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How can a 240V single phase split ac work in the US which has a 120V 2 phase system?
Wiki User
∙ 12y ago
Note
"2-phase" to describe US residential service is depricated nomenclature. US residential service is single phase because the two hot supply phases have 0 degrees of separation between their phases: therefore they are in phase.
The two phases are pulled from 2 out of 3 corners on a 240v (line-to-line) 3-phase delta-primary transformer, usually out in the street. (Sometimes at your house if it's a big one). Basically all power is generated and transmitted as 3-phase. Usually around 415V 3-phase comes into the primary of the 3-phase transformer. (It could be delta- or wye-connected.) The secondary windings for all three phases will each have a center-tapped connection, and that's grounded at the panel. This is the neutral wire. All circuits in houses return via the "common" or "neutral" wire to this point, which happens to be grounded at the panel. Note: no neutral wires should be grounded anywhere else. The two "corners" are 240v relative to each other, and 120v each to the center tap. Each 240V circuit really is two hot wires plus a neutral, which is why it's often wrongly called two-phase when in fact it's just single-phase. For each 120V circuit in the house you're going to use one hot wire and one neutral wire. The neutral wire provides a return path for currents back to the generating station. In some installations, such as apartment blocks, the third leg of power would be at 208V with respect to the center tap.
Another answer
Just what does "220v single-phase split ac in the US which has a 110v 2-phase system" mean?
The vast majority of electricity in the US is delivered as single phase or three phase. The only areas in the US that use 2-phase [for industrial and commercial purposes] are Philadelphia/South Jersey [where it is being phased out-no joke intended] and somewhere out west...
It was one of the early poly-phase options pursued because of the natural magnetic differential between phases [makes motors spin without a capacitor]
Most residences receive 220-240 volt single phase electricity with a grounded center-tapped neutral, the purpose being to limit voltage to ground to less than 150 volts from either "hot".
Wiki User
∙ 8y ago
Wiki User
∙ 12y agoThe US does not use a two-phase system. In fact, two-phase systems are very rare, these days. A two-phase system is where the phase voltages are displaced by 90 degrees, whereas the system used in the US is a split-phase system in which one secondary phase winding of a distribution transformer is centre-tapped and grounded (earthed). This provides 240 V between opposite ends of the phase winding, and 120 V from either end to the centre tap.
Wiki User
∙ 9y agoIt can't be done because the 240 v supply has a live and neutral. A split-phase 120/240 has a centre-tapped neutral so both outer wires are live at 120 v.
It can only be done with a 240/240 v transformer with a centre-tapped secondary.
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How many volts is there in a single phase?
The number of Volts in a residential service drop in the US is either 120V 2 Wire, 120V-208V Network, or 120-240V 3 Wire. A 120-208V Network service is not single phase, but its 120V portion is.
Can you run single phase on three phase?
Yes, you can use one of the three phase service lines to run the single phase device. However, before you connect it, you must first make sure that both the voltage and the current rating of the device will be suitable for the single phase service that your new connections to the service wiring will produce.The single phase voltage you will get between any one phase line and the neutral point is less than the voltage between any two of the three phase service lines by a factor of 1/1.73. So, because 415/1.73 is about 240, a 415V 3-phase service will produce a single phase voltage of 240V.If you are in one of the many countries which use split single phase wiring - such as USA and Canada - that 240V will actually be available as two 120V "hots" (usually with red and black colored insulation) balanced about the neutral point i.e. +120V / Neutral / -120V.Thus you can actually connect up a new branch circuit either for one 240V single phase device or two 120V branch circuits to supply power to 120V devices.After you have made sure that the current demanded by your single phase device can be supplied by the available 3-phase service, it is vital that you make sure you install the correct size of circuit breaker (voltage and ampacity) and branch circuit wiring having the correct wire size to carry the current load drawn by the single phase device, together with the correct types and sizes of socket outlets. All these details are specified in your country's national electrical codes or regulations.(1.73 is the square root of 3).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 JOBSAFELY AND COMPETENTLYREFER THIS WORK TO QUALIFIED PROFESSIONALS.
What is ac supply in America?
The most common voltage supply to homes is single phase 120V / 240V. In the states for industries, 3 phase 480 Wye 277. In Canadian industries, 3 phase 600 Wye 347 volts.
Are most houses single phase?
Single. 3 phase is uncommon outside of industrial settings. Residental houses in the US are wired with a 240V center tapped transformer. This gives a single phase output, with the center tap as the neutral to give 120V.
Can you take single phase of 120V with a hot wire and a neutral step up to 480v and then step down to 2 phases of 120V or do you have to input 2 phases of 120v to get 240V out?
Theoretically that can be done with transformers, but the power available would still be limited by the circuit breaker on the original 120 v supply.
Can single phase 200v from japan use in US with two phase 120v 240V?
The US system is not a two-phase system; it's a split-phase system. But, to answer your question, probably not without damaging the Japanese device.
How many volts is there in a single phase?
The number of Volts in a residential service drop in the US is either 120V 2 Wire, 120V-208V Network, or 120-240V 3 Wire. A 120-208V Network service is not single phase, but its 120V portion is.
How can you get 240V single-phase power from a 240V 3-phase service Can you just connect to two poles of the 240V 3-phase service?
If the 240V 3-phase service is 240V phase-to-phase, then you can get 240V single-phase by simply picking two phases (poles, as used in the question) and connecting the load across them. This is simply one third of a standard delta connection. If you need 120V/240V split phase, i.e. with a neutral, as used in residential services, you will need a transformer. If the service is actually a four wire "quadraplex" service, however, you will probably already have that 120V/240V with neutral connection phase available. In this case, you will need to pick the two phases correctly in order to get the proper 120V service half.
What is a Single pole electric service?
Do you mean Single Phase? This is what supplies American homes and some commercial buildings. It is 120V/240V.
What is a 100 amp 208 single phase?
That is 20.8 kVa but a 208 v single phase supply is very rare. 208 v is usually three-phase, with 120v between neutral and the live wires.
How the single phase load works on same voltage- two phase supply?
Two-phase supplies are very unusual these days, and describe an a.c. system in which the two phase voltages are displaced by 90 degrees. So you are probably thinking of a split-phasesystem.A split-phase system is created using a transformer with a centre-tapped secondary winding. The centre tap is grounded (earthed) and provides the neutral terminal. The outer terminals (labelled X1 and X2) supply a potential difference of 240 V between them, while terminals X1 to neutral and X2 to neutral each supply potential differences of 120V.
What are the averag volts used in a US Home?
US homes use a 240 volt single phase 'Edison' system. It is a 3-wire (4 with the ground) system. Phase to phase measures 240v, while each phase to neutral measures 120v.
What countries use 240V?
Answer for USA, Canada and countries running a 60 Hertz supply service.The US runs 240V single phase in almost all residential applications.It just so happens that the 240V is center tapped to make 120V/240V split phase, but that is still a single phase application.For more information about the supply services in other countries, please see the answer to the Related Question shown below.
Can you replace 240 volt service with 480 volt service?
240 volt service is residential, split single phase. 480 volt service is commercial/industrial, three phase. In theory, with the approval of your municipality and electric utility, you could replace split single phase with commercial three phase service. However, the equipment for the replacement (transformers, feeder wire) would likely not be provided by the electric utility and would have to be bought by you. This equipment cost usually makes any benefit of such equipment not cost effective. Not to mention the cost doesn't end there. Your building electrical system would have to be rebuilt as a three phase system. That is like apples and oranges. You wouldn't even be able to plug in a typical 120v load without connecting transformers to step down the voltage.
Why 1.732 value is include in three phase calculations?
It is the square root of 3. Multiply 1.732 to 120v. and you get 208. which, on a three phase system, is the voltage from line to ground.
What will happen if two phase supply given to the single phase motor?
Two phase is single phase for today's purposes. We generally do not call 240v single phase "two phase" anymore, although technically that's what it is. 240v two phase has power to both lines to the motor versus 120v single phase has one power line and a neutral. Fortunately most single phase motors today are dual voltage. So check your nameplate data of the motor for guidance. The use of proper motor protection will prevent any damage to motors if wrong voltages are inadvertantly applied.CommentA two-phase system is an archic system, in which two phase voltages are displaced from each other by 90 electrical degrees. Like three-phase, it had the advantage of producing a naturally-rotating magnetic field, so could drive induction motors without any need for a starting capacitor.
Can you run single phase on three phase?
Yes, you can use one of the three phase service lines to run the single phase device. However, before you connect it, you must first make sure that both the voltage and the current rating of the device will be suitable for the single phase service that your new connections to the service wiring will produce.The single phase voltage you will get between any one phase line and the neutral point is less than the voltage between any two of the three phase service lines by a factor of 1/1.73. So, because 415/1.73 is about 240, a 415V 3-phase service will produce a single phase voltage of 240V.If you are in one of the many countries which use split single phase wiring - such as USA and Canada - that 240V will actually be available as two 120V "hots" (usually with red and black colored insulation) balanced about the neutral point i.e. +120V / Neutral / -120V.Thus you can actually connect up a new branch circuit either for one 240V single phase device or two 120V branch circuits to supply power to 120V devices.After you have made sure that the current demanded by your single phase device can be supplied by the available 3-phase service, it is vital that you make sure you install the correct size of circuit breaker (voltage and ampacity) and branch circuit wiring having the correct wire size to carry the current load drawn by the single phase device, together with the correct types and sizes of socket outlets. All these details are specified in your country's national electrical codes or regulations.(1.73 is the square root of 3).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 JOBSAFELY AND COMPETENTLYREFER THIS WORK TO QUALIFIED PROFESSIONALS.
