Description
I. Basic Information
Full Model: 850-E-P5-NN-G5-H-N-N-A-N-N-M-S-S-F-B-SE-N-N-B-4-043X
Brand: GE Multilin
Product Type: Integrated Feeder Protection, Measurement & Control Relay
Application Scope: Industrial and utility overhead/cable feeders, dual-circuit feeders, plant power branch circuits. It provides full protection, remote measurement and control, power quality monitoring, fault recording and data communication for medium and low-voltage power systems, widely used in thermal power, chemical, metallurgy, rail transit and urban distribution networks.
Product Positioning: GE Multilin 850 is the core feeder protection device of the 8-series platform. It integrates protection, measurement, metering, recording, communication and logic control, replacing traditional discrete relays. With FlexLogic programmable logic, high-precision power quality analysis and multi-protocol networking capability, it serves as the core intelligent integrated control unit for medium and low-voltage distribution systems.
Model Code Decoding
850: Standard feeder protection base model
E: Enhanced hardware version with improved sampling accuracy and stability
P5: Wide-range AC/DC universal power supply specification
NN: No additional analog expansion modules, no special customized hardware
G5: Standard communication hardware configuration for mainstream power protocols
H: Standard HMI panel with LCD, keys and status LEDs
NN: No redundant power supply, no special insulation customization
A: Standard basic I/O configuration for conventional feeder measurement and control
NN: No extra digital expansion or temperature acquisition modules
M: Standard fault recording and event record function
S-S: Standard sampling accuracy and system security level
F: Full basic feeder protection functions
B: Standard rear terminal configuration
SE: Advanced power quality monitoring and harmonic analysis function
NN: No customized software or industry-specific programs
B: Standard universal firmware version
4: 4th generation hardware with optimized anti-interference performance
043X: Factory solidified standard setting logic for medium-voltage feeders
Hardware Architecture
1. High-precision Sampling Unit: Integrated isolated multi-channel voltage and current sampling circuits, supporting synchronous acquisition of three-phase voltage, three-phase current and zero-sequence signals, with high precision for power metering and protection judgment.
2. Feeder Protection Logic Operation Unit: Industrial high-speed processor built-in full set of feeder protection algorithms, supporting FlexLogic custom programmable logic, realizing millisecond-level fault judgment and trip output.
3. HMI & Status Indication Unit: Equipped with LCD display, operation keys and tri-color LED indicators for local parameter viewing, fault query, setting modification and manual switching operation.
4. Multi-protocol Communication Unit: Supports Modbus, DNP3, IEC104, SNTP and other mainstream protocols, seamlessly connecting to SCADA/DCS systems to realize remote four-remote functions.
5. Fault Storage & Recording Unit: Large-capacity on-board storage for long-term preservation of event records, fault waveforms and alarm data, supporting up to 25th harmonic analysis.
6. Industrial Power & Anti-interference Unit: Wide-range universal power supply with surge, overvoltage, undervoltage and reverse connection protection, complying with industrial EMC standards to resist complex on-site electromagnetic interference.
Mounting Specifications
Power Supply: Universal AC/DC 88~300VDC / 85~264VAC
Sampling Accuracy: ±0.2%FS (power frequency parameters)
Response Speed: Fault action response ≤10ms
Communication Protocols: Modbus RTU/TCP, DNP3, IEC60870-5-104, SNTP
Mounting Type: Standard embedded panel mounting
Protection Class: IP40 (front panel), IP20 (body)
Power Consumption: Static ≤15W, transient ≤25W
II. Technical Specifications
2.1 Electrical Parameters
Model: 850-E-P5-NN-G5-H-N-N-A-N-N-M-S-S-F-B-SE-N-N-B-4-043X
Power Range: DC 88~300V / AC 85~264V wide-range universal power
Sampling Channels: 3-phase voltage, 3-phase current, zero-sequence voltage and current synchronous sampling
Sampling Accuracy: ±0.2%FS (power frequency), compliant with IEC harmonic standards
Protection Action Time: Main protection ≤10ms, backup protection delay customizable
Time Synchronization: SNTP network timing, time accuracy ≤1ms
Withstand Voltage: 2kVAC/1min isolation for signal and communication circuits
Protection Functions: Overcurrent, instantaneous overcurrent, zero-sequence, over/undervoltage, loss of voltage, auto-reclosing, three-phase unbalance, harmonic over-limit protection
2.2 Mechanical & Environmental Parameters
Mounting: Standard embedded panel installation
Housing: Flame-retardant industrial plastic, dust-proof and vibration-resistant
Operating Temperature: -20℃ ~ +60℃
Storage Temperature: -40℃ ~ +85℃
Humidity: 5%~95%RH, non-condensing, no corrosive gas
III. Key Features
1. Integrated Full-featured Protection：Integrates complete feeder protection functions with main and backup hierarchical protection, matching auto-reclosing logic to maximize power supply reliability.
2. High-precision Power Measurement & Metering：Real-time monitoring of voltage, current, power, power factor, frequency and electric energy, replacing traditional measuring instruments for full-condition data visualization.
3. Advanced Power Quality Analysis：Supports 25th-order harmonic analysis, voltage sag/swell, flicker and unbalance detection to locate power quality defects accurately.
4. Flexible Programmable Logic Control：Built-in FlexLogic custom programming function to adapt to complex interlock, delay and linkage control requirements without external PLC or relays.
5. Complete Fault Recording & Traceability：Automatic waveform recording during faults, complete action sequence and time stamp records for accurate fault analysis and maintenance guidance.
6. Remote SCADA Monitoring：Realizes remote telemetry, telesignal, remote control and remote adjustment via standard protocols, supporting unattended centralized monitoring.
7. Self-diagnosis & Graded Alarm：Self-monitoring of device hardware and software status, graded alarm prompts to pre-judge hidden equipment faults.
IV. Working Principle
After power-on, the device completes full self-inspection of power, sampling, communication and program modules, then synchronizes network time and connects to the monitoring system. It collects real-time analog signals from voltage and current transformers, converts and calculates electrical parameters, and compares with preset protection settings.
Under normal operating conditions, the device uploads operating data and executes local/remote control commands. When feeder faults such as short circuit, overload, overvoltage or undervoltage occur, the processor quickly identifies the fault type, outputs trip commands, latches fault information and uploads alarms. Transient faults are recovered by auto-reclosing, while permanent faults are locked to prevent accident expansion. The device runs real-time self-diagnosis to avoid protection mis-operation or refusal.
V. Application Scenarios
1. Industrial factory medium-voltage feeder and plant power branch protection and measurement control.
2. Urban substation, switching station and distribution network feeder protection and auto-reclosing control.
3. High-reliability power supply loop monitoring for rail transit, data centers and public infrastructure.
4. New energy grid-connected feeder and energy storage access loop protection and power quality monitoring.
5. Intelligent renovation of old distribution rooms to replace discrete protection and measurement equipment.
