Page 99 - CITS - Electrician - Trade Practical

ELECTRICIAN - CITS

MODULE 8: Transformer Connection and Testing

EXERCISE 41 : To measure the transformation ratio of

single ph. transformer

Objectives

At the end of this exercise you shall be able to
• identify the different types of transformers and their rating
• identify the primary and secondary winding, type of core of transformer
• connect the transformer to supply and measure primary & secondary voltage
• measure the transformation ratio of transformer.

Requirements

Tools/Equipments/Instruments
• Combination Plier (165mm, insulated) - 1 No. • Multi meter (Digital, 3 digit) - 1 No.
1/2
• Screw Driver (150mm, insulated stem) - 1 No. • 1 Ph. Auto transformer (0-260 V) - 1 No.
• Neon Tester (75mm, 500 V) - 1 No. Materials/Components
• Electrician knife (Insulated) - 1 No. • PVC copper wire (1.5 sq.mm) - 2 meter.
• Voltmeter (MI, 300 V) - 2 Nos. • Test lamp (100 W, 230V) - 1 No.
• 1 Ph. Step up Transformer • Insulation tape (PVC, 19mm) - 1 role.
(110V/220V) - 1 No. • Cotton waste - as reqd.
• 1 Ph. Step down Transformer
(230V/115V) - 1 No.

Procedure

TASK 1 : Identify primary & secondary of transformer
1 Collect the Tools, equipments and materials required for experiment.
2 Draw the connection diagram of single phase transformer.
3 Check and identify primary & secondary windings and type of core of transformers.
4 Check the primary & secondary voltage rating of transformers in the name plate.

5 Identify the step up OR step down transformer as per primary & secondary voltage ratings.

TASK 2 : Connecting step up transformer and measure transformation ratio

1 Make the connection of step up transformer as per circuit diagram.
2 Check the connections and connect the transformer to the supply through the variac.
3 Switch ON the supply and record the primary & secondary voltages.
4 Switch OFF the supply and disconnect the transformer.
5 Calculate the transformation ratio of transformer as per equation.

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