#5 K3 Listrik - Pengukuran Tahanan Isolasi

Summary

This video provides a detailed guide on measuring insulation resistance in electrical transformers (trafo) using insulation testers. It covers the importance of ensuring that insulation resistance meets international standards before equipment installation. The video explains how to use the tester, including various techniques to measure dielectric absorption and polarization index. It emphasizes safety precautions to avoid electrical shock, and the comparison of resistance values over time to assess the suitability of electrical equipment for use. The process ensures that electrical installations are safe and meet regulatory requirements.

Takeaways

• 😀 The video focuses on measuring insulation resistance in electrical equipment, such as transformers, to ensure they meet safety standards.
• 😀 Insulation resistance is crucial for determining the safety and reliability of electrical equipment before installation.
• 😀 The insulation tester, often referred to by the brand 'Mega,' is used to measure the resistance in megohms.
• 😀 Transformers should have a minimum insulation resistance of 1 megohm to comply with international electrical standards.
• 😀 The insulation resistance is measured using different voltage settings, such as 500V and 1000V, to ensure accurate results.
• 😀 A stopwatch feature on the insulation tester helps track measurement duration and calculate the polarization index for further analysis.
• 😀 Polarization index (PI) is used to assess the quality of insulation, comparing resistance at 1 minute to 10 minutes of testing.
• 😀 If the polarization index is below 1.0, the insulation is considered faulty and the equipment is deemed unsafe for use.
• 😀 Safety precautions are emphasized, as working with live electrical equipment can be dangerous and lead to electric shocks if mishandled.
• 😀 Insulation testing should be conducted even if the equipment has been certified by the manufacturer, to account for any potential changes or damage during transport and installation.
• 😀 The insulation resistance measurement results must be compared with standard tables to determine whether the equipment meets required safety standards.

Q & A

What is the purpose of measuring insulation resistance?

The purpose of measuring insulation resistance is to ensure that the insulation of electrical equipment, such as transformers and motors, is in good condition. This helps to prevent electrical hazards and ensures that the equipment operates safely.

What is an insulation tester, and what does it do?

An insulation tester, also known as an insulation resistance meter, is a device used to measure the resistance of insulation in electrical equipment. It applies a high voltage to the equipment and measures how well the insulation resists the flow of current, indicating its condition.

What is the significance of the 'Mega' term used in insulation testers?

The term 'Mega' refers to the measurement scale used for insulation resistance, typically in Megaohms (MΩ). It is often associated with specific brands of insulation testers, like 'Mega tester,' where 'Mega' indicates the high resistance values being measured, often in the range of Megaohms.

What minimum insulation resistance value should electrical equipment meet?

Electrical equipment like motors and transformers should have a minimum insulation resistance value of 1 Megaohm. For example, a 220V motor should meet the standard of 0.22 Megaohms plus an additional 1 Megaohm, totaling 1.22 Megaohms.

How does the voltage rating of equipment impact insulation resistance measurements?

The voltage rating of the equipment influences the required insulation resistance. For instance, a 220V motor should have a resistance of at least 1 Megaohm, and this value increases with higher voltage ratings to ensure safety and proper insulation integrity.

What is the role of the polarization index in insulation testing?

The polarization index (PI) is used to evaluate the insulation's ability to retain its resistance over time. It is calculated by comparing the resistance at 1 minute with the resistance at 10 minutes. A PI value below 1.0 indicates poor insulation, suggesting potential failure.

What does the dielectric absorption ratio measure?

The dielectric absorption ratio measures the ability of the insulation material to absorb and retain electrical charge over time. This test helps identify the condition of the insulation material and whether it can continue to perform safely.

Why is it important to check insulation resistance even for new equipment?

Even if equipment like transformers or motors is new or has a certificate from the manufacturer, it is important to check the insulation resistance before installation. Transport, handling, and installation can affect the insulation, so testing ensures that the equipment is still safe to use.

What are the safety precautions when using an insulation tester?

When using an insulation tester, safety precautions include handling the tester carefully to avoid electric shock, ensuring proper connections, and following safety protocols due to the high voltage involved in the testing process.

How long should the insulation resistance be measured during a typical test?

Insulation resistance is typically measured for at least 1 minute, but extended measurements over 10 minutes may be used to assess the dielectric absorption and polarization index. This longer testing period helps to determine the stability of the insulation resistance over time.