At LUX Solar - our mission is for everyone to have the power to be free, which includes providing solar in the most cost and time-effective way - including via our prewired, "plug and play" kits.
However, some off-grid solar (including some Caravan solar installations) legally require a prescribed electrical worker (registered electrician or sparky). Even in the case where a system is not regulated, we do not recommend DIY'ing it if you do not know what you're doing. If in any doubt, engage a professional.
What can Go Wrong?
It's not just a matter of box-ticking - people have died from electrocution from off-grid solar installations, even at low voltages. An investigation in Queensland Australia of an off-grid solar electrocution found the solar PV system operating at around 100VDC, had been operating at an extra low voltage (not exceeding 50VAC or 120V ripple-free DC). The person performing the work was not required to be a licensed electrical worker, however, this incident highlights the real risk of working on such installations.
Anyone working on solar PV systems requires specific skills and knowledge to understand electrical safety and installation requirements, particularly when it comes to DC voltages.
- Even at extra low voltage there can be significant electrical current in solar PV systems that can cause arcs and burns to the body (even solar panels operating at extra low voltage create electricity while the sun shines on the panels). Panel-to-panel connections and disconnections are a significant risk.
- Health issues could compromise situations, even at extra low voltages, because cuts, wounds, or ulcers can reduce resistance or medical issues involving pacemakers can be aggravated.
- Environmental conditions (such as high humidity or wet seasons and heavy rain) can increase risks, especially if the extra low voltage is at the higher range.
- Remote locations may have difficult access which could hamper assistance, so extra precautions are warranted.
- If located on a roof or other structure, there are working from heights and fall risks, as well as when accessing the roof (ensuring secured ladders).
- Failure to weatherproof the electrical parts creates a fire risk.
- Safety standards to ensure safe means of isolation should be followed.
The exact effect from extra low voltages depends on the size of the voltage, which parts of the body are involved, how damp the person is, and the length of time the current flows.
Regardless of voltages present, safety standards for equipment and installations should be followed to reduce risks associated with any solar PV systems. It’s also important, especially in a remote area where there may be high humidity, that risk assessments and mitigating actions are taken to reduce chance of shock, burns, or fires, while working on or using extra low voltage solar PV systems.
At LUX Solar we want to ensure anyone installing solar has the knowledge and confidence to install solar safely, compliantly, and correctly. We believe this can be done cost and time efficiently too - but safety must come first!
What do NZ's Regulations Say? Certification Requirements - See Worksafe's Guide
A licensed electrician must be engaged to carry out work involving the installation and maintenance of solar PV systems that are operating at and above low voltage (greater than 120 volts DC and greater than 50 volts AC).
Hint: If you don't know what the voltage of your solar system will be, you probably need to talk to an electrician!
PV Systems can comprise different combinations, for example, the systems may have a combination of extra low voltage (ELV) and low voltage (LV). Such a system may include a parallel mains inverter or it may be a standalone system that includes an inverter, or battery storage.
The work carried out to install the PV system may include prescribed electrical work (PEW): “the installation of conductors and the fittings attached to those conductors.”
An inverter[1] is defined as a fitting, it is not an appliance, and therefore any PEW includes the inverter. The inverter, being a fitting attached to the conductors, becomes part of the installation and will require certification.
Where there is a mains inverter within the PV system, which is a low voltage[2] mains parallel system that is connected to the national grid, the inverter must be installed to comply with the standards AS/NZS 3000 and AS 4777.1. This work is categorised as high-risk PEW which will require certification and a record of inspection (ROI).
The work carried out to install a PV system that operates at LV is PEW and will require certification. The PV system must be installed to comply with the standards AS/NZS 3000 and AS/NZS 5033. Additionally the LV-direct current (DC) component of the PV system is categorised as high risk PEW which will require an inspection and a ROI.
In a PV system that operates with a combination of ELV[3] and LV the system must be installed to comply with the standards AS/NZS 3000 and AS/NZS 5033. The work on the ELV-DC side of the system is not PEW, therefore will not require certification or inspection. However the work on the LV-alternating current (AC) side of the system, including the inverter, is PEW and will require certification. If this PV system is an independent supply and the inverter is not paralleled to a mains supply it will not require an inspection.
When a PV system operates entirely at ELV the work on that system will still have to be installed to comply with the standards AS/NZS 3000 and AS/NZS 5033; however the work will not be PEW, therefore will not require certification or an inspection.