Quick guide
Single-phase or three-phase power?
Not sure what your home has? The quickest way to tell is at your switchboard (meter box). Match what you see to one of the two below.
Single phase
Most homes
The standard household supply and by far the most common in Perth homes. Fine for most ducted systems up to around 14 kW.
How to tell
- The main switch in the meter box is narrow (one or two poles wide)
- One or two service fuses
- A thinner supply cable coming in
Three phase
Larger homes & big loads
A higher-capacity supply, more common in larger homes or homes with pools, workshops, or big ducted or commercial systems.
How to tell
- The main switch spans three poles side by side, clearly wider
- Three service fuses grouped together
- A thicker supply cable coming in
Look, don’t touch. You can read the labels on a closed switchboard, but never remove covers or touch anything inside. Still unsure? Choose “Unsure” in the estimator. We confirm your supply on a free, no-obligation site assessment.