Product Details

The ABB UNS4881b,V4 3BHE009949R0004 is an original AVR unit for ABB UNITROL 5000 generator excitation control systems. As a core ABB UNITROL 5000 voltage regulator, this ABB UNS4881b,V4 AVR unit delivers high-precision voltage regulation, reliable excitation control and comprehensive generator protection functions. It supports multiple control modes and communication protocols, with strong anti-interference ability and stable performance to guarantee safe operation of power generation equipment.

Product Uses

This AVR unit is designed for excitation control and voltage stabilization of synchronous generators. It is widely applied in hydropower stations, thermal power plants, gas turbine generator sets and other power generation projects. It can automatically adjust excitation current to stabilize generator output voltage under variable load conditions, and implement overvoltage, overcurrent and loss-of-excitation protection. When the original excitation controller fails or ages, the ABB UNS4881b,V4 AVR unit can serve as replacement spare hardware to restore generator control performance and reduce power system downtime.

Product Parameters

Brand: ABB

Model: UNS4881b,V4

Part No.: 3BHE009949R0004

Type: UNITROL 5000 AVR Unit

Application: Synchronous generator excitation and voltage regulation

Operating temperature: -25℃ ~ 70℃

Storage temperature: -40℃ ~ 80℃

Relative humidity: 5% ~ 95%, non-condensing

Feature: high regulation accuracy, multi-protection functions, flexible communication interface

Product Specifications

Original industrial spare part, integrated cabinet-mounted unit design. Equipped with built-in signal acquisition circuit and control logic. Supports parameter configuration and fault diagnosis via dedicated software. Manufactured according to strict power industry standards, good shock and vibration resistance for power plant environments. Capable of long-time continuous operation. Each unit undergoes complete functional testing before shipment to ensure stable performance after installation.