0
If I have 1 KW In 3 Phase it will give 1.54 A and In single phase it will give 4.6 A
For cosF 0.9
V 415 3 ph
V 240 1 ph
It seems the reason is because the current is carried on more wires. Also, remember that if wattage stays constant, then as voltage increases, current decreases.
AnswerIt really depends on the load. Are you assumining the three-phase load to be the same as the single-phase load or, as it is likely to be in practice, three times the value of the single-phase load?
But, in either case, the single-phase current will not be double the the three-phase (line) current!
The equation for the load current supplying a single-phase is: I = P / (E x power factor)
The equation for the line current supplying a balanced three-phase system is: IL = P / (1.732 x E x power factor)
If you insert real figures into these equations, (240 V for the single-phase voltage and 415 V for the three-phase line voltage) then you will find that, when the three-phase load is threetimes that of the single-phase load, the supply currents will be exactly the same. On the other hand, if you assume that the three-phase load is exactly the same as the single-phase load, then you will find that the three-phase line current will be one-third that of the single-phase current.
Wiki User
∙ 11y ago
Add your answer:
Earn +20 pts
What are advantages of three phase ac and a single phase ac?
In a typical 3 phase system you have multiple voltages and configurations that can be used in either single phase or 3 phase, depending on how the circuit is designed. A single phase system is just single phase. You can have multiple voltages but it is always single phase.For example, in a typical 277/480v 3 phase system you can power 277v single phase lighting or equipment, 480v single phase lighting or equipment (which uses 2 legs of the 3 phase system but operates like any other single phase circuit), or 480v 3 phase motors.When comparing motors, a 3 phase motor will be substantially smaller than a single phase motor of the same horsepower. You can also reverse a 3 phase motor by switching any 2 leads. A single phase AC motor runs in one direction regardless of how the leads are connected.AnswerFor a given load, a three-phase transmission system requires less volume of copper in terms of conductor size, compared to single phase, so it is more economical to use three-phase.
What is the US 3 phase voltage?
A balanced three phase system is composed of three single phase voltages having the same amplitude and frequency but displaced from one another by 120 degrees (1/3 cycle).We know that a single coil (winding) rotating in a magnetic field produces a single phase alternating voltage. Similarly, three phase voltage can be produced by a set of three coils separated from each other by 120 electrical degree. Three phase power is so popular because of following advantages.For a given size of frame, a three phase generator or motor has a bigger output than a single- phase machine.To transmit a given amount of power at a given voltage over a given distance, a three phase transmission line requires less copper than a single phase line.Three phase motors are self starting; single phase motors are not self startingParallel operation of three phase alternators is simpler than that of a single phase alternators.
How much more efficient is a 2 hp 240 v 3 phase motor compared to a 120 v single phase 2 hp motor?
I would guess it would use a third less than a single phase motor. The voltage differences don't save but 3 phase does. A 3 phase motor also starts easier.
Is 3 phase power equal to 3 times the single phase power?
Single phase has two line voltage wires, separate from each other; three phase power has three line voltage wires, actually saving more energy and thus money. +++ The difference is that the power is transmitted divided into 3 parallel lines with the wave forms 120º apart. Energy saving is achieved by using very high transmission voltages hence low currents, feeding step-down transformers in the users' locality.
What is the difference between a single phase and a three phase inverter?
The Single and Three phase refer to Alternating Current electrical power supply outlet system and the corresponding equipment requirements. The single phase system is generally used thepower requirements are low or moderate as for household applications , while the Three phase supply system is used for High power industrial applications. Thenumbers of phases refer to Alternating Current Supply lines which are delivering the power or the sytem requirement of the equipment for operation. Thus a single phase supply cannot operate a three phase equipment or vice versa. However a ThreePhase supply can be used individually as Three different Single Phase supply systems In case of Three Phase systems the electrical supply waveforms are such that at any given instant there is a 120 degree phase difference between any two supply lines , which also results in higher magnitude of supply voltage than the corresponding single phase supply. Now refering to the inverter which is nothing but a device to convert the electrical supply from one source or magnitude ( typically DC from a Battery Bank ) to the required form and Magnitude. Thus it simply generates the equivalent electrical supply either as Singleor Three Phase , which ideally will be the same as available available from the wall outlet
What is the advantages and disadvantages of single phase and three phase?
Single phase inherently requires less equipment (it's cheaper). Three phase motors are more efficient than single phase.
Single phase is more hazardeous than three phase?
Not necessarily.
Why three phase meter is better than single phase meter?
A three-phase meter can be used for single phase while the reverse is not the case.
When installing photovoltaic system is 3 phase more expensive than single phase?
The only real difference would be the inverter and panelboard, and yes, 3-phase inverters are more expensive than single-phase.
What are the advantages of poly phase over single phase?
The primary advantage is that, for a given load, a three-phase system requires less copper for tranmission/distribution than an equivalent single-phase system would require. Other advantages include the fact that three-phase machines are smaller than single-phase machines of similar rating.
Why 3 phase ac systems is preferred to 4 phase?
3 phase system has more power than a single phase system
What are some advantages of 3-phase power over 1-phase power?
There are several advantages of 3-phase power over single phase power. First, with 3-phase power, more power can be transferred with the same amount of wire (meaning the amount of copper used in all of the conductors transferring that power) as with single or 2-phase power. Also, power is transferred more "evenly" with 3-phase power because the "next peak" is closer than it is with single and 2-phase power. The 3-phase motors run more smoothly than those run on fewer phases. Also, there are motor design considerations (one being control of the direction of rotation) regarding the motor that make 3-phase power more attractive. Use the link to the Wikipedia article on 3-phase power and skim it. It isn't long and it is quite readable.
What are the uses of three phase transformer over single phase and their losses?
For a given load, a three-phase system requires around 75% of the volume of copper required by a corresponding single-phase system and, so, is more economical. A three-phase supply also delivers power more or less continuously, whereas a single-phase supply delivers power in pulses. Finally, three-phase motors are self-starting and physically smaller than single-phase machines of the same power rating.
What are the Advantage of three phase motors over single phase?
A 3 phase system needs only to use 3 or 4 conductors, as against 6 conductors if it were 3, single phase conductors The amount of copper used in a 3 phase is much less than what would be needed in a single phase system carrying the same current, this reduction in copper allows for weight reduction and cost savings. The power losses in a 3 phase system are much less than in a single phase system.
Do mixtures always have more than one phase Why?
No. Mixtures can be a single phase, such as in the case of salt water. This is a homogeneous mixture. A heterogeneous mixture would have more than one phase.
What is the advantage of 3 phase system compared to single phase system?
3 phase motors are more efficient than single phase motors. That is why many factories use 3 phase, because they save on their electricity bills. However, it is more expensive to supply the wiring to bring in 3 phase electricity; so it is not used in residences.AnswerThere are three main reasons for generating three-phase electricity. The first reason is that, for a given load, a three-phase supply uses less volume of copper (around 25% less) and is, therefore, more economical than a corresponding single-phase supply. The second reason is that it delivers continuous energy, rather than in a series of 'pulses', which is the case with single phase. The third reason is that a.c. motors are self-starting and more compact than a single-phase motor of similar power rating.Incidentally, three-phase residential supplies are common in some countries, because service conductor size is lower, therefore less expensive, than the corresponding single-phase conductors.
What are the advantages between 3 phase and 1 phase?
For a given load, a three-phase system uses less volume of copper (therefore is more economical) than a corresponding single-phase system, while supplying approximately-constant power. From the users' point of view, three-phase motors are self-starting and more compact than the equivalent single-phase motor.
