• Measures primary-to-secondary turns ratio on power, potential (VT/PT), and current (CT) transformers
• VT/PT ratio range auto-ranging 0.8000:1 to 8000.0:1; CT ratio range auto-ranging 0.8000 to 1000.0
• VT/PT accuracy to plus or minus 0.1 percent of reading (10.000 to 999.99 band); CT accuracy plus or minus 0.5 percent of reading
• Also measures excitation current (up to 2 A), polarity, winding continuity, and percent nameplate deviation
• Injects into the primary and reads the secondary for improved operator safety; automatic self-calibration, no balancing
• Automatic test cycle checks for open windings, short circuits, incorrect lead placement, and reverse polarity
• Backlit LCD 20 characters by 4 lines; six languages (English, Spanish, French, Italian, German, Portuguese)
• Stores up to 9801 measurements; USB communication and included DataView software for setup, transfer, and reporting
• Powered by (6) internal rechargeable AA NiMH batteries or 12 Vdc external supply with intelligent charging; measurement method per IEEE Std C57.12.90

• On-site acceptance and routine testing of power transformers
• Ratio, polarity, and excitation checks on potential (VT/PT) and current (CT) transformers
• Verifying transformer nameplate values and detecting winding faults before energizing
• Utility, substation, and industrial transformer maintenance and commissioning

• Type: portable digital transformer ratiometer (turns ratio, polarity, excitation current, winding continuity, nameplate deviation)
• VT/PT ratio range: auto-ranging 0.8000:1 to 8000.0:1
• VT/PT accuracy (of reading): ratio 0.8000 to 9.9999, plus or minus 0.2 percent; 10.000 to 999.99, plus or minus 0.1 percent; 1000.0 to 4999.9, plus or minus 0.2 percent; 5000.0 to 8000.0, plus or minus 0.25 percent
• CT ratio range: auto-ranging 0.8000 to 1000.0
• CT accuracy: plus or minus 0.5 percent of reading
• Excitation current: up to 2 A
• Output voltage (VT/PT): 30 V at 64 Hz; output voltage (CT): 2 V at 64 Hz
• Phase (phase displacement) measurement: to be confirmed
• Measurement method: in accordance with IEEE Std C57.12.90
• Display: LCD, 20 characters by 4 lines, adjustable contrast and backlight
• Languages: English, Spanish, French, Italian, German, Portuguese
• Communication: USB Type-A to Type-C, USB 2.1
• Data storage: 9801 measurements
• Buttons: 6 total (one to start testing, five for navigation)
• Power supply: (6) internal rechargeable AA NiMH batteries; USB Type-C and 12 Vdc charger; intelligent battery charging
• Battery life: 500 VT/PT tests; battery charge time: 10 h (see user manual for full details)
• Reference condition: (23 plus or minus 5) C, (50 to 70) percent RH, full battery charge, no external fields or noise
• Weight: 7.1 lb (3.2 kg)
• Ingress protection: IP53 (with case lid closed)
• Safety compliance: IEC 61010-2-030, IEC 61326-1, IEC 60529, IEC 60068-2-6, IEC 60068-2-27, IEC 60068-2-31, Pollution Degree 2
• Power adapter: 110/220 V (Cat. #2136.55)

The AEMC DTR 8511 measures how a transformer is actually wound. Connect it to a de-energized power, potential, or current transformer and it reports the primary-to-secondary turns ratio, along with polarity, excitation current, winding continuity, and percent deviation from stored nameplate values. It injects a low test signal into the primary and reads the secondary, which is safer for the operator, and it self-calibrates at each measurement with no manual balancing or range selection.

The VT/PT ratio range auto-ranges from 0.8000:1 to 8000.0:1, with accuracy as tight as plus or minus 0.1 percent of reading in the 10.000 to 999.99 band. The CT ratio range auto-ranges from 0.8000 to 1000.0 at plus or minus 0.5 percent of reading, and excitation current reads up to 2 A. Measurements follow IEEE Std C57.12.90. At each test the instrument checks for open windings, short circuits, incorrect lead placement, and reverse polarity, so faults are caught during testing rather than after.

A backlit 20-character by 4-line display, six-language support, and polarized H and X input connectors speed setup in the field. Up to 9801 measurements store on board, and included DataView software handles nameplate setup, data transfer, and reporting. The instrument runs on internal NiMH batteries or external supply, with intelligent charging.