It's the question we get asked more than any other when it comes to buying electric catering appliances. "What is the difference between single phase and 3 phase power?"

If you're planning to invest in new machinery for your kitchen, understanding the differences between the two is extremely important. Choose the wrong power type, and you probably won't be able to connect your new machine at all.

Knowing your own kitchen's power requirements is equally important. If you're in any doubt at all, we recommend consulting a qualified electrician for professional advice as to which commercial kitchen machines would be safe and suitable to use.

To quickly summarise the key differences between single phase and 3 phase power:

• Single phase power has one live wire, 3 phase power has three
• Single phase electricity is usually connected at 230/240V, 3 phase power at 400/415V
• Single phase power is the standard domestic choice, 3 phase power is more common in industrial or commercial settings
• Single phase appliances usually (not always) come with a domestic three-pin plug, 3 phase appliances generally require a hardwired connection

With three live wires, 3 phase power generates a smoother and more constant current which makes it the most reliable option for the larger and more powerful industrial appliances such as large commercial combi ovens or pass through dishwashers.

3 phase appliances can not be plugged in to domestic 10A or 15A outlets. In fact, they will not be supplied with a standard three-pin plug and generally require a hardwired connection. This should be carried out by a professional electrician.

How do I know if I have 3 phase power?

Examine your kitchen's existing setup. Are the majority of machines plugged in to a standard domestic outlet? If not, and they are hardwired, you may well have a 3 phase connection.

Check your appliance user manuals to see how much power they require. If you've lost them, you can always visit manufacturer websites to see their electricity ratings (volts, watts, amps). Some machines will even have this information displayed on a ratings plate.

Which power supply should I choose?

Avoid trying to look at which power supply is 'best'. What you should be considering is which one will be most efficient to run in your kitchen.

The best advice is to choose a like-for-like replacement of your old appliance. That way, you already know it can be connected and that your kitchen's electric circuit can handle the machine's power without overloading.

You could even replace it with a slightly less powerful alternative - not only will it reduce strain on your circuit, it will reduce your energy bills as well.

➧ If you're in ANY DOUBT about your kitchen's ability to power your replacement appliance, we highly recommend requesting professional advice from a qualified electrician before making any purchase. This is even more important if you are setting up a commercial kitchen for the first time.