Table of Contents
What is Megger value of transformer?
(2) IR Value for Transformer:
| Transformer Coil Voltage | Megger Size | Min.IR Value Liquid Filled T/C |
|---|---|---|
| 0 – 600 V | 1KV | 100 MΩ |
| 600 V To 5KV | 2.5KV | 1,000 MΩ |
| 5KV To 15KV | 5KV | 5,000 MΩ |
| 15KV To 69KV | 5KV | 10,000 MΩ |
How does Megger test work?
The Megger test is a method of testing making use of an insulation tester resistance meter that will help to verify the condition of electrical insulation. The IR gives a measure of the enduring power of an insulator to bear the service voltage without any current leakage path.
What is pi test of transformer?
Polarization Index Test (PI Value Test) along with Insulation Resistance Test (IR Value Test) is conducted on HV electrical machine to determine service condition of the insulation. IP test is conducted especially to determine the dryness and cleanliness of the insulation.
Why tests are performed in transformer?
Turns ratio transformer testing is commonly used to ensure that the winding ratio between the primary and secondary coils are aligned to recommended specifications. This type of transformer testing also ensures the transformer will provide either step-up or step-down voltage.
What is Megger test and how is it performed?
The Megger test is a method of testing making use of an insulation tester resistance meter that will help to verify the condition of electrical insulation. Insulation resistance quality of an electrical system degrades with time, environment condition i.e. temperature, humidity, moisture and dust particles.
How to use a Megger insulation tester?
Switch off power to the circuits you are testing. If you are not sure which breakers or fuses control the circuits,switch off the main breaker.
What is an acceptable Megger reading?
If the megger reads a resistance between 1-1.25 on your meter, then the cable passes. Any reading above 1.25 is considered excellent. Continue to monitor the megger over 30-second intervals. If the resistance reading continues to increase, the cable insulation is in excellent condition.
What is the resistance of a transformer?
The ideal transformer has no resistance, but in the actual transformer, there is always some resistance to the primary and secondary windings. For making the calculation easy the resistance of the transformer can be transferred to the either side.