Dielectric oil breakdown voltage meter is an automatic test device for measuring the breaking point of insulating oils. This test is a fundamental part of the basic oil quality assessment trio (alongside Moisture and Acidity) in transformers and other electrical equipment. The instrument works by observing the break-down of sparks between two electrodes immersed in the oil and separated by a gap. The test can be carried out in the laboratory or in the field for commissioning and maintenance tasks.
Detection Method
A Dielectric oil breakdown voltage meter is an instrument used to determine the ability of an insulating fluid to withstand electric stress. This critical test helps you understand the condition of your transformer insulating oil and is part of an essential trio of tests (also including moisture and acidity) to help assess oil quality.
The testing method involves placing a sample of insulating oil into an oil cup and applying a controlled rate of voltage increase. The test continues until either the insulating oil breaks down or the voltage reaches a specified test voltage value.
The OTS PB and OTS AF range of automatic insulating oil testers use precision shatterproof test vessels that are easy to clean and provide repeatable results. All models feature a large, clear test chamber so you can easily view the process and results. This allows you to easily identify any impurities or moisture within the oil. The results are then clearly displayed on the digital screen to ensure accuracy.
Testing Method
The breakdown voltage test is the first step in evaluating the condition of an insulating oil or liquid. It is a critical test to determine the ability of the oil to withstand electric stress, and should be conducted before performing other tests such as the moisture content test and the specific gravity test. During the BDV test, an AC power supply is applied to the disc electrodes of the tester. The voltage is boosted at a uniform speed to achieve the required breaking point of the oil sample. This process is repeated six times to measure the breakdown voltage of the sample. The average of the measured results is then taken as the BDV value of the oil sample.
BDV testing is a highly controlled and sophisticated process. YUNENG transformer oil testers are designed to meet the precise requirements of this process, ensuring accurate and repeatable results. The internal design and use of high-voltage switches that cut off supplied voltage within 0.02 seconds protects the tester against external influences that can affect the test results.
Instrumentation
The insulating oil dielectric strength tester also called BDV meter measures the ability of the insulating liquid to resist electrical stress in transformers and other electrical equipment. It is a fully automatic device that complies with IEC 60156, ASTM D877 and ASTM D1816 standards and user procedures.
The test consists of applying a high voltage (eg 2 kV) across the electrodes in a cell filled with insulating oil. This creates a spark at the gap between them and gives an indication of the breakdown strength of the oil sample.
The measurement is a repeatable process and the results are stored in a non-volatile memory. The TOR-80 is easy to use and has a large test vessel and a clear lid for ease of viewing the results. It is equipped with a fast high-voltage switch off time, which cuts off the supply of voltage within 10 seconds after the electrodes have touched the sample, and this ensures the safety of the operator.
Results
A Dielectric oil breakdown voltage meter is a device for measuring the dielectric strength (BDV) of insulating oils that are used in electric apparatuses such as transformers and switchgears. This test is performed on a sample of the oil and provides an indication of the condition of the liquid in terms of its ability to withstand a high voltage stress. The insulating quality of an oil can deteriorate over time, due to the presence of impurities and moisture. This deterioration affects the conductivity of the oil, and as a result, the BDV value decreases significantly.
The BDV of a transformer oil is measured by observing at what voltage sparks are generated between the electrodes immersed in the oil and separated by a gap. This value is taken 3 to 6 times and the average is calculated. This enables the BDV of a sample to be determined in a quick and easy manner. The BA75 breakdown analyzer makes onsite testing of the BDV of transformer oil simple, fast and accurate.
Wrapping It Up
Insulating oil breakdown voltage meter is a testing mechanism that helps to assess the dielectric strength of insulating oils poured in electrical apparatuses. It is a very useful and efficient industrial instrument. During the test, the sample oil is placed in an oil cup between two standard-compliant electrodes with a gap of 2.5 mm and a test voltage is increased with a controlled rate until breakdown occurs.
