Current Transformer (CT) tester UHV-107A

resistancepolarityVolt-ampere

UHV-107A CT PT Volt-ampere Analyzer is a portable field instrument for automated, comprehensive testing of protection-class (P-class) and metering-class CTs and PTs. It integrates excitation curve measurement with automatic knee-point detection, 5%/10% error-curve generation, ratio and polarity verification, secondary burden testing, on-board reporting and data export capabilities.

Key advantages

• Standards compliance: certified for GB 20840.3-2013 and IEC 60044.
• All-in-one field solution: portable design ≤22 kg; no external equipment required.
• On-site reporting: instant micro-thermal printing (~8 s) and USB export for Word/PDF reports.
• High-precision automation: AI-assisted knee-point calculation with ≤0.5% repeatability and dynamic error mapping for 5%/10% composite curves.
• Rugged data storage: >3,200 test records on military-grade flash with supercapacitor backup; verified operation from -25°C to 55°C.
• Fast commissioning: intuitive graphical UI and guided workflow enabling CT commissioning in under 15 minutes.

Main functions

• Excitation curve measurement with automatic knee-point detection.
• Automatic generation of 5% and 10% error curves (composite accuracy mapping).
• CT/PT ratio verification and polarity check.
• Secondary burden (actual load) testing and secondary winding resistance measurement without external instruments.
• Integrated high-voltage and high-current outputs enabling tests up to device limits; built-in thermal printer and USB data export.

Technical specifications

• Working power supply: AC 220V ±10%, 50Hz.
• Device output: 0 ~ 2500 V, 5 kVA (maximum setting value 20 A).
• High current output: 0 ~ 600 A.
• Excitation precision: ≤0.5% (0.2% * reading + 0.3% * range).
• Secondary winding resistance measurement — Range: 0.1 ~ 300 Ω; Precision: ≤1.0% (0.4% * reading + 0.6% * range).
• Secondary actual load measurement — Range: 5 ~ 500 VA; Precision: ≤0.5% (0.2% * reading + 0.3% * range) ± 0.1 VA.
• Phase (angle difference) measurement — Precision: ±4 min; Resolution: 0.1 min.
• Contrast precision: 0.05%.
• CT ratio measurement — Range: ≤25000 A/5 A (5000 A/1 A); Precision: ≤0.5% (0.2% * reading + 0.3% * range).
• PT ratio measurement — Range: ≤500 kV; Precision: ≤0.5% (0.2% * reading + 0.3% * range).
• Working environment — Temperature: −10°C to 40°C; Humidity: ≤90%; Altitude: ≤1000 m.
• Size: 410 mm × 260 mm × 340 mm.
• Weight: ≤22 kg.

Maintenance and Care

• 1. Verify the availability of the device
• Before using the transformer ratio polarity tester, first observe whether the appearance of the instrument is damaged. After powering on, check whether the instrument's LCD display screen is displaying properly and whether the display is complete. For instruments that have not been used for a long time, check whether the output terminals are corroded or aged. Otherwise, they should be cleaned up in a timely manner before use.
• 2. Equipment maintenance
• After each experiment, clean the wires on the instrument terminals, turn off the power, disconnect the power plug, and place it in a dry, dust-free, ventilated, and non corrosive gas room.
• 3. Check the reliable connection of all parts, especially the secure connection of the ground wire.
• 4. When not in use, the instrument should be packed and sealed. After each test, clean the wiring on the instrument terminal, turn off the power, disconnect the power plug, and place it in a dry, dust-free, ventilated, and non corrosive gas room.