SEL-849

Motor Management Relay

The SEL-849 is a compact motor management relay optimized for installation in motor control centers (MCCs). It integrates protection, metering, monitoring, control, and communications into a single package to ensure the safety and process continuity of low- and medium-voltage motors. A standout feature is its built-in Rogowski coil-based current transformers, which simplify installation. It is a flexible solution that can be configured for standard motors, variable-frequency drive (VFD) motors, or feeder protection.

Key Features

Enhanced Thermal Model Protection

Provides precise thermal protection with features like locked-rotor start, starts-per-hour limits, and an anti-backspin timer to maximize motor availability.
Ultra-Fast Arc-Flash Protection

Quickly detects and clears arc-flash events within the MCC to prevent personnel injury and minimize equipment damage.
Built-in Rogowski Coil CTs

Measures phase currents up to 256 A FLA without the need for external CTs, simplifying wiring and saving cabinet space. (External CTs can be used for applications exceeding 256 A).
Sensitive Ground-Fault Detection

Supports an external core-balance CT (CBCT) to accurately detect minute ground faults, even in high-impedance grounded systems.
VFD Motor Support

Equipped with dedicated protection algorithms specifically designed for the characteristics of motors driven by variable-frequency drives.
Power Quality Monitoring

Analyzes motor performance and system quality in real-time by metering harmonics (up to the 15th) and Total Harmonic Distortion (THD).
Comprehensive ANSI Protection

Includes a full suite of protection elements, such as under/overvoltage (27/59), overcurrent (50/51), current unbalance (46), and load loss (37).

MCC-Specialized Design

Features a compact form factor designed for easy mounting in the restricted spaces typical of motor control centers.
Ethernet-Based Integration

Supports major industrial protocols, including EtherNet/IP, Modbus TCP, DNP3, IEC 61850 Edition 1, and PRP, ensuring easy integration into modern control networks.
Remote Control and Monitoring

Enables secure remote control signals and data collection via Ethernet or serial communications, reducing the need for manual on-site operations.
Dedicated HMI Interfaces

Compatible with front-mounted HMI devices (such as the SEL-3421 or SEL-3422) for intuitive local monitoring and motor operations like start/stop and local/remote switching.
Universal Power Supply

Available in high-voltage (110–240 Vac, 125–250 Vdc) or low-voltage (24–48 Vdc) models to accommodate various site power requirements.
Rugged Environmental Adaptability

Basic models operate reliably in extreme temperatures ranging from –40° to +85°C, maintaining high performance in harsh industrial conditions.
Efficient Configuration Software

Allows users to quickly and easily configure settings using intuitive software tools, consistent with other modern SEL relays.

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