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In normal use a 3-phase supply is balanced so that the three phase wires would be of equal size because they carry equal current. When in balance the system draws no current in the neutral wire (if present).
In some conditions different currents are taken from a 3-phase supply, for example three houses connected to the different phases will probably take different currents, and in that case the neutral could carry a current up to or equal to that in one of the phase wires. Therefore in supplying a street, the four wires of a 3-phase supply would all be of equal size.
Wiki User
∙ 9y ago
Wiki User
∙ 13y agoOnly if the loads are imbalanced. In a normal balanced three phase power supply, current is equal on all three conductors, so they should be the same size. However, it is not unusual to provide a three phase power supply, and then to use it for both three phase loads and for split phase single phase loads. In this case, two of the conductors would have higher current, so they should be larger.
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How many wires are in a 3 phase circuit?
A ground, or earth, conductor is never included in the conductor count. So, a three-phase, three-wire, system has three line conductors, whereas a three-phase, four-wire system, has three line conductors and a neutral conductor.
Can 3phase source supplies single phase load?
For a three-phase, four-wire, system, single-phase loads can be connected between any pair of line conductors. For a three-phase, four-wire, system, single-phase loads can be connected between any pair of line conductors, or between any line conductor and the neutral conductor. The choice depends on the voltage requirements of the load.
Where are three phase transformer systems used?
Any where that a three phase supply distribution is needed to operate three phase equipment.
Can a single phase supply be used in a three phase supply?
Yes. This is often done in distribution boards.
What is a phase?
When the conversion of a system, process, etc. Is completed in phases rather than a complete transformation at one time.
What is phase conductor?
There is no such thing as a 'phase conductor'. The correct term is 'line conductor'. Line conductors are the three energised conductors that supply a three-phase load.
Is line to line fault a 3 phase fault?
'Line conductors' are the three 'hot' conductors (A-B-C) that connect a three-phase supply to a three-phase load. In some cases, a pair of line conductors (e.g. A-B, B-C, or C-A) is used to supply a single-phase load. A 'line fault' can be a short-circuit fault between all three, or any two, of these line conductors -whether they supply a three-phase load or a single-phase load.
Line to line voltage?
The conductors between a three-phase supply and a three-phase load are called line conductors not phase conductors, and the voltage measured between them are line voltages, not phase voltages. In the case of a delta supply, the line voltages are numerically equal to phase voltages, but the name remains the same!I have to admit that many people call line conductors 'phase conductors', but many people also say 'irregardless' -that doesn't make it a real word!!
What is phase supply and three phase supply?
I think you mean 'single-phase supply', rather than 'phase supply'. All high-voltage a.c. transmission and distribution systems are three-phase systems. This is because, for a given load, a three-phase system uses less copper than a single-phase system. Three-phase generators produce three 'phase voltages', each displaced, by 120 electrical degrees. These voltages are produced in three windings which are electrically connected in what is called a 'delta' configuration, with each 'corner' of the delta connected to the transmission system by 'line' conductors. Three-phase systems are either 'three-wire' or 'four-wire' systems. Generally, three-phase, three-wire, systems are used for high-voltage transmission and distribution, whereas three-phase, four-wire, systems are typically (but not always) used for low-voltage distribution. Three-wire systems comprise three conductors called 'line conductors'; four-wire systems comprise three 'line conductors' and a 'neutral conductor'. Depending the voltage standards used in the country in which you live, a single-phase supply is obtained either by connecting single-phase load between any two line conductors, or between any one line conductor and the neutral conductor.
How you can convert 1-phase voltage to 3-phase voltage and vice-vars a?
A single-phase supply is obtained between any two line conductors or between a line and neutral conductor of a three-phase supply. To obtain a three-phase supply from a single-phase source is far more difficult, and requires additional equipment.
Why to knw phase sequence?
If you reinstall a three-phase motor with two of the supply conductors interchanged, then the resulting negative phase sequence will cause the motor to run in reverse.
What is a single phase supply?
is the measured voltage,generated between a line voltage and the starting point of a three phase transformer, which is the neutral point. Answer: it is an ac circuit in which the supply has a live and neutral wire, usually at one of the standard voltages 110/120v or 220/240 v. A three-phase circuit is a combination of three single-phase circuits with the phases of the voltages 120 degrees apart so that they peak in a regular sequence.
How do you know if the single line is single phase or 3 phase?
If the single line is compared to another single line and the voltage that you need is correct then you are looking as a singly phase supply. The electrical classification of single phase is that any two legs of a three phase supply can be called single phase. Look on the nameplate of the distribution panel. There it will state what the panel is, either single phase or three phase. Look at where the distribution enters the building from the utility supply. If there are three insulated conductors (red, black and blue) wrapped around a bare aluminium messenger wire it is a three phase wye connection service. If you see two black insulated conductors wrapped around a bare aluminium messenger it is a single phase service.
What is the difference between a one phase and a three phase motor. And if a three phase motor is given a single phase supply will it run or not?
The difference between a single phase and a three phase motor is the amount of power conductors that feed the device. As to the other part of the question a three phase motor will not start or run on single phase. The phase angles on three phase are 120 degrees apart on a single phase system they are 180 degrees apart.
How do you start a three phase motor to a single phase power supply?
You don't. A three phase motor will not start unless it is connected to a three phase supply.
How do connect no of 1phase lamp series connection in 3phase?
Your question is not clear. Are you asking how you can obtain a single-phase supply from a three-phase system? If so, then it depends on the type of three-phase supply and the voltage you require. For example, a three-phase, three-wire, system, single phase is obtained between any two line conductors. For a three-phase, four-wire, system, single phase is obtained either between any two line conductors, or between any line conductor and the neutral conductor. In the case of the latter, two voltages are available, a line voltage and a phase voltage, with the line voltage being 1.732 x larger than the phase voltage.
How many voltage 3phase line?
For a three-phase, three-wire, system there are three conductors called 'line conductors', and there is a voltage between any pair of line conductors, so there are three voltages.For a three-phase, four-wire, system there are four conductors: three 'line conductors' and a 'neutral' conductor. So there are three line voltages (voltages between lines) and three phase voltages (voltages between any line conductor and a neutral conductor).
