# Questions tagged [y-to-delta]

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### 3-Phase system Voltage conversion

If we are converting from Y to delta configuration or vice-versa, how do we convert the phases of our voltages? I've seen that we need to add or subtract 30 degrees from one another, but I don't ...
39 views

### How to find the "voltage across each winding" for different delta and star connections in a three phase transformer system? [closed]

I have got results from testing with delta/delta, delta/star, star/delta and star/star configurations. I've got the line and phase voltages for each configuration for both primary and secondary coils. ...
• 13
101 views

### Wye to delta transformation

I'm trying to find a more intuitive equation for wye to delta formations (going from delta to wye, the traditional equations make sense to me). I came up with the following solution, but I'm not 100% ...
1 vote
43 views

### Delta-Y transformation and dual circuits

I have been thinking about the relationship between delta-Y transforms and the dual of a given circuit and I am confused about a sort of overlap I see. Take a delta circuit with resistances as shown, ...
45 views

### Delta to delta or delta to wye transformer

I am going to feed 240Vac 1-phase into a rotary phase converter the resulting 240 3-phase needs to power two robot controllers, but the controllers require 200-230Vac 3-phase or 400 - 480Vac 3 phase. ...
• 11
117 views

### 4 pronged star to two Y resistor network

Is there any transform that relates four resistors meeting at a central node simulate this circuit – Schematic created using CircuitLab to a set of two Y resistors networks as shown below ...
1 vote
432 views

### Breaker trips after switch from wye to delta

I'm replacing a pump: 400 V, 4 kW, 2 pole. It is a wye-delta startup. The control circuit is working correctly, as I've double checked it and extended the lead to feed another 4 kW motor. When it ...
825 views

### Extending the Delta-Wye/∆-Y Transformation to higher polygons

I was looking at the derivation of the ∆-Y Transformation and decided to replicate the process with a square and its diagonals, i.e. I tried to create a Square-Cross/□-X transformation. But the ...
• 91
171 views

### Delta-Wye for voltage sources?

My question is if, and how I can find an equivalent network, which includes resistors and voltage sources in series with arbitrary voltages and resistances, so that to the outside the networks are ...
46 views

### Star to Delta conversion with current simulation in Micro-cap error

Converted Star to Delta resistor circuit, but Micro-Cap dynamic DC simulation show similar, but different result.. 141,518 vs 140,498 V. Is it some kind of Micro-Cap error? Formulas used in Matlab: <...
174 views

### BLDC motor: low Kv with high duty cycle VS high Kv with low duty cycle, will the latter cause significant efficiency loss?

Suppose I have an ESC + BLDC motor setup and it's working fine. Now I want it to have some burst ability, that is to produce much more mechanical power in a few seconds. But the Kv is too low, so I ...
289 views

### Zero current assumption in star - delta transformations derivations

The formula used for star delta transformations are: $$R_A = \frac{R_{AB} R_{AC}}{R_{AB}+R_{AC}+R_{BC}}$$ and $$R_{AB} = \frac{R_AR_B + R_AR_C + R_BR_C}{R_C}$$ The normal way that these formulae ...
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### How do I use Norton's Theorem to find the current in this resistor? [closed]

I've been trying to solve this question but it seems impossible
1 vote
238 views

### Can I solve Y-Δ circuit by converting it to Y-Y? Or do I need to solve it using Y-Δ formula?

Above is the picture of how I approach the 3(ii) question. My question is,which way is the correct way of finding line/phase currents/voltages? Why is the line/phase current different for each method? ...
238 views

### Delta to star transform currents

When we transform a delta circuit to a star circuit it is easy to transform the voltages and the resistances. In the case of a delta circuit between current flows only between 2 nodes while in a ...
• 111
1 vote
40 views

### □ -> X Conversion

In cicuit analasys to make a circuit easier you can use delta wye conversion. This means that when there part of a circuit with 3 nodes, where each of the 3 resistors ar in betwen 2 nodes, this can be ...
138 views

### How can I show that there is no current over resistor

I made a contest question regarding find the entire current provide from voltage source 45V connected between a-c terminals. Follow the picture below: Original circuit My resolution I can made it ...
364 views

### Which branches should I convert for this star-delta transformation?

For those who can't see the image: SO there is an outer delta with two 1 ohms and a 2 ohm. Then an inner Y with three 2 ohms. Within the Y, there is a delta formed on it's two lower legs with three 1 ...
354 views

### Star to delta transformation circuit

Is it possible to use star-to-delta transformation on this specific circuit below? If it is possible, can someone give me a hint on how to do it? I tried to do delta-to-star transformation and got the ...
229 views

### Wye to delta 3 phase

Can someone please explain to me the following. For the last part, why did they use the Van to find Vab( secondary line voltage of the delta). I did it and my magnitude matches the solution but the ...
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865 views

### Star-Delta starter connection of motors

The Star Delta Starter is a very common type of starter and is used extensively. It is said that a star delta is used for a cage motor designed to run normally on the delta connected stator winding. ...
141 views

I was trying to solve this problem (number 27) and as per the KCL equations I am getting that an infinite number of Ammeter readings are possible. I used KCL after taking the outer loop as the ...
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2k views

### what will happen if the motor that is designed for delta connected in star connection

I have a motor which is designed for 3 phase, 380V. The power rating of motor is 132kw and motor stator winding is connected in delta connection. If I connect the same motor stator winding in star ...
720 views

### creating artifical neutral point in delta connection

I am trying to measure 3 phase 3wire and 3 phase 4 wire L_L voltage and L_N voltage.Circuit i am looking is common for both. In star connection i will get an neutral point for reference to read the ...
• 27
2k views

### Balanced delta source to Wye source by considering magnitude only is ok?

I read and derived formulas for balanced delta source to Wye source; it is given by Vy = Vd / sqrt(3)<30 but in some places I see people only dividing by sqrt(3) for conversions are keeping angle 0,...
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404 views

### Proof that Delta and Y transformer have the same power?

I'm trying to proove that a Delta and Y transformer both have the same power. Somewhere I must get wrong in my process... I have a reading in voltage and current in a Star transformer: 600 V line-...
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1 vote
264 views

### How do I refer an impedance from the delta side of a transformer to the WYE side?

My question is regarding the simple arrangement below: It is simply a three phase source feeding a load through Z1, followed by an ideal WYE DELTA transformer, followed by Z2. My question is how do ...
• 91
1 vote
255 views

### Y-Δ transform proof using superposition

In the Wikipedia page and in every book they prove the transformation by equaling the equivalent resistance between any pair of terminals while disconnecting the other node. https://en.wikipedia.org/...
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1 vote
2k views

### Does the motor speed change with the fully automatic star(wye)/delta starter?

At no load, I connected a 380V motor to start in the star connection for 5 seconds and thereafter change to the delta connection. I understand that torque will change since the current will change as ...
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3k views

### Running a 3ph motor rated for 380v star on 220v delta

I've got an old Soviet 4kW motor, made in 1983. The dilemma is that the nameplate info states a Y-connection/380v/8.7amps and I want to run it on delta using my VFD which produces 3ph 220v. All my ...
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670 views

### Why isn't there a $\small\sqrt 3$ factor between rated currents on the delta-wye transformer?

When calculating the rated current on either side of a delta-wye transformer, we will use the following equation: $$I_{LL}= \dfrac{S_{3\Phi}}{\sqrt 3\cdot V_{LL}}$$ Since this same equation is used ...
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1 vote
1k views

### How to Transform AC Current from Wye to Delta?

What is the correct formula to transform AC current from a Wye connection to a Delta connection? I am not an electrical engineer, and this is my first question on this part of StackExchange. I hope ...
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45k views

### Problem in star delta starter in air compressor

I am a beginner in electrical engineering. I am trying to understand how motors are connected in a star and delta system. I studied the star delta starter from this link. It describes the connection ...
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1 vote
2k views

### Resistance between the terminals of a star configuration?

The derivation of the delta-star transformation rules is based on the fact that the resistance between terminals 1,3 is R1+R3 I can't see how we can consider R1,R3 just two resistances connected in ...
• 11
247 views

### 3-Phase Theory vs Practical example confusion

In theoretical examples, 3-phase circuits are shown as either Wye or Delta type. Wye obviously containing a neutral line. Recently I watched a Youtube video where the uploader re-purposed an old ...
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1 vote
160 views

### Without converting the secondary side to "Y", how would one solve this question?

The question: "A three-phase 230 V, 27 kVA, 0.9 PF (lagging) load is supplied by three 10 kVA, 1330/230 V, 60 Hz transformers connected in Y-Δ by means of a common three-phase feeder whose impedance ...
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333 views

### Y-Delta Transformation Voltage across resistor

In effort to solve for Vx, I would like to transform the Delta network (the 3 3 ohm resistors) to a Y network. My question is, where would Vx be read ? Thanks, Liam
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### delta-wye with dependent sources

I was looking through some problems in Nilsson's book and this one caught my attention: The variable of the dependente source is in the $4\Omega$ resistor, which is part of a "delta" type of ...
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