ABB DSSR122M 48990001-LR Excitation Thyristor Trigger Unit

I. Basic Information
Brand: ABB, belonging to the UNITROL series of generator excitation control system
Full model: DSSR122M, material code 48990001-LR
Product category: Static excitation thyristor power interface board (SCR trigger / pulse amplification board)
Model suffix LR: Long cable matching version, equipped with extended pulse wiring adapter, standard cabinet for long-distance installation
Life cycle: Older excitation spare parts, originally factory discontinued, only for disassembly, refurbishment, and inventory spare parts circulation
Applicable systems: UNITROL 5000 / UNITROL F synchronous generator excitation cabinet, thermal power, hydropower generating units
Model Interpretation
DSSR: Dynamic SCR Trigger Module Thyristor Trigger Board Series
122M: Hardware version M type, compatible with three-phase fully controlled bridge excitation power cabinet
48990001: Original factory material part number
LR = Long Reach Long-distance pulse output version, compatible with power cabinet and control cabinet separated layout scenarios

Core Functions
Receive the phase-shifting control pulses output by the main control unit UNITROL regulator
Power amplify six-channel synchronous trigger pulses, drive three-phase fully controlled rectifier bridge SCR thyristors
Synchronous voltage sampling, complete phase synchronization, zero-crossing detection, ensure precise phase shifting of thyristors
Built-in pulse monitoring, lost pulse, abnormal synchronization hardware fault detection
Output fault alarm dry contact, connected to the unit’s FSSS/ECS monitoring system
Have pulse blocking function, immediately lock excitation output during faults, protect the generator rotor

Electrical Specifications
Power supply: 24VDC control power supply (standard cabinet of excitation system provides power)
Synchronous sampling input: AC 100V terminal synchronous voltage
Pulse output: Six-channel isolated strong trigger pulses, with short-circuit protection
Signal isolation: Control circuit, synchronous sampling, trigger pulse fully electrical isolation, resistant to strong electromagnetic interference of power plants
Contact output: Fault alarm relay, contact capacity 250VAC 5A

Installation and Environment
Installation: Standard ABB excitation frame card-type installation
Protection: IP20, used in control cabinet
Operating temperature: 0℃ ~ +65℃
Anti-vibration: Complies with power plant industrial control equipment vibration standards, suitable for turbine, steam turbine room environment

Accessories and Applications
Accessories
UNITROL series excitation regulator mainboard
ABB three-phase thyristor rectifier power bridge
Synchronous voltage PT acquisition board, excitation current feedback board Application scenario
Static excitation systems for steam turbine generators and hydro turbine generators
Excitation control cabinets for independent power plants and gas turbine units
Excitation regulation devices for large industrial synchronous motors