AS/NZS 3010 is the Australian and New Zealand standard for electrical installations involving generating sets. The current edition was released in 2017, with an amendment in 2020 to refine some of the rules.

This standard gives us guidance on the correct installation practices for internal-combustion engine-driven generator sets that operate at low voltage—up to 1,000 volts AC or 1,500 volts DC. It doesn’t deal with solar, wind, UPS systems, or battery inverters. The focus is purely on engine-powered generators, like those running on diesel or petrol.

Whether the generator is a permanent fixture or a portable backup unit, if it’s being wired into an electrical installation, AS/NZS 3010 applies.

Why We Should Care About This Standard

Generators might seem like a simple solution when the power goes out, but improper installation can be extremely dangerous. We’re talking about the risk of backfeeding electricity into the grid, electrocution hazards for workers, equipment damage, and potential fire.

AS/NZS 3010 isn’t just about ticking boxes on a compliance checklist. It’s about ensuring generators are safe to operate—for the building occupants, the utility network, and electrical workers.

Imagine this: a tradesperson plugs in a portable generator to a switchboard without a proper changeover switch. Power flows backwards into the street mains. A utility worker gets shocked while repairing lines they assumed were de-energised. That’s the kind of incident this standard is designed to prevent.

Generator Supply Arrangements – With Examples

Normal supply – The generator is the sole power source.
Example: A mobile workshop trailer powered by a diesel generator. There’s no grid connection—just the generator running the tools and lights.

Alternative supply – The generator kicks in when the grid fails.
Example: A rural home with a backup generator wired to a changeover switch. When the power goes out, the homeowner manually switches to generator mode.

Parallel supply – The generator works in conjunction with the grid.
Example: A commercial building with a generator that runs in parallel during peak hours to reduce grid demand. This setup requires synchronisation equipment and extra protection measures.

Isolated supply – The generator powers an installation that’s not connected to the network.
Example: A remote telecom repeater site running off a generator and battery bank, completely separate from the grid.

Each of these arrangements has its own requirements under AS/NZS 3010, especially in terms of switching and earthing.

Earthing and Neutral Connections – Why It Matters

This is one of the most critical areas in generator installations. The 2017 standard, along with Amendment 1 (2020), clarified the rules on earthing and neutral connections.

Let’s say we’ve got a small 6kVA petrol generator plugged into a socket-outlet on a switchboard. The generator has a built-in neutral-to-earth link. If we connect it without isolating the main neutral bar from the grid, we end up with two parallel neutral-earth connections—one at the main switchboard and one at the generator. That can cause earth loop currents and unsafe voltages on exposed conductive parts.

AS/NZS 3010 requires that the neutral and earthing arrangements are clearly defined, and that generators with their own MEN connection are either:

Permanently wired with proper switching and interlocking, or

Connected via an inlet with an appropriate changeover system that switches both active and neutral conductors.

In a residential backup setup, for example, if we’re using a two-pole manual changeover switch (active and neutral), it must be clearly labelled and designed to prevent any backfeed.

Switching and Protection – Getting It Right

Protection devices and proper switching are non-negotiable under this standard. The type of changeover switch depends on the generator configuration and the load type.

Example: A café installs a standby generator to protect against outages. The electrician uses a four-pole manual transfer switch (three phases + neutral) to fully isolate the generator from the grid when switched over. The switchboard also includes an earth-fault protection relay, ensuring that faults are quickly cleared if they occur during generator operation.

AS/NZS 3010 also specifies requirements for:

Circuit breakers with appropriate fault ratings
Overcurrent protection based on generator output
Socket-outlets on portable generators that require RCD protection
Interlocks to stop unsafe switching

It’s especially important to size the protection correctly. Too many times we’ve seen a 20kVA generator installed with breakers too large to protect the downstream wiring. That’s a disaster waiting to happen.

Labels and Documentation

The standard places emphasis on labelling and documentation—things that often get overlooked in a rush job.

If we’re installing a generator with a changeover switch, we need to label the switch to indicate its function. If the generator has a built-in MEN link, that needs to be clearly marked.

In commercial or industrial settings, AS/NZS 3010 encourages the use of wiring diagrams and documentation showing:

Switchboard layout
Earth connections
Load distribution
Generator specifications

This kind of documentation helps future electricians or inspectors understand the system quickly and avoid dangerous mistakes.

Example: A mining camp generator setup includes a laminated drawing fixed inside the main switchboard. It shows the generator inlet, switch arrangement, MEN location, and cable sizes. This single page saves hours of guesswork during future maintenance.

Portable Generators – Small Doesn’t Mean Simple

We’ve all seen portable generators used on construction sites, especially for small power tools or lighting towers. AS/NZS 3010 still applies here, even if the generator isn’t permanently installed.

Example: A 3.5kVA petrol generator is used to power a concrete mixer via an extension lead. If the generator doesn’t have RCD protection, the lead and appliance must be protected by an RCD installed in a portable outlet board or inline device. The site manager also needs to ensure the generator is suitable for the environment (IP rating) and isn’t being overloaded.

Even portable units can cause injuries if not earthed properly or if extension leads are run carelessly. This standard helps keep these setups safe and legally compliant.

Inverter Systems – Keep Them Separate

AS/NZS 3010 warns us not to connect grid-tied inverters downstream of generator changeover switches. It’s a crucial point.

Example: A home has rooftop solar with a hybrid inverter and a generator backup. If the generator runs during a blackout and the inverter is still trying to feed into the network, we could end up with voltage regulation issues or equipment failure. Proper isolation is key—either via interlocked switching or automatic load control.

The standard doesn’t cover inverters directly, but it tells us how to keep those systems separate from generator circuits unless specialised integration equipment is used.

Diagrams and Figures – A Real Help

One of the best things about AS/NZS 3010 is its visual guides. The standard includes diagrams showing:

Changeover switch arrangements
MEN link configurations
Socket-outlet connections for portable gensets
Multi-phase installations

These illustrations are helpful, especially when you’re training apprentices or trying to explain a safe connection method to a client.

Example: A regional hospital installs a new 80kVA diesel generator. The AS/NZS 3010 figure showing a three-phase changeover system with a switched neutral helps the electrical contractor design a compliant connection between the genset and the emergency supply board.