IEC 62446:2009

IEC 62446 ®
Edition 1.0 2009-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Grid connected photovoltaic systems – Minimum requirements for system
documentation, commissioning tests and inspection

Systèmes photovoltaïques connectés au réseau électrique – Exigences
minimales pour la documentation du système, les essais de mise en service et
l’examen
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IEC 62446 ®
Edition 1.0 2009-05
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Grid connected photovoltaic systems – Minimum requirements for system
documentation, commissioning tests and inspection

Systèmes photovoltaïques connectés au réseau électrique – Exigences
minimales pour la documentation du système, les essais de mise en service et
l’examen
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
T
CODE PRIX
ICS 27.160 ISBN 978-2-88910-712-4
– 2 – 62446 © IEC:2009
CONTENTS
FOREWORD.4
INTRODUCTION.6
1 Scope and object.7
2 Normative references .7
3 Terms and definitions .7
4 System documentation requirements .8
4.1 General .8
4.2 System data .8
4.2.1 Basic system information.8
4.2.2 System designer information .8
4.2.3 System installer information.9
4.3 Wiring diagram .9
4.3.1 General .9
4.3.2 Array - general specifications .9
4.3.3 PV string information .9
4.3.4 Array electrical details .9
4.3.5 Earthing and overvoltage protection .9
4.3.6 AC system .10
4.4 Datasheets.10
4.5 Mechanical design information .10
4.6 Operation and maintenance information .10
4.7 Test results and commissioning data.10
5 Verification .10
5.1 General .10
5.2 General .11
5.3 Inspection .11
5.3.1 General .11
5.3.2 DC system inspection .11
5.3.3 Protection against overvoltage / electric shock .12
5.3.4 AC system .12
5.3.5 Labelling and identification .12
5.4 Testing .13
5.4.1 General .13
5.4.2 Continuity of protective earthing and/or equipotential bonding

conductors.13
5.4.3 Polarity test .13
5.4.4 PV string - open circuit voltage measurement .13
5.4.5 PV string - current measurement .14
5.4.6 Functional tests .15
5.4.7 PV array Insulation resistance test .15
5.5 Verification reports .17
5.5.1 General .17
5.5.2 Initial verification .17
5.5.3 Periodic verification .17
Annex A (informative) Model verification certificate.18
Annex B (informative) Model inspection report .19

62446 © IEC:2009 – 3 –
Annex C (informative) Model PV array test report .21
Annex D (informative) PV array infrared camera inspection procedure.23

Table 1 – Minimum values of insulation resistance.17

– 4 – 62446 © IEC:2009
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
GRID CONNECTED PHOTOVOLTAIC SYSTEMS –
MINIMUM REQUIREMENTS FOR SYSTEM DOCUMENTATION,
COMMISSIONING TESTS AND INSPECTION

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
international co-operation on all questions concerning standardization in the electrical and electronic fields. To
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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 publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 62446 has been prepared by IEC technical committee 82: Solar
photovoltaic energy systems.
The text of this standard is based on the following documents:
FDIS Report on voting
82/558A/FDIS 82/564/RVD
Full information on the voting for the approval of this standard can be found in the report on
voting indicated in the above table.
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

62446 © IEC:2009 – 5 –
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
– 6 – 62446 © IEC:2009
INTRODUCTION
Grid connected PV systems are expected to have a lifetime of decades, with maintenance or
modifications likely at some point over this period. Building or electrical works in the vicinity of
the PV array are very likely, for example roof works adjacent to the array or modifications
(structural or electrical) to a home that has a PV system. The ownership of a system may also
change over time, particularly for systems mounted on buildings. Only by the provision of
adequate documentation at the outset can the long term performance and safety of the PV
system and works, on or adjacent to the PV system, be ensured.
This standard is split into 2 parts:
• System documentation requirements (Clause 4) – This clause details the information
that shall be provided, as a minimum, within the documentation provided to the customer
following the installation of a grid connected PV system.
• Verification (Clause 5) – This clause provides the information expected to be provided
following initial (or periodic) verification of an installed system. It includes requirements for
inspection and testing.
62446 © IEC:2009 – 7 –
GRID CONNECTED PHOTOVOLTAIC SYSTEMS –
MINIMUM REQUIREMENTS FOR SYSTEM DOCUMENTATION,
COMMISSIONING TESTS AND INSPECTION

1 Scope and object
This International Standard defines the minimal information and documentation required to be
handed over to a customer following the installation of a grid connected PV system. This
standard also describes the minimum commissioning tests, inspection criteria and
documentation expected to verify the safe installation and correct operation of the system.
The document can also be used for periodic retesting.
This standard is written for grid connected PV systems only and not for AC module systems or
systems that utilize energy storage (e.g. batteries) or hybrid systems.
NOTE It is expected that additional information and commissioning tests will be required in some circumstances,
e.g. for large commercial installations.
This standard is for use by system designers and installers of grid connected solar PV
systems as a template to provide effective documentation to a customer. By detailing the
expected minimum commissioning tests and inspection criteria, it is also intended to assist in
the verification / inspection of a grid connected PV system after installation and for
subsequent re-inspection, maintenance or modifications.
2 Normative references
The following referenced documents are indispensable for the application of this standard. For
dated references, only the edition cited applies. For undated references, the latest edition of
the referenced document (including any amendments) applies.
IEC 60364 (all parts), Low-voltage electrical installations
IEC 60364-6, Low-voltage electrical installations – Part 6: Verification
IEC 60364-7-712:2002, Electrical installations of buildings – Part 7-712: Requirements for
special installations or locations – Solar photovoltaic (PV) power supply systems
IEC/TR 60755:2008, General requirements for residual current operated protective devices
IEC 61557 (all parts), Electrical safety in low voltage distribution systems up to 1000 V AC
and 1500 V DC – Equipment for testing, measuring or monitoring of protective measures
IEC 61730-1, Photovoltaic (PV) module safety qualification – Part 1: Requirements for
construction
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply:
3.1
verification
all measures by means of which compliance of the electrical installation to the relevant
standards is checked
– 8 – 62446 © IEC:2009
NOTE it comprises inspection, testing and reporting.
3.2
inspection
examination of an electrical installation using all the senses in order to ascertain correct
selection and proper erection of electrical equipment
3.3
testing
implementation of measures in an electrical installation by means of which its effectiveness is
proved
NOTE It includes ascertaining values by means of appropriate measuring instruments, said values not being
detectable by inspection.
3.4
reporting
recording of the results of inspection and testing
3.5
data sheet
a basic product description and specification
NOTE Typically one or two pages. Not a full product manual.
4 System documentation requirements
4.1 General
The purpose of this Clause is to list the minimum documentation that should be provided
following the installation of a grid connected PV system. This information will ensure key
system data is readily available to a customer, inspector or maintenance engineer. The
documentation includes basic system data and the information expected to be provided in the
operation and maintenance manual.
4.2 System data
4.2.1 Basic system information
As a minimum, the following basic system information shall be provided. This “nameplate”
information would typically be presented on the cover page of the system documentation
pack.
a) Project identification reference (where applicable).
b) Rated system power (kW DC or kVA AC).
c) PV modules and inverters - manufacturer, model and quantity.
d) Installation date.
e) Commissioning date.
f) Customer name.
g) Site address.
4.2.2 System designer information
As a minimum, the following information shall be provided for all bodies responsible for the
design of the system. Where more than one company has responsibility for the design of the
system, the following information should be provided for all companies together with a
description of their role in the project.
a) System designer, company.
62446 © IEC:2009 – 9 –
b) System designer, contact person.
c) System designer, postal address, telephone number and e-mail address.
4.2.3 System installer information
As a minimum, the following information shall be provided for all bodies responsible for the
installation of the system. Where more than one company has responsibility for the
installation of the system, the following information should be provided for all companies
together with a description of their role in the project.
a) System installer, company.
b) System installer, contact person.
c) System installer, postal address, telephone number and e-mail address.
4.3 Wiring diagram
4.3.1 General
As a minimum, a single line wiring diagram shall be provided. This diagram shall be annotated
to include the information detailed in the following subclauses:
NOTE In general, it is expected that this information will be presented as annotations to the single line wiring
diagram. In some circumstances, typically for larger systems where space on the diagram may be limited, this
information may be presented in table form.
4.3.2 Array - general specifications
The wiring diagram shall include the following array design information
a) Module type(s)
b) Total number of modules
c) Number of strings
d) Modules per string
4.3.3 PV string information
The wiring diagram shall include the following PV string information
a) String cable specifications – size and type.
b) String over-current protective device specifications (where fitted)- type and voltage/current
ratings.
c) Blocking diode type (if relevant).
4.3.4 Array electrical details
The wiring diagram shall include the following array electrical information
a) Array main cable specifications – size and type.
b) Array junction box locations (where applicable).
c) DC isolator type, location and rating (voltage / current).
d) Array over-current protective devices (where applicable) – type, location and rating
(voltage / current).
4.3.5 Earthing and overvoltage protection
The wiring diagram shall include the following earthing and overvoltage protection information
a) Details of all earth / bonding conductors – size and connection points. Including details of
array frame equipotential bonding cable where fitted.

– 10 – 62446 © IEC:2009
b) Details of any connections to an existing Lightning Protection System (LPS).
c) Details of any surge protection device installed (both on AC and DC lines) to include
location, type and rating.
4.3.6 AC system
The wiring diagram shall include the following AC system information
a) AC isolator location, type and rating.
b) AC overcurrent protective device location, type and rating.
c) Residual current device location, type and rating (where fitted).
4.4 Datasheets
As a minimum, datasheets shall be provided for the following system components
a) Module datasheet for all types of modules used in the system - to the requirements of
IEC 61730-1.
b) Inverter datasheet for all types of inverters used in the system.
NOTE The provision of datasheets for other significant system components should also be considered.
4.5 Mechanical design information
A data sheet for the array mounting system shall be provided.
4.6 Operation and maintenance information
Operation and maintenance information shall be provided and shall include, as a minimum,
the following items:
a) Procedures for verifying correct system operation.
b) A checklist of what to do in case of a system failure.
c) Emergency shutdown / isolation procedures.
d) Maintenance and cleaning recommendations (if any).
e) Considerations for any future building works related to the PV array (e.g. roof works).
f) Warranty documentation for PV modules and inverters - to include starting date of
warranty and period of warranty.
g) Documentation on any applicable workmanship or weather-tightness warranties.
4.7 Test results and commissioning data
Copies of all test and commissioning data shall be provided. As a minimum, these shall
include the results from the verification tests detailed in Clause 5 of this standard.
5 Verification
5.1 General
Much of the verification of a grid connected PV system should be done with reference to
IEC 60364-6 which provides the requirements for initial and periodic verification of any
electrical installation.
This Clause provides the requirements for the initial and periodic verification of a grid
connected PV electrical installation in particular. It references IEC 60364-6 where appropriate
and also details additional requirements or considerations for the verification of a PV system.

62446 © IEC:2009 – 11 –
Initial verification takes place upon completion of a new installation or completion of additions
or of alterations to existing installations. Periodic verification is to determine, as far as
reasonably practicable, whether the installation and all its constituent equipment remain in a
satisfactory condition for use.
NOTE Typical verification test sheets are provided in the annexes to this standard.
5.2 General
Every installation of subsystems and components shall be verified during erection, as far as
reasonably practicable, and on completion, before being put into service by the user with
reference to IEC 60364-6. Initial verification shall include comparison of the results with relevant
criteria to confirm that the requirements of IEC 60364 have been met.
For an addition or alteration to an existing installation, it shall be verified that the addition or
alteration complies with IEC 60364 and does not impair the safety of the existing installation.
Initial and periodic verifications shall be made by a skilled person, competent in verification.
5.3 Inspection
5.3.1 General
Inspection shall precede testing and shall normally be done prior to energizing the installation.
The inspection shall be done to the requirements of IEC 60364-6.
It is to be ensured that the following items, specific to grid connected PV systems, are
included in the inspection:
5.3.2 DC system inspection
Inspection of the DC installation shall include, at least verification that:
a) The DC system has been designed, specified and installed to the requirements of
IEC 60364 in general and IEC 60364-7-712 in particular.
b) All DC components are rated for continuous operation at DC and at the maximum possible
DC system voltage and maximum possible DC fault current (V corrected for local
oc stc
temperature range and based on module type; and current at 1,25 × I according to
sc stc
IEC 60364-7-712.433:2002).
c) Protection by use of class II or equivalent insulation adopted on the DC side – yes / no
(class II preferred - IEC 60364-7-712.413.2:2002).
d) PV string cables, PV array cables and PV DC main cables have been selected and
erected so as to minimize the risk of earth faults and short-circuits (IEC 60364-7-
712.522.8.1:2002). Typically achieved by the use of cables with protective and reinforced
insulation (often termed “double insulated”).
e) Wiring systems have been selected and erected to withstand the expected external
influences such as wind, ice formation, temperature and solar radiation (IEC 60364-7-
712.522.8.3:2002).
f) For systems without string over-current protective device: verify that the module reverse
current rating (I ) is greater than the possible reverse current; also, verify that the string
r
cables are sized to accommodate the maximum combined fault current from parallel
strings (IEC 60364-7-712.433:2002).
g) For systems with string over-current protective device: verify that the string over-current
protective devices are fitted and correctly specified to local codes or to the manufacturer’s
instructions for protection of PV modules according to the NOTE of IEC 60364-7-
712.433.2:2002.
h) Verify that a DC switch disconnector is fitted to the DC side of the inverter (IEC 60364-7-
712.536.2.2.5:2002).
– 12 – 62446 © IEC:2009
i) If blocking diodes are fitted, verify that their reverse voltage rating is at least 2 × V of
oc stc
the PV string in which they are fitted (IEC 60364-7-712.512.1.1:2002).
j) If one of the DC conductors is connected to earth, verify that there is at least simple
separation between the AC and DC sides and that earth connections have been
constructed so as to avoid corrosion (IEC 60364-7-712.312.2:2002).
NOTE 1 Inspection of the DC system requires knowledge of the maximum system voltage and current.
• The maximum system voltage is a function of the string / array design, the open circuit voltage (V ) of the
oc
modules and a multiplier to account for temperature and irradiance variations.
• The maximum possible fault current is a function of the string / array design, the short circuit current (I ) of
sc
the modules and a multiplier to account for temperature and irradiance variations (IEC 60364-7-712.433:2002).
NOTE 2 Where a module reverse current rating (I ) is not provided by the manufacturer it should be taken to be
r
1,35 × the modules over-current protection rating.
NOTE 3 Module over-current protection rating should be taken as the value provided by the manufacturer as per
the requirements of IEC 61730-1.
5.3.3 Protection against overvoltage / electric shock
Inspection of the PV system shall include, at least verification that:
a) Verification of type B RCD where: an RCD is installed and the PV inverter is without at
least simple separation between the AC side and the DC side, - according to IEC 60755
(IEC 60364-7-712.413.1.1.1.2:2002 and Figure 712.1).
b) To minimize voltages induced by lightning, verify that the area of all wiring loops has been
kept as small as possible (IEC 60364-7-712.444.4:2002).
c) Where required by local codes, verify that array frame and/or module frame protective
earthing conductors have been correctly installed and are connected to earth. Where
protective earthing and/or equipotential bonding conductors are installed, verify that they
are parallel to, and bundled with, the DC cables (IEC 60364-7-712.54:2002).
5.3.4 AC system
Inspection of the PV system shall include, at least verification that:
a) a means of isolating the inverter has been provided on the AC side;
b) all isolation and switching devices have been connected such that PV installation is wired
to the “load” side and the public supply to the “source” side? (IEC 60364-7-
712.536.2.2.1:2002);
c) the inverter operational parameters have been programmed to local regulations.
5.3.5 Labelling and identification
Inspection of the PV system shall include, at least, a verification that:
a) All circuits, protective devices, switches and terminals are suitably labelled.
b) All DC junction boxes (PV generator and PV array boxes) carry a warning label indicating
that active parts inside the boxes are fed from a PV array and may still be live after
isolation from the PV inverter and public supply.
c) The main AC isolating switch is clearly labelled.
d) Dual supply warning labels are fitted at point of interconnection.
e) A single line wiring diagram is displayed on site.
f) Inverter protection settings and installer details are displayed on site.
g) Emergency shutdown procedures are displayed on site.
h) All signs and labels are suitably affixed and durable.

62446 © IEC:2009 – 13 –
5.4 Testing
5.4.1 General
Testing of the electrical installation shall be done to the requirements of IEC 60364-6.
Measuring instruments and monitoring equipment and methods shall be chosen in accordance
with the relevant parts of IEC 61557. If other measuring equipment is used, it shall provide an
equivalent degree of performance and safety. The test methods described in this Clause are
given as reference methods; other methods are not precluded, provided they give no less
valid results.
In the event of a test indicating a fault: once that fault has been rectified, all previous tests
shall be repeated in case the fault influenced the result of these tests.
The following tests shall be carried out where relevant and should preferably be made in the
following sequence:
a) Tests to all AC circuit(s) to the requirements of IEC 60364-6.
Once tests to the AC circuit(s) are complete, the following tests shall be carried out on the DC
circuit(s) forming the PV array.
b) continuity of protective earthing and/or equipotential bonding conductors, where fitted (see
5.4.2);
c) polarity test (see 5.4.3);
d) string open circuit voltage test (see 5.4.4)
e) string short circuit current test (see 5.4.5)
f) functional tests (see 5.4.6);
g) insulation resistance of the DC circuits (see 5.4.7).
In the event of any test indicating failure to comply with the requirements, that test and any
preceding test that may have been influenced by the fault shall be repeated.
5.4.2 Continuity of protective earthing and/or equipotential bonding conductors
Where protective or bonding conductors are fitted on the DC side, such as bonding of the
array frame, an electrical continuity test shall be made on all such conductors. The connection
to the main earthing terminal should also be verified.
5.4.3 Polarity test
The polarity of all DC cables shall be verified using suitable test apparatus. Once polarity is
confirmed, cables shall be checked to ensure they are correctly identified and correctly
connected into system devices such as switching devices or inverters.
NOTE For reasons of safety and for the prevention of damage to connected equipment, it is extremely important
to perform the polarity check before other tests and before switches are closed or string over-current protective
devices inserted. If a check is made on a previously connected system and reverse polarity of one string is found,
it is then important to check modules and bypass diodes for any damage cause by this error.
5.4.4 PV string - open circuit voltage measurement
The open circuit voltage of each PV string should be measured using suitable measuring
apparatus. This should be done before closing any switches or installing string over-current
protective devices (where fitted).

– 14 – 62446 © IEC:2009
Measured values should be compared with the expected value. Comparison to expected
values is intended as a check for correct installation, not as a measure of module or array
performance. Verification of module / array performance is outside the scope of this standard.
For systems with multiple identical strings and where there is stable irradiance conditions,
voltages between strings shall be compared. These values should be the same (typically
within 5 % for stable irradiance conditions). For non stable irradiance conditions, the following
methods can be adopted:
• testing may be delayed
• tests can be done using multiple meters, with one meter on a reference string
• an irradiance meter reading may be used to adjust the current readings.
NOTE Voltages less than the expected value may indicate one or more modules connected with the wrong
polarity, or faults due to poor insulation, subsequent damage and/or water accumulation in conduits or junction
boxes. High voltage readings are usually the result of wiring errors.
5.4.5 PV string - current measurement
5.4.5.1 General
Like the open circuit voltage measurements the purpose of a PV string current measurement
test is to verify that there are no major faults within the PV array wiring. These tests are not to
be taken as a measure of module / array performance.
Two tests methods are possible and both will provide information on string performance.
Where possible the short circuit test is preferred as it will exclude any influence from the
inverters.
5.4.5.2 PV string – short circuit test
The short circuit current of each PV string should be measured using suitable test apparatus.
The making / interruption of string short circuit currents is potentially hazardous and a suitable
test procedure, such as that described below, should be followed.
Measured values should be compared with the expected value. For systems with multiple
identical strings and where there are stable irradiance conditions, measurements of currents
in individual strings shall be compared. These values should be the same (typically within 5 %
for stable irradiance conditions).
For non-stable irradiance conditions, the following methods can be adopted:
• testing may be delayed
• tests can be done using multiple meters, with one meter on a reference string
• an irradiance meter reading may be used to adjust the current readings.
5.4.5.2.1 Short circuit test procedure
Ensure that all PV strings are isolated from each other and that all switching devices and
disconnecting means are open.
A temporary short circuit shall be introduced into the string under test. This can be achieved
by either:
a) A short circuit cable temporarily connected into a load break switching device already
present in the string circuit.
b) The use of a “short circuit switch test box” – a load break rated device that can be
temporarily introduced into the circuit to create a switched short circuit.

62446 © IEC:2009 – 15 –
In either case the switching device and short circuit conductor shall be rated greater than the
potential short circuit current and open circuit voltage.
The short circuit current can then be measured using either a clip on ammeter or by an in-line
ammeter.
NOTE A “short circuit switch box” is an item of test apparatus that can be used for both short circuit tests and
also array insulation tests (see 5.4.7).
5.4.5.3 PV string – operational test
With the system switched on and in normal operation mode (inverters maximum power point
tracking) the current from each PV string should be measured using a suitable clip on
ammeter placed around the string cable.
Measured values should be compared with the expected value. For systems with multiple
identical strings and where there are stable irradiance conditions, measurements of currents
in individual strings shall be compared. These values should be the same (typically within 5 %
for stable irradiance conditions).
For non-stable irradiance conditions, the following methods can be adopted:
• testing may be delayed
• tests can be done using multiple meters, with one meter on a reference string
• an irradiance meter reading may be used to adjust the current readings.
5.4.6 Functional tests
The following functional tests shall be performed:
a) Switchgear and other control apparatus shall be tested to ensure correct operation and
that they are properly mounted and connected.
b) All inverters forming part of the PV system shall be tested to ensure correct operation.
The test procedure should be the procedure defined by the inverter manufacturer.
c) A loss of mains test shall be performed: With the system operating, the main AC isolator
shall be opened – it should be observed (e.g. on a display meter) that the PV system
immediately ceases to generate. Following this, the AC isolator should be re-closed and it
should be observed that the system reverts to normal operation.
NOTE The loss of mains test can be amended during stable irradiance conditions. In such cases, before opening
the main AC isolator, loads within the building can be selected so as to match, as close as is practical, the power
being generated by the PV system.
5.4.7 PV array insulation resistance test
5.4.7.1 General
PV array DC circuits are live during daylight and, unlike a conventional AC circuit, cannot be
isolated before performing this test.
Performing this test presents a potential electric shock hazard, it is important to fully
understand the procedure before starting any work. It is recommended that the following basic
safety measures are followed:
• Limit the access to the working area.
• Do not touch and take measures to prevent any other persons to touch any metallic
surface with any part of your body when performing the insulation test.
• Do not touch and take measures to prevent any other persons from touching the back of
the module/laminate or the module/laminate terminals with any part of your body when
performing the insulation test.

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• Whenever the insulation test device is energised there is voltage on the testing area. The
equipment is to have automatic auto-discharge capability.
• Appropriate personal protective clothing / equipment should be worn for the duration of the
test.
NOTE For some installations, for example larger systems or where insulation faults due to installation or
manufacturing defects are suspected, or where the results of the dry test are questionable, a wet array insulation
test may be appropriate. Wet array insulation test procedures can be found in ASTM Std E 2047, Test Method for
Wet Insulation Integrity Testing of PV Arrays.
5.4.7.2 PV array insulation resistance test - test method
The test should be repeated for each PV array as a minimum. It is also possible to test
individual strings if required. Two test methods are possible:
TEST METHOD 1 - Test between array negative and earth followed by a test between array
Positive and Earth.
TEST METHOD 2 - Test between earth and short circuited array positive and negative.
Where the structure/frame is bonded to earth, the earth connection may be to any suitable
earth connection or to the array frame (where the array frame is utilised, ensure a good
contact and that there is continuity over the whole metallic frame).
For systems where the array frame is not bonded to earth (e.g. where there is a class II
installation) a commissioning engineer may choose to do two tests: a) between array cables
and earth and an additional test b) between array cables and frame.
For arrays that have no accessible conductive parts (e.g. PV roof tiles) the test shall be
between array cables and the building earth.
NOTE 1 Where test method 2 is adopted, to minimise the risk from electrical arcs, the array positive and negative
cables should be short-circuited in a safe manner. Typically this would be achieved by an appropriate short-circuit
switch box. Such a device incorporates a load break rated DC switch that can safely make and break the short
circuit connection - after array cables have been safely connected into the device.
NOTE 2 The test procedure should be designed to ensure peak voltage does not exceed module or cable ratings.
5.4.7.3 PV array insulation resistance - test procedure
Before commencing with the test: limit access to non-authorized personnel; isolate the PV
array from the inverter (typically at the array switch disconnector); and disconnect any piece
of equipment that could have an impact on the insulation measurement (i.e. overvoltage
protection) in the junction or combiner boxes.
Where a sho
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