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I assume that you have a phasor diagram of a transformer, and wish to identify the primary phasors and the secondary phasors?

For a three-phase transformer, this is fairly straightforward, provided the usual procedure for drawing a phasor diagram has been followed. Whenever you start to draw anysort of phasor diagram, you usually start by selecting a phasor of reference and draw that in the horizontal positive direction. For a three-phase transformer, the phasor of reference is usually the primary phase voltage A (or however else it is identified: R, red, or whatever). The remainder of the primary phase voltages are then drawn, enabling the primary line voltages to be constructed (which, in the case of a primary delta are the same as the primary phase voltages!). So if you can identify the phasor of reference, then you have identified the primary-winding phasor diagram. As the primary and secondary voltages are not usually drawn to scale, relative to each other, you can't assume a turns ratio from the phasor diagram. The labelling might also help, as high-voltage phase and line voltages are identified by upper-case letters, while low-voltage phase and line voltages are identified using lower-case letters -but, remember, these identify high- and low-voltages, not which is primary and which is secondary (primary winding is connected to supply/secondary winding is connected to load).

For single-phase transformer, the phasor of reference is the flux set up in the magnetic circuit, and voltages/current phasors are drawn relative to this. In this case, the primary line and induced voltages are usually identified as V1 and E1, and the secondary induced voltage as E2 (sometimes, the Es and Vs are interchanged). Again, the lengths of the primary and secondary voltages are not necessarily to scale relative to each other.

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Q: How do you identify step up or step down transformer from phasor diagram?
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What is the vector diagram of ynd11 transformer?

In the vector group representation for this transformer, the letter 'y' represents a wye- or star-connection, and the letter 'd' represents a delta- or mesh-connection (I have no idea what 'n' stands for -anyone?). An upper-case letter indicates the higher voltage, while a lower-case letter represents the lower voltage. The sequence of the letters indicates the primary and the secondary windings. So the transformer in question is a wye-delta connection (presumably the 'y' should have been capitalised, meaning that this is a step-down transformer: i.e. Yd11).The number appearing after the letter group (in this case '11') is a multiplier of 30o and indicates the transformer connection's angular displacement (or phase displacement). In this case, the angular displacement is 11 x 30o = 330o.As angular displacement is defined as 'the angle by which the secondary line voltages lag the primary line voltages', this means the secondary line voltages of this particular transformer lags its corresponding primary line voltages by 330o.So, to draw the phasor (not 'vector') diagram for this particular transformer, you would start by drawing the phase voltages (VAN, VBN, and VCN) of the primary wye connection (using VAN as the phasor of reference), from which you would then construct the corresponding line voltages (VAB, VBC, and VCA). To finish the diagram, you will then draw the secondary delta phasor diagram, starting with Vab lagging VAB by 330o (or, if you prefer, leading by 30o), then drawing Vbc and Vca displaced by 120o.


How potential transformer works explain with circuit diagram?

A potential transformer steps the high voltage down to a level of 120 V to measure them safely and easily.


How can you identify the primary secondary of a transformer on a schematic if it is not indicated?

Without knowing the type of transformer (audio/power, step-up, step-down, etc.) it's difficult to offer any advice.


What is the purpose of transforms?

A transformer is used to step up or step down a Voltage supply.


What is the name of the transformer that reduces the voltage?

a step down transformer is used to lower the voltage from the powerlines into your home. a common slang term for this type of transformer is a pole pig.


How is a transformer utilized?

Transformer is used for stepping up or down the voltage.


What is the different between et up and set down transformer?

the difference between a step up transformer and a step down transformer is that, in a tsep up transformer, the voltage secondary is greater than the primary side but in a step down transformer, the voltage secondary is lesser than the primary side


When using a step down transformer is amperage affected?

Yes, when using a step down transformer the amperage is affected.


Why transformer is used?

A transformer used to step up or down the value of voltage.


What type of transformer decreases the voltage produced by the source.?

step-down transformer


How do you produce a step-up transformer in an ordinary transformer?

Transformer function is either to step-up or down the voltage. There is nothing like an ordinary transformer.


How can you identify which one is step up or step down transformer?

A transformer has two windings, termed the 'primary winding' and the 'secondary winding'. The primary winding is the winding connected to the supply, while the secondary winding is connected to the load. The secondary voltage of a 'step up' transformer is higher than the primary voltage; the secondary voltage of a 'step down' transformer is lower than the primary voltage. The simplest way to determine whether a transformer is a step up or step down, is to measure the primary and secondary voltages. If you are simply looking at a transformer, then the transformer's insulated bushings will give you a clue -the higher voltage bushings are much bigger than the lower voltage bushings. If you have access to the inside of the transformer, then the higher voltage windings are thinner and have a greater number of turns than the lower-voltage winding.