GE Multilin 889 Generator Protection System

GE Multilin 889 Generator Protection System

Product Overview

Core functions

The 889 generator protection system is a microprocessor based device used for primary and backup protection of small and large generators, with protection, control, and asset monitoring functions. It can monitor the imbalance, differential, overexcitation, demagnetization and other states of the generator, and meet different industry standards and user needs through flexible configuration.

Main features 

Protection function: covering various protection elements such as percentage differential protection, overcurrent, overvoltage/undervoltage, frequency abnormality, demagnetization, reverse power, etc. (see ANSI equipment numbering table for details).

Flexibility: Supports custom logic (FlexLogic), programmable curves (FlexCurve), multiple sets of setpoints, and default settings simplify initial configuration.

Monitoring and recording: Real time monitoring of parameters such as current, voltage, and power, with functions such as event recorder (1024 events), transient recorder (waveform capture), and fault report (15 events).

Communication capability: Supports multiple protocols such as Modbus, DNP3.0, IEC 60870-5-103/104, IEC 61850, etc., with optional interfaces such as Ethernet, RS485, Wi Fi, etc.

Installation instructions

1. Mechanical installation

Size and installation method: Supports standard panel installation, drawer installation, and can be matched with a depth reducing ring to adapt to narrow spaces; The full-size weight is about 9kg, and ventilation gaps need to be reserved at the top and bottom.

Key component installation: The power module and magnetic module (CT/VT) need to be plugged and unplugged according to the steps. Before removing the magnetic module, the system power must be disconnected and the CT secondary side short circuited to prevent high voltage hazards.

Installation of arc light sensor: The optical fiber should avoid bending with a radius less than 25mm, and the installation position should be unobstructed. It supports 4 point sensors and has a standard fiber length of 18 feet (maximum 32 feet).

2. Electrical installation

CT/VT connection: CT supports 1A/5A secondary, VT supports star/triangle connection, pay attention to phase sequence and polarity to ensure correct protection function.

Grounding requirements: The system rack, EMI shielding, and cables must be reliably grounded, and the grounding resistance of the intrinsic safety system must be<1 Ω.

Wiring specifications: The control power supply should match the rated range (such as 110-250V AC/DC), and the communication line should use shielded twisted pair. The maximum distance of RS485 is 1200 meters.

Interface Description

1. Front panel interface

Display screen and buttons: graphic LCD display, supports menu navigation (Targets, Status, Metering, etc.), 5 navigation keys+3 programmable function keys, 17 LEDs (including programmable status indication).

Operation function: It can view real-time data, set parameters, reset alarms, support single line diagram (SLD) display, and can configure default screens and color schemes.

2. Software interface (EnerVista 8 Series Setup)

Function: Used for configuring parameters, upgrading firmware, viewing records, drawing custom SLDs, etc., supporting online/offline operations.

Connection method: Connect via USB, Ethernet, Wi Fi, and configure communication parameters such as IP address and port.

Advanced features: SLD configurator (custom single circuit diagram), FlexCurve editor (custom protection curve), transient recorder (waveform analysis), etc.

Detailed explanation of core functions

1. Protection function

Differential protection: including generator stator differential (87G), overall differential (87O), supporting dual slope characteristics, 2nd/5th harmonic braking.

Overcurrent protection: including phase/neutral/ground overcurrent (50/51 series), supporting multiple inverse time curves (IEEE, IEC, etc.).

Voltage protection: Over/Under voltage (59/27 series), Negative sequence overvoltage (59_2), Voltage Hertz protection (24), etc.

Other protections: demagnetization (40), reverse power (32), abnormal frequency (81U/O/R), arc protection (AFP), etc.

2. Monitoring function

Real time monitoring: current, voltage, power, frequency, harmonics, temperature (RTD), etc., with an accuracy of ± 0.25% (current) and ± 0.5% (voltage).

Recording function: Event recording (timestamp accurate to microseconds), transient recording (waveform before and after fault), data log (configurable with 16 analog quantities).

3. Control function

Circuit breaker control: supports opening/closing, locking, and bypass, adopts the "select first, operate later" mechanism, and is compatible with local/remote control.

Synchronization check (25): Monitor voltage, frequency, and phase difference to ensure that the grid connection conditions are met.

Arc protection: Detecting arc light through fiber optic sensors, quickly triggering tripping, and reducing equipment damage.

Set point configuration

Device settings: including clock synchronization (IRIG-B, PTP, SNTP), security (user roles, password policies), and communication protocol parameters.