How do you convert a 3-phase power supply to a single phase supply?

Answer 1

The simplest answer is that the electric utility uses a transformer across 2 of the 3 hot leads to develop a single hot lead with an earth reference. What follows below is frequently edited by both amateurs and professionals, with mixed results. Wikipedia is a better source of more detailed information on this subject, in part because the article on three phase power has pictures.

Answer 2

You don't have to "convert" it because, using three phase in star or 'Y' connection mode, just one phase line and the common neutral will give you a single phase service.

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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

Answer 3

Three phase power can be split into single phase power. A three phase transformer has three sets of coils that are connected internally together. The terminal points are L1, L2 and L3. By using any two of these three terminal points a single phase voltage can be obtained. An example, you have an electric heater that requires 600 single phase voltage to operate. All that was available was a three phase 600 volt service supply. The connection would be L1 and L2 = 600 volts, or L2 and L3 = 600 volts, or L3 and L1 = 600 volts. These single voltages from a three phase transformer, in electrical terms, are classed as single phase supplies.

Alternative Answer

For European low-voltage three-phase systems, four conductors are used. These are three line conductors and a neutral conductor. To obtain a single-phase supply, the load is connected across any one of the line conductors and the neutral conductor.

Answer 4

For three-phase, three-wire, systems, single phase is obtained by connecting the load between any two of the three line conductors (not 'phase conductors'!).

For three-phase, four-wire, systems, single phase is obtained by connecting the load between any two of the three line conductors, or between any one of the line conductors and the neutral conductor -depending on which connection gives you the appropriate voltage.

Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

Answer 5

There is no conversion. A three phase system comprises 3 lines. To obtain single-phase power all that's needed is to connect the load across any two of the lines...

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Not necessarily correct. There is more that needs to be known about the generator to do this connection CORRECTLY.

The above statement is true IF the generator's output is compatible... meaning, it is a Y-configured output AND is at proper voltage. Y (neutral) of the generator's output, must be connected to neutral of your load.

Your generator's output MUST be in the the same general range as your load!!!

Let's say that your home is a common North American 240v single-phase load... you have two hot leads (L1 and L2) and one neutral. You have 120v between L1 and Neutral, 120v from L2 to neutral, and 240v from L1 to L2.

If your generator is configured for 3-phase 240v DELTA, then you cannot 'directly' connect the 3-phase generator, because it has L1, L2, and L3, but no neutral... you'll have fried equipment inside your house.

If your generator is a 208/125Y, it will have L1, L2, L3, and Neutral... where 125v exists from any of the Ls to N, and 208 between any of the L's.

If your generator has an internal panel with additional connections to reconfigure it to different outputs (i.e 230v delta, 480/277Y, etc), then it's also possible to configure it for Double-Delta output (a way of yielding single-phase output from a delta-wound 12-wire generator.

In short, it's be best to know more about the generator AND the load, before going further. There are excellent resources for these issues in generator and power forums online- a web search will quickly find them, and the people who know your generator and power system well.

Answer 6

For a three-phase, three-wire, system you will obtain a single-phase supply between any two line conductors. For a three-phase, four-wire, system you will obtain a single-phase supply between any line conductor and the neutral conductor.

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As always, if you are in doubt about what to do, the best advice anyone should give you is to call a licensed electrician to advise what work is needed.

Before you do any work yourself,

on electrical circuits, equipment or appliances,

always use a test meter to ensure the circuit is, in fact, de-energized.

IF YOU ARE NOT ALREADY SURE YOU CAN DO THIS JOB

SAFELY AND COMPETENTLY

REFER THIS WORK TO QUALIFIED PROFESSIONALS.

Answer 7

A three phase supply can supply a single phase device, usually by connecting between one live wire and neutral in a 4-wire system, or between two live wires in a 3-wire system. It is important to check that the voltage is correct in both cases.

If there is more than one single-phase load it is usual to share the loads out between the three phases to maintain balance as far as possible.

Answer 8

Use a 3 phase inverter that works off a single phase supply

Answer 9

Any 2 legs of a three phase system is considered single phase. Three phase legs, L1, L2, L3. Single phase options, L1 - L2, L2 - L3, L3 - L1.