The modules are a scalable solution that can be easily integrated into a plant’s control and information system. They are designed to meet the unique needs of applications requiring absolute shaft measurements and applications requiring redundant overspeed protection. The XM-121A measures a turbine shaft’s vibratory motion relative to free space, which is an important diagnostic metric on some large steam turbines. The XM-442 provides four high-power relays—three that serve as redundant shutdown relays, and one that serves as the alarm relay, and a redundant logic circuit that allow the XM-442 module to operate correctly even in the presence of a single internal circuit fault.
Turbine Supervisory Instrumentation Modules
Designed to fulfill the requirements of Turbine Supervisory Instrumentation (TSI) series of measurements established by the ISA, the Allen-Bradley XM 121A Absolute Shaft Module and XM 442 Voted Electronic Overspeed Detection System (EODS) Relay Module provide cost-effective monitoring and protection of critical plant-floor assets, says the vendor.