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It is either a delta or a star, it can't be both. A delta system doesn't have a neutral so the question must be about a star system. A high neutral current happens for example when one line is disconnected, and the neutral current then equals the current in the other two lines, which is the same current as when two lines are disconnected leaving only one line.
There might be ways of calculating how to make the neutral current larger by using unusual power factors, but the above is a useful working maximum that allows all four wires of a four-wire star system to be the same size.
AnswerThe term, 'delta-star', refers to a three-phase transformer connection in which the primary windings are connected in delta while the secondary windings are connected in star (wye). This is the standard three-phase connection, in Europe, for distribution Transformers. Single-phase loads are connected to the secondary between alternate lines and neutral, in order to try to and balance the resulting load and minimise any resulting neutral current. Obviously, however, without having any specifications supplied, it is quite impossible to answer this question.
What else can I help you with?
What is the difference between Load Current Line Current and Phase Current?
A load current is a current drawn by an electrical load. In other words, it is the current flowing from the source to the load.For a single-phase system, a line current is a current flowing through the line, or 'hot', conductor, while the current through the neutral conductor is called the neutral current.For a three-phase system, the three 'hot' conductors between the load and the source are called 'lines' and, so, the currents passing through them are called 'line currents'. For a three-phase system, loads are either connected between line conductors (delta-connected system) or between each line and the neutral (star- or wye-connected system), and represent the phases -so the currents passing through the loads are called 'phase currents'.For a balanced three-phase system, the line current is 1.732 times the value of a phase current, where the phases (loads) are connected in delta. For phases (loads) connected in star (or 'wye') the line current is numerically-equal to the phase currents.
What is the relationship between phase and line values of current and voltage quantities for star and delta connected systems?
A: A DELTA transformer is a 1:1 voltage transfer delta to Y IS 1:2 voltage transfer. That is for 3 phase system, If the phases are not exactly matched or the voltage is not exactly right then on a Y setup there will be circulating current at the common node.
Why do you balance single phase loads across a 3-phase supply system?
On a Delta 3-phase you connect the single phase loads between pairs of the 3-phases. Warning both sides of these loads will be hot! You may want to use 3 isolation transformers so that the real loads have a neutral line.On Y 3-phase you connect the single phase loads between one of the 3-phases and neutral.In each case to balance the loads, try to put similar loads on each phase (or pair of phases).
Does current ever flow in the neutral wire?
In 120 VAC circuits, the neutral wire carries all the return current from the hot wire. In a single phase 120 VAC circuit, such as found in US homes, the neutral wire carries exactly the same amount of current as the hot wire (unless there is a fault in the device). The difference is that the neutral wire is connected to the ground bus in the load center (also called "breaker box" in the Southern US).In a three phase circuit, as was pointed out by another person, the neutral wire will carry any current that results from an imbalance in the phases. If the three phases are perfectly balanced, for example when connected to a motor, there will be no current in the neutral conductor. (In fact, in a three phase delta connection, there is no neutral. But I will not attempt to explain that here, beyond simply mentioning it.)Nevertheless, anything that causes an imbalance in the phases of a three phase system will cause neutral current to flow. The amount of neutral current in a three phase system may be calculated using the phase relationships of the three phases, provided the imbalance is known, or simply measured with a standard AC current meter. (However, I must qualify this by saying that three phase systems are complex and hard to understand. It is easy to be fooled when working with such a system, and I would not undertake it without a thorough review of the principles involved. They do not behave in a simple and obvious manner.) However, I do believe that the neutral wire in a three phase system is often much smaller than any of the phase wires, because it is not called upon to carry the full current, but only the relatively small currents resulting from load imbalances.In a 240 VAC system, such as is used to supply power for an AC unit in the US, again typically the neutral will not carry current unless there is some sort of problem. Rather, the current flows in the two hot wires. As before, the neutral wire is connected to ground at the load center, and is usually connected to the metal chassis of the device being powered, whether it be an air conditioning system, electric range, or hot water heater. This is to provide safety for the user, and also will help to trip the breaker if there is an insulation breakdown within the device.Modern 120 VAC systems in the US have three wires. A safety ground wire has been added, and this is always connected to the metal chassis, except in certain devices that have extra insulation, such as power drills and most lamps. This ground wire is only for safety purposes, and normally does not carry any current. While the neutral wire is also connected to ground at the load center, it is a current carrying wire in a 120 V system, so is not usable for grounding the chassis as in the 240 VAC system. However, if there is an insulation breakdown problem in the device, the safety ground will conduct current and trip the breaker at the load center.Interestingly, the fact that the neutral carries the same current as the hot wire in a 120 VAC system is used as the operating principle for Ground Fault Detectors. An electronic circuit in the GFD device compares the current in the hot and neutral wires. If they are not equal, the device trips a relay, removing power from the device. If the hot and neutral currents are not equal, this indicates an insulation breakdown, where some of the current is leaking to an improper place within the device. The Ground Fault circuit detects this and shuts down the device very quickly, preventing electric shock and potential loss of life.
What is the advantage of a Star Delta Motor Starter?
The inrush current to the starting motor is lower due to the the motor coils being in series across the line creating a higher impeadence. When the starter connects to delta connection the motor is already turning and it does not have to go through the locked rotor phase. This system is being phased out now with the use of electronic soft starts and by-pass contactors.To start a motor direct on line (DOL) in delta requires approximately 6 to 8 times the full load current of the motor and delivers full torque. Delta places 415v across each of the windings on the motor. A Star-Delta starter starts the motor in Star which places 240v across each winding on the motor. This results in a lower starting current and also a lower starting torque.
Why neutral line is 230 v in three phase ac supply?
3 phase supply can be configured in delta or Y. In delta configuration, think of the Greek letter delta (a triangle). The voltage is taken across two of the 'vertices' of the triangle. In Y configuration, the voltage is taken between a point and the 'neutral'. In a perfectly balanced system, no current would flow through the neutral line, but in the real world, no system is perfectly balanced. If you look at overhead power lines, the neutral line will be of a much smaller gauge wire than the 3 'hot' wires, because you can achieve close to a balanced load, therefore not much current will need to travel through the neutral.
Why set an overload relay to full load current divide by root three in a star delta starter?
In a Wye/star system the overloads look at the phase to neutral/ground current; not phase to phase current. Which is always calculated as root three or 1.73205.............etc. Therefore the overloads have to be set to the phase to neutral/ground current.
Why is there no neutral point for delta?
There is no neutral in a delta connection, because that is the definition of delta, a power configuration where current flows from phase hot to phase hot. The loads are A-B, B-C, and C-A. Contrast this with star, where there is a neutral, and the loads are A-N, B-N, and C-N.
What dou you mean by phase?
If you are referring to an alternating current system, then a phase describes a winding, or a load, that is connected between any two line conductors in a delta-connected system, or between any line and the neutral conductor in a wye-connected system.
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 difference between Load Current Line Current and Phase Current?
A load current is a current drawn by an electrical load. In other words, it is the current flowing from the source to the load.For a single-phase system, a line current is a current flowing through the line, or 'hot', conductor, while the current through the neutral conductor is called the neutral current.For a three-phase system, the three 'hot' conductors between the load and the source are called 'lines' and, so, the currents passing through them are called 'line currents'. For a three-phase system, loads are either connected between line conductors (delta-connected system) or between each line and the neutral (star- or wye-connected system), and represent the phases -so the currents passing through the loads are called 'phase currents'.For a balanced three-phase system, the line current is 1.732 times the value of a phase current, where the phases (loads) are connected in delta. For phases (loads) connected in star (or 'wye') the line current is numerically-equal to the phase currents.
How do you calculate current on delta to star transformer?
To calculate the current on a delta to star transformer, first identify the line current in the delta configuration (I_line). The phase current in the star (wye) configuration (I_phase) can be calculated using the formula: I_phase = I_line / √3. This relationship arises because the line current in a delta system is √3 times the phase current in a star system. Therefore, knowing the line current allows you to easily find the phase current in the star configuration.
Can you list the Advantages of delta system over star system?
Delta system requires only three primary conductors compared to the star system, which requires four conductors. Delta system provides a higher line voltage compared to star system for the same phase voltage levels. Delta system does not require a neutral wire, making it more cost-effective in certain applications where neutral wiring is not needed.
Can delta connection be used on 3 phase 4 wire system?
A delta connected appliance can be connected to a 3-phase system by leaving the neutral unconnected. The appliance must be properly earthed.
When is a motor in star or delta connection?
Star (or wye) connection is where each of the three phases has a fourth conductor, neutral, as its current return. Current flow in this configuration is phase to neutral, which is also grounded back at the distribution center. There will be five total connections, phase A, B, and C, neutral, and (protective earth) ground. Delta connection is where each of the three phases uses the prior phase as its current return. Current flow in this configuration is phase to phase, and there is no neutral, though there is still a ground. There will be four total connections, phase A, B, and C, and (protective earth) ground.
What is the voltage-to-ground on a 4160 V delta circuit?
There should be no voltage to ground on a delta system. That is the reason that these types of systems have to have a set of grounding lights to warn when the system inadvertently grounds. A delta system is a three wire connection, no neutral. A voltage to ground is only available on a three phase four wire (star or wye) connection system. The fourth wire being a neutral which is grounded thereby giving a voltage from each leg to neutral.
When a system is at equilibrium what is delta S?
At equilibrium, the change in entropy (ΔS) of the system is zero. This means that the system is in a state of maximum entropy where there is no further tendency for change in the system.
