TR 300


The TR 300 offers selectable test voltages of 5, 50, and 100V. Optionally, a 250V test voltage is available for testing in electrically noisy environments. The higher test voltages increase the measurement accuracy, especially at high turns ratios.

In addition, the test frequency of the voltage is 55 Hz so power frequency interferences of the substation do not affect the turns ratio measurement. Higher test voltages, coupled with off frequency measurement, make the TR 300 an ideal instrument for high accuracy testing.

To prevent an accidental wrong test lead hookup, such as when the operator reverses H and X leads, the TR 300 outputs a low-level test voltage to verify the hookup condition before applying the full test voltage to the transformer. Higher test voltages allow the TR 300 to test CT’s and PT’s, as well as power transformers.

Product Details

Outstanding Features:

  • Off power frequency test voltages for high accuracy in electrically noisy high voltage sub stations
  • Optional battery backup for up to 3 hours of testing
  • Wide Ratio range: 0.8 - 50,000: 1, covers all types of transformers
  • Capable of detecting all types of 3-phase transformers defined by ANSI, IEC, and Australian standards
  • 4 available voltages: 5Vac, 50Vac, 100Vac, and 250 Vac (optional)
  • Phase angle and excitation current measurement covers all types of transformers including phase shifting transformers
  • Bluetooth and USB PC interfaces
  • Optional built-in 3.5-inch wide thermal printer for quick field analysis of test results

Technical Specifications:

Physical Specifications Dimensions: 21"w x 8" H x 17" D (53 cm x 20.5 cm x 43 cm)
TR 300 Weight without Battery: 24 lbs. (11 Kg)
TR 300 Weight with Battery: 26 lbs. (12 Kg)
Operating Voltage 90- 240 Vac, 50/60 Hz
Measuring Method ANSI/IEEE C57.12.90
Turns Ratio Accuracy 4 Vac: 0.8 - 20,000: ±0.05% typical max 0.3% for the entire range
40 Vac: 0.8 - 50,000: ±0.05% typical max 0.2% for the entire range
100 Vac: 0.8 - 50,000: ±0.05% typical max 0.2% for the entire range
250 Vac: 0.8 - 50,000: ±0.05% typical max 0.2% for the entire range
Phase Angle Measurement 0 - 360 degrees
Accuracy ±0.2 degree (±1 digit)
Polarity Reading In-phase or out-of-phase indication
Current Reading Range 0 - 1 Ampere; Accuracy: ±0.1 mA, ±2% of reading (±1 mA)
Display 800 x 480 pixels back-lit color LCD; viewable in direct sunlight and low light
Computer Interfaces USB 2.0, Bluetooth
Internal Data Storage 128 records of 99 readings
Internal Test Plan Storage Stores up to 128 transformer test plans; test plans can be transferred to PC
External Data Storage USB flash drive interface (drive not included)
Tap Changer Contacts 240 V AC, 2A
Battery Back-up (optional) 12 V AC, 7 AH for 3 hours of operation
Printer (optional) 3.5" wide thermal printer
Test Results Auto-detection of transformer configuration
PC Software Windows®-based transformer analysis software is included
Safety IEC/EN 61010-1, EN 61326-1, EN 61000-3, and EN 61000-4 certified.
UL 61010A-1, and CSA-C22.2 standards.
Humidity 90% RH @ 40°C (104°F) non-condensing
Temperature Operating: -10°C to +50°C (+15°F to +122°F)
Storage: -30°C to +70°C (-22°F to +158°F)
Altitude 2,000 m (6,562 ft)
Included Cables One 15' (4.57m) sing-phase cable set, one 15' (4.57m) 3-phase cable set, one 25' (7.62m) exctension cable set, one safety ground cable, one USB cable, cable bag
Warranty Two years on parts and labor
Options Shipping case (can hold unit and cables), printer, battery back-up