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Type A RCBO

03/11/2025
by Rick Coleman
Type A RCBO

If you've had a squiz at a new, schmick-looking switchboard lately, you've probably seen a neat row of slim switches, each with its own "Test" button. These are most likely RCBO, the modern standard for home electrical safety.

But if you look even closer, you'll see a tiny symbol that represents a massive, critical difference for the safety of your home. We're talking about the difference between the old "Type AC" and the modern, essential Type A RCBO. Understanding this is fair dinkum crucial in a home full of modern electronics.

A Quick Refresher: What's an RCBO, Anyway?

Before we get into "Type A," let's just remember what an RCBO is. It's a "Residual Current Breaker with Overload protection" – a proper two-for-one deal for your switchboard:

  1. It's a Circuit Breaker (MCB): It protects your home's wiring from overloads (too many appliances) and short circuits, which stops fires.
  2. It's a Safety Switch (RCD): It protects you and your family from fatal electric shock by detecting tiny "leaks" of current and tripping in a fraction of a second.

The Big Difference: Type AC vs. Type A RCBO

Righto, this is the most important bit. For decades, the standard safety switch in Australia was Type AC.

  • Type AC (The Old Standard): A Type AC safety switch is designed to detect a fault where the electrical current is leaking in a standard 'sine wave' pattern. This is the kind of fault you'd get from a simple, old-school appliance like a basic toaster or a simple heater.
  • Type A RCBO (The Modern Standard): A Type A RCBO is much cleverer. It can detect the same AC faults, but it's also specifically designed to detect "pulsating DC" fault currents.

Why Does Pulsating DC Matter? Because Your Whole House Runs on It!

You might be thinking, "My house runs on AC, mate, not DC." But here's the kicker: all your modern electronics create DC.

That includes:

  • Washing machines and dryers (with variable speed motors)
  • Dishwashers
  • Induction cooktops
  • Solar inverters
  • Air conditioner inverters
  • LED light drivers
  • Phone and laptop chargers (switch-mode power supplies)
  • Computers and TVs

When these electronic devices develop a fault, they don't leak a nice, simple AC current. They leak a 'pulsating DC' current.

Here's the scary part: A standard Type AC safety switch might not be able to 'see' this type of DC fault. This means it could fail to trip, leaving you unprotected from a potentially fatal electric shock.

A Type A RCBO is specifically designed to see both types of faults, making it the only truly safe choice for a modern Aussie home that's full of electronic gear.

How to Check What You Have (Safely!)

Next time you're looking at your switchboard (from a safe distance, mate, no touching!), have a squiz at the symbols on your safety switches.

  • Type AC will have a symbol of a simple wavy line (a sine wave).
  • Type A will have the same wavy line plus a symbol for a pulsating DC wave (looks like a wave with a hump on top).

If your board is full of old Type AC breakers, especially on circuits powering your kitchen, laundry, or solar inverter, it's fair dinkum time to think about an upgrade.

Installation is Strictly for a Licensed Pro

We cannot be clearer on this. Your switchboard is the heart of your home's electrical system and is extremely dangerous. Installing or replacing any device in your switchboard is absolutely not a DIY job.

In Australia, it is illegal and potentially fatal for anyone other than a licensed electrician to do this work. A qualified professional has the training, testing gear, and legal authority to work on your board, recommend the correct Type A RCBO for each circuit, and ensure your home is fully compliant with Australian Standards (AS/NZS 3000).

A Professional Job Needs Professional Gear

A safe, modern switchboard is the foundation of a safe home. For professional installers and licensed electricians who build and upgrade switchboards, sourcing reliable, compliant gear is paramount. As one of Australia's most comprehensive electrical wholesaler and suppliers, Schnap Electric Products stocks a complete range of trade-quality switchboard gear. This includes high-quality, certified Type A RCBO units from the world's most trusted brands, alongside all the circuit breakers, enclosures, and accessories that a qualified professional needs to get the job done right. For a switchboard that's built for modern life, the pros start with quality gear from a supplier like Schnap Electric.