ATRT-03 S2

3-Phase Transformer Turns Ratio Tester

The Vanguard Instruments ATRT-03 S2 is the third generation, microprocessor-based, automatic, three phase, transformer turns-ratio tester. This light weight, rugged, portable unit is designed for transformer testing at utility power substations.

The ATRT-03 S2 determines the transformer turns ratio using the IEEE C57.12.90 measurement method. The ATRT-03 S2 outputs an excitation test voltage to the transformer primary windings. The induced secondary voltage is sensed and the transformer turns ratio is calculated. The ATRT-03 S2 is capable of measuring turns ratios from 0.8 to 15,000. The transformer turns-ratio, excitation current, and phase angle readings are displayed on the large LCD. The automatic transformer type detection feature allows the ATRT-03 S2 to detect and test 130 transformer types defined by ANSI, CEI/IEC and Australian standards.

  • Highest ratio: 0.8 – 15,000
  • Capable of detecting 130 different 3-phase transformer types defined by ANSI, IEC, and Australian standards
  • 3 Test voltages available: 8Vac, 40Vac, 100Vac
  • Phase angle and excitation current measuring
  • Computer Interface (RS-232C and USB Port)
  • USB flash drive interface
  • Name-plate turns ratio calculation
  • Computed % error based on measured and calculated ratio
  • Optional 4.5″ thermal printer
  • Powered from a single phase 100-264 Vac 50/60 Hz


TYPE Portable, lightweight, automatic, 3-phase transformer turns-ratio meter
PHYSICAL SPECIFICATIONS18”W x 7”H x 15”D (45.7 cm x 17.8 cm x 38.1 cm); Weight: 20 lbs (9.0 kg)
OPERATING VOLTAGE100 – 240 Vac, 50/60 Hz
TURNS-RATIO ACCURACY 0.8 – 1,999: ±0.1%, 2,000 – 3,999: ±0.25%. 4,000 – 15,000: ±1% @ 8 Vac 0.8 – 1,999: ±0.1%, 2,000 – 3,999: ±0.20%. 4,000 – 15,000: ±1% @ 40 Vac 0.8 – 1,999: ±0.1%, 2,000 – 3,999: ±0.15%. 4,000 – 15,000: ±1% @ 100 Vac
TEST VOLTAGES 8 Vac @ 1Amp, 40 Vac @ 0.2 Amp, 100 Vac @ 0.1 Amp
EXCITATION CURRENT READING RANGE0 – 1 Ampere; Accuracy: ±0.1 mA, ±2% of reading (±1 mA)
PHASE-ANGLE MEASUREMENT0 – 360 Degrees; Accuracy: ±0.2 degree (±1 digit)
DISPLAYBack-lit LCD screen (64 x 128 dot graphic display); Viewable in bright sunlight and low-light levels
PRINTERBuilt-in 4.5-inch wide thermal printer (Optional)
EXTERNAL DATA STORAGEOne USB Flash drive interface port; Up to 999 transformer test records can be stored on a USB Flash drive (not included).
PC SOFTWAREWindows® XP/Vista-based Transformer Turns-Ratio Analyzer application is included with purchase price
INTERNAL TEST RECORD STORAGEstores 112 complete transformer test records, each record holding the test record header and up to 99 readings
INTERNAL TEST PLAN STORAGECan store 128 transformer test plans internally. Test plans can be transferred to the unit from the PC via the RS-232C/USB port or via the USB Flash drive interface
SAFETYDesigned to meet UL 61010A-1 and CAN/CSA C22.2 No. 1010.1-92 standards
ENVIRONMENTOperating: -10˚ to 50˚ C (15˚ to +122˚ F); Storage: -30˚ C to 70˚ C (-22˚ to +158˚ F)
CABLESOne 15-foot Single-phase set, One 15-foot 3-phase set, One 25-foot extension set, One safety ground, One USB, One RS-232C, cable bag
OPTIONSTransportation Case
WARRANTYOne year on parts and labor
ATRT-03 S2 Datasheet
Customer References
ATRT-03 S2 User's Manual (English)
ATRT-03 S2 Manual Del Usuario (Español)
TTRA S2 Software Manual (English)