1. Basic Information

2. Technical Specifications

2.1 Basic Parameters

• Model: REF620E_F NBFNAAAANDA1BNN1XF
• Device Type: Medium Voltage Feeder Protection & Control IED
• Structure: 4U Rack Mount, Plug-in Modular Design
• Weight: 8.0kg
• Protection Class: Front IP54, Rear IP20

2.2 Sampling & Accuracy

• Sampling Rate: 2000 samples/s
• Measurement Class: 0.2S High Precision
• Protection Response: ＜1ms Ultra-fast action
• Setting Groups: 6 independent switchable parameter groups

2.3 I/O Configuration

• Digital Input: 16-channel DI
• Relay Output: 8-channel DO
• Analog Acquisition: 3-phase current & voltage synchronous sampling
• Terminal Type: Ring ear stable wiring terminals

2.4 Communication Parameters

• Ethernet Port: Dual redundant industrial Ethernet ports
• Serial Port: 1×RS485
• Protocol Support: IEC61850, Modbus TCP, Modbus RTU
• Function: Remote control, parameter setting, data upload, wave recording retrieval

2.5 Electrical & Environmental Parameters

• Power Supply: 80～250V AC/DC Wide-range universal power
• Operating Temperature: -25℃～+70℃
• Storage Temperature: -40℃～+85℃
• Humidity: 5%～95%RH (Non-condensing)
• Feature: High EMC anti-interference, vibration resistance, anti-aging

3. Main Features

• Full-range Feeder Protection: Integrates overcurrent, earth fault, over/under voltage, overload, frequency protection, as well as advanced HIZ, CFD and AFD arc fault detection functions to cover all common feeder faults.
• Ultra-fast Millisecond-level Protection: ＜1ms rapid tripping response effectively isolates short circuit, grounding and arc faults to minimize grid impact and equipment damage.
• High-precision Power Measurement: 0.2S-level accuracy realizes full electrical parameter measurement, power statistics and power quality analysis for medium-voltage feeders.
• Multi-working-condition Adaptive Switching: 6 independent setting groups support flexible parameter switching to adapt to grid load changes and diversified operation modes.
• Complete Fault Recording & Event Logging: High-frequency transient wave recording and full-time event recording support accurate fault tracing and system operation analysis.
• Dual Redundant Stable Communication: Dual Ethernet redundant architecture ensures uninterrupted data transmission and stable remote monitoring of digital substations.
• Plug-and-maintain Modular Design: Removable modular structure enables fast replacement and convenient maintenance, adapting to unattended substation operation scenarios.
• Harsh Environment Adaptability: High-standard EMC design ensures stable long-term operation under strong electromagnetic interference and wide temperature fluctuation conditions.

4. Working Principle

1. Power-on Self-check Initialization: Complete hardware self-inspection, program loading and communication initialization after power-on, and enter normal monitoring state.
2. High-speed Signal Sampling: Synchronously collect three-phase voltage, current and switch state signals at 2000Hz, with filtering and anti-interference processing.
3. Real-time Logic Judgment: Compare real-time sampling data with preset protection values to monitor various fault characteristics and operating conditions.
4. Fast Protection Action Output: Trigger tripping and alarm instructions within milliseconds when faults occur to isolate faulty circuits and prevent fault expansion.
5. Fault Data Recording: Automatically record transient waveforms, event sequences and action logs to retain complete fault analysis data.
6. Remote Data Interaction: Upload operating data and receive remote control commands through redundant communication ports to realize intelligent remote operation and maintenance.

5. Applications

5.1 Industrial Medium-voltage Distribution Room

5.2 Municipal Substation Distribution System

5.3 New Energy Grid-connected System

5.4 Digital Substation Renovation

5.5 Old Equipment Maintenance & Replacement