praktek cara pengukuran tahanan isolasi dgn 2 unit motor listrik 3 phase menggunakan megger digital

Summary

In this tutorial, the presenter demonstrates how to measure the insulation resistance of a 22kW electric motor using a megger, explaining the process step-by-step. Viewers learn how to properly connect the megger to the motor and interpret the readings to determine whether the motor's insulation is in good condition. The video also covers how to handle various cables and connections, as well as how to interpret values like 1.2 Megaohms, which indicate that the motor is not suitable for use. The tutorial emphasizes proper technique to ensure accurate measurements and safe handling of electrical components.

Takeaways

• 😀 Always disconnect external conductors from the motor before measuring insulation resistance to ensure accurate readings.
• 😀 Use a megger set to 500 volts DC for testing the insulation resistance of electric motors to prevent electrical damage.
• 😀 If the insulation resistance values are higher than 10 MΩ, the motor is in good condition and can be used safely.
• 😀 Values between 5–10 MΩ are acceptable, indicating the motor is in decent working condition.
• 😀 Insulation resistance values below 1 MΩ, such as 1.2 MΩ, indicate the motor is no longer usable and should be replaced.
• 😀 As the megger is used, resistance values should increase, indicating good insulation and proper functioning of the motor.
• 😀 Always test multiple parts of the motor (e.g., terminals, windings) to get a comprehensive understanding of its insulation status.
• 😀 When measuring resistance for motor body insulation, higher values (100–1000 MΩ) indicate good insulation; lower values indicate damage.
• 😀 A motor with damaged insulation will show a significant drop in resistance, often resulting in a failed test (e.g., 1.2 MΩ).
• 😀 The megger readings should be consistently higher in good condition motors, whereas poor insulation will show fluctuating or low values.
• 😀 Always check the final insulation resistance readings; values above 100 MΩ are excellent, while values lower than that indicate problems.

Q & A

What is the purpose of using a megger in this tutorial?

The megger is used to measure the insulation resistance of a 22kW 3-phase electric motor. It helps determine whether the insulation is in good condition or if it needs to be replaced.

How do you prepare the motor for insulation resistance testing?

Before performing the test, you should remove any conductors that may be attached to the motor, ensuring accurate measurements. This step is crucial to avoid errors during the test.

What is the significance of the insulation resistance values obtained from the megger test?

The insulation resistance values indicate the quality of the motor's insulation. A higher resistance value (typically above 5 Megaohms) indicates that the motor's insulation is in good condition, while a lower value suggests the insulation may be faulty.

Why is it important to adjust the megger to 500V for the insulation resistance test?

The megger is set to 500V because the motor operates at a high voltage (380V). This ensures that the test simulates the actual operating conditions of the motor, providing accurate results.

What is the acceptable range for insulation resistance in this case?

An acceptable range for insulation resistance is typically between 5 Megaohms and 10 Megaohms. Values above this indicate excellent insulation, while values significantly below this suggest potential insulation failure.

What does a reading of 1.2 Megaohms on the megger indicate?

A reading of 1.2 Megaohms indicates poor insulation. This value is too low, meaning the motor's insulation is not reliable and the motor should be replaced or repaired.

Why are the readings for the different parts of the motor being measured separately?

Measuring different parts of the motor separately helps identify whether specific components, such as cables or windings, have insulation issues. It provides a more detailed and accurate assessment of the motor's overall condition.

What should you do if the insulation resistance value keeps rising during the test?

If the insulation resistance value keeps rising, it generally indicates that the motor's insulation is in good condition. The value should stabilize at a high level, indicating that the insulation is not compromised.

What does a consistent reading of 34.5 Megaohms or higher signify?

A reading of 34.5 Megaohms or higher indicates that the insulation is in excellent condition, meaning the motor is safe to use and its electrical components are well protected.

How can a body shot test help assess the condition of the motor?

The body shot test involves measuring the resistance between the motor body and the cables. It helps determine whether there is any electrical leakage or damage to the motor's external insulation, which can prevent electrical hazards.