Insulating oil plays an important role in various electrical components like circuit breakers and transformers. Insulating oil servers as a dielectric and at the same time as a heatsink. It is important to keep the oil free from contaminants like moisture, acids, organic materials and carbon deposits. These contaminants are conductive and can cause stray currents to flow. This may result in short circuits and failure of the electrical component. To test for the purity of insulating oils, an oil test set is used. This device conducts a dielectric strength tests on a sample to determine if the oil is still within the safe operating limits. An oil test set passes an electrical current through the test sample. The voltage is slowly increased or held constant until the insulating oil reaches electrical breakdown.
With the number of oil test sets on the market today, you may have questions when in choosing the most suitable tester. A lot of testers claim that they are the best, however, the truth is, there isn’t a best tester. Each tester has unique features that are suitable for certain applications. For example, some testers are best for application A but may lack features not suitable for application B.
To help you choose an ideal tester, here is a comparison of popular oil test sets from Megger.
The OTS-60PB is a portable, semi automatic oil test set that is suitable for field applications. It can be powered from various mains and has a maximum output of 60 kiloVolts.The output test voltage allows you to carry out tests on various electrical components like circuit breakers, transformers and other electrical equipment. It has an easy to use interface and has a LED read-out that displays the test results. It is microprocessor controlled and lets your choose from a wide selection of voltage rise rates. If the test sample breaks down, the OTS-60PB will stop the applied test voltage and display the breakdown voltage. You also have the option to pause the applied voltage anytime to conduct a dielectric withstand test. The test voltage will be held constant for 1 minute and will be raised after until the sample reaches electrical breakdown. The OTS-60PB has a durable steel casing to tolerate rough conditions. It also has a viewing mesh screen so you can see the oil breakdown.
This OTS-60SX offers automatic oil dielectric strength testing with advanced features. It lets you load a test sample in the test chamber and conduct a sequence of tests. These tests include sit and stand times and average breakdown voltage. You also can conduct withstand testing for 1 minute. It has a clear LCD display that shows the menu, test progress and test results. You have the option to set the display of test results as a numerical average or a pass/fail message. You can set the display to show options in various languages like English, Italian, Portuguese, Spanish and French. This Megger meter has a maximum output test voltage of 60 kiloVolts and can be powered by batteries or by a 12 volt line from a cigarette lighter in a vehicle. This makes the OTS-60SX portable and suitable for on-site diagnostics.
If you need a tester that can carry out basic oil dielectric strength tests, the OTS-60SX is sufficient. But for more advanced diagnostics and results analysis, the OTS-60PB is the perfect choice. Getting the right tester will help you get the most out of your investment.
Protec Equipment Resources can provide you with the electrical test equipment you need. You can choose to lease, rent or purchase tester according to your needs. Our inventory carries a wide selection of equipment from trusted manufacturers like Megger, Doble, Raytech, Fluke and more. You can reach us at 1-866-352-5550 for assistance in selecting the best option for test equipment rental.