WHAT EXACTLY IS AN ELECTRICAL CIRCUIT?

We all know what a circuit is like something out of Mario Kart, but what does it actually mean electrically? In its simplest form, a circuit is the path electricity takes from A to B, whether that be your switchboard to an appliance, or your phone’s battery to its camera.

Electrical circuits come in all sizes, but in a home can be split up into different circuits that can be dedicated to powering loads like lighting, or a circuit for one or more power points, or a dedicated circuit for appliances like EV chargers or air conditioners.

Why do homes have different electrical circuits? Having electrical circuits that power different loads can help with troubleshooting and helps spread the electrical load. If one circuit goes down, it won’t necessarily mean your entire house loses power.

WHAT DOES A CIRCUIT BREAKER DO?

So, you have an electrical circuit that connects your switchboard to the load, but how do you stop the circuit from flowing without damaging it? This is where circuit breakers come in.

Difference between Fuses & Circuit Breakers? Older-style homes generally use fuses which are single use and need to be replaced every time they are blown, but circuit breakers are now used where a circuit is tripped, can be flicked back on without needing replacement.

What makes a circuit breaker trip? A circuit breaker trips when it overloads and there are too many things running on the same circuit. It’s also designed to trip when there’s short-circuits or other faults that could pose risks.

DIFFERENCE BETWEEN AN RCD VS. CIRCUIT BREAKER?

An RCD or Residual Current Device, otherwise known as a safety switch, is designed to detect leaking where electricity shouldn't go like through a person.

Difference between RCDs & Circuit Breakers? Whilst circuit breakers are designed to protect against overloading and short circuiting, RCDs focus more on preventing electrical shocks and user safety. RCBOs take this to the next level.

What’s an RCBO? An Residual Current Circuit Breaker with Overcurrent protection (RCBO) is a compact unit that integrates both an RCD (protecting against leakages), and against overcurrent faults as a circuit breaker. This simplifies wiring and provides protection for the two safety requirements in the single unit.

WHAT ARE FUSES & ARE THEY STILL USED?

Like circuit breakers, fuses are the old-school style that protect against overloading. Instead of a switch, a fuse has a little wire that is designed to handle a certain amount of current (amps), and if overloaded will actually melt the wire and stop the flow of electricity.

Fuses aren’t really used anymore for newer homes as we have better options available. Every time a fuse ‘trips’, the blown fuse needs to be replaced and can’t be reset like a breaker.

Older homes will still have fuses in older switchboards and can also be found in certain appliances.

DEDICATED CIRCUIT VS. ENTIRE HOME BACKUP

When a solar battery is installed with backup capability, it won’t automatically power your entire home during a blackout. Generally, batteries are installed to backup specific circuits to continue powering the home’s more essential loads like the fridge etc. but can be extended to cover your entire home.

Your battery installer will generally give you 2 options, a dedicated circuit backup where essential loads like the fridge, internet, and lights stay powered on, and a whole home backup where everything can stay powered. These are dependent mostly on the requirements of the customer, as well as their budget as partial backup is generally more cost-effective.

UPGRADING YOUR SWITCHBOARD: WHAT'S INVOLVED?

Acting as the control centre for your electricity, your switchboard is essential for any home and its electricity distribution.

As time continues and properties get older, homes begin to be due for a switchboard upgrade as they struggle to keep up with modern electrical demand.

What are the signs a switchboard needs replacing? A switchboard may need replacing when things like older fuses are still installed, there’s not enough space for new circuits, you’re adding additional components like solar and battery, or your breakers are tripping frequently.

As homes use more power than they used to, older homes may struggle to keep up with the requirements of modern appliances.

HOW TO TELL IF YOUR HOME IS SINGLE OR THREE-PHASE?

The primary difference between single and 3-phase in its simplest way is how power is delivered to your property. A single-phase property only has one ‘line’ or ‘pathway’, where a three-phase has 3 that can deliver more power for more power-hungry properties like businesses.

To find out if your home is single or three-phase, there are a few methods you can try. Firstly, you can check your switchboard’s smart meter or see how many switches there are under the ‘main switch grid supply’. More info on how to tell if a home is 1 or 3-phase here.

Do I need to upgrade my house to three-phase? Not every home needs the capability of three-phase power. Most homes run on single-phase power with no issues, so determining whether to upgrade to three-phase power will depend on what you’re trying to power.

For example, if you have an electric vehicle and want to charge it quickly, the maximum rate of charge on single phase is 7kW. For a three-phase property, it is up to 22kW which greatly reduces the time it takes for a full EV recharge.

WHAT HAPPENS TO SOLAR DURING A BLACKOUT?

One thing that people assume is that solar continues to power a home during a blackout. Unfortunately, this isn’t the case as solar systems shut down during grid outages even if the sun is shining. This is primarily designed to protect the grid from solar exports as network crews work on power lines.

If your property consists of a backup capable solar battery, the system will engage as soon as it detects a grid outage. Depending on your battery’s configuration, it will either provide backup power to dedicated circuits or the whole home.