Single-phase electricity is the normal electricity we use to power our appliances in our homes. It’s 230 volts at 50 hertz and the standard for the socket is AS/NZS 3112.
Most properties in Australia only have a single-phase connection.
Three-phase is a higher voltage. Instead of 230 volts, a much higher voltage of 400 volts comes out of the socket. A property with three-phase electricity is connected to the grid through three live wires, compared to just one for a single-phase property.
Three-phase electricity isn’t designed to power your home appliances (such as TV and toaster). Instead, it’s for appliances that draw a lot of electricity. Like heavy-duty compressors, industrial freezers/air conditioners, industrial ovens, etc.
These are mostly things you’ll find in industrial and large commercial environments, but sometimes also in large homes that can have large air conditioners or pool pumps running.
How do you know what you have at home?
Most people that have three-phase electricity in their home are well aware that they have it as there are higher connection fees and higher annual charges from your electricity company.
If you’re not sure, however, you could obviously have a look to see if you have one of those bigger AS/NZS 3123 sockets anywhere, but the simplest way is to have a look at your home’s switchboard.
When you’ve located the switchboard in your home, find the circuit breaker that is labelled ‘Main Switch’. If this is a single circuit breaker, you have single-phase electricity. If you see three circuit breakers joined together, you have three-phase electricity.