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Star connections allow for grounding of the system, which is required for single phase loads, and beneficial for three phase for a number of different reasons. Because it can be grounded, it can also supply ground current to operate protective devices. There may be other more specific reasons applicable to what exactly you are looking at (special case application? voltage level? surrounding system? etc.).
Wiki User
∙ 12y ago
Wiki User
∙ 6y agoBecause it has to deal with a higher current. Since the secondary power rating is practically equal to the primary power rating, the lower voltage winding must handle a larger current than the higher voltage winding. So the lower voltage winding must use a heavier conductor.
However, the question should ask "Why does the low-voltage winding of a transformer use thicker wire?"
Remember, the terms 'primary' and 'secondary' have nothing to do with voltage! The primary winding is the winding connected to the supply, whereas the secondary winding is the winding connected to the load!
So, for a 'step down' transformer, the secondary voltage is lower while, for a 'step-up' transformer, the secondary voltage is higher.
Wiki User
∙ 12y agodelta-star Transformers have star winding in secondary.these transformers are normally using for lighting load.because the lighting load needs neutral and balanced current
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Why is star connection used in a three phase transformer?
The power of all three phases can be transmitted on three conductors.A star connection, as opposed to a delta, provides a grounding reference. Also, for ground faults on the secondary (assuming no delta third winding, or source third winding) will be a direct ratio similar to phase faults, instead of 57%. Another reason is to avoid the inherent phase shift involved in a delta/star configured transformer.Another AnswerA 'star-connected' secondary is the standard European connection for a three-phase distribution transformer, as it provides a line voltage of 400 V together with a phase voltage (i.e. line to neutral) of 230 V.
What is the use of a transformer with turns ratio 1?
isolation if you are in the usa and must service electronics the neutral is grounded the power supply is a voltage doubler one side is 170v+ to ground the other is 170v negative to ground so if you run the power thru the transformer first you stand a better chance of staying alive these transformers are quite often used to trigger scrs or triacs for the same reason
Does the fuse on the primary side of a transformer protect the secondary side?
Yes, but it's usual to have fuses on both sides of the transformer.
How can a delta circuit be converted into a star circuit?
With a transformer...
If a dc voltage of 12v is added to the secondary of step down transformer and rating of transformer is 220 input and 12v output what will be the result from primary of transformer?
A DC voltage added to one side of a transformer has no effect on the other side.
Why neutral is ground in the circuit?
In the transformer at the secondry side one end of the winding will make star connection means 0 point there will be no voltage at that end if any leake voltage appear at that point it have to ground that what all the neutral points to be grounded
How many bushing do you get on delta to star transformer?
Your use of the word "bushings" implies you are dealing with a high-voltage transformer (over 600 volt). A three phase STEP-DOWN transformer normally has 3 bushings on the Primary side regardless of whether it is star-delta or another type. The Secondary side might have 3 or 4. A single phase transformer normally has 2 bushings on the Primary side and 2 or 3 on the Secondary side. If the transformer is being used to STEP-UP, it would be reversed from above. If this does not answer your question, I need more info.
How do you Ground a 3 wire service?
If you do not have a underground metal water pipe coming into the building then you put a ground rod at least 2 feet from the buildingf into the ground attach one end of the wire to ground rod run your ground wire and attach the other end to the neautral bar in the panel box. You need special transformer called as grounding transformer for this purpose. Grounding transformer is basically Wye-Delta type transformer with Wye connected winding connected to 3 line wires and derived neutral from Wye side grounded through desired grounding device. Delta side winding of grounding transformer is kept at no load.
Why is the neutral point grounded on a transformer?
The secondary side (output) of a three phase transformer develops a "separately derived system". That is why you do notsupply a neutral to a three phase transformer. It develops its own reference to ground by being bonded to the transformer casing and to a substantial earth ground, such as a ground rod. The XO tap on a transformer provides the neutral to the secondary line. It will have a double wire lug. The neutral wire going to the panel being supplied goes under one lug and the same size wire is to go to the ground lug on the transformer chassis The ground lug is also a double with the other lug to be wired to the earth ground.
Star-star connection of transformer?
Star Star TransformerStar Star Transformer is formed in a 3 phase transformer by connecting one terminal of each phase of individual side, together. The common terminal is indicated by suffix 1 in the figure below. If terminal with suffix 1 in both primary and secondary are used as common terminal, voltages of primary and secondary are in same phase. That is why this connection is called zero degree connection or 0o - connection.If the terminals with suffix 1 is connected together in HV side as common point and the terminals with suffix 2 in LV side are connected together as common point, the voltages in primary and secondary will be in opposite phase. Hence, Star Star Transformer connection is called 180o - Connection, of three phase transformer.Vikram Meena
Where is the use of earth transformer?
It is used in where the transformer are connected in star delta.
How transformer conduct current through ground?
A transformer doesn't 'conduct current through the ground'. However, in the event of a ground fault in the circuit supplied by a grounded transformer, the resulting fault current will flow through the earth back to the grounded terminal of that transformer's secondary winding.
Why you uluminium on primary side of transformer?
This isn't the case. You can have aluminium or copper on primary or secondary side of a transformer.
How tertiary winding of power transformer acts as stabilizing winding?
in star-star neutral transformer at unbalanced load condition zerosequnce current will be flows in secondary side but this current can not be balanced by primary side because its not having neutral to circulate zerosequence current.due to this unbalance voltage will appeared in primary side but the tertiary delta winding allows circulate the zerosequence current so the primary voltage will get stabilized.
What the purpose of the H1 terminal on a transformer?
The terminals H1 and H2 an a transformer indicate the primary side of the transformer. The secondary side is usually identified as X1 and X2.
Why we use delta-star transformer instead of star-star transformer in a consumer plant.?
There is a problem called "neutral phase shift" in star-star transformer, if we connect unbalance load(single phase load at secondary), then the phase point is shifted towards neutral. we require sinusoidal secondary voltage at secondary, for this flux must be sinusoidal. Flux will be sinusoidal, if it contains the third harmonic component of exciting current. so third harmonic current can not flow in star-star transformer. so we use delta-star transformer,in delta , third harmonic component can flow & get sinusoidal output.
What are the problems associated with the three-phase transformer connection?
One must check the design of the transformer windings. STAR - Delta or Star to star or Delta - star or Delta Delta. Wiring must be done accordingly.
