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Difference Between Single Phase and Three Phase Power Supply

Difference Between Single Phase and Three Phase Power Supply

Single Phase and Three Phase Power Supply

In industrial property context, besides ampere (A) we usually come across such terms like single phase and three phase power supply for Industrial properties such as factories or warehouses in Singapore.

Let’s find out what’s the key difference between the two.

Alternating Current

Alternating current or AC power is an electric current which is constantly alternating or reversing in directions. Alternating current has been used for both residential and industrial properties since many years back.

Both single phase and three phase power use alternating current (AC) power however, the main difference between the two types of power is the frequency of delivery.

For most businesses and industrial factories, it is usually in three phase to support heavier loads, whereas for residential properties, single phase is generally sufficient for our usual day-to-day household use.

Single Phase

In simple terms, the single phase system needs two wires to complete the circuit, namely the conductor wire, which is the wire with current flowing through as well as the neutral wire. The conductor wire is the wire that carries the current while the neutral wire is the return path of the current. For single phase, the voltage supplied the voltage supplied is up to 230 volts (V).

For residential properties, single phase power is sufficient for home appliances such as fan, aircon, heater, microwave, tv, vacuum cleaner etc.

single phase industrial power supply

If we look closely at the chart above, we notice that the voltage (V) peaked and also dipped in each cycle, and that power is not supplied constantly all the time. Although there is no constancy in power all the time, it is sufficient for daily residential household use.

Three Phase

Unlike single phase, the three phase circuits consist of four wires in total, three are conductor wires which carry the power and a neutral wire which is the return path of the current.

For three phase systems, power supply is constant and does not completely fall to zero, unlike single phase systems.

If we look closely at the chart above, upon completion of a full cycle, all three phases peaked and also dipped. The chart above shows that the three phase power system is able to supply a continuous and constant stream of power. This enables a three phase to carry more load as compared to a single phase circuit.

One additional plus point for three phase systems is that since it has three phases, if a fault happens to occur on any one of the three phases, the other two will still continue to supply power. However, for single phase systems, if a fault happens to occur, the system fails.

For three phase systems, the voltage supplied is up to 415 volts (V).

Should I Use Single Phase Or Three Phase Power for My Business?

Most of the time, for residential property users, single phase would be sufficient for day-to-day use. This is why single phase systems are found in almost every household in Singapore.

For industrial property users, single phase may be sufficient for small businesses or warehouse units used mainly for storage purposes. However, if your equipment and machines require more load, three phase systems may be the ideal choice.

Selecting a single phase or three phase system all depends on the power requirements of your business operations. If you have many heavy duty machineries, you may require three phase power supply as single phase may not be sufficient to carry heavier loads.

Single phase supply is mostly used for residential properties while the three phase supply is used for larger industries to run heavier loads.

To be sure, consult an experienced electrical contractor or licence electrical worker (LEW) who will be able to advise you based on your company’s operational requirements.