Atec TTR100 User Manual

TTR™100

Handheld TTR

TTR™100

Handheld TTR

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Fully automatic; fast; easy-to-use;
handheld; robust; lightweight

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Battery powered with power-saving and
shutdown function

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Tests turns ratio, phase displacement,
excitation current, winding resistance
and polarity

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Meets all IP54 requirements

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RS232 for data transfer and printing

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Stores 200 test results and 100 user­defined transformer test settings

DESCRIPTION

The Megger TTR100 is an automatic handheld, battery
operated transformer turns ratio test set used to measure
the turns ratio, excitation current, phase displacement, dc
resistance and polarity of windings in single- and three­phase distribution transformers (tested phase by phase),
potential & current transformers, and tapped transformers.
Deviations in the mentioned measurements will quickly
indicate problems in transformer windings or in the
magnetic core circuits.

The unique design of the TTR100 allows the user to
operate the test set while holding it in one hand. No other
transformer test set offers this capability. It effectively
eliminates the user from having the kneel or bend down
to operate the instrument and speeds up testing time.

Realizing the extreme environments in which the TTR100
must operate, special attention has been paid to making it
extra rugged, with a high impact, shock resistant case, yet
incredibly lightweight at 3.3 lb. (1.5 kg). It weights less
than any other commercially available instrument on the
market.

Its rugged and robust design makes this instrument well
suited for use in a variety of harsh environments. The
TTR100 is particularly suited for testing in substations and
transformer-manufacturing environments where testing
single and three-phase transformers can be performed.
The TTR100 pr
determining the condition of the transformer under test. It
features a high contrast LCD screen which can be seen in
bright or ambient light.

ovides r

eliable r

esults, helping the user in

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Six user-selectable languages

The TTR100 comes equipped with specially designed leads
which provide the necessary flexibility needed in all
weather conditions.

This unit measures the highest turns ratio in the industry
with an accuracy of 0.1% or better and with the lowest
excitation voltage. No other instrument’s performance is
comparable that is commercially available today. Another
excellent feature of this TTR is the ability to accurately
measure phase deviation (in minutes or centiradians) of
the transformer primary versus secondary. This
measurement is also useful in verifying phase errors in PTs
and CTs.

The TTR100 features special software capabilities. It comes
equipped with sufficient onboard memory to store up to
200 test results (including test report header information)
in the field for later retrieval, as well as 100 user

mer settings. Test r

transfor
optional serial printer whenever a hard copy is desired, or
the data can be downloaded to a PC. Identification of
individual test r
software allows entry of the transformer alphanumeric
serial number, transformer type and tap information
(numerical, alphabetical, or alpha-numerical) for each test
performed.

The TTR100 comes with a Windows

ogram that per

pr
instrument to a PC database. Data stored in the database
can be retrieved at a later date and test reports can be
printed to assist in the pr
analysis reports. These reports are easily transmitted via
e-mail.

eadings is also easily done. The system

mits download of test data fr

esults can be printed on an

®

based software

eparation of management and/or

-defined

om the

TTR™100

andheld TTR

H

APPLICATIONS

The proper operation of a transformer relies almost

ntirely on the electrical properties of its windings. To

e
ensure continued proper operation, transformers are tested
to verify that their electrical properties have not changed
from design specifications. A TTR is an extremely useful
instrument for testing transformer windings because it can

ocate several types of problems within a single- or a

l
three-phase transformer. It is also ideal to use for testing in
meter shops for the inspection of CTs and PTs. It can
determine the no-load accuracy of CTs and PTs and also

etermine the need to further test faulty CTs and PTs.

d
The TTR100 applies voltage, with voltage ratio being

directly proportional to turns ratio, to the high-voltage
winding of a transformer and accurately measures the
resulting voltage from the low voltage winding. In addition
to turns ratio, the unit measures excitation current, phase
angle deviation between the high and low voltage
windings, percent ratio error, dc winding resistance and
polarity.

Transformer Turns Ratio

Transformer Turns Ratio is the ratio of the number of turns
in the high voltage winding to that in the low voltage
winding.

A Transformer Turns Ratio Test Set such as the TTR100 can
directly measure the ratio of single phase, as well as three
phase transformers. Transformer ratio can change due to
several factors, including physical damage from faults,
deteriorated insulation, contamination and shipping
damage. If a transformer ratio deviates more than 0.5
percent from the rated voltage ratio, it may not operate
reliably. To measure small ratio changes such as this, the
accuracy of a Megger TTR100 is needed.

Excitation Current

The TTR100 is capable of measuring exciting current by
applying voltage to one of the transformers windings. An
accurate measurement of exciting current can provide
information about the condition of a transformer’s core.
Unwanted circulating currents or unintentional grounds
can affect the exciting current and indicate a problem.

Phase Angle Deviation

The phase angle deviation is the relationship between the
voltage signal applied to the high voltage winding and the
voltage signal extracted from the low voltage winding.

The phase deviation between the high and low side of a
transformer is generally very small. However, the phase
deviation can change significantly if there is deterioration
or damage in the transformer core. The TTR100 can
measure this phase relationship with the resolution
necessary to detect a pr

oblem.

Additional information about a transformer’s electrical
properties can be found in the IEEE Standard Test Code
for Transformers, C57.12.90, or by contacting Megger’s
technical support group.

Winding Resistance

Measuring the DC resistance of transformer windings will
aid in identifying problems such as shorted or open
windings, as well as loose connections.

The Megger TTR100 can measure the DC resistance of
both single phase and three phase transformer windings.

Transformer Polarity

Polarity of a distribution transformer becomes of interest in
order to determine its proper connection within a power

etwork.

n

he Megger TTR100 will identify subtractive and additive

T
polarity of the single-phase distribution transformers.

FEATURES AND BENEFITS

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Faster, easier handheld operation. User no longer has to
kneel or bend down to operate the instrument.

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Powered by rechargeable battery, provides up to fifteen
hours of field operation.

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Report header infor

mation such as company name,
substation name, transformer manufacturer, transformer
ratio, operator, temperature and %RH can be entered
and saved via the alphanumeric keypad.

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Measures the widest turns ratio range in the industry
(20,000:1) with the highest accuracy (±0.1%, 0.8 to 2000)
at a low excitation voltage.

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Enables the operator to enter the ratio of the transformer
and all of its taps. This allows the operator to know
immediately when a tap is outside the acceptable limits
so that problem taps can be easily identified.

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Records ratio errors for bushing CTs to an accuracy of
±0.1% nameplate. This reduces the need for additional
test equipment and improves set-up time.

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Measures the phase deviation (in minutes, degrees or
centiradians) of the transformer primary versus
secondary. This quickly indicates problems in the
transfor

mer such as partial shorted turns and core faults.
This measurement is also useful in verifying phase errors
in all types of PTs and CTs.

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Perfect for meter shops, the TTR100 can be used for
inspection purposes by using it to determine the no-load
accuracy of most CT

s and PTs. It also can be used to
determine the need to further test potentially faulty CTs
and PTs.

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The TTR100 is ideal for use by transformer
manufactur

ers. Its unique testing pr

ocedures and storage
capability allows an operator to set up and test single
and three-phase transformers (with multiple tap
changers and bushing CTs) in minimal time.

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A “Quick Test” mode provides a fast determination of
the turns ratio, excitation current, phase angle deviation,
and winding resistance in single- and three-phase
transformers and CTs. In addition, polarity is provided
for CTs and single-phase transformers.

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Displays all measured and calculated values for each test
including ratio, excitation current, ratio error, phase
angle deviation, transformer vector group, winding

esistance and polarity thus pr

r

oviding compr

ehensive

and conclusive data