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AIM:
To determine the performance characteristics of the given single phase induction motor by direct loading.
APPARATUS REQUIRED:
Precaution
The motor should be started without any load.
Procedure
1. Note down the name plate details of motor. Connections are given as per the circuit diagram.
2. The DPST is closed in the supply side.
3. The motor is started by gradually varying the autotransformer and the rated voltage is applied.
4. At no load, the speed, current, voltage and power are noted down.
5. The load is gradually applied with the help of spring balance and brake drum arrangement.
6. The speed, current, voltage, power and spring balance reading are noted for various loads up to the rated current.
7. The motor is switched off after releasing the load.
FORMULA USED:
1. Radius of brake drum ® = (Circumference/2π) in meters
2. Torque (T) = (S1~S2) x 9.81x r in Nm
3. Power output (Po) = 2πNT / 60 in Watts
4. Power input (Pi) = VL x IL Cos Φ Watts (Power input is given by the wattmeter reading)
5. %Efficiency (η) = Po / Pi x 100 in %
6. BHP = Po / 735.5