- Simple to use.
- Low cost, low weight (17,5 kg) (38.5 lbs).
- Strong, safe construction.
- Suitable for testing to national standards.
- Auto 1 minute timer for easy withstand testing.
- 0,1 kV measurement resolution.
- Large, clear LED display.
- Reliable operation controlled by microprocessor.
- Powered from a range of mains supplies.
- Wide range of optional vessels.
- Easy to clean vessel and chamber.
The Megger® OTS60SX is a lightweight, semi-automatic, oil dielectric strength test set. The instrument is suitable for field use and can be powered from a range of mains supplies. The maximum 60 kV output allows tests to be performed on oil from a wide variety of electrical installations including transformers, circuit breakers and other equipment. The operation of the test set is extremely simple and the results are displayed on a bright
LED display. A selection of vessels allows the instrument to be configured for a variety of test standards.
The microprocessor controlled, semi automatic operation allows the user to select a choice of voltage rise rates as specified in many national standards. The start button will then initiate the test. If oil breakdown occurs the
instrument will remove the test voltage and display the breakdown value. Alternatively the user can pause the test voltage at any time to carry out a withstand test. The voltage will be maintained at this level for one minute or until breakdown. After one minute the voltage will automatically continue to rise until breakdown occurs or to the maximum output of the instrument.
A sheet steel enclosure makes the instrument rugged and safe. A strong polycarbonate window covers the high
voltage chamber. A mesh screen enables the oil breakdown to be viewed and reduces electro-magnetic
emissions. Operator safety is ensured by an interlock on the chamber door. The power cord and other accessories are stored in a pouch which is fitted to the side of the test set. An optional carrying bag with shoulder strap is also available.
The oil vessel is located in the top of the instrument. An external nut varies the electrode gap. The design of the vessels and test chamber makes them easy to clean. The instrument is supplied with a spacing gauge for setting the electrode gap.
A range of vessels are available suitable for testing to a wide range of national specifications. Three types of electrode are available; spherical (IEC type), mushroom (VDE/ASTM D1816) and cylindrical (ASTM D877). The oil sample can be stirred by a motor driven propeller available in some of the vessels. Spare electrodes can also be supplied suitable for all types of oil testing.
Oil has been used as an insulating medium in transformers for over one hundred years. From the earliest days of transformer design, oil has been recognized as being an efficient coolant with a high flash point and high electric strength. Oil can be used in electrical equipment for a long time if adequately maintained.
Many factors can lead to a weakening of the insulation properties of oil. Oil degradation takes place due to
oxidation, acids, sludge, gas and water absorption. These processes change the electrical properties of the oil which can be seen from a dielectric strength test.