Short Circuit Test of Transformer

                             Short Circuit Test of Transformer

While a transformer short circuit the other hand ammeters watt meter and voltmeter with Connected to supply transformer short circuit test is that the test will be called. The transformer equivalent Resistance, impedance   evaluate and determine the copper loss is short-circuit test.

Tested for transformer short circuit coils full load current to flow in the equivalent electrical outlets.

Tested for transformer short circuit transformer and low - voltage of the circuit is short because of the -

1. Less than the full load current of high voltage electrical outlets are used for low rang ammeters and watt meters.

The. Supply only 4% of the rated voltage is 10% of the supply is not a problem.

3. It is the correct voltage for full load outlets.

Transformers short circuit test method is described

Normally the transformer and low - voltage short circuit in the high voltage side of the meter and the watt meter ammeters volts is connected to the supply. Variable voltage supply source or from the series resistance 2% of rated voltage connection of the supply voltage with a gradual increase in the full-load current to flow until the transformer. High voltage to low voltage at full load current to flow when a particular certificate will not be short of the full load current to flow. The ammeters watt meter and volts meters are read into the record.

Received watt meter reading = Psc

Ammeter text = Isc

And voltmeter readings = Esc

Psc = transformer copper loss,

 Re = Psc / I ² sc

Ze = Esc / Isc

Xe = √ Z ² e - √ R ² e

Mentioned that, for Re, Ze and Xe equivalent to the value of the high voltage.

Transformer short circuit test is when you are careful.

1. Transformer low fat side of the terminal, in short by resistance .

The. High side of transformer and the appropriate ratings -'s watt-meter, Volt meter, you will ammeter connection.

3. Ammeter range of outlets than the little ones to be loaded.

4. Transformer and voltage rating in volts meters range is about 10%.

5. 4% or 10% of the high-side voltage is applied. The voltage It is so full load current flow is ammeter.

The low core loss is needed voltage is inconsiderable.

Both coil full load current is flowing because this is the time to get Transformer that it accepts full load copper loss.

For example of mathematics

1. A 100 KVA 2400/240 V distribution Transformer short circuit test results are as follows -

Esc = 60 V, Isc = 34.67 A, Psc = 819.4 W transformer full load copper loss determined now.

Answer: -

Transformer IFL = 100,000 / 2400 = 41.6 A

Isc = 41.6 A.

Here,

I'sc = 34.67 A

P'sc = 819.4 W

Psc = (Isc / I'sc) ² × 819.4

   = 1180 Watt.

2. A 100 KVA 2400/240 V distribution Transformer short circuit test results are as follows -

Esc = 60 V, Isc = 34.67 A, Psc = 819.4 W load, the transformer

1. 125 KVA,

2. 75 KVA

3. 0.772 power factor 85 KW to determine if each of the copper loss.

Answer: -

Transformer IFL = 100 × 1000/2400 = 41.6 A

 Full load copper loss Psc = 1180A.

Here,

1. PscL = (125/100) ² × 1180 = 1845 W

2. PscL = (75/100) ² × 1180 = 663 W

3. KVAL = 85 / 0.772

               = 1180 Watt.

PscL = (85/100 × 0.772) ² × 1180 = 1430 W

Open Circuit / No Load Test on transformer.

                                  Open Circuit / No Load Test on transformer.

                                    

One side the other side of the transformer and open circuit watt meter and voltmeter Ammeter  connection with the supply voltage to the full test is called the open circuit test.

Transformer and four parameters - 1.resistance equivalent(Re). Reactance equivalent (Xe) 3. Core Loss, Conductance (Go) 4. Magnetizing  or reactance transformers tests for the diagnosis of (Xo). The core loss, copper loss and specific test for the diagnosis of polarity.

The two most widely used test of transformer -

1. No - load test or open circuit test.

2. Short circuit test.

The back-to-back test for the diagnosis and polarity Los polarity test for the diagnosis. Open circuit test another no - load test. Transformer no - load current and power factor angle determine the core loss of the open circuit test.

Transformer and open circuit test / no - load test method described as follows: -

High open-circuit voltage of the transformer and the low - voltage side ammeter, volts watt meter and Frequency meter connection with the rated supply voltage is reached. The watt meter that measures the power of the transformer core loss and the current size of the ammeter no - load current. Now, the core loss -

Pc = EocIocCosΦoc

When,

Eoc = Open Circuit Voltage

Ioc = Open Circuit Current

Φoc = open circuit voltage and the phase difference between outlets.

Φoc = Cos ֿ ¹ Pc / Eoc Ioc

The Ioc = IN and Φoc = ΦN

If  Iw = IN Cos ΦN

       Im = IN Sin ΦN

The open-circuit test transformer or no - load test that shows all the information -

. Core Loss

. No - load current.

. Transformer and power factor.

. Loss conductance core,

. Magnetizing reactance.

Open circuit test transformer / No - only no-load transformer test of time - full load current flowing in the load outlets that only 2% of 3% and it is the only one Coil  flow. The copper loss is very minor. As a result of the full supply voltage is generated disables full Flux. It disables the hysterics  and Eddie Current full marks loss. The reason watt transformer and open circuit test meters only shows the core loss and loss of full core.

For example of mathematics :-

1. A 50 KVA 4600/230 V, 60 Hz transformer and open circuit test results are as follows -

Eoc = 230 V, Ioc = 12.5 A.

Pc = 285 W.

Working Current transformer or magnetic current component and component tracking now.

Solution: -

Φoc =Cos ֿ ¹  Pc / Eoc Ioc

= Cosֿ¹ Pc / Eoc Ioc

Cosֿ¹ 285 /230 × 12.5

= 84.3º

Im = IN Sin ΦN = 12.5 Sin 84.3º

= 12.44 A

Iw = IN  Cos ΦN

= 12.5 Cos 84.3º

= 1.24 A.