The KDJB-S30 is a compact, microcontroller-based, handheld relay protection tester designed for field use. Its portability and straightforward operation make it ideal for technicians and engineers performing on-site testing and commissioning of protective relays and automatic safety devices in power systems.

Key Testing Capabilities: The KDJB-S30 offers a comprehensive suite of testing functions to verify the performance of various protective elements:

• Manual Testing: Independently controls the amplitude, phase angle, and frequency of 4-phase AC voltage (0-130V) and 3-phase AC current (0-10A) outputs for precise, step-by-step testing of relay pickup/dropout values.
• State Sequence Testing: Simulates complex multi-state fault scenarios (up to 5 states) for testing high-voltage line protection (distance, zero-sequence, differential), auto-reclosing, breaker failure, and whole-system relay group transmission. Supports manual, time-based, or contact-triggered state transitions.
• Underfrequency Load Shedding (UFLS) Testing: Accurately tests UFLS relay settings, including frequency pickup value, operating time, rate-of-change-of-frequency (ROCOF/dF/dt) blocking, voltage blocking, and current blocking thresholds.
• Synchronism Testing: Tests automatic synchronizing relays by allowing controlled adjustment of the phase angle of a "generator-side" voltage relative to a "system-side" voltage to verify closing angle limits.
• Harmonic Testing: Specifically designed for testing transformer differential protection harmonic restraint functions (2nd, 3rd, 5th harmonics), crucial for verifying inrush current blocking.
• AC Sampling Testing: Evaluates the accuracy of AC sampling devices (e.g., in RTUs or meters) by outputting precisely controlled voltage and current with defined power factors and displaying calculated active/reactive power values.
• Remote Signal Testing / SOE Simulation: Generates precisely timed sequences of contact closures (resolution: 1ms) on its two output relays, ideal for testing Sequence of Events (SOE) recorders.
• Millisecond Timer : Measures time intervals between external contact closures received on its two input channels with high resolution (0.1ms).

Technical Specifications:

• AC Voltage Output: 4 channels, 0-130V (default 66V), Accuracy: ≤±0.1% ±2mV (5-120V), Load: ≥30VA/phase.
• AC Current Output: 3 channels, 0-10A, Accuracy: ≤0.1% ±2mA (0.5-10A), Load: ≥20VA/phase. (Note: 10A output limited to 8 seconds).
• Phase Angle: 0-360°, Accuracy: 0.2°, Resolution: 0.1°.
• Frequency: 10-500Hz, Accuracy: <1mHz (10-65Hz).
• Harmonics: Capable of simulating up to the 10th harmonic.
• Digital I/O:
  • Inputs: 2 isolated channels (compatible with dry contacts or 32-250V potential, auto-polarity detection).
  • Outputs: 2 optically isolated relay contacts (time resolution: 0.1ms).
• Power: Internal rechargeable lithium battery (8 hours typical use), DC 16.8V/5A adapter.
• Physical: Compact handheld design, 255 x 210 x 78 mm, Weight: 2.6 kg.

User Interface: Controlled via an intuitive keypad featuring dedicated function keys (Fn) for quick access to variables, settings,开出量 control, and special functions like short-circuit calculation. Navigation is simple using arrow keys and numeric entry.

Applications: This versatile tester is suitable for:

• Testing electromechanical and static AC relays (pickup, dropout, timing).
• Commissioning and maintenance of microprocessor-based protection relays for lines (overcurrent, distance, zero-sequence, reclosing) and transformers (differential with harmonic restraint).
• Verifying UFLS schemes and synchronizing check relays.
• Calibrating AC sampling equipment.
• Validating SOE systems and measuring contact operation times.

1. Compact & Portable Design: Handheld form factor (2.6kg, 255x210x78mm) with a built-in lithium battery for up to 8 hours of field operation, ideal for on-site testing.
2. Multi-Function Testing Suite: Integrates 8 distinct testing modules into one device: Manual Test, State Sequence, Underfrequency Load Shedding (UFLS), Synchronism Check, Harmonic Test, AC Sampling Test, Remote Signal (SOE) Test, and Millisecond Timer.
3. Flexible AC Output:
   • 4-Channel Voltage: 0-130V (user-selectable max, default 66V), high accuracy (≤±0.1% ±2mV), ≥30VA/phase.
   • 3-Channel Current: 0-10A, high accuracy (≤0.1% ±2mA for 0.5-10A), ≥20VA/phase. (Note: 10A limited to 8s).
   • Precise Control: Independent control of amplitude, phase angle (0-360°, 0.2° accuracy), and frequency (10-500Hz, <1mHz accuracy for 10-65Hz) for all outputs.
4. Advanced State Sequence Simulation: Capable of simulating complex, multi-state (up to 5 states) fault scenarios for comprehensive testing of distance protection, zero-sequence protection, auto-reclosing (including post-acceleration), and breaker logic. Supports multiple trigger conditions (Manual, Time, Contact Input 1, Contact Input 2).
5. Specialized Protection Testing:
   • UFLS Testing: Dedicated module for testing frequency pickup, operating time, ROCOF (dF/dt) blocking, voltage blocking, and current blocking values.
   • Harmonic Testing: Specifically designed for verifying transformer differential protection harmonic restraint (2nd, 3rd, 5th harmonics).
   • Synchronism Testing: Tests automatic synchronizing relays by allowing controlled phase angle adjustment of the "generator" voltage.
6. High-Resolution Digital I/O:
   • 2 Isolated Inputs: Compatible with dry contacts or 32-250V potential, auto-polarity detection.
   • 2 Opto-Isolated Outputs: For triggering or simulating relay contacts, with 0.1ms time resolution.
7. SOE & Timing Functions:
   • Remote Signal (SOE) Test: Generates precisely timed sequences of contact closures (minimum 1ms interval) for SOE system validation.
   • Millisecond Timer: Measures time intervals between external contact closures with 0.1ms resolution.
8. AC Sampling Calibration: Dedicated mode for testing the accuracy of AC sampling devices, displaying calculated active and reactive power values for various power factors.
9. User-Friendly Interface: Simple keypad operation with dedicated function keys (Fn) for quick variable selection control, and access to utilities like short-circuit calculation and quick angle presets (e.g., positive/negative sequence).
10. Robust Construction & Safety: Features overload protection, distortion detection, and is designed for continuous output under rated conditions (with current limits as specified).
11. Convenient Power Options: Operates on internal rechargeable battery or via included 16.8V/5A DC adapter.

Technical Specifications
AC voltage output: 4 channels: 0-130V continuously adjustable, default 66V
Output accuracy: Accuracy: 0~5V Accuracy error ≤ ± 2mV, 5V~120V; Accuracy error ≤± 0.1% ± 2mV; Resolution: 1mV
Load capacity: ≥ 30VA/phase
Response time: Voltage 5V~130: THD% ≤ 0.5%, voltage rise and fall time less than 100 µ s
Security protection and output time: overload protection and automatic distortion detection. Under rated conditions, continuous output.
Phase: 0-360 ° continuously adjustable; Accuracy 0.2 °; Resolution 0.1 °
AC current output: 3 channels: 0-10A continuously adjustable
Output accuracy: Accuracy: 0.2~0.5A, error ≤ 2mA, accuracy of 0.5~10A; Error ≤ 0.1% ± 2mA; Resolution: 1mA
Load capacity: ≥ 20VA/phase
Response time: Current 0.5A~Imax: THD% ≤ 0.5%; Current rise and fall time is less than 100 µ s
Output time: Continuous output<1A, 5A output 90S, 10A output 8S.
Phase: 0-360 ° continuously adjustable; Accuracy 0.2 °; Resolution 0.1 °
Output frequency: 10-500Hz, can simulate 10th harmonic
Accuracy: Frequency range: 10-65Hz Accuracy<1mHz; 65 Hz~500Hz accuracy ＜ 10mHz
Input capacity: 2-channel isolation voltage of 500V, with open contacts and 32V~250V; Potential compatibility, automatic polarity recognition;
Output quantity: 2-channel output quantity type: optocoupler output, time resolution of 0.1ms.
Adapter: DC 16.8V 5A
Built in battery&endurance: Built in lithium battery; Normal use for 8 hours
Weight: 2.6kg (handheld type)
Size: 255x210x78 (mm)