What is Three-Phase House Wiring?

What is Three-Phase House Wiring?

Weigh the benefits of three-phase wiring against other residential power distribution methods

By Sabah Karimi

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The way power is received and distributed to the power outlets and appliances in your home depends largely on the type of house wiring installation. In a three-phase house wiring system, power is channeled into the house from three hot legs and distributed evenly to all the major appliances and outlets at a certain voltage. While this type of wiring system offers several benefits, it is not necessarily the best match for residential properties.


The three-phase house wiring system provides a steady supply of electrical power to the power outlets and major appliances throughout your home. If you are looking for an efficient way to run certain appliances inside and outside your home, consider hiring an electrician or general contractor to install a three-phase wiring system because unlike a single-phase wiring system, the three-phase wiring provides a constant voltage supply for appliances that demand heavy load times.

Types of Applications

In a residential setting, the three-phase wiring system is used to power large appliances and systems such as the home's heating and air conditioning system. A three-phase house wiring system may also be used for supplying electricity to the pool heater and heavy-duty pool cleaners. Three-phase wiring systems connected to a power grid from a power company are used to power your plumbing system, telecommunication equipment, antenna wiring and grounding electrodes around your property.

Types of Tools

To install and run a three-phase electrical wiring system, use certain hand tools and power tools including hammers, drills, screwdrivers, wire strippers, side-cutter pliers, needle-nose pliers, cable strippers, three-prong outlet testers, voltage detectors, fish tape and electrical tape. If you are hiring an electrician or general contractor to perform the three-phase wiring installation, he or she may also use specialized tools and equipment to perform the installation safely and efficiently.


A building contractor or architect may provide you with a choice of a single-phase or three-phase electric service, so it's important to understand the key benefits of a three-phase vs. a single-phase service are for residential purposes. Almost all residential appliances require 120 volts of power, and this power can be sourced from one of the two hot legs used in a single-phase wiring system. The extra leg from the three-phase wiring system is most beneficial for commercial properties that use appliances that need 240 volts of power or more.


When you are installing a three-phase wiring system, find out how long the warranty on the service is from your power company or electrician. In many cases, a single-phase wiring system has a longer warranty than a three-phase wiring system. A three-phase house wiring system is typically much more expensive than a single-phase house wiring system, and installing this type of system will not necessarily improve the power flow in your home.

About the Author

Sabah Karimi is a regular contributor to DexKnows.

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