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Megger TTRU3
  • Megger TTRU3
  • Megger TTRU3
  • Megger TTRU3
  • Megger TTRU3

Megger TTRU3 Transformer Turns Ratiometer

Megger approved distributor and service centre.

Includes: 3Ø Transformer Turns Ratio Test Set, AC Power Cord & Adapters, USB 2.0 Cable, Tap Changer, Canvas carrying bag for test leads, Ground Cable, Thumb Drive, Triple Function Pen.

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The Megger TTRU3 ratio meter test set is a fully automatic, self-checking, menu-driven turns ratiometer. The test set measures the turns ratio, vector relationship, excitation current as well as transformer diagnostic health indicators of power, distribution, and instrument transformers. The design of this instrument is such that it operates properly, independent of line voltage quality and frequency. This allows use of any generator driven power source of 500W or higher.

The TTRU3 is designed to test ALL power, instrument, and distribution transformers without the need of traditional high voltage excitation. With our patent pending step up technique, you are no longer required to know the “proper” test voltage to apply to obtain a “good” result - the test set decides for you - all in a box that is up to 35% smaller and lighter than other turns ratio meters.

With 3Ø excitation, testing is up to five times faster than previous phase-by-phase switching single instruments, and errors due to loading of delta secondary and tertiaries are problems of the past.

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 – 2013 and IEC 60076-1 standards. For three-phase measurements, the test set is connected to all three phases of the transformer to be tested. The TTRU3 applies all three phases simultaneously which permits automatic measurement of all phases without changing connections.

The TTRU3 is also designed to operate single phase on three phase transformers to help isolate transformer phase related issues. The TTRU3 measures turns ratio, phase deviation and excitation current readings which are displayed on the built in 7 inch color display or customer PC.

Unlike other transformer ratiometers, the TTRU3 operates in both step up and step down ratio mode. Step down ratio excites the primary and measures the induced voltage on the secondary, while step up excites the secondary and measures the induced voltage on the primary.


3Ø test voltage - fast testing of all transformers.
Patent pending 3Ø Step Up Testing.
Confirm expected nameplate vector configuration.
Ability to measure actual vs expected phase shift.
Unique kelvin clamps with adjustable 3-inch jaw.
Banana plug input for connection to terminal blocks.
Turns ratio % error vs nameplate with pass/fail.
PC interface via USB for remote control operation and downloading of test results.

Megger TTRU3 Product Video

TTRU3 Selection Guide
Max Turns Ratio 50,000 Down / 200 Up 50,000 Down / 200 Up 50,000 Down / 100 Up
Max Induced Voltage 250 V 250 V 125 V
Ø Shifting TX’s Measurement up to 50,000 records and 2,000 photos up to 10,000 records up to 2,000 records
Magnetic Balance Optional Optional
Printer Optional Optional
Power DB Control Optional Optional
Clone facility to set up multiple testers Optional Optional

Megger TTRU3 Specifications
Input Power 90-264 VAC, 47-63 Hz, 250 VA Max.
Voltage 3Ø, 1-48 VAC, up to 250 V on Primary.
Frequency 50-480 Hz.
Current 0.1 mA - 1 A, Max 1 A @ 48 V.
Turns Ratio Measurement Methods 3Ø Step Up
3Ø Step Down
1Ø Step Up
1Ø Step Down.
Turns Ratio Range and Accuracy - Guaranteed accuracy from -20°C to +50°C.
Step Down Excitation
25-48 V ±0.05% 0.8 - 1000
±0.10% 1001 - 2000
±0.30% 2001 - 15000
±1% 15001 – 50000.
1-24 V ±0.10% 0.8 - 1000
±0.20% 1001 - 2000
±0.60% 2001 - 15000.
Step Up Measurement
25-250 V ±0.05% 0.8 - 200 (most Power Tx).
1-24 V ±0.10% 0.8 - 200.
Excitation Current Measurement
Resolution 0.1 mA 0.1 mA - 100 mA - 1 mA 101-1000 mA.
Accuracy ± 1% ±0.1 mA.
Frequency Measurement
Resolution 0.1 Hz.
Accuracy ±0.1% ±0.1 Hz.
Transformer Phase Measurement
Range 0 - 360 Degrees.
Accuracy ± 0.05 Degrees.
General Specifications
Operating Temperature -20°C to +50°C (-4°F to +122°F).
Storage Temperature -30°C to +70°C (-22°F to +158°F).
Relative Humidity 0-90%, non-condensing.
Safety IEC 61010-1:2010 + AMD1:2016.
EMI/EMC IEC 61326-1:2012.
RoHS2 EN50581.
Display 180mm (7 in.)
800 x 480 Resolution
1100 NITS.
Transformer Testing Standards IEEE C57.152-2013
IEC 60076-1:2011
AS/NZS 6076 1:2014
CIGRE 445 2011.
Internal/External Data Storage Up to 2000 sets of 3 phase results internal storage
Transferable via USB 2.0/3.0 thumb drive.
Communication/Control Software 180mm (7in) built it display running custom GUI
USB Interface for PC Control running custom GUI.
Printer Output 51mm (2in) thermal printer
Prints all measurement data displayed on GUI.
Case Ruggedized case with fold out feet
Canvas carrying bag for leads and accessories.
Weight 6.5 Kg (14lbs).
Dimensions 406 x 304 x 254mm (16 x 12 x 8in.)
Megger TTRU3 warranty One-year.


Megger TTRU3 Datasheet

PDF Specifications of the Megger TTRU3 True 3 Phase Transformer Turns Ratiometer.

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