0
You are unqualified to do. This is not a simple wiring problem. 3 phase is industrial power and should be handled by someone licenced. There are dozens of reasons why. Hi I think we need more info on what you are trying to do. 3 phase to 3 phase up or down, or 3 phase to single phase
The reply that from If you have to ask ... is not in keeping with the spirit of WikiAnswers.
First off, this could be a request from an engineering or engineering technology student.
Second, 3-phase power is not industrial power --- every home has at least 2 3-phase connections (i.e., dryer and range outlets).
Third, many engineers who do work in the power/energy sectors are not licensed electricians. Depending on the employer (e.g., Federal govt, aerospace, defense), they may not even be a licensed PE, much less a licensed PE in EE or NE. Many do not even have an FE/EIT certificate.
The question though, is rather vague and should be written in a more descriptive manner.
The following links are useful in providing information:
http://ecmweb.com/mag/electric_basics_deltawye_transformers/
http://www.frost.com/prod/servlet/market-insight-top.pag?docid=10530632
http://www.federalpacific.com/university/transbasics/chapter3.html
Wiki User
∙ 15y ago
Wiki User
∙ 14y agoDelta is where you have 3 hot legs and no neutral, so power is transferred from hot to hot in a rotating three phase pattern.
Wye is where you have 3 hot legs and a neutral, so power is transferred from hot to neutral, for each of the three phases. (Still rotating, of course)
The choice of delta or wye is based on the presence or absence of neutral, with one exception...
The exception is when neutral is not balanced, such as in a quadraplex system where neutral is actually the center point of one of the phase Transformers, used to supply both straight three phase power and 120/240 split phase. In that case, you must go delta.
And don't forget that you can convert to and from delta and wye, or go straight from delta to delta or wye to wye, based on the transformer configuration, so, for example, if you have a delta supply and need a wye load, you can do it.
Wiki User
∙ 8y agoDelta and star are two alternatives for power transmission. Delta is normally described as three-phase three-wire, while star is three-phase four-wire.
Three wires are used for balanced systems where the three currents are equal. Four wires are used for local supplies where the power is split down into single-phase supplies for individual consumers. For this each single-phase supply is connected from one live wire to neutral, and the aim is for a group of consumers together to present a balanced load. As the number of consumers supplied increases, the supply is better balanced as variations become levelled out.
Add your answer:
Earn +20 pts
Where do you use star-star connection in electrical system?
i think its use for 3 phase connection.
Is delta connection also called a star-star connection?
the delta has a higher voltage to ground on the B phase and is identified by the orange color for identification means so its easier to smoke equipment if not careful.hardly see delta connections anymore so old school and outdated. it just makes economic sense to use a star connection.On the above answer there should be no voltage to ground on a delta connection. All three phase coils are connected in series with each other and at no point in the delta are they grounded. Most of the commercial and industrial motor connections are connected delta. In installations where the motor inrush is above utility company specifications the Star- Delta connection is used. This limits the inrush current in the star configuration and then after a time delay connects the motor in a delta configuration. With delta systems the use of grounding lights are mandatory. These are used to detect if a phase grounds out. One phase and the motor can still be in operation, two grounds represent a short circuit and the system will trip.CommentThe second answer is not altogether correct... In the USA and Canada, it is common practise for one phase of the delta-connected secondary windings of a three-phase transformer bank, to have an earthed (grounded) centre tap. With each phase providing 240 V; the centre-tapped phase then provides a combination of 240 V line-to-line together with two 120-V line-to-neutral (earth) voltages which is the standard supply method for residences in North America. The point of common connection between the two remaining phases is termed the 'high leg' of that particular transformer connection, having a potential of 208 V with respect to earth (although this is not used). To summarise, this method provides a 240-V three-phase supply, combined with a single-phase 240/120-V supply, which is useful for small businesses (e.g. garages) which might need to operate three-phase motors.However, the second answer is perfectly true for the UK (and, possibly, elsewhere in Europe) where residences are supplied with just one voltage (230 V) -unlike North America- and delta-connected supplies are relatively unusual.
What is the difference between star delta and wye delta?
With a delta connection, picture a triangle. Each side of the triangle is a transformer or motor winding. Call the 3 corners of the triangle A, B, and C. There are only 3 wires except for a safety ground, which has no connection to, nor is any part of, the power transmission service lines.but for the star connection take our triangle above and use your wire cutters (literally) to cut the triangle apart at the corners. rearrange the three sides (transformer or motor windings) to form a Y. Where the three sides join in the centre, connect a fourth wire. Call this wire "neutral". Call the three ends A, B, and C. Connect the 3 supply service lines to A, B, and C.
Why most generation firm uses delta connection in the secondary side?
Many industrial installation use delta a secondary connection because it reduces the cost associated with a fourth wire.
How do you take a single phase output by giving 2phase input in transformer?
You are not really connecting two phases to the primary of the transformer; you are connecting one phase. In delta configuration, each phase is actually the connection of two legs, AB, BC, and CA. Even though you are connecting two legs to the transformer, there is only one phase involved. In star configuration, however, each phase is the connection of one leg to neutral, AN, BN, and CN. In star, you would only use one of AN, BN, or CN to connect to the transformer's primary winding. Star configuration is preferred, and is actually used in the transmission/distribution system, because in delta, loss of one leg takes out two phases. Star configuration, however, would not be preferred if your local distribution was based on a non-centered neutral, such as a quadraplex connection providing split phase simultaneously with three phase. (120/240-240/3) The neutral in that case is not at the center of the star triangle - it would be at the center of one of the phase pairs.
Where do you use star-star connection in electrical system?
i think its use for 3 phase connection.
Explain the open delta fault in the power system.what is the use of the protection.?
There some kind of relays that need measure zero sequence voltage. For instance: - To polarize a phase-to-neutral distance relay - To detect a fault-to-ground in a system grounded by thre-phase generator with star connection. A TP in a star-open delta connection can provide a 3V0 information.
What do you mean by star delta connection?
A star connection is one with 3 hot conductors returning power to a (usually grounded) common return (neutral) conductor. If the three hots are called A, B, and C, and the neutral is called N, then the three phases are connected AN, BN, and CN. If the star connection is balanced, (it must be, for efficient use of power), then the three hots are also equidistant from each other, though with a different voltage, so you could rewire as delta. (A typical 13.2kv system in the US is 13.2kv phase to phase, and 7.6kv phase to ground.) A delta connection is one with three hot conductors returning power to each other. Using the earlier convention, the three phases would be connected AB, BC, and CA. The ground connection is connected to the frame as a safety, but it provides no power. The choice between star and delta is one of design objective. If your load requires three phase power, then it cannot tolerate loss of even one phase. In that case, it would not matter if you chose star or delta, but you must consider the different voltage in each configuration. If your loads, such as in multiple and distinct star connections, do not require three phase power, then loss of one phase only affects one third of the system, but it you wired delta, then loss of that one phase leaves you with only one third of the system operational. If the neutral conductor is not balanced, such as in a quadraplex connection where there are three phases, with the neutral being at the 120/240 split phase point in the middle of one phase, then star connection is not possible. If you wanted star in this case, you would need three transformers with the primaries wired delta and the secondaries wired star.
Is delta connection also called a star-star connection?
the delta has a higher voltage to ground on the B phase and is identified by the orange color for identification means so its easier to smoke equipment if not careful.hardly see delta connections anymore so old school and outdated. it just makes economic sense to use a star connection.On the above answer there should be no voltage to ground on a delta connection. All three phase coils are connected in series with each other and at no point in the delta are they grounded. Most of the commercial and industrial motor connections are connected delta. In installations where the motor inrush is above utility company specifications the Star- Delta connection is used. This limits the inrush current in the star configuration and then after a time delay connects the motor in a delta configuration. With delta systems the use of grounding lights are mandatory. These are used to detect if a phase grounds out. One phase and the motor can still be in operation, two grounds represent a short circuit and the system will trip.CommentThe second answer is not altogether correct... In the USA and Canada, it is common practise for one phase of the delta-connected secondary windings of a three-phase transformer bank, to have an earthed (grounded) centre tap. With each phase providing 240 V; the centre-tapped phase then provides a combination of 240 V line-to-line together with two 120-V line-to-neutral (earth) voltages which is the standard supply method for residences in North America. The point of common connection between the two remaining phases is termed the 'high leg' of that particular transformer connection, having a potential of 208 V with respect to earth (although this is not used). To summarise, this method provides a 240-V three-phase supply, combined with a single-phase 240/120-V supply, which is useful for small businesses (e.g. garages) which might need to operate three-phase motors.However, the second answer is perfectly true for the UK (and, possibly, elsewhere in Europe) where residences are supplied with just one voltage (230 V) -unlike North America- and delta-connected supplies are relatively unusual.
What is the difference between star delta and wye delta?
With a delta connection, picture a triangle. Each side of the triangle is a transformer or motor winding. Call the 3 corners of the triangle A, B, and C. There are only 3 wires except for a safety ground, which has no connection to, nor is any part of, the power transmission service lines.but for the star connection take our triangle above and use your wire cutters (literally) to cut the triangle apart at the corners. rearrange the three sides (transformer or motor windings) to form a Y. Where the three sides join in the centre, connect a fourth wire. Call this wire "neutral". Call the three ends A, B, and C. Connect the 3 supply service lines to A, B, and C.
What would be the effect on the neutral bar of a 3 phase D B if the main incoming neutral is lost?
A three phase delta system does not use a neutral in its operation.
What is the use of 240 three phase delta?
240 volt delta systems were used a lot in automotive garages and small manufacturing facilities. This system works great for motor loads because of the phase to phase voltage of 240 vac, motors run better (lots of motors were manufactured to operate on 240 only) on the higher voltage compared to 208 vac. Also the availability of 120 vac on the same system was a plus, however on a delta system you have one phase with a higher voltage to ground (high leg) usually about 190 vac. You have to be careful not to use this phase in certain applications.
What type of connection do you use in household connections?
its simple: its either single phase or three phase connection
Why most of the 3-Phase transformer use Y connection instead of Delta Connection?
This is certainly the case in the UK, where a three-phase distribution transformer's secondary windings are wye, or 'star', connected. The reason is that it provides a four wire distribution system comprising three line conductors and a neutral conductor, operating at 400 V line-to-line and 230 V line-to-neutral which enables the provision of single-phase 230-V services to residential loads (line-to-neutral connection) and a 400/230-V three-phase supply to small businesses if required.
Why delta connection is used in load side?
There are a number of advantages why three phase (delta or Y configuration) is preferred over single phase circuit. The best advantage is that the each of the three lines in a three phase circuit can act as single phase thus effectively getting three single phase circuits in one transmission. Another advantage is whether it's single phase or three phase, the generation is the same, therefore three phase has more practical value. Also, the instantaneous power in single phase falls to zero but in three phase system, the net power from all the phases is continuous.
Why most generation firm uses delta connection in the secondary side?
Many industrial installation use delta a secondary connection because it reduces the cost associated with a fourth wire.
Is transmission line voltage phase to phase?
Yes usually it would be phase to phase voltage because most transmission lines are set up in a delta configuration. This means that there is no neutral conductor to use as a reference. So any voltage would be measured with reference to another phase.CommentLet's get the terminology correct. The voltages between the three 'hot' lines of a three-phase, three- or four-wire, system are called 'line voltages' even though, in the case of a delta-connected system, they are numerically-equal to the corresponding phase voltages. Therefore, we call the conductors 'line conductors', not 'phase conductors'.There is simply no such thing as a 'phase-to-phase' voltage. Just think about it; you can only measure a voltage acrossan individual phase, so how can you possible measure a voltage 'phase-to-phase' -I mean, where would you place a voltmeter to do that?For a delta system, the line voltage (or line-to-line) voltage is numerically equal to the phase voltage (notphase-to-phase). For a star (or 'wye') system, the line voltage is equal to 1.73 x the phase voltage.
