Transformer Turns Ratio and DC Resistance Tester

I. Product Overview
The HZ2162 Transformer Comprehensive Tester is a high-performance device that integrates DC resistance testing and transformer turns ratio testing into one unit, specifically designed for the complete testing of high-capacity power transformers.

II. Product Features

1. Overall Design

One-time wiring completes all test items, significantly reducing the workload for on-site testers.

Features a 7-inch color touch LCD screen with an intuitive and user-friendly interface.

Built-in micro printer for on-site printing of test results.

USB storage function for easy external saving of test data.

One isolated RS232 communication interface supporting standard protocol communication.

Integrated Bluetooth communication module for standard protocol wireless data transmission.

Utilizes a highly reliable RS485 bus for internal communication.

Isolated circuit design effectively eliminates interference between test functions. Combines hardware and software filtering to enhance anti-interference capability. Excellent grounding and shielding measures further improve the overall noise immunity.

2. DC Resistance Test

Supports simultaneous three-phase testing and automatic demagnetization.

High and low-voltage side current and potential test leads can be connected once, eliminating the need for lead changes during testing.

For star-connected windings with a neutral point, allows simultaneous testing of A0, B0, and C0 phase resistances, greatly saving test time.

For internally delta-connected three-phase five-limb transformers, the automatic excitation method can be used during low-voltage side testing, offering fast testing speed.

Displays and prints all test data for high, medium, and low-voltage windings. Automatically calculates the three-phase unbalance rate and prints resistance values converted to the rated temperature.

Comprehensive back EMF protection.

3. Transformer Turns Ratio Test

Chinese/English menu prompts for simple and convenient operation.

For three-phase testing, simply input the high-voltage side connection method to automatically identify the group.

Supports single-phase measurement and automatic testing of three-phase windings. The connection group can be arbitrarily selected, completing the measurement of ratio, error, and group for AB, BC, and CA phases in one step.

Includes high and low-voltage reverse connection protection.

Fast testing speed, completing a single-phase test in just 15 seconds.

Features protection against transformer short-circuit and inter-turn short-circuit.

III. Measurement Parameters Description

DC Resistance
DC resistance refers to the inherent static resistance presented when a DC voltage is applied across a component. When AC is applied to a coil, impedance is present in addition to the DC resistance, leading to different resistance readings under AC and DC. The DC resistance of equipment like transformers, mutual inductors, generators, and motors is typically very low, requiring appropriate methods (such as the Kelvin four-wire measurement technique) for accurate measurement to reduce errors. The four-wire method uses separate current and voltage electrodes, effectively eliminating the influence of lead and contact resistance, significantly improving measurement accuracy.

Transformer Turns Ratio
The transformer turns ratio refers to the voltage ratio between its primary and secondary windings. According to relevant national standards, the turns ratio test is a mandatory item during the production, handover, and maintenance testing of power transformers. This test effectively monitors product quality during manufacturing and use, helping to timely identify issues such as inter-turn short circuits, open circuits, incorrect connections, and internal contact faults in the tap changer.