Allen-Bradley 1402-LS51 Line Synchronization Module

Allen-Bradley 1402-LS51 Line Synchronization Module (LSM) is a two-slot Bulletin 1402 module designed to mount directly into a 1771-series I/O chassis to synchronize two independent three-phase power buses. It provides automatic synchronization, load sharing, and high-speed power-system monitoring, and it measures 5 A full-scale current with a 100/120 VAC sensing range. The unit supports three synchronization methods: PID control using the PLC-5 PID instruction, discrete I/O signaling via LSM error outputs, and the clipped-gain method using BTR data tables, with update rates including bus-error parameter updates at about 100 ms and load-share/monitor activity at about 200 ms when synchronization is inactive or about 1 s when active. It operates from 0 to 60 C and offers a dielectric withstand of 2500 V RMS, with backplane current draw of roughly 1.1 A at 5 V DC (2.2 A inrush). The 1402-LS51 is intended for retrofitting PLC-5 systems and is compatible with Allen-Bradley 1771 backplanes.