Why ct secondary is shorted

The reason is very high voltages will be induced at the terminals. To understand this, first we should know the basic difference be. Current transformer is used in power circuit for metering or protection.

Its current though primary winding depends on power system current(current though that branch in which CT is connected), not on CT loading. So you can assume that current is.

In the next tutorial about Transformers we will look at what happens when we connect together three .

The output of the CT is normally connected to the relevant ammeter which has very low impendence and secondary remains almost short circuited.

If the primary circuit has current flowing the secondary circuit should never be opened. This can cause very high voltages to occur due to the Ampere-Turns of the primary that start magnetizing the core. A current transformer should never be open-circuited while main current is passing through the primary winding. If the load is removed from the secondary winding while the main circuit current is flowing, most of the primary winding current become. The test is conducted on the high-voltage (HV) side of the transformer where the low-voltage (LV) side or the secondary is short circuited.

A wattmeter is connected to the primary. An ammeter is connected in series with the primary winding. A voltmeter is optional since the applied voltage is the same as the voltmeter reading . More discussion on CT is perhaps out of the scope of this question and CT will probably be . Mind that the same is not true for CT. Electrical measurement,avometer device,voltameter,fundamter testing techniques,digital voltameter.

CT secondary terminals should never be kept open. However, due to the nature of the CT , the current leaving the CT is usually within. See IEEE 5 Application Guide for Grounding of Instrument Transformer Secondary Circuits and Cases.

Magnetizing Inductive Reactance Versus Time. If this type transformer is used with more than one primary turn, the loop should be at least inches in diameter. Make sure that the secondary leads are twisted closely together and carried out without passing through the field of the primary conductors. It is not necessary that the bus exactly fill the window . The CT ratio is the ratio of primary current input to secondary current output at full load. Verify that the shorting device on the CT is properly connected until the CT is ready to be installed.

Current Transformers (CTs) can be used for monitoring current or for transforming primary current into reduced secondary current. USERS must ensure that external shorting links are NOT installed on POTENTIAL circuits. The CT primary is connected in series between the source and load. With the secondary shorted , voltage across the secondary is zero. Adjusted by the turns ratio, voltage across the CT primary is also zero.

The loa therefore, sees full system voltage and normal current.