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.