Dielectric Breakdown Voltage (VDE Electrodes)
Standard Test Method Dielectric Breakdown Voltage Using VDE Electrodes, ASTM D1816
Dielectric Breakdown Voltage is an electrical property of new oil. The measurement of Dielectric Breakdown Voltage has application both to the function of new oil and to its purity. The D1816 method has been used by many standards organizations to replace the D877 method as both a new oil test and as an in-service oil test because the VDE electrodes more closely resemble the geometry of conductors inside operating electrical equipment and because the test is much more sensitive to moisture and to cellulose particles. There are two possible gap settings for the electrodes: 1 mm (approximately 0.04 inches) and 2 mm (approximately 0.08 inches). Typical specification values for new oil as received from a supplier are a minimum of 20 kV for a 1 mm gap and a minimum of 35 kV for a 2 mm gap. For new oil installed in new equipment and for in-service oil, the acceptable values depend on the voltage class of the equipment. A difficulty with the method is that it is also sensitive to dissolved gases, which may not present any sort of operational problem at levels that affect the test. So, while an acceptable D1816 value can be interpreted as an indication of normal operation, a questionable or unacceptable value may not automatically be interpreted as a definite sign that something is wrong; further investigation is needed.
Dielectric Breakdown Voltage is an electrical property of new oil. The measurement of Dielectric Breakdown Voltage has application both to the function of new oil and to its purity. The D1816 method has been used by many standards organizations to replace the D877 method as both a new oil test and as an in-service oil test because the VDE electrodes more closely resemble the geometry of conductors inside operating electrical equipment and because the test is much more sensitive to moisture and to cellulose particles. There are two possible gap settings for the electrodes: 1 mm (approximately 0.04 inches) and 2 mm (approximately 0.08 inches). Typical specification values for new oil as received from a supplier are a minimum of 20 kV for a 1 mm gap and a minimum of 35 kV for a 2 mm gap. For new oil installed in new equipment and for in-service oil, the acceptable values depend on the voltage class of the equipment. A difficulty with the method is that it is also sensitive to dissolved gases, which may not present any sort of operational problem at levels that affect the test. So, while an acceptable D1816 value can be interpreted as an indication of normal operation, a questionable or unacceptable value may not automatically be interpreted as a definite sign that something is wrong; further investigation is needed.