Megger TTR320 Series, Instruction Manual

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AVTMTTR320-EN Rev A Oct 2008
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Getting to know the TTR320
Product Overview
The Three-Phase TTR® Test Set is fully automatic, self-checking, menu-driven
unit. The test set measures the turn ratio, phase shift, and excitation current of
power, distribution, and instrument transformers. A “-47” suffix added to the
catalog number denotes a 230-V input power supply, rather than the standard
120-V supply. The test set is a portable instrument housed in a sturdy plastic case
with removable lid and carrying strap. The inside lining of case is metal shielded.
A canvas carrying bag is supplied to hold all accessories.
The test set can be used to test single-phase and three-phase transformers, both
with and without taps in accordance with the requirements of the IEEE
C57.12.90 – 1997 standards. For three-phase measurements, the test set is
connected to all three phases of the transformer to be tested. The TTR lead
selection circuitry permits automatic measurement of all phases without changing
connections. This feature eliminates the need to refer to hook-up charts when
testing three-phase transformers. Turn ratio, phase shift and excitation current
readings are displayed on a large LCD. Transformer excitation current as well as
phase shift angle helps to detect transformer shorted turns or an unequal number
of turns connected in parallel. Operating condition (error) messages identify
incorrect test connections, abnormal operating condition, or winding problems.
Test results can be saved either to internal memory, to an external USB storage
device, or can be uploaded to a personal computer (PC) via an ethernet port.
Features include:
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Fully automatic operation.
ƒ
Self-checking at power-up.
ƒ User-friendly, menu-driven operation.
ƒ Test turn ratio, phase shift (in both degree and centiradian), and excitation
current.
ƒ Easy measuring of regular windings, tertiary windings, and CTs.
ƒ Storage capacity to handle over 1000 test files (depending on size).