Portable 20A Digital DC Resistance Tester for Transformer Winding XHZ1020 7-Inch Touch Screen Bluetooth Data Storage

Transformer DC resistance testing is a mandatory preventive test item specified by power sector regulations. It verifies the welding quality of winding joints, detects inter-turn short circuits, confirms tap changer contact condition and position accuracy, identifies broken lead wires, and finds strand breakage in parallel-wound conductors. Any of these defects can lead to localized overheating, accelerated insulation aging, and eventual transformer failure if undetected. Regular DC resistance testing provides early warning of developing problems before they escalate into costly outages.

The XHZ1020 offers six selectable current ranges from <20mA to 20A. The appropriate current depends on the winding resistance value and transformer size. Higher current settings provide faster core magnetization and quicker measurement for low-resistance, high-power windings. The <20mA range is suitable for high-resistance windings or small instrument transformers. If the selected current exceeds the range capability, the instrument remains in "charging" status without completing the measurement — simply press reset and select a lower current range.

Transformers are highly inductive devices. During DC resistance measurement, the winding stores significant magnetic energy. If test leads are disconnected before the stored energy is safely dissipated, the collapsing magnetic field generates a high-voltage inductive kickback that can cause severe Electrocution to personnel and damage the instrument. The XHZ1020 features a built-in automatic discharge circuit that safely dissipates stored energy after measurement or reset. The audible discharge alarm and visual indicator confirm when discharge is complete. Always wait for the indication to stop before removing connections.

Yes. The XHZ1020 supports remote control via Android smartphones and tablets. Download the dedicated app through the WeChat public account. After searching for the instrument, download and install the app. The app connects to the instrument via Bluetooth, enabling full remote control of all measurement functions, real-time data display, test data storage and upload, and convenient historical data review — ideal for field testing where direct instrument access may be limited.

Key safety requirements: verify the transformer is de-energized before connection; ensure instrument case is grounded; do not switch tap changers during measurement; if power is lost during testing, wait 30 seconds before disconnecting; do not short other windings; check supply voltage (AC 220V ±10% 50Hz). Each XHZ1020 ships as a complete kit with test leads, power cable, grounding cable, printer paper, and user manual. Standard delivery is 5–8 working days with 1-year warranty and lifetime technical support. Minimum order is 1 unit with T/T payment terms.