Can you Megger a generator?

If it does not meet the requirements, it means that the generator windings have been damped and should be dried. Judging whether the rotor is qualified: As long as the insulation resistance of generator rotor winding is not less than 0.5MΩ, it can be considered qualified.

Why AC generator is not used in Megger?

Therefore, if we apply AC voltage during IR test then there will always be a flow of current through the capacitor and thus a leakage current to the ground. Therefore, the resistance measured by Megger will not actually represent the Insulation Resistance.

What are the disadvantages of Megger?

Disadvantages of Hand Operated Megger

• At least 2 person required to operate i.e. one for rotation of crank other to connect megger with electrical system to be tested.
• Accuracy is not up to the level as it’s varies with rotation of crank.

Which generator is used in the Megger?

Hand driven PMDC generator is used in this test.

What is the minimum acceptable insulation resistance?

Insulation resistance should be approximately one megohm for each 1,000 volts of operating voltage, with a minimum value of one megohm. For example, a motor rated at 2,400 volts should have a minimum insulation resistance of 2.4 megohms.

Why is DC used for IR testing?

Insulation testers apply a DC voltage across insulation, which triggers a small leakage current—or resistive current—through it. Your tester will then calculate the resistance with Ohm’s law and shoot out a measurement on the screen.

What is the purpose of Megger?

Definition: The Megger is the instrument uses for measuring the resistance of the insulation. It works on the principle of comparison, i.e., the resistance of the insulation is compared with the known value of resistance.

What is megger used for?

An instrument that is used to measure insulation resistance is a Megger. It is also known as meg-ohm-meter. It is used in several areas like multi-meters, transformers, electrical wiring, Etc. Megger device is used since the 1920s for testing various electrical devices which can measure greater than 1000meg-ohms.

What is Megger used for?

How does Megger work?

Megger works on the principle of electromagnetic attraction. When a primary coil that is carrying current is placed under the vicinity of a magnetic field it experiences a force. This kind of force generates a torque that is made to deflect the pointer of the device which gives some reading.