ITI Electrician 2nd Year | Practical No. 3 | DC Shunt Generator Voltage Build-Up | Sambalpuri

Aim To perform the voltage build-up of a DC shunt generator and observe the rise of terminal voltage. Principle A DC shunt generator builds up voltage due to residual magnetism in its field poles. When the armature rotates, this residual flux produces a small EMF. This EMF sends current through the shunt field winding, increasing the flux and hence the generated EMF. This process continues until the voltage reaches its stable value. Required Equipment DC shunt generator DC motor/prime mover Voltmeter Ammeter Field rheostat Switch/MCB Connecting wires Tachometer Procedure Inspect the machine and ensure all connections are tight. Connect the shunt field winding in parallel with the generator armature terminals. Keep the field rheostat at minimum field-current resistance. Keep the generator load switch OFF. Start the prime mover and bring the generator to its rated speed. Observe the voltmeter. A small voltage should appear due to residual magnetism. Gradually adjust the field rheostat to increase the field current. Observe that the generated voltage increases. Continue the adjustment carefully until the voltage reaches the required/rated value. Record the field current and terminal voltage at different settings. After completing the practice, reduce the field current and switch OFF the generator safely.