Megger ® TTR25 Handheld
Transformer Turns Ratio Testers
- Single- and three-phase transformer testing
- Fully automatic; fast; easy-to-use; robust; lightweight
- Battery powered
- Tests turns ratio, excitation current, and polarity
- Simple, one-button operation
- Quick-start guide on front panel
- Operator-selectable languages
The Megger TTR25 is an automatic hand-held battery operated transformer turns ratio test set. It is used to measure the turns ratio, excitation current and polarity of windings in single- and three-phase distribution and power transformers (tested phase by phase), potential & current transformers, and tapped transformers.
The unique design of the TTR25 allows the user to operate the test set while holding it in one hand. It effectively eliminates the user from having to kneel or bend down to operate the instrument and speeds up testing time. Realizing the extreme environments in which the TTR25 must operate, special attention has been paid to making it extra rugged, with a high impact, shock resistant case, yet incredibly lightweight at a mere 870 g (1.9 lbs). Its design makes this instrument well suited for use in a variety of harsh environments. The TTR25 is particularly suited for testing in substations, transformer-manufacturing environments, and meter shops. It features a high-contrast, backlit LCD screen which can be seen in bright or ambient light.
This unit measures a high turns ratio of 20,000:1 accurately with the lowest excitation voltage. The excellent repeatability of the TTR25 helps the users to determine the condition of transformers under test. It is designed for simple, one button operation with the measured results displayed directly on the easy to read LCD or printed to the optional printer. The TTR25 needs no additional software and comes ready to use complete out of the box.
- Fast, easy hand-held operation. No need to kneel or bend down to operate the instrument.
- Powered by six standard “AA” alkaline batteries; no charger needed. Provides up to 12 hours of field operation.
- Measures turns ratio range of 20,000:1, with a high accuracy (±0.1%, 0.8 to 2000) at a low excitation voltage.
- 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.
- Perfect for meter shops, the TTR25 can be used for inspection purposes to determine the no-load accuracy of most CTs and PTs. It also can be used to determine the need to test potentially faulty CTs and PTs.
- Automatic self-calibration for each test.
|Excitation Voltage:||8 V rms for testing distribution or power transformers and PTs; 0.5, 1.5, or 8 V ac rms for testing CTs. The excitation voltage is switched automatically if excitation current exceeds a preset value.|
|Test Frequency:||55 Hz internally generated providing a universal 50/60 Hz test set|
|Excitation Current Range:||0 to 100 mA, 4-digit resolution|
|Turns Ratio Range :||0.8 to 20,000, 5 digit resolution|
|Transformer Winding Phase Relationship:||ANSI C57.12.70-1978CEI/IEC 76-1:1993 and Publication 616:1978 AS-2374, Part 4-1982 (Australian Standard)|
|Current (rms) accuracy:||
(2% of reading + 1 digit)
|Turns Ratio Accuracy :||
0.1% (0.8 to 2000)0.15% (2001 to 4000) 0.25% (4001 to 10,000) 0.5% (10,001 to 20,000)
|Display full graphics :||LCD module, adjustable back-lighting, wide temperature range, 128 x 64 dots (21 characters by 8 lines)|
Type of Power Six standard “AA” (IEC LR-6) alkaline batteries Battery Life: 12 hours of field operation Safety/EMC/Vibration: Meets the requirements of IEC-1010-1, CE and ASTM D999.75 Temperature Range: Operating: -20º C to 55º C (-5º F to 130º F) Storage: -50º C to 60º C (-55º F to 140º F) Relative humidity: Operating: 0 to 90% noncondensing Storage: 0 to 95% noncondensing Protective Devices: High voltage side shorting relay, transient voltage suppressors and gas surge voltage protectors Measuring Time Less than 5 seconds Measurement Method ANSI/IEEE C57.12.90 Dimensions: 240 H x 115 W x 50 D mm (9.5 H x 4.5 W x 1.9 D in.) Weight: Approximately 1.3 kg (2.8 lb), including leads