Impedance tester UHV-370

voltagephaseoperational

Product overview
The UHV-370 is a portable transformer short-circuit impedance tester designed for rapid on-site detection of transformer winding deformation and short-circuit impedance measurement. It combines a wide voltage and current measurement range with a 7.0-inch touch display and built-in high-precision clock for intuitive operation and time-stamped results.

Product parameters
The tester uses a primary-connection method and does not require an external voltage regulator. After entering test parameters the instrument initiates automatic three-phase testing and calculates impedance error percentage for each phase, delivering clear numerical results for quick assessment of winding condition.

Technical parameters
Voltage measurement range: 5~400 V
Current measurement range: 0.1~20 A
Measurement accuracy: 0.2 d
Operating power supply: AC 220 V ±10%
Power frequency: 50 Hz
Operating temperature: -10 ℃ to 50 ℃
Ambient humidity: ≤85% RH
Net weight: 6 kg

Features

• Powered from AC 220 V source; supplies test current automatically to AB, BC and CA windings and collects phase data simultaneously.
• Automatic three-phase testing using primary connection (no inverse connection with test leads required).
• Supports single-phase and three-phase tests with manual or automatic operation modes.
• Automatic output-current adjustment to match the device under test impedance limits.
• Measurements possible without external voltage regulator.
• Zero-sequence impedance measurement capability.
• Inductance measurement support.
• 7.0-inch touch LCD with on-screen guidance and Chinese menu option for simplified operation.
• Result printing and storage functions; compact and lightweight for field use.

Technical specifications

• Model: UHV-370
• Voltage measurement range: 5~400 V
• Current measurement range: 0.1~20 A
• Measurement accuracy: 0.2 d
• Operating power: AC 220 V ±10%
• Power frequency: 50 Hz
• Operating temperature: -10 ℃ to 50 ℃
• Ambient humidity: ≤85% RH
• Net weight: 6 kg
• Display: 7.0-inch touch LCD with on-screen guidance
• Built-in high-precision clock for time-stamped measurements
• Functions: three-phase automatic testing (primary connection), single/three-phase testing, automatic impedance error calculation, zero-sequence impedance and inductance measurement, automatic current adjustment, printing and storage
• Application: fast on-site detection of transformer winding deformation and short-circuit impedance measurement

Application significance

• This instrument is a precision detection device suitable for low-voltage load impedance testing in factory inspection, major maintenance, preventive testing, and handover testing of power transformers (single-phase or three-phase). Low voltage short-circuit impedance test, as a core detection method, can directly identify whether the winding of a transformer in operation has deformed after being subjected to short-circuit current impact or mechanical impact during transportation and installation. It plays a crucial role in determining whether the transformer can be safely put into operation and is also one of the key criteria for determining whether it needs to be disassembled for inspection. Its application value is particularly prominent.

Precautions

• 1. Please read the instruction manual carefully before using the instrument.
• 2. During the testing process, the instrument should be reliably grounded to ensure good contact, and the test pliers should not be moved.
• 3. Pay attention to low-voltage short-circuit current, the current carrying capacity of the short-circuit wire should be sufficient, and the contact should be good.
• 4. If any abnormalities occur during the instrument testing process, please shut down and restart.
• 5. When applying pressure during the experiment, pay attention not to exceed the rated voltage and current of the instrument to avoid damaging it. When measuring samples that exceed the voltage and current range of the instrument, PT and CT measurements can be used.
• 6. When measuring impedance voltage, it should be measured at the rated tap position.