Solar PV installation guidance

Audit checklist item: Wiring 4, DP 4, Wiring 3 and Roof 21.

Audit checklist questions:

Where PV d.c. wiring system are not installed directly behind and adjacent to PV modules, have they been identified by distinctive labels with the word "SOLAR" at intervals not exceeding 2m and visible after mounting?

Is any PV d.c. wiring located in a ceiling space between a disconnection point and a load break disconnection device, not installed within 0.6m above the surface of the ceiling unless it is within 1m from the internal surface of an external wall?

For all PV d.c. cables that are installed within buildings has the following mechanical protection been provided?

• Cables located within ceiling space, wall cavities or under a floor are enclosed in metal or heavy-duty insulating conduit.
• Installed in medium duty insulating wiring enclosure in all other internal locations within a building (e.g. non concealed surface mount).

Is any PV d.c. wiring located in a ceiling space between nonadjacent groups of PV modules, not installed within 0.6m above the surface of the ceiling unless it is within 1m from the internal surface of an external wall?

Standards referenced:

• AS/NZS 5033:2021 Clause 4.4.5.2.2
• AS/NZS 5033:2021 Clause 4.4.5.2.3
• AS/NZS 5033:2021 Clause 5.3.1.1
• AS/NZS 5033:2021 Clause 4.4.5.2.4

Guidance:

Audit checklist item: PVA 38

Audit checklist question:

If circuit breaker has been used as overcurrent protection, do they conform to the following requirements?

• Are in accordance with AS/NZS 60898. or AS/NZS IES 60947.2.
• Are not polarity sensitive.
• Are rated for d.c. use.
• Are rated to interrupt full load current and prospective fault currents from the PV array and any other connected power sources such as batteries, generators and the grid if present?
• Have a degree of protection of at least IPXXB or IP 2X.

Standards referenced: AS/NZS 1170.2:2021 Appendix B6

Guidance:

Installing an array adequately includes several key processes. The design of systems is the responsibility of the accredited designer signing off on the job.

Things to consider when installing a system that has been designed by an accredited designer or installer:

• Ensure the design will fit on the roof space compliantly before commencing the installation. To do this you need to consider the dimensions of the panels and the clamping zones as well as the fixing points to the roof structure. You can find this information on the panel manufacturer’s data sheet.
• Ensure water ingress protection does not change after the bracketing system is installed (a particular issue for tile roofs).
• Ensure the array can be installed so that it complies with AS/NZS 1170.2 in relation to the wind loading and roof zones. This information can be found in the rail manufacturers documentation.
• If the accredited designer/installer cannot confirm these requirements prior to installation, then a redesign and acceptance from the system owner will be required prior to installation.
• Make sure you have an agreement in place with any retailers you work for that protects you. For example, you should have the opportunity to conduct a site visit before the installation or be compensated for your time if you get to site, and it cannot be installed compliantly with the design provided.

Audit checklist item: Doc 1 and Doc 12

Audit checklist question:

Basic system information, including system rating and component ratings, and combining date.

Equipment manufacturer's documentation and handbooks for all equipment supplied. As a minimum the following shall be included:

• (i) panels
• (ii) mounting frame
• (iii) inverter
• (iv) isolators
• (v) cable
• (vi) monitoring devices.

Audit checklist item: Wiring 23.

Audit checklist question:

Has all electrical equipment (not previously covered in this checklist) been installed according to all applicable standards and additional manufacturers requirements? If not, could the applicable defects cause a potential safety concern at some stage now or in the future?

Standards reference: AS/NZS 3000:2018 clause 1.7.1(c) and 4.1.2

Guidance:

The compliant installation of all electrical equipment is a basic, fundamental principle of electrical work.

Along with the requirement in the relevant Australian Standards, ensure that all equipment manufacturer’s installation instructions are followed including:

• Mounting instructions – fixing specifications and locking screws.
• Suitable locations – ventilation, direct sun, and moisture.
• Specified clearances – ventilation around equipment, clearances from other equipment or services.

Audit checklist item: PVA 19 and PCE 37.

Audit checklist question:

Have all array plugs, sockets and connectors been installed to the following requirements?

• Installed to minimize strain on the connectors.
• Installed to maintain the IP rating.
• Installed on PV d.c. cables conforming to the plug, socket and connector manufacturer's requirements.
• Only mated with those from the same manufacturer and designed to be mated together.

Terminated using a tool (where required) designed for the purpose and technique specified by the plug, socket or connector manufacturer's instructions.

If installed have all PCE DC plugs, sockets and connectors been installed to the following requirements?

• Installed to minimise strain on the connectors.
• Installed to maintain the IP rating.
• Installed on PV d.c. cables conforming to the plug, socket, and connector manufacturer's requirements.
• Only mated with those from the same manufacturer and designed to be mated together.
• Terminated using a tool (where required) designed for the purpose and technique specified by the plug, socket or connector manufacturer's instructions.

Standards referenced: AS/NZS 5033 Clause 4.3.9.1

Guidance:

The requirement for installers to only use d.c. connectors of the same type from the same manufacturer. The reason this requirement exists is to prevent poor contact joins in dc connectors which can lead to several issues including string failure, overheating, arcing and potentially fire.

The obligation to comply with this requirement is solely the responsibility of the accredited installer that signs the Certificate of Electrical Safety for the installation.

• In order to comply with this requirement, the accredited installer must ensure they are only using the same connector from the same manufacturer. This can be done by reviewing the panel manufactures specification sheet for the panels you install and then making sure you have a separate supply of the correct make and model of connector for use in your installations. Having a good relationship with the solar retailer/s and wholesalers you work with is essential to meet this obligation.
• If you cannot install connectors of the same make, from the same manufacturer do not complete the installation until the appropriate connectors can be sourced. Note: cutting the manufactures connector off a panel will most likely void the panel warranty.
• Another important thing to remember is to use the correct size connector and tool for the cable.
• Poor connections and incorrectly sized cable glands often lead to water ingress into the connections.

Be wary of terms like “MC4 compatible” as this does not mean connecting to an MC4 meets the requirements of the standards. The term “MC4” is a term used by industry but is in fact a specific brand and type of connector in itself.

There is one specific case where industry has been provided guidance that a genuine Staubli MC4 connector can be used with a Staubli MC4-EVO2© connector because they have been tested and certified as compatible by the manufacturer.

For more detailed information, download Energy Safe Victoria’s guide to identifying mismatched d.c. connectors.