Single Phase Generator vs. Three Phase Generator Explained

If you are not an electrical minded person, electrical jargon such as single-phase and three-phase type of generator can be overwhelming. To figure out which generator may meet your power need, it is helpful to learn the fundamentals of power supply system and the major difference between the two-generator power system.

The generator's power supply system is basically classified into two types; single phase and three phase system. The single phase is used ideally for an application where less power is required or for running the small loads such as home appliances. The three-phase power supply system suits best for a large application for example; industrial site, factories or a manufacturing unit where a large amount of power is needed.

Fundamental of Single-Phase Power System

The single-phase power requires two wires for completing the circuit - the conductor and the neutral. The conductor carries the current and the neutral is the return path of the current. The single phase supplies the voltage up to 240 volts. It is mostly used for running the small appliances.

Fundamental of Three Phase Power System

The three-phase system is made up of four wires, three conductors and one neutral. The conductors are out of phase and at 120º apart from each other. The three-phase system is also used as a single-phase system. For the low load, one phase and neutral can be taken from the three-phase supply.

The three-phase power supply system is continuous and will not drops power to zero. In three phase system power can be drawn either in a star or delta configuration. The star connection is used for long distance transmission because it has neutral for the fault current. While, the delta connection consists three phase wires and no neutral.

Comparison of Pros & Cons

Single Phase System

Three Phase System

The power flows through 1 conductor

The power flows through 3 conductors

Requires 2 wires (one phase and one neutral) to complete the circuit

Requires three phase wires and one neutral wire to complete the circuit.

Up to 240 volts

Up to 415 volts

Operates in only one phase wire which means if fault occurs on the network, the power supply will completely drop

Because it operates in three phases, so if ever fault happens on any one of the phases, the others will still supply the power.

Less efficient compared to the three-phase system

More efficiency

When the network or power supply fails completely, it requires more maintenance and will end up costly

Avoid complete down time which can be costly for maintenance

Ideal for house appliances or devices that requires small loads

Ideal for large loads applications such as industrial use.


In conclusion, choosing between single phase or 3 phase generators mainly depends on your power requirement and your budget. Both brings convenience in powering needs whether living off grid or simply a backup power for home or to power industrial site. The major difference is the number of conductors the power flows through which can be a huge impact of a generator's power supply and efficiency. However, if you only need to power small loads home appliances and prefer a cheap initial cost, you probably be settling with the single-phase generator. Otherwise, if you are running industrial site and want to avoid costly downtime maintenance, you would surely appreciate the generator with 3 phase power supply system.