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3phase to single-phase -Simple Ways to Convert Three Phase to Single Phase

Shifting from a three-phase to a single-phase power system is a commonplace need. It is because a single-phase load is relatively lower than a three-phase. For example, power for household use is the 3phase to single-phase type. Most home appliances use low power, which makes the single-phase the feasible option. 

You can opt to remain with three-phase power, but this is only useful in running heavy machinery. Therefore, if you intend to meet the typical household uses, a single-phase is the reasonable alternative. You can quickly achieve this by having the right equipment

If you have such a need, read on. 

3phase to Single-phase –What is Three-phase Power?

A 3 phase Power Supply System

Figure 2: A 3 phase Power Supply System

Three-phase power is AC that is carried by three live wires and one neutral. All the phases have the same voltage and amplitude, set at a phase difference of 120 degrees.  Most people use Three-phase power for industrial purposes as its carries a larger volume of current. 

3phase to Single-phase –What is Single-phase Power?

A Single-phase Power Supply System

Figure 3: A Single-phase Power Supply System

When one single live wire and a neutral are used to carry current, this is a single-phase system. Therefore, only one wire has current, unlike in three-phase where there are three wires. 

Is 3 Phase Better Than the Single Phase?

3 Phase Electricity Lines

Figure 4: 3 Phase Electricity Lines

When considering the volumes of power loads, the three-phase is better than the single phase. The three-phase guarantees a stable supply of power at a constant rate. It is not the case for the single-phase system. It is prone to experiencing dips and peaks and thus unfavorable for commercial use. 

Also, a three-phase system will supply a higher amount of power than a single-phase system. A three-phase can provide thrice what a single phase can offer. 

Even though the three-phase system uses three wires while the single-phase uses two, the former uses lesser conductor material. For instance, to transmit, say 120V of power, a single-phase will require more conductor material than a three-phase. 

There are instances when a single phase is better than the three phases, especially when considering the use of the power. An individual who only wants the ability to use his household appliances will need single-phase power. Thus, it might be necessary to shift from the superior three-phase power system for such household uses. It is the rationale for converting three-phase to single phase. 

3phase to Single-phase –How to Convert Single-phase to Three-phase

A Technician Repairing a Power Supply Line

Figure 5: A Technician Repairing a Power Supply Line.

As highlighted above, sometimes, it is necessary to convert a three-phase to a single phase. If that is your cardinal concern, there are several means of shifting three-phase into an easier-to-use power form. You just need to have the right equipment. Every transformation system is unique, but its cardinal aim is to convert power to the same format. Nonetheless, some are more accurate and effective than others. Therefore, you need to pick the one that best fits your needs. 

Among the most common ways include:

Use a Neutral Wire

A Simple Electrical Circuit

Figure 6: A Simple Electrical Circuit

It is the most common and most accessible means of conversion and is ineffective in giving the desired current. You, therefore, need to be careful when doing it. To use it, you need to ignore two phases out of the three live wires. You then use a single-phase together with a neutral wire, making it a single-phase system. 

Nonetheless, it is not a too accurate technique. It is advisable to use it only when you do not require a stable and precise power supply. Otherwise, it’s one of the simplest ways of conversion. Also, you do not need to invest in any converting device, unlike in the other conversion techniques. 

Use a Phase Converter

A Phase Converter Unit

Figure 7: A Phase Converter Unit

A professional would most likely advise you to use a phase convertor instead of the neutral wire way. This technique is more effective in giving a real conversation than the unbiased wire method. All you need is to have an electronic converter that will first convert the AC to DC. A phase converter can then convert this current to a single-phase AC. 

The technique is straightforward, and all you require is a rectifier, and you’re good to go. 

3phase to single-phase –Use a Single Phase Transformer

An Illustration of a Single-phase Transformer

Figure 8: An Illustration of a Single-phase Transformer.

 As shown above, you do not necessarily have to go through the hassle of converting power to DC and then back to AC. When you invest in a suitable transformer, you can quickly realize the desired outcome.

However, this method is only applicable when dealing with power less than 5 KVA. For higher power, it would be imperative to use another technique. 

Use the Open Delta Transformer

Figure 9: A Simple Transformer Silhouette 

It is the ideal technique of converting more than 5 KVA three-phase power to a single phase. This transformer is powerful and well-built to facilitate high power conversions. 

3phase to single-phase –Use the Le-Blanc Transformers 

Figure 10: Side View of a Simple Transformer Silhouette

It is the ideal machine for converting high power such as currents above 5 KVA and 400 V. The primary upside of this transformer is that it guarantees accurate conversions. Some devices are sensitive to the accuracy of the currency, and this is the best converter for such systems.

Use the Scott T Transformers

This type ranks among the best in the list of powerful transformers fit for converting three-phase to single-phase.  It features a unique form of connection that mainly involves a teaser transformer and the main transformer. The two transformers work in tandem to realize the conversion from three-phase to single phase. 

One of the key advantages of this transformers is that it produces balanced current. It is thus perfectly fit for systems that need a single-phase proportional current. 


In a nutshell, some situations may necessitate the conversion of three-phase to single phase. For instance, to use power for household uses, a single-phase is imperative. You can achieve this by using the above-highlighted ways. Also, visit our site for deeper insights on how to convert three-phase to single-phase successfully. We have the necessary equipment to assist you in achieving the best results. 

Hommer Zhao
Hi, I am Hommer, the founder of WellPCB. So far, we have more than 4,000 customers worldwide. If you have any questions, you can feel free to contact me. I really appreciate any help you can provide.