the following parts, under the general title Hydrogen generators using water electrolysis
process:
—  Part 1: Industrial and commercial applications
—  Part 2: Residential applications
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ISO 22734-2:2011(E)
Introduction
The technology in this part of ISO 22734 is as follows.
In a hydrogen generator cell, electricity causes dissociation of water into hydrogen and oxygen molecules.
An electric current is passed between two electrodes separated by a conductive electrolyte or “ion transport
medium”, producing hydrogen at the negative electrode (cathode) and oxygen at the positive electrode (anode).
As water is HO, twice the volume of hydrogen is produced compared with oxygen.
2
Hydrogen gas produced using electrolysis technology can be utilized immediately or stored for later use.
The cell(s), and electrical, gas processing, ventilation, cooling, monitoring equipment and controls are
contained within an enclosure. Gas compression and feed water conditioning and auxiliary equipment may
also be included.
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INTERNATIONAL STANDARD ISO 22734-2:2011(E)
Hydrogen generators using water electrolysis process —
Part 2:
Residential applications
1 Scope
This part of ISO 22734 defines the construction, safety and performance requirements of packaged hydrogen
gas generation appliances, herein referred to as hydrogen generators, using electrochemical reactions to
electrolyse water to produce hydrogen.
This part of ISO 22734 is applicable to hydrogen generators that use the following types of ion transport
medium:
—  group of aqueous bases;
—  solid polymeric materials with acidic function group additions, such as acid proton exchange membrane
(PEM).
This part of ISO 22734 is applicable to hydrogen generators intended for indoor and outdoor residential use
in sheltered areas, such as car-ports, garages, utility rooms and similar areas of a residence. This part of
ISO 22734 includes cord-connected equipment for outdoor and garage use only.
Portable generators as well as hydrogen generators that can also be used to generate electricity, such as
reversible fuel cells, are excluded from the scope of this part of ISO 22734.
Hydrogen generators that also supply oxygen as a product are excluded from the scope of this part of ISO 22734.
This part of ISO 22734 is intended to be used for certification purposes.
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 1182, Reaction to fire tests for products — Non-combustibility test
ISO 3746, Acoustics — Determination of sound power levels and sound energy levels of noise sources using
sound pressure — Survey method using an enveloping measurement surface over a reflecting plane
ISO 3864-2, Graphical symbols — Safety colours and safety signs — Part 2: Design principles for product
safety labels
ISO 4126-1, Safety devices for protection against excessive pressure — Part 1: Safety valves
ISO 4126-2, Safety devices for protection against excessive pressure — Part 2: Bursting disc safety devices
ISO 4126-6, Safety devices for protection against excessive pressure — Part 6: Application, selection and
installation of bursting disc safety devices
ISO 7000, Graphical symbols for use on equipment — Index and synopsis
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ISO 22734-2:2011(E)
ISO 7010, Graphical symbols — Safety colours and safety signs — Registered safety signs
ISO 7866, Gas cylinders — Refillable seamless aluminium alloy gas cylinders — Design, construction and
testing
ISO 9300, Measurement of gas flow by means of critical flow Venturi nozzles
ISO 9951, Measurement of gas flow in closed conduits — Turbine meters
ISO 9614-1, Acoustics — Determination of sound power levels of noise sources using sound intensity — Part 1:
Measurement at discrete points
ISO 9809-1, Gas cylinders — Refillable seamless steel gas cylinders — Design, construction and testing —
Part 1: Quenched and tempered steel cylinders with tensile strength less than 1 100 MPa
ISO 10286, Gas cylinders — Terminology
ISO 10790, Measurement of fluid flow in closed conduits — Guidance to the selection, installation and use of
Coriolis meters (mass flow, density and volume flow measurements)
ISO 11119-1,  Gas cylinders of composite construction — Specification and test methods — Part 1: Hoop
wrapped composite gas cylinders and tubes
ISO 11119-2,  Gas cylinders of composite construction — Specification and test methods — Part 2: Fully
wrapped fibre reinforced composite gas cylinders with load-sharing metal liners
ISO 11119-3,  Gas cylinders of composite construction — Specification and test methods — Part 3: Fully
wrapped fibre reinforced composite gas cylinders and tubes with non-metallic and non-load-sharing metal
liners
ISO 12100, Safety of machinery — General principles for design — Risk assessment and risk reduction
ISO 12499, Industrial fans — Mechanical safety of fans — Guarding
ISO 13709, Centrifugal pumps for petroleum, petrochemical and natural gas industries
ISO 13850, Safety of machinery — Emergency stop — Principles for design
ISO 13854, Safety of machinery — Minimum gaps to avoid crushing of parts of the human body
ISO 13857, Safety of machinery — Safety distances to prevent hazard zones being reached by upper and lower
limbs
ISO 14511, Measurement of fluid flow in closed conduits — Thermal mass flowmeters
ISO 14687 (all parts), Hydrogen fuel — Product specification
ISO 14847, Rotary positive displacement pumps — Technical requirements
ISO 15534-1, Ergonomic design for the safety of machinery — Part 1: Principles for determining the dimensions
required for openings for whole-body access into machinery
ISO 15534-2, Ergonomic design for the safety of machinery — Part 2: Principles for determining the dimensions
required for access openings
ISO 15649, Petroleum and natural gas industries — Piping
ISO/TR 15916, Basic considerations for the safety of hydrogen systems
ISO 16111, Transportable gas storage devices — Hydrogen absorbed in reversible metal hydride
ISO 16528-1, Boilers and pressure vessels — Performance requirements
ISO 17398, Safety colours and safety signs — Classification, performance and durability of safety signs
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ISO 22734-2:2011(E)
ISO 22734-1,  Hydrogen generators using water electrolysis process — Part 1: Industrial and commercial
applications
ISO 26142, Hydrogen detection apparatus — Stationary applications
IEC 60034-1, Rotating electrical machines — Part 1: Rating and performance
IEC 60068-2-18:2010, Environmental Testing — Part 2-18: Tests — Test R and Guidance: Water
IEC 60079-0, Explosive atmospheres — Part 0: Equipment — General requirements
IEC 60079-2:2007, Explosive atmospheres — Part 2: Equipment protection by pressurized enclosures “p”
IEC 60079-10-1, Explosive atmospheres — Part 10-1: Classification of areas — Explosive gas atmospheres
IEC 60079-29-2,  Explosive atmospheres — Part 29-2: Gas detectors — Selection, installation, use and
maintenance of detectors for flammable gases and oxygen
IEC 60079-30-1,  Explosive atmospheres — Part 30-1: Electrical resistance trace heating — General and
testing requirements
IEC 60146 (all parts), Semiconductor converters
IEC 60204-1:2005, Safety of machinery — Electrical equipment of machines — Part 1: General requirements
IEC/TR 60269-5, Low-voltage fuses — Part 5: Guidance for the application of low-voltage fuses
IEC 60335-1:2010, Household and similar electrical appliances — Safety — Part 1: General requirements
IEC 60335-2-41, Household and similar electrical appliances — Safety — Part 2-41: Particular requirements
for pumps
IEC 60335-2-51, Household and similar electrical appliances — Safety — Part 2-51: Particular requirements
for stationary circulation pumps for heating and service water installations
IEC 60335-2-80, Household and similar electrical appliances — Safety — Part 2-80: Particular requirements
for fans
IEC 60364-4-43, Low-voltage electrical installations — Part 4-43: Protection for safety — Protection against
overcurrent
IEC 60364-6:2006, Low-voltage electrical installations — Part 6: Verification
IEC 60417, Graphical symbols for use on equipment
IEC 60439-1, Low-voltage switchgear and controlgear assemblies — Part 1: Type-tested and partially type-
tested assemblies
IEC 60439-2, Low-voltage switchgear and controlgear assemblies — Part 2: Particular requirements for busbar
trunking systems (busways)
IEC 60439-3, Low-voltage switchgear and controlgear assemblies — Part 3: Particular requirements for low-
voltage switchgear and controlgear assemblies intended to be installed in places where unskilled persons have
access for their use — Distribution boards
IEC 60439-5,  Low-voltage switchgear and controlgear assemblies — Part 5: Particular requirements for
assemblies for power distribution in public networks
IEC 60445, Basic and safety principles for man-machine interface, marking and identification — Identification
of equipment terminals, conductor terminations and conductors
IEC 60364-6:2006, Low-voltage electrical installations — Part 6: Verification
IEC 60529, Degrees of protection provided by enclosures (IP Codes)
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ISO 22734-2:2011(E)
IEC 60534 (all parts), Industrial-process control valves
IEC 60695-11-10, Fire hazard testing — Part 11-10: Test flames — 50 W horizontal and vertical flame test
methods
IEC 60695-11-20, Fire hazard testing — Part 11-20: Test flames — 500 W Flame test methods
IEC 60730-1:2010, Automatic electrical controls for household and similar use — Part 1: General requirements
IEC 60747 (all parts), Semiconductor devices — Discrete devices
IEC/TR 60877,  Procedures for ensuring the cleanliness of industrial-process measurement and control
equipment in oxygen service
IEC 60947-2, Low-voltage switchgear and controlgear — Part 2: Circuit-breakers
IEC 60947-3, Low-voltage switchgear and controlgear — Part 3: Switches, disconnectors, switch-disconnectors
and fuse-combination units
IEC 60947-4-1,  Low-voltage switchgear and controlgear — Part 4-1: Contactors and motor-starters —
Electromechanical contactors and motor-starters
IEC 60947-4-2, Low-voltage switchgear and controlgear — Part 4-2: Contactors and motor-starters — AC
semiconductor motor controllers and starters
IEC 60947-4-3, Low-voltage switchgear and controlgear — Part 4-3: Contactors and motor-starters — AC
semiconductor controllers and contactors for non-motor loads
IEC 60947-5-1,  Low-voltage switchgear and controlgear — Part 5-1: Control circuit devices and switching
elements — Electromechanical control circuit devices
IEC 60947-5-2, Low-voltage switchgear and controlgear — Part 5-2: Control circuit devices and switching
elements — Proximity switches
IEC 60947-5-3, Low-voltage switchgear and controlgear — Part 5-3: Control circuit devices and switching
elements — Requirements for proximity devices with defined behaviour under fault conditions
IEC 60947-5-5, Low-voltage switchgear and controlgear — Part 5-5: Control circuit devices and switching
elements — Electrical emergency stop device with mechanical latching function
IEC 60947-6-1, Low-voltage switchgear and controlgear — Part 6-1: Multiple function equipment — Transfer
switching equipment
IEC 60947-6-2, Low-voltage switchgear and controlgear — Part 6-2: Multiple function equipment — Control
and protective switching devices (or equipment)
IEC 60947-7-1, Low-voltage switchgear and controlgear — Part 7-1: Ancillary equipment — Terminal blocks for
copper conductors
IEC 60947-7-2, Low-voltage switchgear and controlgear — Part 7-2: Ancillary equipment — Protective conductor
terminal blocks for copper conductors
IEC 60950-1:2005, Information technology equipment — Safety — Part 1: General requirements
IEC 61000 (applicable parts), Electromagnetic compatibility (EMC)
IEC 61010-1:2010,  Safety requirements for electrical equipment for measurement, control, and laboratory
use — Part 1: General requirements
IEC 61069-7, Industrial-process measurement and control — Evaluation of system properties for the purpose
of system assessment — Part 7: Assessment of system safety
IEC 61131-1, Programmable controllers — Part 1: General information
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ISO 22734-2:2011(E)
IEC 61131-2, Programmable controllers — Part 2: Equipment requirements and tests
IEC 61204-1, Low-Voltage Power Supply Devices, D.C. Output — Part 1: Performance Characteristics
IEC 61508, Functional safety of electrical/electronic/programmable electronic safety-related systems
IEC 61511-1,  Functional safety: Safety instrumented systems for the process industry sector — Part 1:
Framework, definitions, system, hardware and software requirements
IEC 61558-1, Safety of power transformers, power supplies, reactors and similar products — Part 1: General
requirements and tests
IEC 61558-2-17,  Safety of power transformers, power supply units and similar ― Part 2-17: Particular
requirements for transformers for switch mode power supplies
IEC 61672-1, Electroacoustics — Sound level meters — Part 1: Specifications
IEC 61672-2, Electroacoustics — Sound level meters — Part 2: Pattern evaluation tests
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 22734-1 and the following apply.
3.1
accessible part
part or surface that can be touched by means of test probe B of IEC 61032, and if the part or surface is made
of metal, any conductive part connected to it
3.2
all-pole disconnection
disconnection of all supply conductors by a single initiating action
NOTE  For three-phase hydrogen generators, the neutral conductor is not considered to be a supply conductor.
3.3
built-in hydrogen generator
fixed hydrogen generator intended to be installed in a cabinet, in a prepared recess in a wall or in a similar
location
3.4
fixed hydrogen generator
hydrogen generator that is intended to be used while fastened to a support or while secured in a specific
location
NOTE  Adhesives are not recognized as a means for fastening a fixed hydrogen generator to a support.
3.5
hazard
potential source of harm
3.6
mechanical ventilation
replacement of air inside an enclosure with fresh air accomplished by a mechanical device (such as a fan) to
prevent or eliminate hazardous concentrations of hydrogen
3.7
natural ventilation
replacement of air inside an enclosure with fresh air accomplished exclusively by a natural draft caused, for
example, by the effects of wind, temperature gradients or buoyancy effects, to prevent or eliminate hazardous
concentrations of hydrogen
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ISO 22734-2:2011(E)
3.8
normal condition
condition in which all means for protection against hazards are intact
3.9
normal use
operation, including stand-by, according to the instructions for use or for the obvious intended purpose
NOTE  In most cases, normal use also implies normal condition, because the instructions for use will warn against
using the hydrogen generator when it is not in normal condition.
3.10
permanently connected
electrically connected to a supply by means of a permanent connection, which can be detached only by the
use of a tool
3.11
portable hydrogen generator
hydrogen generator that is intended to be moved while in operation or a hydrogen generator other than a fixed
hydrogen generator having a mass less than 18 kg
3.12
residential
relating to the use of hydrogen generators by laymen in private households (non-commercial and non-industrial
use)
3.13
single fault condition
condition in which one means for protection against hazard is defective or one fault is present which could
cause a hazard
NOTE  If a single fault condition results unavoidably in another single fault condition, the two failures are considered
as one single fault condition.
3.14
supply cord
flexible cord, for supply purposes, that is fixed to the hydrogen generator
3.15
tool
external device, including keys and coins, used to aid a person to perform a mechanical function
4 Operating conditions
4.1 Energy consumption
4.1.1 Electrical
The manufacturer shall specify, as outlined in IEC 60204-1, the electrical input rating for the hydrogen generator
in volts, amps or watts (W or VA) and hertz.
4.1.2 Other utilities
The manufacturer shall specify any other utilities required.
4.2 Feed water specifications
The manufacturer shall define the specifications for the feed water to be used in the hydrogen generator.
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ISO 22734-2:2011(E)
4.3 Ambient environment
The manufacturer shall specify the physical environment conditions for which the hydrogen generator is
desi
...