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Description
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.
Applications
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. |
