








Product Introduction
The LDJB-703 Three-Phase Relay Protection Tester features standard four-phase voltage and three-phase current outputs, allowing for testing both traditional relays and protective devices as well as modern microcomputer protections. It is particularly convenient for testing transformer differential protection and backup power supply units.
The LDJB-703 Three-Phase Relay Protection Tester complies with the national standard GB/T 7261-2016 "Basic Test Methods for Relay Protection and Safety Automatic Equipment" and meets the standard of GB/T 7261-2016 "Technical Conditions for Relay Protection Microcomputer Test Devices" (DL/T 624-2010).
The LDJB-703 Three-phase Relay Protection Tester features a classic Windows XP operating interface, offering a user-friendly and easy-to-operate interface; a high-performance embedded industrial control computer, and a 10.4-inch true-color LED display with a resolution of 800×600, providing rich and intuitive information, including the current working status of the equipment and various helpful messages.
Product Alias: Microcomputer Relay Protection Tester, Microcomputer Relay Protection Device, Relay Protection Tester, Three-Phase Relay Protection Tester, Relay Protection Device, Three-Phase Relay Protection Device, Three-Phase Relay Protection Verifier, Relay Protection Verifier, Three-Phase Relay Protection Verifier, Relay Device, Relay Protection Equipment Tester
Product Features
The device comes with built-in Windows XP system recovery features to prevent system crashes due to improper shutdowns or accidental operations.
The device is equipped with ultra-thin multifunctional quick-release keys and an optical mouse, allowing for various operations to be completed through the keyboard or mouse, just like operating a standard PC.
The main control board utilizes a DSP+FPGA architecture, featuring a 16-bit DAC output. It can generate a high-density sine wave with 2000 points per cycle for the fundamental frequency, significantly enhancing waveform quality and increasing the accuracy of the tester.
The amplifier uses a high-fidelity linear power amplifier, ensuring both precision with low current and stability with high current.
◆ Communicates directly with PC via USB interface, no additional cables needed for convenience.
◆ Compatible with laptop connection (optional). The laptop runs the same software as the industrial computer, eliminating the need to relearn operation methods.
◆ Equipped with GPS synchronization testing function. The device can be integrated with an optional GPS synchronization card and connected to a PC via an RS232 port, enabling synchronization and exchange tests between two testers at different locations.
◆ Equipped with an independent dedicated DC auxiliary voltage source output, with output voltages of 110V (1A) and 220V (0.6A). Designed to supply DC working power for relays or protective devices.
The software self-calibration feature eliminates the need to open the case and adjust potentiometers for precision calibration, significantly enhancing the stability of accuracy.



























