This current is known as line current. Terms of Service | I thought Y systems had lower line currents and that was one advantage to using them. Line Currents and Phase Currents in Star Connection It is seen from fig (3a) that each line is in series with individual phase winding, therefore, the value of line current is same as in Phase windings to which the line is connected. Thus, for the star-connected system line voltage = √3 × phase voltage. This would greatly reduce the presence of harmonics in the primary system, partly due to the absence of a neutral connection. ‘Phases‘, on the other hand, are connected between any pair of line terminals. ‘Phases‘, on the other hand, are connected between any pair of line terminals. Y-connected sources and loads always have line voltages greater than phase voltages, and line currents equal to phase currents. In a star system the line current is equal to the phase current (IL = IP) ENGINEERING.com encourages users to seek the services of a professional engineer for any engineering advice they may require. If you have an earth with pilecap then your resistance is Similarly, the magnitude of the voltage across yellow phase is VY and the magnitude of the voltage across blue phase is VB. In Delta winding however line current gets divided in two LINE CURRENT.AND IN DELTA CONNECTIONS LINE CURRENT IS EQUAL The terms line current and phase current follow the same logic: the former referring to current through any one line conductor, and the latter to current through any one component. This configuration is called a “wye,” because in an electrical drawing it looks like the letter Y. In three phase balanced system, it may be R phase current or Y phase current or B phase current. Any help greatly appreciated! The terminals of a three-phase source (generator or transformer) or of a three-phase load, to which line conductors are connected are termed ‘line terminals‘. ILLUSTRATE CURRENT IS 1.732 TIMES OF LINE CURRENT AND LINE CURRENT IS From the diagram, it is found that Copyright © 2005-2019 ALLInterview.com. In a star-connected system, even though the line current is numerically-equal to the corresponding phase current, we must always retain the correct terms, according to WHERE those currents are being measured —as illustrated below: Line conductors and line terminals are identified in accordance with national standards. To test Transformer we give HT side 440V to see wheather {int m = 30;} This month we turn our attention to the differences between delta and wye transformers and to wye transformer calculations. systems. between any phase,line current is d current betwen one In the balanced star system, magnitude of phase voltage in each phase is Vph. If the primary phase voltage in a typical delta/delta system is 480V, the secondary phase voltage is 240V. Full disclaimer here. The Table sums up the kVA for each phase of each load. In a star system the line current is equal to the phase current (IL = IP) in a delta system, the line current is divided by 1.732 to get the phase current (IP = IL/1.732) Is This Answer Correct ? Another issue is proper transformer loading. At this point, you can efficiently work with a transformer supplier to develop a good solution. Again, phase current, Iph of each phase is same as line current IL in star connected system. really low. The Ask@ service is a forum for members to exchange ideas relating to the world of engineering. To post a question please visit the new. delta system occured line current will equal 1.732*phase ∴ VR = VY = VB = Vph. ∴ IR = IY = IB = IL = Iph. ENGINEERING.com has updated it's forum. Again, if you apply a load to that phase, then phase current results. 2. In a 3-phase system current accross any one phase and One distinct advantage of a Δ-connected system is its lack of a neutral wire. current, Line current is the current that is flowing from an AC supply and Phase current is the current that is flowing through each phase in the system. switchyard? i.e. We caution users not to accept any responses that they receive without further validation, and not to rely on any engineering advice that they may get from other members of the Ask@ forum. Initially we explored the idea of three-phase power systems by connecting three voltage sources together in what is commonly known as the "Y" (or "star") configuration. Really appreciate you sharing this blog post.Really thank you! The voltage between any two line conductors are termed ‘line voltages‘ and the current that passes along each line conductor is termed a ‘line current‘. Any way I’ll be subscribing to your feed and I hope you post again soon. If you overload the transformer, though, it goes into core saturation and output consists of distorted waveforms. 1. This configuration of voltage sources is characterized by a common connection point joining one side of each source. int m = 20; Fig. ‘Phase A-N‘, ‘Phase B-N‘, and ‘Phase C-N‘. then what will happen to HT voltage ?