26-02-2013, 10:55 AM
To Measure Single Phase Power by Three Ammeter Method.
Measure Single Phase.docx (Size: 11.55 KB / Downloads: 38)
APPARATUS:
•Ammeter 3
•Voltmeter 1
•Wattmeter 1
•Resistor 1
•Inductive load
•Connecting wires
THEORY:
Like 3 Voltmeter method, 3 Ammeter method is also used for the measurement of single
phase power. The disadvantages of measurement of power by 3 voltmeters are overcome
in this method. The relations for the measurement of power and power factor are as
follows.
The accuracy of this method is higher than 3 Voltmeter method.
PROCEDURE:
1. Connect the circuit as shown in circuit diagram.
2. Switch on the power supply and measure V, I1, I2, I3and P’L as shown by
wattmeter.
3. Calculate PL and Power factor by using formulae.
4. Find %error between P’L and PL.
5. Vary resistance or inductive load and repeat above steps.