Beckwith M-3430 Generator Protection Relay

4.3 Status Input and Output Programming

Six programmable state inputs can be used to lock any protection function or trigger waveform recording. The input is in dry contact mode, with an internal 24Vdc wet power supply. Eight programmable output contacts (six type A and two type C) can be configured for tripping or signal output of any protection function, achieving flexible combinational logic.

4.4 IRIG-B time synchronization

The rear BNC interface supports modulated IRIG-B signal input, which is used to calibrate the internal clock of the device and ensure that the time labels of events and recorded data are synchronized with the entire station.

Selection, Configuration, and Installation Points

5.1 Hardware selection

CT rating: Optional 1A or 5A CT input, must be specified when ordering.

Frequency: Available in 50Hz or 60Hz models.

Power supply: The standard is a single power supply (wide range 85~265Vac or 80~288Vdc), with optional redundant power supply (dual power module).

Display and operation: Optional M-3931 HMI module (2 × 24 character LCD, six key operation) and M-3930 target module (24 target LEDs+8 output LEDs).

5.2 Attention to External Wiring

PT connection: The PT at the machine end and system side can be connected in a line to ground or line to line manner, and the phase sequence (ABC/ACB) can be selected through software.

Generator circuit breaker status: Input 1 must be connected to the auxiliary contact (closed when the circuit breaker is in the open position) at position 52, for circuit breaker position discrimination and circuit breaker failure logic.

Neutral point CT: Used for differential protection and grounding protection, it needs to be connected to the neutral point side CT of the generator.

5.3 Installation Environment

Mechanical dimensions: 19 "wide x 6.96" high x 10.2 "deep (standard 2U rack), horizontal installation is standard, and vertical installation is optional.

Environmental tolerance: -40 ℃~+85 ℃ operating temperature, 95% humidity (no condensation), PCB three proof coating.

Electrical safety: Meets IEC 60255-5 and ANSI/IEEE C37.90.1 standards, with input and output isolation withstand voltage of 3500Vdc.

Communication and monitoring integration

M-3430 supports two mainstream communication protocols:

MODBUS: widely used in SCADA systems, supports reading and writing of set values, real-time measurement reading, and target information retrieval (does not support downloading of waveform data).

BECO 2200: Beckwith Electric proprietary protocol, supporting all functions (including waveform data download).

Communication port configuration:

Front panel RS-232 (COM1): used for local laptop connection and debugging.

Rear RS-232 (COM2): Can be used to connect with remote RTUs or modems.

Rear RS-485 (COM3): Supports multi-point bus network, suitable for centralized monitoring of multiple protection devices.

IPScom software (M-3800A or S-3400, the latter compatible with Windows 7 and above) provides complete functions such as setting value management, real-time monitoring, waveform data download, and target analysis.