Single-Phase Vs. Three-Phase Power Explanation


AC power supply is the most common type of electricity supply for houses and commercial buildings. It enables frequent change of direction in the current. There are two types of power supply systems – single-phase and three-phase. The primary difference between the single-phase and 3-phase transformer is that the former is used in homes and residential buildings while the latter is used in factories and commercial buildings with heavy power load.

A phase-in current in electric transformers refers to the current or voltage in the existing wire and the neutral cable. Therefore, the phase is the distribution of the power load between a single wire in single-phase and three wires in a 3-phase transformer.

Single-phase power comprises a single wire and one conductor to regulate and distribute the power load. On the other hand, three-phase is made of three conductors and one neutral wire for completing the circuit.

Difference between single-phase and three-phase power

Both single-phase and three-phase use the AC power supply for managing the flow of current. The current flow that utilizes the AC power is in the alternating direction. Let’s look at some of the major differences between these two types of electrical transformers

Single-phase power supply

The most common type of small-scale power supply, single-phase supplies power through one conductor. There is a simultaneous modification in all the supply voltages. The major benefit of using a single-phase power supply that it can effectively handle the load of home appliances that have a heat and lightning motor.

In a single-phase electric transformer, there is no rotating magnetic field. It requires an extra circuit for operation. The direct power doesn’t offer any stability in the single-phase power supply system. It can carry a voltage of 230V, most common in houses. The design of the power supply is less complex because there is no magnetic rotation. It also costs less to install but has minimum power transfer capability. The power supply is excellent to run motors up to 5 horsepower(hp).

Three-phase power supply

The three-phase power supply is mostly used in industrial spaces and factories that have heavy power requirements. It has 4 wires – 3 conductor wires and one neutral wire. The 3 conductors have a 120-degree phase angle from each other.

The major benefit is that for a small-load, 1 phase AC power supply can be used from the 3-phase transformer. It provides a constant power supply and does not drop to zero value. The three-phase system doesn’t have a coil. It is an extremely efficient and economical AC power supply system for heavy loads. For the most part, the 3-phase power supply is used in industrial motors, electric grids, aircraft, data centres, shipboards, and system which have to load more than 1000 watts.

If you want to convert single phase into the three-phase power supply, it doesn’t have to be much hassle. You can use a static converter, rotary phase converter, or variable frequency drive converter. For higher power requirements, it is recommended to use 3-phase transformers for efficient results.