Why Your Battery Backup Needs Type A RCBOs

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If you're getting a battery system with blackout protection installed, there's a wiring rules requirement your electrician needs to address. It affects your switchboard, it's been mandatory since 2023, and it's worth understanding before you sign off on a system.

This post explains what changed in the Australian wiring rules, why it matters for battery systems in particular, and what we do at Flux to make sure installations are done to current standard.

What Changed in the Wiring Rules?

As of 1 May 2023, electricians across Australia are no longer permitted to install Type AC RCDs on new or upgraded electrical circuits.

The standard now requires Type A RCDs or Type A RCBOs on all new final sub-circuits. An RCBO combines RCD and circuit breaker protection in a single device. Type A is the rating required where battery storage, solar, or EV chargers are present.

Why Type A RCBOs Are Now Required

Solar inverters, EV chargers, and battery systems can introduce pulsating DC currents into your wiring.

Type AC RCDs are only designed to detect AC earth faults. They won't trip if DC leakage occurs. That's a real gap in protection when modern energy equipment is in the circuit.

Type A RCBOs detect both AC and pulsating DC earth leakage. That's the protection you need when a battery, inverter, or EV charger is involved. It's why the standard changed.

How to identify Type AC vs Type A RCDs/RCBOs by the symbols on the front face

Protection Type	AC Faults	Pulsating DC Faults	Required for New Installs?
Type AC RCD	✓	✗	No longer compliant
Type A RCBO	✓	✓	Yes - required

Battery Backup Systems and Blackout Protection

For battery systems with blackout protection, there's one clear requirement:

During a blackout, your battery takes over and powers selected circuits in your home. Those circuits are still live. If a fault occurs, you need a safety switch that will actually detect it and trip.

Type A RCBOs give those circuits the correct level of protection while the system runs on battery power.

What This Means in Practice

When we install a battery backup system, we assess your switchboard and identify which circuits are going on backup power. Those circuits need Type A RCBOs. No exceptions.

Common backed-up circuits include:

• Lighting circuits
• Refrigerator/freezer
• Internet/router
• Security systems
• Garage door
• Select power points

If any of those are on older Type AC protection, we replace them as part of the installation.

What About Existing Type AC RCDs?

If your switchboard already has Type AC RCDs, they don't need to be replaced unless those circuits are being altered, extended, or added to the backup supply.

However, if you're:

• Upgrading your switchboard
• Installing a new electrical system
• Adding solar panels or a battery system
• Installing an EV charger
• Extending or modifying existing circuits

...then we upgrade those affected circuits to Type A RCBOs as part of the work.

Why Does This Matter for Solar and EV Owners?

Solar inverters and EV chargers convert DC to AC or vice versa. That conversion process produces the pulsating DC currents that Type AC RCDs can't detect.

If you have:

• Solar panels - the inverter converts DC from the panels to AC for your home
• Battery storage - batteries store DC and convert to AC when discharging
• EV charger - converts AC from the grid to DC for your vehicle

All of these can introduce DC leakage into the circuit. Type A RCBOs are designed to detect it.

How We Handle This at Flux

We don't cut corners. Whether we're installing a complete solar and battery system or upgrading a switchboard, we include whatever switchboard work is needed to bring the installation up to current standard.

When we do a battery installation, you can expect:

• A full assessment of your current switchboard
• Clear explanation of what needs upgrading and why
• Type A RCBO upgrades where required, included in the scope
• Full compliance with AS/NZS 3000:2018 Amendment 2
• Documentation for your records

Reference: AS/NZS 3000:2018 Wiring Rules - Amendment 2, Clause 2.6.2.2.2