While solar is governed by its own set of standards, installers must ensure they comply with all the relevant electrical standards, particularly AS/NZS3000:2018, writes Thomas Seymour.
Installing solar is a tricky business. The fast pace of technology development and the way that drives change across the multiple standards we all work under makes it hard to keep up at times. However, there is one standard in particular that we all work to that doesn’t get the love it deserves – AS/NZS3000:2018.
As AS/NZS3000:2018 is such an important part of the solar installation process, it is worth revisiting to look at some of the sections of the standard that are most commonly misunderstood or overlooked.
The 2018 version of AS/NZS3000 brought in some changes that have had an impact on the way we install solar, with mechanical protection, pressure relief vents on IP-rated systems and clearances from gas being the biggest ones. Although we will touch on mechanical protection, what I want to address here are the more fundamental requirements contained in AS/NZS3000:2018 around the installation of wiring systems and wiring enclosures. These are often forgotten in the quest to adhere to all the requirements of AS/NZS5033:2014 amendments 1 and 2.
Work in progress
The standard AS/NZS5033:2014 covers the PV array up to the DC input terminals of the inverter. The standard has undergone a huge amount of change in the last couple of years, with two amendments, and it is currently being rewritten by Standards Australia, with the Clean Energy Council leading the rewrite. The standard places additional requirements, such as installing DC PV cabling in HD conduit, but the basic principles of wiring system and wiring enclosure installation are found in AS/NZS3000:2018 Section 3, Selection and Installation of Wiring Systems.
To give some perspective, AS/NZS5033:2014 Sections 4.3.6 and 4.4.4 contain most of the requirements for the installation of DC PV cabling. Combined they represent around nine pages, whereas AS/NZS3000:2018 Section 3.9, Installation Requirements, is 16 pages on its own.
Understanding the installation of wiring systems under AS/NZS3000:2018 is just as important for solar installation as any other type of electrical work.
Sadly, we see a huge amount of non-compliance in this area, such as:
- inadequate support of conduits in roof spaces: spans of up to 2.5m without a saddle, no saddles at all, a couple of cable ties or lying on some air-conditioner ducting
- inadequate support of cabling on the roof: cables touching the roof or cabling wrapped around tin feet or up against cut sections of rail
- change of direction requirements not met: cabling tied from rail to rail and pulled so hard that the sheath is torn on the steel tie and the minimum bend radius of the cable is not met
- conduits not glued both on the roof and in the roof cavity: this leads to compromised IP ratings and mechanical protection requirements not being met as conduits come apart
- conduits tied from rail to rail in an accessible area on the roof with no additional mechanical support
- cabling in HD conduit in a 90mm stud wall, putting it within 50mm of a building surface without additional mechanical protection.
When discussing these matters with installers, it becomes apparent that they were unaware of the requirements. There is such a strong focus on AS/NZS5033:2014 that the main electrical standard gets forgotten.
Fortunately, when it comes to the AC wiring of an installation, we see a lot less non-compliance. Issues such as incorrectly rated circuit protection and cable size do come up but are uncommon. That said, it does appear to be on the rise as more apprentices complete their training in companies whose sole focus is solar. So, if you are solar contractor with apprentices, make sure they are getting their heads around the wiring of AC installations and their obligations under AS/NZS3000:2018.
Section 1.7 of AS/NZS3000:2018, Selection and Installation of Electrical Equipment, is another often misunderstood or overlooked part of AS/NZS3000:2018. But it is extremely important as it covers the main components of a solar installation.
This section of the standard is a tripping point for many in the solar industry. This seems to occur mainly because of the amount of manufacturer-specific requirements for the installation of equipment.
The standard AS/NZS3000:2018 Clause 1.7.1 (c) states “electrical equipment shall be installed in accordance with the requirements of this Standard and the additional requirements as specified in the manufacturer’s instructions”.
Unlike much of the work in the electrical industry, solar installers must be across the specific manufacturer’s requirements for so many different pieces of equipment and be sure that they can interact with one another in a compliant and safe manner. The main areas of manufacturer-specific product knowledge are:
- PV racking
- panel clamping zones
- PV module electrical characteristics
- DC isolator configurations and ratings
- inverter electrical characteristics
- inverter locations.
There are many different technologies in this space, each with different characteristics and requirements. The installation instructions for one product may greatly differ from another, even though they serve the same function and appear very similar. Couple this with a constantly evolving landscape of product technology and it can be very hard to keep up.
This can be especially tricky for sub-contracting installers who may be working with different equipment every day of the week. It is therefore important to develop good relationships with the people you work for and ask them to provide you with the information you need to do your job properly. It is to their benefit, too, as better installations reduce non-compliance and result in happy customers and improve a business’s reputation.
The underlying message here is know your products. As hard as it is, knowing all of the manufacturer’s requirements for the products you install is critical to remining compliant with AS/NZS3000:2018. And keep in mind, rectification work is done at the time and expense of the installer.
The underlying message in all of this is: get to know AS/NZS3000:2018.
There are of course many other requirements from the standard that are not covered in this article. The important thing is that we always work with reference to AS/NZS3000:2018, regardless of what type of electrical work we are undertaking.
After all, even if solar is 100% of your work, you are still a sparky first and foremost.
Thomas Seymour is a technical support officer at the Clean Energy Council.