Description
ABB LDSYN-101 (3BHE005555R0101) — Synchronization Voltage Measurement and Communication Control Board
Product Overview
The LDSYN-101 (part number 3BHE005555R0101) is a synchronization voltage measurement and communication control board manufactured by ABB for excitation systems. It is a core module within the ABB UNITROL 6000 series excitation control platform, designed to precisely measure three-phase synchronization voltage signals, manage phase synchronization control, and handle communication interfaces. It serves as a direct and improved replacement for the earlier model 3BHE005555R0001.
In simple terms, this board is the “timing eye” of the excitation system — it tells the controller exactly when the generator voltage matches the grid so that safe synchronization and grid connection can occur.
LDSYN-101 3BHE005555R0101 ABB PC BOARD
Core Functions
Synchronization Voltage Measurement — The board accurately acquires three-phase voltage signals from the generator or grid bus. These signals provide the reference for the excitation controller to perform automatic synchronization (synch-check), phase angle control, and protective relay logic. Without precise sync voltage measurement, the generator cannot be safely connected to the grid — making this function mission-critical.
Communication Control — The LDSYN-101 features dual Ethernet ports (RJ45) for connecting to plant control networks, plus RS-232 serial ports (one with modem control signals, one isolated) for engineering tool connection. Each board has a factory-programmed hardware MAC address, providing a unique identity on the network.
System Synchronization Assurance — It ensures tight phase and frequency alignment between the excitation unit and the power system, supporting fault recording, disturbance analysis, and overall plant stability.
Key Technical Specifications
The board operates on 24V DC power supply and is designed for medium-voltage excitation systems (typically 3 kV to 11 kV class). Signal outputs include standard analog synchronization voltages and digital status signals. The operating temperature range is -20°C to +70°C, with storage capability from -40°C to +85°C. Humidity tolerance is 5% to 95% non-condensing. The protection rating is IP20, intended for mounting inside a control cabinet.
Physical dimensions are approximately 150 mm × 100 mm × 50 mm, and the unit weighs only about 0.15 kg. It mounts via DIN rail or panel bracket into standard ABB excitation system card slots. Electromagnetic compatibility meets IEC 61000-4 series standards — it withstands 10 kV electrostatic discharge and 4 kV burst interference. Mean time between failures (MTBF) is rated at ≥100,000 hours.
Compatible Systems
The LDSYN-101 is primarily designed for the ABB UNITROL 6000 series excitation system. Typical applications include:
- Hydroelectric power plants
- Thermal and combined-cycle power plants
- Pumped-storage facilities
- Marine and shipboard power generation
- Mining and industrial captive power plants
It is also used within the ABB Advant OCS 800xA system architecture as a communication controller unit, supporting redundant CPU configurations, real-time clock, and status LED indicators with an INIT button for local reset.
Status and Availability
This is an actively supported ABB product — not obsolete. The part is manufactured in Switzerland and widely stocked by authorized ABB distributors and industrial spare parts suppliers worldwide. In the Chinese market, prices typically range from ¥2,680 to ¥7,700 RMB (approximately 370–1,060 USD), with stock items shipping within 1–5 days. New units usually ship within 4–8 weeks.
The direct replacement for the older 3BHE005555R0001 is this R0101 revision, which offers improved performance and broader compatibility — new installations should specify R0101 directly.
Bottom Line
The ABB LDSYN-101 (3BHE005555R0101) is the synchronization and communication backbone of ABB UNITROL excitation systems — precisely measuring grid-generator voltage alignment while managing Ethernet and serial communication with the plant DCS. It is essential for safe generator synchronization, grid connection, and system stability monitoring. Actively manufactured, globally available, and fully supported by ABB.
