It is capable of testing various types of relays—including current, voltage, inverse-time, directional power, impedance, differential, under-frequency, synchronization, frequency, DC, auxiliary, and time relays—as well as microprocessor-based protection systems. Furthermore, it can simulate a wide range of complex transient, permanent, and evolving faults to facilitate comprehensive system-wide testing.

It is capable of executing various large-scale and complex verification tasks with a high degree of automation.

The Relay Protection Tester features 8 contact inputs and 4 pairs of dry contact outputs.

The standalone unit is operated via a large-screen LCD interface, utilizing a convenient and flexible rotary mouse for control.

The HCJB-702 Three-Phase Relay Protection Tester utilizes a high-speed, high-performance digital control processor as its central control unit. Its software employs double-precision algorithms to generate highly accurate, arbitrary waveforms for each phase. Thanks to its integrated structural design—where all components are tightly coupled and data transmission paths are minimized—the device features a remarkably compact form factor. This design effectively overcomes the limitations inherent in laptop-controlled testing systems, specifically addressing the issue of insufficient waveform data points often caused by long data communication lines and narrow bandwidths.

The HCJB-702 employs high-speed, high-resolution Digital-to-Analog (D/A) converters, thereby guaranteeing exceptional accuracy and linearity for both current and voltage outputs across their entire respective ranges. Benefiting from high D/A resolution and high-density waveform synthesis, the device exhibits minimal waveform distortion and low harmonic content. This places minimal demands on low-pass filters, resulting in excellent transient response, phase-frequency characteristics, and amplitude-frequency characteristics. Consequently, it facilitates precise phase shifting and harmonic superposition with ease, maintaining high accuracy even at elevated frequencies.

Rather than relying on current or voltage booster transformers, the HCJB-702 utilizes a direct output architecture for each current and voltage phase. This enables the current and voltage sources to directly generate waveforms ranging from pure DC to complex signals containing various frequency components—such as square waves, composite waveforms formed by superimposed harmonics, and fault transient waveforms. This capability allows the device to accurately and effectively simulate the specific current and voltage characteristics associated with a wide variety of short-circuit faults.

The HCJB-702's digital input circuitry is designed to be compatible with both dry contacts (potential-free contacts) and live contacts with voltage levels ranging from 0 to 250V. When operating in the live-contact mode, a voltage range of 0–6V is interpreted as a "closed" state, while 11–250V is interpreted as an "open" state. These digital inputs allow for the convenient and precise measurement of the operating times of individual switch contacts across all phases, as well as the timing differences between them.

The HCJB-702 features a high-resolution 320×240 dot-matrix LCD screen with a blue backlight for its display interface. The entire testing process—from configuration to execution—as well as the final test results are clearly displayed on this screen. The device features a fully localized Chinese-language user interface that is both clear and aesthetically pleasing. Operational control is managed via a rotary encoder (acting as a "rotary mouse") and two pushbuttons; all data entry and test parameters are configured directly on the screen using this rotary control mechanism. The interface is intuitive and user-friendly, making it exceptionally easy to master. The HCJB-702 Three-Phase Relay Protection Tester features an adjustable DC power supply output mounted on the chassis baseplate. This output offers two selectable voltage settings—110V and 220V—and serves as an auxiliary power source for field testing. The maximum output current of this power supply reaches 1.5A. Additionally, the baseplate houses a cooling fan, a power inlet, a grounding terminal, and three fuses. Of these three fuses, one is dedicated to the auxiliary DC power supply (2A/250V), while the remaining two are designated for the voltage circuits (2A/250V).

Product Aliases: Microcomputer-based Relay Protection Tester, Microcomputer-based Relay Protection Instrument, Relay Protection Tester, Three-Phase Relay Protection Tester, Relay Protection Test Set, Three-Phase Relay Protection Test Set, Three-Phase Relay Protection Verifier, Relay Protection Verifier, Three-Phase Relay Protection Verifier, Relay Protection Instrument, Relay Protection Device Tester.