GE Multilin 469 Motor Protection System

Complete integrated protection and

management of medium and large motors

The MultilinTM 469 Motor Protection System, a member of the SR family of relays,

provides protection, control, simplified configuration and advanced communications in

a cost effective industry leading draw-out construction. Designed for medium voltage

motors, the 469 delivers advanced protection with customizable overload curves and

single CT differential protection for added flexibility. The 469 also provides simplified

configuration using the Motor Settings Auto-Configurator, providing a quick and easy

set-up of motor parameters. Coupled with advanced protection and diagnostics, the 469

provides users the flexibility of multiple communication protocols allowing integration

into new and existing control networks.

Key Benefits

• Comprehensive motor protection plus voltage dependant overload curves, torque

metering and protection, broken rotor bar protection

• Most advanced thermal model-Including multiple RTD inputs for stator

thermal protection

• Minimize replacement time-Draw-out construction

• Complete asset monitoring-Temperature, Analog I/O, full metering including

demand & energy

• Improve uptime of auxiliary equipment-Through I/O monitoring

• Reduce troubleshooting time and maintenance costs-Event reports, waveform

capture, data logger

• Built in simulation functions simplify testing and commissioning

• Cost Effective Access to information-Through standard RS232 & RS485 serial ports,

and optional Ethernet and DeviceNet Ports

• Field upgradable firmware and settings

• Optional Conformal coating for exposure to chemically corrosive or

humid environments

Applications

• Protection and Management of three phase medium and large horsepower motors

and driven equipment, including high inertia, two speed and reduced-voltage

start motors

Protection and Control

The 469 is a digital motor protection system designed to protect and manage

medium and large motors and driven equipment. It contains a full range of

selectively enabled, self contained protection and control elements as

detailed in the Functional Block Diagram and Features table.

Motor Thermal Model

The primary protective function of the 469 is the thermal model with six key elements:

• Overload Curves

• Unbalance Biasing

• Hot/Cold Safe Stall Ratio

• Motor Cooling Time Constants

• Start Inhibit and Emergency Restart

• RTD Biasing

Overload Curves

The curves can take one of three formats: standard, custom, or voltage dependent.

For all curve styles, the 469 retains thermal memory in a thermal capacity

used register which is updated every 0.1 second. The overload pickup determines

where the running overload curve begins.

The 469 standard overload curves are of standard shape with a multiplier value of

1 to 15.

The voltage dependent overload curves are used in high inertia load applications,

where motor acceleration time can actually exceed the safe stall time and motor

thermal limits. During motor acceleration, the programmed thermal overload curve

is dynamically adjusted with reference to the system voltage level. The selection

of the overload curve type and the shape is based on motor thermal limit curves

provided by motor vendor.