This model incorporates a dedicated protection module for synchronous motors, featuring high-speed protection, flexible programmable logic, advanced motor monitoring and diagnostics, as well as highly compatible communication capabilities. It enables seamless integration into industrial process and electrical control systems, while also supporting rapid upgrade and retrofit from the SR 469 relay. It is suitable for harsh industrial applications including oil and gas, mining and metallurgy, cement production, and wastewater treatment.

Technical Specifications

1. Electrical Parameters

• Power Supply: 110–230 VAC / 110–250 VDC
• Current Inputs: Standard 1A/5A CT inputs
• Voltage Inputs: 10–260 V, frequency range 20–65 Hz
• Frequency Tracking: 3–72 Hz (for VFD-driven motors)
• Operating Temperature: -40℃ ～ +60℃
• RTD Temperature Range: -40℃ ～ +250℃
• Ingress Protection: Front panel IP54
• Manufacturing Standards: IPC A-610-E Class 3, electrolytic capacitor-free design

2. Model Code Interpretation (869EP5NN0BHRRANNMMPFESENNBN)

• 869: Product series (dedicated motor protection)
• EP5: Advanced protection and control package
• NN0: Standard I/O and communication base configuration
• B: Front panel type (color graphical HMI)
• HRR: Hardware interface and extension module configuration
• ANN: Synchronous motor protection functions enabled
• MMP: Advanced motor monitoring and diagnostics
• FES: Arc flash protection and fault recording
• ENN: Network communication and security configuration

• BN: Customized hardware and software version

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3. Core Protection Functions

3.1 Comprehensive Motor Electrical Protection

• Overcurrent / Earth Fault: 50/51 (instantaneous / time-overcurrent), 50G/51G (earth fault), 50SG (sensitive earth fault), 50N/51N (neutral overcurrent)
• Voltage / Frequency Protection: 27P/59P (undervoltage / overvoltage), 81O/81U (overfrequency / underfrequency), 81R (rate of change of frequency), 24 (volts per hertz)
• Unbalance / Negative Sequence: 46 (current unbalance), 50_2/59_2 (negative-sequence overcurrent / overvoltage)
• Starting / Locked Rotor: 48 (start time supervision), 50LR (locked rotor / mechanical jam), 66 (maximum start limit)
• Synchronous Motor Dedicated: 40/41 (loss of field), 78 (out-of-step), 26F/27F/37F/59F (excitation temperature / voltage / current protection), 95 (synchronization / resynchronization)

3.2 Advanced Thermal Protection Models

• Speed-Biased Thermal Model: Based on time-speed curves, suitable for high-inertia loads and reduced-voltage starting
• Independent Stator / Rotor Thermal Protection: Separates thermal accumulation in squirrel-cage rotors and stator windings for accurate overheating warning
• TCU (Thermal Capacity Utilization): Real-time monitoring and early warning of motor thermal stress to prevent insulation aging and burnout
• VFD Harmonic Thermal Compensation: Automatically calculates extra heat generated by VFD harmonics for improved thermal protection accuracy

3.3 Arc Flash Protection (AFP)

• Integrated optical sensor + overcurrent dual criteria, detects arc flash faults in switchgear / MCC within 2 ms
• Fast tripping reduces incident energy, minimizing equipment damage and personnel risk
• Supports 4 arc flash sensors with self-diagnostics and status indication

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4. Monitoring & Diagnostics

4.1 Motor Health Diagnostics (MCSA/ESA)

• Patented Motor Current Signature Analysis (MCSA) detects the following without additional sensors:
• Stator inter-turn short circuits, broken rotor bars
• Bearing faults, foundation looseness, air-gap eccentricity, shaft misalignment
• Abnormal mechanical loads and early fault warnings
• Generates motor health reports with trend analysis for predictive maintenance

4.2 Environmental & Status Monitoring

• Patented environmental monitoring system for real-time tracking of relay operating conditions (temperature, humidity, etc.)
• RTD Temperature Monitoring: Multi-point temperature acquisition for stator, bearings, field windings (38/49S/26F)
• Fault Recording & Event Logging: High-speed fault waveform capture, supports SOE (Sequence of Events) and fault playback

5. Communication & Network Integration

5.1 Communication Protocols

• Ethernet: Dual independent Ethernet ports, supporting IEC 61850 Ed2, IEC 62439/PRP, Modbus TCP, DNP3.0, IEC 60870-5-104
• Serial: Modbus RTU, IEC 60870-5-103
• Local Interface: Front USB, optional Wi-Fi (WPA-2 security), supports remote configuration and diagnostics

5.2 Cybersecurity

• Supports AAA (RADIUS/LDAP), RBAC (role-based access control, up to 5 roles & 8 users), Syslog event auditing
• Complies with industrial cybersecurity standards including NERC CIP

6. Typical Applications

• Medium & large induction / synchronous motors: Main and auxiliary motor protection in oil & gas, mining, cement, wastewater treatment, and power generation
• Special-load motors: High-inertia loads, two-speed motors, VFD-driven motors, cyclic-load motors
• Synchronous motor applications: Excitation system control, loss-of-field / out-of-step protection, full-dimensional stator & rotor protection
• System upgrade & retrofit: Rapid replacement of SR 469 relays without rewiring or drawing modifications, upgrade completed in as fast as 21 minutes