Single Phase vs. Three Phase Power

Single phase is more widely available in residential settings and is less expensive to purchase than three phase power units. Single phase is commonly called “residential voltage” for many reasons; one of which, is that most homes use it (it’s the power present in wall plugs). This type of power relies on two wire conductors to distribute power, which create a single sine wave (low voltage).

Three Phase

Three Phase power is most commonly used at commercial/professional sites and is recommended for larger ponds. These units are less expensive to operate than Single Phase power units. Units with this type of power only come in 5HP or higher. Three phase power relies on three coils mounted on the rotor at 120 degree intervals, which produce three sine wave voltages (high voltage). It’s used universally for power distribution.

Single Phase

• Motors are driven by pulsating torque (like a pulsating shower head)
• Motors require capacitors and/or start switches-- extra parts that need to be monitored
• Experiences more interruptions in electrical flow
• Motors have a shorter lifespan

Three Phase

• Three Phase power isn't available at all locations (check with your local power company to see availability)
• Costs can be exorbitant when installing three phase power
• Units are more efficient to run, but more expensive to purchase
• Has a smooth and continuous flow of power
• Allows for longer cord lengths/cable runs
• Motors may experience rotation issues if installed improperly
• Motors are generally more efficient, some convert 97% of electrical energy into useable mechanical energy
• Motors have a longer lifespan

When it comes down to it, which is better depends on:

What type of power is available at the site?

What type of unit is being installed?

Single phase is best used:

• With fractional or low horsepower units (less than 5 HP)
• At residential sites and small ponds

Three Phase is best used:

• With any high horsepower unit (5 HP or more)
• At commercial/professional sites or larger ponds

For more information about Single or Three Phase power, please contact your local power company.