Three Methods for testing electromagnetic potential transformer

Publish Time: 2021-11-30     Origin: Site

Three Methods for testing electromagnetic potential transformer


1. Oil immersion, SF6 gas type and solid transformer three method for potential transformer testing

2. Electromagnetic potential transformer method outlines test cycle, test content and recommended products

3. This technical methods is in line with the relevant specifications of the "Power Preventive Test Procedures"


Testing Method One- Oil immersion type for Electromagnetic potential transformer


Testing  Name

Testing  Content

Reference Equipment




AC withstand voltage testing

1. primary winding 0.8 times vaule test based on factory vaule

2. The secondary winding and the ground power frequency withstand voltage are 2 kV (use Mega)

3. Crack-type or hierarchical transformer multiplier induction withstand voltage test,

4. If 110kV voltage capacity is 5%, 220kV is 10%





2500V insulation resistance tester


Water content in oil

The content of dissolved gas components in oil (μ L / L):

H2:150

At 220kV, the C2H2 value is: 2

At 110kV, the C2H2 value is: 3


SF6 micro water tester


Partial discharge test

(PD Test)

In the 110KV and 220KV system, using oil-immersive method to test  potential transformer,

once voltage is 1.2 um√3, and the local discharge is not greater than 20PC.


Partial discharge test system


Testing Method Two- SF6 Gastype for Electromagnetic potential transformer

Testing  Name

Testing  Content

Reference Equipment



Water content in gas


The content of dissolved gas components (μ l / L) in the gas:

H2: 150

At 220kV, the C2H2 value is: 2

At 110kV, the C2H2 value is: 3




SF6 micro water tester


AC withstand voltage test

1.Primary winding 0.8 times vaule test based on factory vaule

2.The secondary winding and the ground power frequency withstand voltage are 2 kV (use Mega)

3.Crack-type or hierarchical transformer multiplier induction withstand voltage test,

If 110kV voltage capacity is 5%, 220kV is 10%


5000V insulation resistance tester

Infrared test

At least once  per  year


Infrared thermal imager

Testing Method Tree- solid type for Electromagnetic potential transformer

Testing  Name

Testing  Content

Reference Equipment


Anemone current and excitation properties


If there is no significant difference in the no-load current and the factory value at the rated voltage, no-load current at the following test voltage is not greater than the maximum allowable current:

Neutral point non-effective grounding system: 1.9UN / √3;

Neutral point grounding system: 1.5UN / √3




Transformer capacity and empty load tester


winding connections and polarity

Checking winding connections and polarity whther is same as nameplate after replacing the windings.


Ratio tester


Note: Above electromagnetic potential transformer configuration are just a conventional configuration, just for reference only, if you have any product questions,please feel free to contact us!

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