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PV d.c. isolators and systems

Guidance about PV d.c. isolators – in addition to the requirements of applicable standards.

Industry guidance

This guidance is intended to assist industry with the installation of PV d.c. isolators. It is in addition to the requirements of AS/NZS 3000, AS/NZS 5033 and all other applicable standards.

Note: this document uses the term d.c. isolator for simplicity and has been used to describe a load break switch disconnector device.

General

To reduce water ingress and premature failure of the d.c. isolator, minimum installation safety requirements must be met in accordance with AS/NZS 5033:2021 Cl. 4.4.7 including:

  • Strain relief provided for conductors (where conduit is not used to enter the enclosure)
  • Maintaining IP66 Ratings of the d.c. isolator, only manufacturers entry points to be used.
  • Cable glands, conduits and fittings shall not enter/exit the top face of the enclosure.
  • Sealing or gluing of conduit glands and adapters.
  • Where entry is via a cable gland, IP rated glands and multi-hole grommets to suit the number of conductors entering shall be used
  • Use of silicon to seal enclosures is not permitted, unless specified by the manufacturer
  • Only manufacturer mounting points shall be used.
  • Where conduit systems have a section in an outdoor environment and terminates into an enclosure with a d.c. isolator, the conduit shall have a drain device fitted at the lowest point.
  • Anti-condensation valves shall be used where condensation issues exist AS/NZS 3000:2018 Cl. 1.7.2
  • Install a shroud over the d.c. isolator, of adequate size and compliant to clause 4.4.7.3, unless installed within the 30° protection of the soffit.

ESV recommends using d.c. isolators that have external mounting points

Terminations

  • Ensure terminals are tightened to manufacturer’s requirements; this includes terminals for bridging links.
  • Do not assume the manufacturer has tightened bridging link terminals, they can also loosen during transit.
  • Ensure termination of multistranded cable correctly retains the stranded conductors (see AS/NZS 3000 Cl. 3.7.2.5).

PV d.c. isolator for inverter isolation

AS/NZS 5033:2021 Cl. 4.5.3.1 outlines the two methods of inverter isolation. These are:

  • An adjacent and physically separate d.c. isolator
  • A d.c. isolator that is part of and within the PCE, where the device and the PCE confirm to AS/NZS 4777.2.

ESV strongly recommends using inverters that contain an integrated d.c. isolator.

Guidance for integrated d.c. isolators

For an inverter which has an integrated d.c. isolator, the integrated d.c. isolator must be registered as a level 3 product on the National Equipment Registration SystemExternal Link as integrated into the specific inverter (See EESS Information Bulletin #20-018External Link for more information).

AS/NZS 5033 has an additional requirement that with the integrated d.c. isolator in the OFF position there shall be no risk of electrical hazards when the cover is removed, and there is separate screening from touch of live parts of the PV array side of the d.c. isolator when the external cover is removed.

AS/NZS 5033 also has additional requirements. This includes the requirement for the integrated d.c. isolator being capable of being secured in the OFF position.

Where the above requirements are met ESV deems this compliant to the standard and does not require an additional d.c. isolator to be installed adjacent to the inverter.

Note: the manufacturer of the inverter should provide a ‘Letter of Certification’ to certify the specific model of inverter is compliant to the additional requirements of AS/NZS 5033.

Adjacent and physically separate d.c. isolator

When using an adjacent and physically separate d.c. isolator, due to the inverter not having an integrated isolator or the integrated isolator not meeting the requirements outlined above, ESV recommends installing the d.c. isolator on a non-combustible surface.

Where the surface is combustible AS/NZS 5033:2021 Cl. 4.5.4.1 requires a non-combustible barrier between the d.c. isolator and combustible surface. The non-combustible barrier should extend 200mm past the sides of the d.c. isolator. Any penetration of the barrier that has an internal free space greater than 5 mm diameter must be sealed with a fire retardant sealant.

Appendix

Guidance for non-combustible material

Non-combustible material has the same meaning in this document as is outlined in AS/NZS 5139 in Cl. 4.2.4.2, 5.2.4.2, 6.2.4.2 and AS/NZS 5033:2021 Cl. 4.3.5.3.1.

The material is deemed to be not combustible when tested in accordance with AS 1530.1. Materials exempt from the need to be tested to AS 1530.1 and considered to be suitably non-combustible are:

  • Brick or masonry block
  • Concrete
  • Compressed cement sheeting
  • Ceramic or terracotta tiles

PV systems documentation

AS/NZS 5033 & AS/NZS 4777.1 requirements

Documentation is an important requirement outlined in the installation standards, AS/NZS 5033 & AS/NZS 4777.1 which must be complied with when installing a PV system.

The standards specify the documentation that must be supplied to the PV system owner. AS/NZS 5033:2021 Section 6 and AS/NZS 4777.1:2016 Section 7, provides detailed lists of the required documentation.

When the required documentation is not completed satisfactorily, this presents a safety risk.

The importance of correct documentation

Providing the system owner with the required documentation is fundamental to the system being operated and safely maintained over its lifetime. It is also necessary to effectively carry out an inspection of the solar installation.

Supporting compliance

ESV has released guidance on the testing of solar panel installations:

How to ensure you have a compliant PV installation

This guidance includes a process to upload documentation and results to ESVConnectExternal Link so an LEI can undertake an efficient and effective inspection of the installation. This will assist in the PV system being signed off as compliant in a timely manner.

New regulatory focus

ESV will increase auditing and monitoring to improve compliance rates in relation to the provision of correct documentation to PV system owners.

Infringement notices will be issued if required.

This regulatory focus will be in addition to our ongoing emphasis on the compliance of system installation testing, including earthing of solar panels, as well as mismatched d.c. connectors.

Webinar: Documentation requirements of AS/NZS 5033

In November 2021, ESV’s Solar Safety team presented a webinar for Licensed Electrical Inspectors (LEIs) on the documentation requirements of AS/NZS 5033, to ensure this requirement is complied with.

We encourage you to watch recording of the webinar hereExternal Link .

Date: 08/02/2023 6:27

The material in this print-out was accurate at the time of printing.

Reviewed 28 January 2023

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