ELECTRIC MACHINES || What is no load current on Xmer ? || Draw the circuit diagram for open circuit test on single-phase transformer ?||Describe sumpner`s test on transformer with neat diagram?||Draw the circuit diagram for load test on single phase Xmer?

What is no load current on Xmer ?

When the secondary winding of transformer is open (no load connected) and supply voltage source is connected to the primary side on Xmer , So the current is flowing in primary circuit is called no load current . which is represent by Io .

Draw the circuit diagram for open circuit test on single-phase transformer ?

Open circuit

Draw the circuit diagram for short circuit test on single-phase transformer ?

Short circuit

Describe sumpner`s test on transformer with neat diagram?

The open and short circuit test cannot be used foe the 'heat run' test wherein the purpose is to determine the steady temperature rise if the transformer was fully loaded continuously ; this is so because under each of these test the power loss to which the transformer is subjected is either the core loss or copper loss but not both . The way out of this impasse without conducting an actual loading test is the SUMPNER`s test which can only be conducted simultaneously on two identical transformer .

Sumpner`s test

Draw the circuit diagram for load test on single phase Xmer?

Circuit diagram for load test

GK_GOURAV

What Is Auto Transformer || Explanation ...

Auto Transformer :-

It is a type of Transformer , It`s working principle is same as normal transformer, which is   " FARADAY`S LAW OF ELECTOR-MAGNETIC INDUCTION " .
Which states that ;
' When a conductor is placed in a varying magnetic field, an EMF is induced which is known as Induced EMF. If the conductor circuit is closed, a current is
also induced which is known as Induced Current. It has two Windings  ;

             1.) Primary Winding ,
     2.) Secondary Winding.

In auto Transformer number of turns in primary winding is constant but we can change number of turns in the secondary winding with the help of a Rotating Disk.
So we are eligible to take output as much as we want under the capacity of the transformer.
We can represent Auto-Transformer by the following symbol :

AUTO Xmer

As we know ;

         N1/N2 = E1/E2

Means the induced voltage depends on the number of turns in the windings. We can change the output by changing the number of turns in the winding in the
Single Transformer.

VIDEO:-

Use :-

It is mainly used in laboratories in schools, colleges and research labs Because in labs we are used to work with different voltages, it is very useful
to work with An Auto-Transformer.