What Is Megger Test and How Is It Performed?
The Megger is an important device from per testing point of view. It came in limelight in 1920 and as of now, we have seen some real-time improvement for its quality and design in this decade. Now we have some quality options which mark its feasibility and safe for use.
The megger is mainly used for tracking the level of electrical insulation with the help of insulation resistance.
It is necessary to monitor the insulation level of industrial equipment as we know about the degradation of its level as per environment, humidity, temperature, moisture, and specks of dust. Some related mechanical and electrical stress also impact the insulation level as well. Henceforth, we must check the Insulation Resistance of the electrical apparatus to be free from shock or fatal accidents in the future.
The IR provides an idea about the potential of the enduring power of that insulation. We can measure the voltage level without any leakage. Hence, we get aware of the condition of the insulator. All these are measure using the help of Megger Testing Servicesby theimpression of DC voltage. It is so much popular that sometimes we use the term “Insulation Resistance” testing.
Why Do We Use Megger Testing?
Insulation resistance does not remain as it is in the electrical equipment. It fades with time as per humidity, temperature, moisture, and other environmental challenges.
Some fatal accidents like a fire inside the home when the electric company will turn off the electricity and gas supply. Megger Testing Services in Dubai are done to save your life as electrical shock can be more lethal if the entire wiring system in your house is fired. Even insurance companies would check the insulation level of the home wiring system using this megger test.
When any heat or fire event takes place, it will adversely affect the wiring system. All physical compounds and metals have specific melting points. Of course, in most cases, melting points are surpassed and you need to bear a huge shock by compromising electrical integrity.
The insulation and wires are melted. You do not have any clear idea that what will next happen to your premise. It is the loss of property and many lives.
Megger testing may provide information regarding advanced safety for your home. You must be secure to check the insulation resistance across various wiring systems. Even you do not need to drill any holes in the wall. Rather, the probe testing is quite easier to resolve further issues.
The testing voltage is about 0.5 to 1 kV which is quite low. Here you may skip some of the punctures in the insulation. You will get the idea of winding faults, moisture, deterioration, etc. including leakage current.
Pre-requisites of Megger Testing:
The circuits can be tested for melted faults and existing connections that may have taken place during the fire event. Then specific areas are replaced or isolated based on the analysed results. It is ensured that there is no other fault in the circuit.
You may have a conversation with the tester and check if megger testing is needed now. Insurance claims are covered by companies once they are sure about the results, and you have applied for a new domicile.
The results come from megger testing is filed and logged with local building norms as well as insurance carriers. Significant help is provided to install a new system of wiring as per electrical needs.
How Is Megger Testing Performed?
Experts use Multimeter for insulation testing and in most cases, a continuity check is performed. But for testing and detecting leakage current for overloaded or normal conditions, a special insulation tester must be there.
The electrical leakage is measured, and then electric currents are passed in the device for the proper testing phenomenon. The insulation level of any device like cable, motor, general installation, and generator winding is verified.
It is popular testing in electrical industries for long years ago. It will not detect the punctures, but it will show the actual result like leakage current, moisture level, etc.
Procedure For Megger Testing:
• Neutral terminals and all live wires are disconnected from the transformer.
• Megger test takes place between HV and LV bushing studs to find the IR level between them.
• Leads are joined to the transformer tank and HV bushing for measuring the IR between earth and HV bushings.
• Similarly, we can measure the IR between earth and LV bushings as well.
There is a general procedure for the measurement of insulation resistance. It can be measured between earth and individual phase or between three phases. It is also genuine to measure the IR for the equipment body. The voltage levels are different as per cable size and rating. IR is generally measured in megaohm and sometimes it can reach a few Giga-ohm.
There are few advantages we get from the megger test.
• IR value is easier to read in the digital value,
• One person is enough to operate the megger testing,
• It is quite safe and handy.
