Final answer:
The Dielectric Strength Test determines insulation breakdown levels, the Polarization Index Test assesses winding contamination, the Megohm Test checks insulation resistance to ground, and the Dissipation Factor Test measures dielectric losses in insulation for a motor.
Step-by-step explanation:
To conduct tests on a motor to assess its electrical insulation, the following tests are most applicable:
Non-linear breakdown (discharge) of insulation: The Dielectric Strength Test is used to determine the maximum electric field strength that insulation can withstand before it breaks down and conducts. This test applies a high voltage to the insulation material until it starts to break down, helping to identify the maximum voltage the material can tolerate.
Degree of winding contamination (index): The Polarization Index Test is relevant here. It measures the ratio of the insulation resistance after a specified time to the resistance at the beginning of the test, providing an indication of the cleanliness and moisture of winding insulation.
Insulation resistance to ground: Megohm or Insulation Resistance Test can accurately determine the resistance of motor insulation to the ground. A high resistance value typically indicates good insulation.
Electrical losses in the insulation (dielectric losses): The Dissipation Factor Test measures dielectric losses by calculating the ratio of the power loss in the insulation to the total power applied during the test. This indicates the efficiency of the insulation.